JP2010070067A - Valve device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve device capable of enhancing the sealing performance between a check valve and a valve seat when tank internal pressure is held to such an extent that the check valve does not open, and capable of smoothly introducing outer air when the tank internal pressure is negative. <P>SOLUTION: The valve device 10 includes a valve case, a float valve 50, the check valve 60, and a communicating port 25 wherein its lower surface periphery serves as the first valve seat 27, and its upper surface periphery serves as the second valve seat 71. The check valve 60 is provided with a negative-pressure flow passage 65 for communication between a float chamber and a vent chamber with the second valve seat 71 in contact with the check valve 60, and a valve body 66 which closes the negative-pressure flow passage 65 at normal times and opens the negative-pressure flow passage 65 when the pressure in a fuel tank is lowered by a predetermined value or more relative to the outside pressure. The valve body 66 is constituted so that the valve body 66 is positioned inside the second valve seat 71 when the check valve 60 is lowered and abuts on the second valve seat 71. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a float valve that is attached to a fuel tank of an automobile or the like and prevents the fuel swung by turning or tilting of the automobile from leaking out of the fuel tank, and fuel vapor to the canister according to the pressure in the fuel tank. The present invention relates to a valve device including a check valve for sending.

  In general, a fuel tank of an automobile is provided with a cut valve that prevents the fuel in the fuel tank from leaking out of the fuel tank when the automobile turns or tilts. In addition, when the pressure inside the fuel tank rises, the fuel tank discharges the fuel vapor to the outside to prevent the fuel tank from bursting. When the pressure inside the fuel tank drops, outside air flows from the outside of the fuel tank. It is also common to install a check valve that prevents the fuel tank from being crushed.

  Moreover, the valve apparatus which combines a cut valve and a check valve is also used. For example, in Patent Document 1 below, a float valve is accommodated inside, a housing having an opening in the upper wall, a disk-shaped check valve is disposed inside the housing, and communicates with the outside. A mounting member having a nozzle, and a cylindrical valve seat is erected from the periphery of the upper surface of the opening so that the check valve contacts and separates from this, and the float valve contacts and separates from the periphery of the lower surface of the opening A fuel vapor control valve configured as described above is disclosed. Furthermore, a notch is formed in the cylindrical valve seat. Further, the check valve is normally in contact with the cylindrical valve seat by its own weight and closes the opening.

When the fuel level rises, the float valve comes into contact with the peripheral edge of the lower surface of the opening to close the opening and prevent fuel from leaking out of the tank. Further, when the tank internal pressure rises, the check valve moves away from the valve seat and the opening opens, and fuel vapor is sent to the external canister or the like through the opening and the nozzle to suppress the rise of the tank internal pressure. On the other hand, when the tank internal pressure decreases, external air is introduced into the tank through a notch provided in the cylindrical valve seat through the external canister and the nozzle to suppress a decrease in the tank internal pressure.
US Pat. No. 6,758,235

  In Patent Document 1, since the notch is provided in the cylindrical valve seat, the opening is not completely closed even when the check valve descends and comes into contact with the valve seat. Therefore, when the tank internal pressure is such that the check valve does not open, such as when the vehicle is stopped or fuel is being refueled, the fuel vapor will flow to the external canister through the notch, resulting in a seal between the check valve and the valve seat. There was a problem.

  The notch serves as an outside air inlet when the tank internal pressure is lower than the outside air pressure. However, the size of the notch affects the ease with which the outside air is introduced. However, in consideration of the sealing performance between the check valve and the valve seat described above, it is difficult to form the notch with a large opening area. In this case, there is a problem that the external pressure cannot be introduced smoothly.

  Therefore, the object of the present invention is to improve the sealing performance between the check valve and the valve seat when the pressure in the tank is such that the check valve does not open, and the tank pressure has decreased by a predetermined value or more from the external pressure. Sometimes, it is providing the valve apparatus which can introduce external air smoothly.

In order to achieve the above object, a first aspect of the present invention includes a valve case provided with a float chamber communicating with the inside of the fuel tank below and a vent chamber communicating with the outside of the tank above the partition wall,
A float valve disposed in the float chamber so as to be movable up and down;
A check valve disposed in the vent chamber;
The partition wall is formed to communicate with the float chamber and the vent chamber, and a lower surface periphery of the partition wall forms a first valve seat to which the float valve contacts and separates, and an upper surface periphery of the partition wall contacts and separates from the check valve. With a two-seat communication port,
A cylindrical wall surrounding the communication port is formed on the upper surface of the partition wall on the vent chamber side,
The check valve is disposed inside the cylindrical wall so as to be movable up and down, abuts on the second valve seat until a pressure in the fuel tank exceeds a predetermined value, and when the pressure exceeds a predetermined value, the first valve It is configured to open the communication port away from the two valve seats,
Further, the check valve has a negative pressure flow path communicating with the float chamber and the vent chamber in contact with the second valve seat, and the negative pressure flow path is normally closed so that the pressure in the fuel tank Is provided with a valve body that opens the negative pressure flow path when the air pressure drops below a predetermined value from the outside air pressure, and the valve body is in contact with the second valve seat when the check valve is lowered. Further, the present invention provides a valve device configured to be positioned inside the second valve seat.

  According to the above invention, when the fuel in the fuel tank oscillates and the fuel level rises, the float valve rises and abuts the first valve seat to close the communication port, thereby preventing fuel from leaking outside. The

  When the pressure in the fuel tank increases, the check valve is pushed up by the pressure from below the communication port and rises in the cylindrical wall. The communication port opens away from the second valve seat, and the fuel in the fuel tank opens. The steam passes through the ventilation chamber and is discharged to the external flow path communicating with the canister, so that the pressure in the fuel tank is maintained at a predetermined value. On the other hand, when the pressure in the fuel tank is in a negative pressure state where the pressure is lower than the external pressure by a predetermined value or more, the valve body is pressed by the external air pressure to open away from the negative pressure flow path, and air is introduced into the fuel tank from the outside. Therefore, the pressure in the fuel tank can be kept within a predetermined range.

  In addition, when the pressure inside the fuel tank is maintained at such a level that the check valve does not rise and the check valve is lowered, the check valve is in contact with the second valve seat and the negative pressure passage is closed. Since the body enters the inside of the second valve seat and the outer periphery of the valve body is covered by the second valve seat, the sealing performance between the check valve and the second valve seat can be improved, and fuel vapor or the like passes through the communication port. Therefore, it is possible to prevent the fluid from flowing toward the ventilation chamber.

  In this valve device, the valve seat is not provided with a notch, and a valve body that opens at negative pressure is attached to the check valve, so that the outside air can be expelled quickly at negative pressure without being affected by the size of the notch. It is possible to maintain the pressure in the fuel tank smoothly at a constant pressure, and when the pressure in the fuel tank is such that the check valve does not rise, the sealing performance between the check valve and the second valve seat is improved. Can be increased.

  According to a second aspect of the present invention, there is provided the valve device according to the first aspect, wherein the check valve has a polygonal plate shape.

  According to the above invention, since the check valve has a polygonal plate shape, the contact area with the inner circumference of the cylindrical wall is small. For this reason, the sliding resistance when the check valve moves up and down in the cylindrical wall is reduced, and the check valve is difficult to bite into the inner periphery of the cylindrical wall. As a result, the check valve can be raised and lowered smoothly and reliably.

  In addition, when the check valve moves up and down in the cylindrical wall, the inner circumference of the cylindrical wall and the check valve itself are less worn, and the check valve may rotate in the cylindrical wall due to turning and tilting of the automobile. Since there is less backlash, wear and damage to the cylindrical wall and the check valve itself can be suppressed.

  Since the check valve has a polygonal plate shape, a relatively large gap can be secured between the outer periphery of the check valve and the inner periphery of the cylindrical wall, so that the resistance to fuel vapor ventilation is reduced. And can flow smoothly.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the negative pressure flow path is formed at a position shifted from a center of the check valve, the valve body has a plate shape, and one end thereof is The valve device is fixed to a position shifted from the center of the check valve to a side opposite to the position where the negative pressure channel is formed, and is attached to the negative pressure channel so as to be openable and closable.

  According to the above invention, since the valve body attached to the check valve can be formed as small as possible, the check valve itself can be downsized and formed compact. As a result, the check valve can be raised more quickly when the pressure in the fuel tank increases.

  According to the present invention, when the pressure inside the fuel tank is maintained at a level that does not raise the check valve and the check valve is lowered, the check valve contacts the second valve seat and the negative pressure flow path is closed. Since the valve body in a state that has entered the inside of the second valve seat and the outer periphery of the valve body is covered by the second valve seat, the sealing performance between the check valve and the second valve seat can be improved, and fuel vapor or the like It is possible to prevent the fluid from flowing to the ventilation chamber side through the communication port.

  In this valve device, the valve seat is not provided with a notch, and a valve body that opens at negative pressure is attached to the check valve, so that the outside air can be expelled quickly at negative pressure without being affected by the size of the notch. It is possible to maintain the pressure in the fuel tank smoothly at a constant pressure, and when the pressure in the fuel tank is such that the check valve does not rise, the sealing performance between the check valve and the second valve seat is improved. Can be increased.

  Hereinafter, a first embodiment of the valve device of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the valve device 10 includes a case main body 20, a lower cap 30 attached to a lower opening of the case main body 20, and an upper cap 40 attached to the upper side of the case main body 20. It has the valve case 15 which becomes. The internal space defined by the case body 20 and the lower cap 30 forms a float chamber R1 in which the float valve 50 is disposed so as to be movable up and down, and the internal space defined by the case body 20 and the upper cap 40 is a check valve. A ventilation chamber R2 in which 60 can be moved up and down is formed. The float chamber R1 communicates with the fuel tank, and the vent chamber R2 communicates with an external flow path leading to the canister. Hereinafter, each component will be described.

  The case main body 20 includes a cylindrical peripheral wall 21 and a partition wall 23 that closes the upper surface thereof, and a communication port 25 passes through the center of the partition wall 23. A cylindrical first valve seat 27 to which a valve head 51 (described later) of the float valve 50 comes in contact with and separates from the lower surface periphery of the communication port 25, and a check valve 60 from the upper surface periphery of the communication port 25. A cylindrical second valve seat 71 which comes in contact with and separates from is projected. In other words, the upper and lower peripheral edges of the communication port 25 form a valve seat where the check valve 60 and the float valve 50 come into contact with and separate from each other. Both the float chamber R1 and the ventilation chamber R2 communicate with each other through the communication port 25. The peripheral wall 21 is formed with a plurality of through holes 21a serving as fuel and fuel vapor passages. Furthermore, a plurality of claw portions 21b are formed below the peripheral wall 21 along the circumferential direction.

  The lower cap 30 includes a circular bottom plate 31 having a through hole 31 a through which fuel can pass, and a cover wall 33 that stands from the periphery of the bottom plate 31 and covers the lower outer periphery of the peripheral wall 21 of the case body 20. A support protrusion 34 that supports one end of the first spring 55 is formed at the center of the bottom plate 31. Further, the cover wall 33 is formed with an engagement hole 33 a that engages with the claw portion 21 b of the case body 20. Furthermore, a stopper wall 37 is formed at one location on the outer periphery of the cover wall 33 via a standing wall 35, and serves to prevent foreign matter from entering into an opening 91 of a valve body housing portion 90 described later (see FIG. 2). ).

  A float valve 50 is slidably accommodated in the float chamber R1. The float valve 50 has a substantially cylindrical shape, and a valve head 51 projects from the center of the upper surface of the float valve 50 so that the valve head 51 contacts and separates from the first valve seat 27. A plurality of ribs 53 extending in the vertical direction are formed on the outer periphery of the float valve 50, and are in sliding contact with the inner periphery of the peripheral wall 21 of the case body 20, thereby guiding the slide operation of the float valve 50.

  The float valve 50 is accommodated in the case body 20 with the first spring 55 inserted in the recess 54 provided at the bottom thereof, and then the lower cap 30 is pushed in, so that the claw portion 21b is inserted into the engagement hole 33a. The lower cap 30 is attached to the lower side of the case main body 20 by engaging them. At the same time, a first spring 55 is interposed between the float valve 50 and the bottom plate 31 of the lower cap 30. The float valve 50 is placed on the bottom plate 31 by compressing the first spring 55 by its own weight without being immersed in the fuel. Further, the first spring 55 gives an upward biasing force to the float valve 50 together with the buoyancy generated in the float valve 50 when the fuel rises due to the inclination of the vehicle and the float valve 50 is immersed in the fuel.

  A frame-like wall 100 is erected from the upper surface of the partition wall 23 of the case body 20. As shown in FIG. 1, the frame-like wall 100 extends long in the direction of a connecting pipe 95 described later so as to surround the upper opening of the valve body accommodating portion 90. Further, the opposite side of the connecting wall 95 of the frame-like wall 100 extends outward from the case body 20, and a downward engaging claw 105 is formed at the tip thereof.

  An annular cylindrical wall 70 is formed inside the frame-like wall 100 and on the upper surface of the partition wall 23 on the side of the ventilation chamber R2 so as to surround the communication port 25. A check valve 60 is arranged inside the cylindrical wall 70 so as to be slidable up and down. A part of the upper end 70 a of the cylindrical wall 70 is lower than the upper end of the frame-like wall 100, and the inner space and the outer space of the cylindrical wall 70 communicate with each other.

  Further, on the upper surface side of the partition wall 23, a plurality of convex portions 72 project from the outer periphery of the second valve seat 71 and the inner periphery of the cylindrical wall 70 with a uniform spacing in the circumferential direction. Each convex portion 72 is formed at a height lower than that of the second valve seat 71. When the check valve 60 tilts in the cylindrical wall during sliding, the check valve 60 comes into contact with the convex portion 72 and the tilt angle is limited, so that the check valve 60 is less likely to bite into the inner periphery of the cylindrical wall 70, It can slide reliably.

  3A to 3C will be described in conjunction with the check valve 60 that is slidable up and down inside the tubular wall 70. The check valve 60 is preferably made of a material that is not easily deformed or corroded by fuel vapor. For example, an iron-based metal such as stainless steel, ceramics, or the like is used. In addition, as a forming method, a method of filling a metal mold or a ceramic material into a predetermined mold and sintering, or a method of cutting a plate-shaped one can be employed.

  The check valve 60 is formed with a smaller diameter than the inner diameter of the cylindrical wall 70. In this embodiment, the check valve 60 has a polygonal plate shape in which a plurality of flat portions 63 are formed along the circumferential direction. The shape of the check valve 60 is 8 to 8 because the contact area with the inner periphery of the cylindrical wall 70 can be reduced, and a sufficient gap can be secured between the inner periphery of the cylindrical wall 70 and the outer periphery of the check valve 60. It is preferable to form a 32 square regular polygon.

  In this embodiment, the upper and lower corners 61, 61 of the check valve 60 are tapered chamfered. Therefore, as shown in FIG. 3 (d), the check valve 60 has a polygonal shape in which the outer peripheral surface in the middle in the thickness direction has a plurality of flat portions 63 along the circumferential direction, and the upper and lower corners in the thickness direction. The twill line 64 has a circular shape. When the upper and lower corners of the check valve 60 are chamfered in a tapered shape, the check valve 60 is difficult to bite in the cylindrical wall 70, and the sliding resistance of the check valve 60 is reduced to reduce the cylindrical wall 70. The inside can be raised and lowered smoothly.

  Further, the check valve 60 is in contact with the second valve seat 71, and the negative pressure flow path 65 for communicating the float chamber R1 and the ventilation chamber R2 and the negative pressure flow path 65 are normally closed so that the inside of the fuel tank is closed. And a valve body 66 that opens the negative pressure flow path 65 when the pressure of the pressure decreases by a predetermined value or more from the external pressure.

  In this embodiment, a circular hole-shaped negative pressure flow path 65 is formed through the check valve 60 at a position shifted from the center C of the check valve 60 in a predetermined direction. Tapered surfaces 65 a and 65 a are formed on the upper and lower opening peripheral edges of the negative pressure channel 65 so as to gradually increase in diameter toward the upper and lower end surfaces of the check valve 60. The upper taper surface 65a facilitates the flow of outside air into the negative pressure flow path 65 when the internal pressure of the fuel tank is equal to or lower than a predetermined value, and the lower taper surface 65a smoothly flows the outside air flowing into the back surface side of the valve body 66. The valve body 66 is easy to open.

  On the other hand, as shown in FIGS. 3B and 3C, the valve body 66 in this embodiment has a thin long plate shape, and the tip portion 66a in the length direction is rounded in an arc shape. Furthermore, the size is smaller than the inner diameter of the second valve seat 71. The valve body 66 is preferably made of a metal material such as an iron-based metal such as stainless steel or a non-ferrous metal such as aluminum, copper, or titanium, and is formed of a material that can be welded to the check valve 60.

  In this embodiment, the base end portion 66b of the valve body 66 is welded to a position shifted from the center C of the check valve 60 to the side opposite to the position where the negative pressure flow path 65 is formed. As a result, the base end portion 66b of the valve body 66 is fixed, the distal end portion 66a can be opened and closed, and the distal end portion 66a is pressed against the opening peripheral edge below the negative pressure flow path 65, so that the negative end is always negative. The pressure channel 65 is closed and can be attached to the check valve 60 (see FIGS. 3B to 3D).

  The check valve 60 is arranged to be movable up and down inside the cylindrical wall 70 so that the valve body 66 faces downward and the valve body 66 is located inside the second valve seat 71. The check valve 60 is in contact with the second valve seat 71 until the pressure in the fuel tank exceeds a predetermined value (see FIG. 2). When the pressure exceeds the predetermined value, the check valve 60 is pushed up by the pressure. Thus, the communication port 25 is configured to open away from the second valve seat 71 (see FIG. 3). In the state shown in FIG. 2, the tip 66a of the valve body 66 is in contact with the lower surface opening of the negative pressure channel 65, so that the negative pressure channel 65 is kept closed. Even when pressure acts from below 66, the tip 66 a is pressed against the lower surface opening of the negative pressure channel 65, so that the negative pressure channel 65 is kept closed.

  Further, as shown in FIG. 5, when the pressure in the fuel tank drops by a predetermined value or more, outside air flows from the upper opening of the negative pressure flow path 65, and the tip 66a of the valve body 66 is pushed down to cause a negative pressure flow. By opening away from the lower opening of the passage 65, outside air is introduced into the fuel tank through the communication port 25.

  Returning to the description of the configuration of the valve device 10, in this embodiment, a valve body housing portion 90 in which the ball valve 80 is housed to be movable up and down is provided below the front projecting portion of the frame-like wall 100. The valve body accommodating portion 90 has an opening 91 on the bottom wall where the ball valve 80 contacts and separates, and further stores a second spring 81 that urges the ball valve 80 toward the opening 91, When the pressure in the tank rises to a predetermined value or more, a relief valve is formed that fulfills the function of discharging fuel vapor out of the fuel tank.

  Further, a connecting pipe 95 for connecting a pipe connected to a canister (not shown) is integrally projected from the valve body accommodating portion 90. As shown in FIG. 2, the connecting pipe 95 communicates with the internal space of the valve body housing portion 90 and constitutes a part of the fuel vapor discharge passage that communicates the inside and outside of the fuel tank.

  An upper cap 40 is attached to the upper opening of the frame-like wall 100. The upper cap 40 includes a ceiling plate 41 and outer peripheral ribs 43 extending from the lower surface periphery so as to conform to the inner periphery of the frame-like wall 100, and ultrasonic welding is performed on the upper opening of the frame-like wall 100. Mounted by etc. In addition, since the internal space and the external space of the cylindrical wall 70 communicate with each other and the internal space of the valve body accommodating portion 90 also communicates, the fuel vapor flowing from the communication port 25 of the partition wall 23 is in a tubular shape with the partition wall 23. It flows through the space surrounded by the wall 70 and the upper cap 40 and into the valve body accommodating portion 90.

  From the lower surface of the ceiling plate 41 of the upper cap 40 and located above the check valve 60, a convex portion 44 protrudes and the check valve 60 is pushed up to the lower surface of the ceiling plate 41 by fuel vapor. At this time, the check valve 60 is difficult to stick to the lower surface of the ceiling plate 41.

  Next, the function and effect of the valve device 10 will be described with reference to FIGS. 2 and 4 and 5.

  The valve device 10 is fixed in the fuel tank by fitting an engaging claw 105 to a fixing bracket (not shown) provided above the fuel tank.

  When the vehicle does not shake, the fuel level in the fuel tank does not tilt, and the float valve 50 is not immersed in the fuel, the first spring 55 is compressed by the dead weight of the float valve 50, and the float valve 50 valve heads 51 are separated from the first valve seat 27, and the lower opening of the communication port 25 is opened (see FIG. 2). Further, as shown in FIG. 2, the check valve 60 is lowered by its own weight and comes into contact with the second valve seat, and the upper opening of the communication port 25 is closed.

  In the above state, when the vehicle turns or greatly tilts and the fuel level rises and the fuel is immersed in the float valve 50 by a predetermined height or more, buoyancy acts on the float valve 50 and the first spring 55 Due to this urging force, the float valve 50 is lifted, and the valve head 51 is brought into contact with the lower inner periphery of the communication port 25 to close the communication port 25. As a result, the fuel is prevented from flowing into the internal space of the cylindrical wall 70 through the communication port 25, and the fuel leakage to the outside of the fuel tank can be reliably prevented.

  Further, in the above state, when a large amount of fuel vapor is generated due to traveling of the vehicle and the pressure in the fuel tank increases, the check valve 60 is pushed up by the pressure and separated from the second valve seat 71. The communication port 25 is opened (see FIG. 4). At this time, the fuel vapor passes through the gap between the outer periphery of the check valve 60 and the inner periphery of the cylindrical wall 70 and moves to the outer space of the cylindrical wall 70, and passes through the inner space of the valve body housing portion 90 and the connection pipe 95. Then, it is sent to a canister (not shown) and discharged to the outside of the fuel tank, and the pressure in the fuel tank is lowered and held at a predetermined value. After the pressure in the fuel tank is lowered, the check valve 60 is lowered by its own weight, contacts the second valve seat 71 and closes the communication port 25 again.

  At this time, since the check valve 60 in this embodiment has a polygonal plate shape, the contact area with the inner circumference of the cylindrical wall can be reduced. As a result, the sliding resistance during the raising / lowering operation of the check valve 60 can be reduced, and the check valve 60 can be raised and lowered smoothly and reliably by making it difficult to bite the check valve 60 into the inner periphery of the cylindrical wall.

  Further, when the check valve 60 moves up and down, the inner circumference of the cylindrical wall and the check valve itself are less worn, and the check valve 60 is rotated or rattled in the cylindrical wall due to turning or tilting of the automobile. This can reduce the wear and damage of the cylindrical wall 70 and the check valve itself.

  Further, since the check valve 60 has a polygonal plate shape, a relatively large gap between the outer periphery of the check valve 60 and the inner periphery of the cylindrical wall 70 can be secured, so that the fuel vapor ventilation resistance Can be made to flow smoothly.

  On the other hand, the pressure in the fuel tank may be reduced by a predetermined value or more than the external air pressure, resulting in a negative pressure state. At this time, in the valve device 10, since the negative pressure flow path 65 and the valve body 66 are provided in the check valve 60, as shown in FIG. 5, the canister or the like outside the fuel tank passes through the connection pipe 95 into the ventilation chamber R2. The introduced outside air flows from the upper opening of the negative pressure flow path 65 as shown by the arrow in the figure, pushes down the tip 66a of the valve body 66, moves away from the lower opening of the negative pressure flow path 65, and flows into the negative pressure flow. A path 65 opens. As a result, since the outside air is introduced into the fuel tank through the communication port 25, the pressure in the fuel tank can be increased and maintained within a predetermined range.

  Further, when the vehicle is stopped, when not much time has passed after the vehicle is driven, or when fuel is refueled, the pressure in the fuel tank is maintained at such a level that the check valve 60 does not rise. At this time, in the valve device 10, the check valve 60 is lowered, contacts the second valve seat 71 to close the communication port 25, and the valve body 66 with the negative pressure flow path 65 closed is the second. Since it enters the inside of the valve seat 71 and the outer periphery of the valve body is covered with the second valve seat 71, the sealing performance between the check valve 60 and the second valve seat 71 can be improved, and fuel vapor or the like passes through the communication port 25. It is possible to prevent the fluid from flowing to the ventilation chamber R2 side.

  As described above, in this valve device 10, the second valve seat 71 is not provided with a notch, and the valve body 66 that opens at the time of negative pressure is attached to the check valve 60. Without being influenced by the size of the notch for introducing the outside air sometimes, the outside air can be introduced quickly at the time of negative pressure, and the pressure in the fuel tank can be kept at a constant pressure smoothly. When the pressure is such that the check valve 60 does not rise, the sealing performance between the check valve 60 and the second valve seat 71 can be improved.

  In this embodiment, the negative pressure channel 65 is formed at a position shifted from the center C of the check valve 60, and one end of the plate-like valve body 66 is formed from the center C of the check valve 60 to form the negative pressure channel 65. Since it is welded at a position shifted to the opposite side to the position, the valve body 66 can be formed as small as possible, and the check valve 60 itself can be made compact and compact. As a result, when the pressure in the fuel tank increases, the check valve 60 can be raised more quickly.

  By the way, there is a case where the pressure in the fuel tank still increases in a state where the liquid level of the fuel rises and the communication port 25 is closed by the float valve 50. In this case, the ball valve 80 that always closes the opening 91 of the valve body housing 90 slides upward against the urging force of the second spring 81 to open the opening 91, and the fuel vapor is discharged out of the fuel tank. Thus, the pressure in the fuel tank is maintained at a predetermined value.

  6A to 6C show a second embodiment of the valve device of the present invention. Note that substantially the same parts as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The valve device 10a of this embodiment is different from the above embodiment in the valve body that opens and closes the negative pressure flow path 65. That is, as shown in FIG. 6C, the valve body 67 has a plate spring shape by bending a plurality of metal plates having a predetermined length at predetermined locations. The valve body 67 in this embodiment has a shape in which an upper end portion 67a and a lower end portion 67b are bent in opposite directions with respect to an intermediate portion of the metal plate.

  Further, a distance W1 (see FIG. 6C) between the upper end 67a and the lower end 67b of the valve body 67 is a distance W2 between the bottom surface of the partition wall 23 and the upper end surface of the second valve seat 71 (FIG. 6A). It is set larger than (see). As a result, when the valve body 67 is disposed inside the second valve seat 71 and the check valve 60 is placed thereon, the valve body 67 is elastically deformed and the upper end of the lower pressure channel 65 is opened at the upper end. The portion 67a abuts elastically, and the negative pressure channel 65 is held in a normally closed state.

  Then, when the pressure in the fuel tank is reduced by a predetermined value or more from the outside air pressure to become a negative pressure state, as shown in FIG. 6 (b), the valve body is caused by the outside air flowing in from the upper opening of the negative pressure flow path 65. The upper end portion 67a of 67 is pressed downward, the negative pressure passage 65 is opened, and the outside air is introduced into the fuel tank. In this embodiment, since the check valve 60 and the valve body 67 can be formed separately, there is no need for mounting work, and an advantage that the cost can be reduced can be obtained.

  7A to 7D show a third embodiment of the valve device of the present invention. Note that substantially the same parts as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The valve device 10b of this embodiment is different from the above embodiment in the configuration of the check valve and the valve body. That is, as shown in FIG. 7C, the valve body 68 of this embodiment is connected to the mounting shaft 68a and the distal end of the mounting shaft 68a, and the skirt obliquely downward toward the base end of the mounting shaft 68a. It is comprised from the umbrella-shaped valve 68b extended in the shape, and the cyclic | annular protrusion 68c provided in the base end of the attachment shaft 68a. The valve body 68 is formed of an elastic material such as silicon rubber such as fluorine rubber or fluorosilicon rubber.

  On the other hand, the check valve 60 has a mounting hole 60a formed at the center thereof, and a plurality of negative pressure flow paths 65 are formed on the outer periphery of the mounting hole 60a at equal intervals in the circumferential direction. Further, the negative pressure channel 65 is formed so as to be located inside the outer peripheral edge of the umbrella valve 68b (see FIG. 7D).

  Then, the valve shaft 68 is attached to the check valve 60 by inserting the attachment shaft 68a from one opening of the attachment hole 60a and engaging the annular protrusion 68c with the opening peripheral edge on the opposite side of the attachment hole 60a. The peripheral edge of the mold valve 68b elastically contacts the lower surface side of the check valve 60, covers the outer periphery of the plurality of negative pressure flow paths 65, and closes them (see FIG. 7C). .

  As shown in FIG. 7A, the check valve 60 to which the valve body 68 is attached as described above is disposed inside the cylindrical wall 70 so that the valve body 68 is positioned inside the second valve seat 71. Be placed. Then, when the pressure in the fuel tank is reduced by a predetermined value or more from the outside air pressure to become a negative pressure state, as shown in FIG. The inner surface of the mold valve 68b is pressed, the peripheral edge thereof is turned up, away from the lower surface of the check valve 60, each negative pressure channel 65 is opened, and the outside air is introduced into the fuel tank. In this embodiment, the umbrella-shaped valve 68b of the valve body 68 formed of rubber or the like elastically contacts the lower surface of the check valve 60. Therefore, even if the check valve 60 has a dimensional variation or the like, the negative pressure channel 65 can be tightly closed.

  8 (a) to 8 (d) show a fourth embodiment of the valve device of the present invention. Note that substantially the same parts as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The valve device 10c of this embodiment is different from the above embodiment in the configuration of the check valve and the valve body. That is, as shown in FIG. 8C, the valve body 69 of this embodiment includes a mounting shaft 69a, a disk-shaped flange valve 69b connected to the tip of the mounting shaft 69a, and a base end of the mounting shaft 69a. And an annular protrusion 69c connected to the. The valve body 69 is formed of an elastic material such as silicon rubber such as fluorine-based rubber or fluorosilicone rubber, like the valve body 68 of the third embodiment.

  The check valve 60 has a mounting hole 60a formed at the center thereof, and a plurality of negative pressure channels 65 are formed at equal intervals in the circumferential direction on the outer periphery of the mounting hole 60a. Each negative pressure channel 65 is connected to the flange valve 69b. (See FIG. 8D).

  Then, the mounting shaft 69a is inserted from one opening of the mounting hole 60a, the annular protrusion 69c is engaged with the opening peripheral edge on the opposite side of the mounting hole 60a, and the center portion of the flange valve 69b is connected to one of the mounting holes 60a. The valve element 69 is attached to the check valve 60 by adhering to the periphery of the opening by vulcanization adhesion. At this time, the flange valve 69b of the valve body 69 is elastically brought into contact with the lower openings of the plurality of negative pressure channels 65 so as to close the respective negative pressure channels 65 (see FIG. 8C). .

  The check valve 60 is arranged inside the cylindrical wall 70 so that the valve element 69 is located inside the second valve seat 71 as shown in FIG. Then, when the pressure in the fuel tank is reduced by a predetermined value or more from the outside air pressure to become a negative pressure state, as shown in FIG. The outer periphery of the valve 69b is pressed from the back surface side, the peripheral edge thereof is turned up, opens away from the lower openings of the plurality of negative pressure channels 65, and the outside air is introduced into the fuel tank. In this embodiment, since the flange valve 69b of the valve element 69 formed of rubber or the like elastically contacts the plurality of negative pressure channels 65, the negative pressure channel 65 even if the check valve 60 has dimensional variation or the like. There is an advantage that can be tightly closed.

It is a disassembled perspective view which shows 1st Embodiment of the valve apparatus of this invention. It is sectional drawing in the AA arrow line of FIG. The check valve of the valve device is shown, (a) is a plan view, (b) is a cross-sectional view taken along the line B-B in (a), (c) is a rear view, and (d) is a perspective view. . It is explanatory drawing in the state which shows the effect | action of the valve apparatus and the pressure in a fuel tank is more than predetermined value. It is explanatory drawing in the state which showed the effect | action of the valve apparatus and the pressure in a fuel tank fell more than predetermined value from the external pressure. The 2nd Embodiment of the valve apparatus of this invention is shown, (a) is the principal part expansion explanatory drawing, (b) is an expansion explanatory drawing in the state in which the pressure in a fuel tank fell more than the predetermined value from the external pressure, (C) is a perspective view of a valve body. 3 shows a third embodiment of the valve device of the present invention, (a) is an enlarged explanatory view of the main part, (b) is an enlarged explanatory view in a state where the pressure in the fuel tank is lower than the external pressure by a predetermined value, (C) is an enlarged explanatory view of the check valve, and (d) is a rear view of the check valve. 4 shows a fourth embodiment of the valve device of the present invention, (a) is an enlarged explanatory view of the main part, (b) is an enlarged explanatory view in a state where the pressure in the fuel tank is lower than the external pressure by a predetermined value or more, (C) is an enlarged explanatory view of the check valve, and (d) is a rear view of the check valve.

Explanation of symbols

10, 10a, 10b, 10c Valve device 15 Valve case 20 Case body 25 Communication port 27 First valve seat 30 Lower cap 40 Upper cap 50 Float valve 55 First spring 60 Check valve 65 Negative pressure channel 66, 67, 68, 69 Valve body 70 Cylindrical wall 71 Second valve seat R1 Float chamber R2 Ventilation chamber

Claims (3)

A valve case provided with a float chamber communicating with the inside of the fuel tank below the partition wall and a vent chamber communicating with the outside of the tank above the partition;
A float valve disposed in the float chamber so as to be movable up and down;
A check valve disposed in the vent chamber;
The partition wall is formed to communicate with the float chamber and the vent chamber, and a lower surface periphery of the partition wall forms a first valve seat to which the float valve contacts and separates, and an upper surface periphery of the partition wall contacts and separates from the check valve. With a two-seat communication port,
A cylindrical wall surrounding the communication port is formed on the upper surface of the partition wall on the vent chamber side,
The check valve is disposed inside the cylindrical wall so as to be movable up and down, abuts on the second valve seat until a pressure in the fuel tank exceeds a predetermined value, and when the pressure exceeds a predetermined value, the first valve It is configured to open the communication port away from the two valve seats,
Further, the check valve has a negative pressure flow path communicating with the float chamber and the vent chamber in contact with the second valve seat, and the negative pressure flow path is normally closed so that the pressure in the fuel tank Is provided with a valve body that opens the negative pressure flow path when the air pressure drops below a predetermined value from the outside air pressure, and the valve body is in contact with the second valve seat when the check valve is lowered. Further, the valve device is configured to be positioned inside the second valve seat.   The valve device according to claim 1, wherein the check valve has a polygonal plate shape. The negative pressure flow path is formed at a position shifted from the center of the check valve,
The valve body has a plate shape, and one end of the valve body is fixed to a position shifted from the center of the check valve to a side opposite to the formation position of the negative pressure flow path, and can be opened and closed with respect to the negative pressure flow path. The valve device according to claim 1 or 2, wherein the valve device is attached.