Valve device

Abstract

The present invention provides a valve device which can reliably raise a pressure regulating valve to a maximum raising position, can make the pressure regulating valve compact, and suppress the enlargement of the device. The valve device (10) comprises a housing (15), a float valve (80) and a pressure regulating valve (90). A first valve seat (26) is formed on the periphery of the ventilation chamber side of the valve hole (25). A housing portion (30) is provided protruding from the ventilation chamber side surface of the partition wall (23). A reduced diameter portion (35) that matches the outer periphery of the pressure regulating valve and an expanded diameter portion (37) that has a larger diameter than the outer periphery of the pressure regulating valve are provided on the inner periphery of the housing portion. The height of the upper end (36) of the reduced diameter portion (35) is set so that when the upper end (36) of the reduced diameter portion (35) abuts against the first valve seat (26) of the pressure regulating valve (90), the height is set to match or be above the surface (92) of the pressure regulating valve (90). When the pressure regulating valve (90) rises to the maximum due to the increase in the internal pressure of the tank, the pressure regulating valve (90) exceeds the upper end (36) of the reduced diameter portion (35).

Description

Technical Field

[0001] The present invention relates to a valve device that is mounted on a fuel tank of an automobile or the like and that can adjust the pressure in the fuel tank. Background Art

[0002] For example, a car's fuel tank is equipped with a pressure regulating valve. When the pressure in the fuel tank rises above a specified value, the pressure regulating valve allows fuel vapor to flow out to the outside to prevent the fuel tank from rupturing. When the pressure in the fuel tank drops below the outside air pressure, the pressure regulating valve allows outside air to flow in from outside the fuel tank to prevent the fuel tank from being crushed.

[0003] As a valve device equipped with such a pressure-regulating valve, for example, Patent Document 1 below describes a valve comprising: a housing having a lower float chamber disposed below and an upper disc chamber disposed above, separated by a partition wall; a float disposed in the lower float chamber so as to be liftable; and a generally disc-shaped disc member (pressure-regulating valve) disposed in the upper disc chamber. Furthermore, a fluid outlet hole is formed in the partition wall, connecting the lower float chamber and the upper disc chamber. Furthermore, an annular hole protrudes from the outer peripheral edge of the fluid outlet hole.

[0004] A cylindrical wall is provided protruding from the upper disc chamber side of the partition wall portion. The inner periphery of the base end side of the cylindrical wall conforms to the circular shape of the outer periphery of the disc member, and the inner periphery of the top end side of the cylindrical wall is larger in diameter than the inner periphery of the base end side. In addition, when the disc member descends due to its own weight, it abuts against the annular hole and blocks the fluid outlet hole. In this state, the upper surface of the disc member exceeds the upper end of the inner periphery of the base end side of the cylindrical wall and is arranged at a position that reaches the inner periphery of the top end side of the cylindrical wall (refer to Patent Document 1). Figure 5 B) When the pressure in the fuel tank rises, fluid such as fuel vapor flows into the upper disk chamber from the fluid outlet hole, pushing up the disk member.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application No. 2013-536926 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] In the valve device of Patent Document 1, as described above, when the disc member abuts the annular hole, closing the fluid outlet hole, the upper surface of the disc member extends beyond the upper end of the proximal inner circumference of the cylindrical wall and is positioned to reach the distal inner circumference. Therefore, when the internal pressure of the fuel tank rises, fluid flowing into the upper disc chamber through the fluid outlet hole passes between the outer circumference of the disc member and the proximal inner circumference of the cylindrical wall and is discharged toward the proximal inner circumference of the expanded cylindrical wall. In other words, the fluid that had been pushing up the disc member is released, making it difficult to push up the disc member and reliably raise the disc member to its maximum raised position (making it difficult to fully stroke the disc member).

[0010] In order to easily push up the disc member, one can consider increasing the outer diameter of the disc member and increasing the pressure-bearing area on the lower surface side of the disc member that receives the fluid pressure. However, this will cause the following problem: the disc member will become larger, causing the entire device to be larger.

[0011] Therefore, an object of the present invention is to provide a valve device that can reliably fully stroke a pressure regulating valve to a maximum lift position and can make the pressure regulating valve compact, thereby suppressing an increase in size of the device.

[0012] Solutions for solving problems

[0013] The valve device of the present invention for achieving the above-mentioned object is characterized in that it comprises: a housing, a valve chamber connected to the inside of the fuel tank is provided at the bottom via a partition wall, and a ventilation chamber connected to the outside of the fuel tank is provided at the top, and a valve hole is formed in the partition wall to connect the valve chamber and the ventilation chamber; a float valve is accommodated in the valve chamber and can be raised and lowered to open / close the valve hole; and a pressure regulating valve for pressure regulation is accommodated in the ventilation chamber and can be raised and lowered, a first valve seat is formed from the peripheral edge of the valve hole on the ventilation chamber side to contact / separate with the float valve, and a second valve seat is formed from the peripheral edge of the valve hole on the valve chamber side to contact / separate with the float valve, and is protruded from the surface of the partition wall on the ventilation chamber side. There is a housing portion that surrounds and houses the pressure regulating valve, the internal space of the housing portion is connected to the valve hole, and the inner periphery of the housing portion is provided with: a reduced diameter portion, which is located on the side of the partition wall and is set to a shape that matches the outer periphery of the pressure regulating valve; and an expanded diameter portion, which is located above the reduced diameter portion and is set to a shape with a diameter larger than the outer periphery of the pressure regulating valve, the height of the upper end of the reduced diameter portion from the surface of the ventilation chamber side of the partition wall is such that, when the pressure regulating valve is in contact with the first valve seat, it is consistent with the surface of the pressure regulating valve or above the surface of the pressure regulating valve, and the pressure regulating valve is configured to exceed the upper end of the reduced diameter portion when the pressure rises to the maximum due to the increase in pressure in the fuel tank.

[0014] Effects of the Invention

[0015] According to the present invention, a reduced diameter portion is provided on the inner periphery of the accommodating portion, and the reduced diameter portion is set to a shape that matches the outer periphery of the pressure regulating valve. The height of the upper end of the reduced diameter portion is consistent with or above the surface of the pressure regulating valve when the pressure regulating valve is in contact with the first valve seat. The pressure regulating valve is configured to exceed the upper end of the reduced diameter portion when it rises to the maximum due to the pressure increase in the fuel tank. Therefore, when the pressure in the fuel tank rises, the fuel vapor or other fluid flowing into the internal space of the accommodating portion from the valve hole is restricted to flow out from the internal space of the accommodating portion toward the expanded diameter portion until the pressure regulating valve rises to the maximum. Therefore, the pushing force generated by the fluid can easily act on the back side of the pressure regulating valve, which can reliably make the pressure regulating valve rise to the maximum rising position (enabling the regulating valve to perform a full stroke).

[0016] Furthermore, since the pressure regulating valve can be fully stroked as described above, it is not necessary to increase the pressure receiving area on the back side of the pressure regulating valve, thereby making the pressure regulating valve more compact and suppressing an increase in size of the valve device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is an exploded perspective view showing one embodiment of the valve device of the present invention.

[0018] Figure 2 is a perspective view of the valve device.

[0019] Figure 3 yes Figure 2 A cross-sectional view taken along the A-A line of sight.

[0020] Figure 4 It is a perspective view of a housing constituting the valve device.

[0021] Figure 5 It is a top view of the housing constituting the valve device.

[0022] Figure 6 yes Figure 2 An enlarged sectional stereoscopic view taken along the BB axis.

[0023] Figure 7 This is an enlarged cross-sectional view of a main portion of the valve device showing a state in which the pressure regulating valve descends and abuts against the first valve seat, thereby closing the valve hole.

[0024] Figure 8 This is an enlarged cross-sectional view of a main portion of the valve device in a state where the pressure regulating valve is raised to the maximum extent to open the valve hole.

[0025] Figure 9 Another embodiment of the valve device of the present invention is shown, and is a perspective view of a housing constituting the valve device.

[0026] Figure 10 It is an enlarged sectional perspective view of the main parts of the valve device.

[0027] Figure 11 This is an enlarged cross-sectional view of a main portion of the valve device showing a state in which the pressure regulating valve descends and abuts against the first valve seat, thereby closing the valve hole.

[0028] Figure 12 This is an enlarged cross-sectional view of a main portion of the valve device in a state where the pressure regulating valve is raised to the maximum extent to open the valve hole.

[0029] Figure 13 This is a graph showing the relationship between pressure and flow rate as test results of Examples.

[0030] Figure 14 (a) is an explanatory diagram showing Comparative Example 1, Figure 14 (b) is a graph showing the relationship between pressure and flow rate as the test results of Comparative Example 1.

[0031] Figure 15 (a) is an explanatory diagram showing a state where the pressure regulating valve of Comparative Example 2 is lowered. Figure 15 (b) is an explanatory diagram of a state in which the pressure regulating valve is raised to the maximum in Comparative Example 2. Figure 15 (c) is a graph showing the relationship between pressure and flow rate as the test results of Comparative Example 2.

[0032] Figure 16 (a) is an explanatory diagram showing a state where the pressure regulating valve of Comparative Example 3 is raised to the maximum. Figure 16 (b) is a graph showing the relationship between pressure and flow rate as the test results of Comparative Example 3. DETAILED DESCRIPTION

[0033] An embodiment of the valve device of the present invention will be described below with reference to the accompanying drawings. It should be noted that, in the following description, "fuel" refers to liquid fuel (including fuel droplets), and "fuel vapor" refers to evaporated fuel. Furthermore, the valve device in this embodiment is a fuel tank valve device installed in a vehicle such as an automobile.

[0034] like Figure 1 As shown, the valve device 10 in this embodiment has a shell 15, which has: a shell body 20, which is roughly cylindrical and has a partition wall 23 on the top; a cover 70, which is attached to the bottom of the shell body 20; and a cover 60, which is attached to the top of the shell body 20.

[0035] like Figure 1 、 Figure 3As shown, the housing body 20 has a generally cylindrical peripheral wall 21, and a generally disk-shaped partition wall 23 is disposed above the peripheral wall 21. It should be noted that the partition wall can be provided, for example, midway in the axial direction of the peripheral wall 21 of the housing body 20. In addition to a simple disk-like shape, the partition wall can also be provided with a cylindrical protrusion at the center and a stepped wall portion (shoulder-shaped wall portion) at its peripheral edge. The position and shape are not particularly limited.

[0036] Furthermore, a flange portion 28 extending outward is formed from the upper outer peripheral edge of the peripheral wall 21. A plurality of insertion holes 28a are formed on the inner peripheral side of the flange portion 28 (see FIG. Figure 5 ). Moreover, a locking protrusion 21a is protrudingly provided at a position on the upper side of the peripheral wall 21 and matching the insertion hole 28a (see Figure 5 ). In addition, a plurality of locking holes 21b are formed below the peripheral wall 21. It should be noted that, although not specifically shown, a plurality of through holes are formed in the peripheral wall 21.

[0037] On the other hand, the cover 70 has a plurality of through openings 71 and a plurality of locking claws 73 formed on its outer periphery. The locking claws 73 of the cover 70 are respectively locked in the locking holes 21b of the housing body 20, thereby attaching the cover 70 below the housing body 20 (see Figure 2 ). As a result, Figure 3 As shown, a valve chamber V communicating with the fuel tank 1 is formed below the housing through the partition wall 23. In the valve chamber V, a float valve 80 having a valve head 81 at the top is configured to be movable up and down via a biasing spring 95 (see Figure 3 ).

[0038] The cover 60 has a substantially cylindrical peripheral wall 61, a top wall 62 that closes the upper portion of the peripheral wall 61, and a flange portion 63 that extends from the lower peripheral edge of the peripheral wall 61 into an annular shape. The cover 60 is substantially in the shape of a top hat. A fuel vapor discharge port 61a (see FIG. 1 ) is formed at a predetermined position of the peripheral wall 61. Figure 3 ), a substantially cylindrical fuel vapor piping 65 is provided extending outward from the outer peripheral edge of the fuel vapor outlet 61a. A tube (not shown) is connected to the fuel vapor piping 65, which is connected to a canister (not shown) disposed outside the fuel tank. In addition, a plurality of locking pieces 67 (see FIG. 1 ) extend from the lower end of the peripheral wall 61. Figure 3 ). It should be noted that, if Figure 3 As shown, the valve device 10 can be mounted on the fuel tank 1 by fixing the lower end portion of the flange portion 63 to the front peripheral edge of the mounting hole 3 of the fuel tank 1 by welding or the like.

[0039] Moreover, if Figure 3As shown in FIG, a position limiting portion 69 in the form of a protruding piece is provided to hang down from the inner surface of the top wall 62 at a predetermined length. Figure 8 As shown, the position restricting portion 69 is provided so that its lower end can abut against a surface 92 of a pressure regulating valve 90 described later, thereby restricting further elevation of the pressure regulating valve 90. That is, the position restricting portion 69 defines the maximum elevation position (full stroke position) of the pressure regulating valve 90.

[0040] Then, with the seal ring 97 attached to the upper outer periphery of the peripheral wall 21 of the housing body 20, the cover 60 is covered from above to hold the seal ring 97, and the locking pieces 67 of the cover 60 are inserted into the insertion holes 28a of the housing body 20 and locked in the corresponding locking protrusions 21a, thereby installing the cover 60 on the upper side of the housing body 20. As a result, a breather chamber R (see FIG. 2 ) communicating with the outside of the fuel tank is formed above the partition wall 23. Figure 3 ).

[0041] The vent chamber R accommodates a pressure regulating valve 90 for regulating the pressure of the fuel tank 1 so as to be able to rise and fall (see Figure 7 and Figure 8 ).like Figure 1 、 Figure 6 As shown, the pressure regulating valve 90 in this embodiment (hereinafter referred to as "regulating valve 90") is in the shape of a circular plate of a predetermined thickness. However, no through-holes or the like are formed in the regulating valve 90 along its thickness. It should be noted that the pressure regulating valve may be shaped not only as a circular plate but also as a square, pentagon, hexagon, or polygon with more than these sides, or as a roughly elliptical or oblong plate. The shape of the pressure regulating valve is not particularly limited.

[0042] In addition, the material of the regulating valve 90 is not particularly limited, but it is preferably a material that is not easily deformed or corroded by fuel vapor. For example, iron-based metals such as stainless steel (SUS304, etc.), Ti-based alloys, Cu-based alloys, Al-based alloys, or ceramic materials, synthetic resin materials, etc. can be used. It should be noted that the regulating valve 90 of this embodiment is made of stainless steel. In addition, as Figure 7 As shown, the surface of the regulating valve 90 facing the first valve seat 26 is referred to as a rear surface 91 , and the surface opposite to the rear surface 91 is referred to as a front surface 92 .

[0043] The regulating valve 90 is only forced toward the valve seat by its own weight. Figure 7 As shown, in normal times, the rear surface 91 of the regulating valve 90 abuts against a first valve seat 26 described later, thereby closing the valve hole 25 .

[0044] If we return to the description of the housing body 20, then Figure 3As shown in FIG. 2 , a circular valve hole 25 is formed in the center of the partition wall 23 so as to penetrate the partition wall 23. The valve chamber V and the ventilation chamber R are connected to each other via the valve hole 25. In addition, a first valve seat 26 is provided protruding upward from the peripheral edge of the valve hole 25 on the ventilation chamber R side. Figure 7 、 Figure 8 As shown, the regulating valve 90 contacts and separates from the first valve seat 26 to open and close the valve hole 25 .

[0045] It should be noted that if Figure 5 As shown, a pair of small notches 26a, 26a are formed in the first valve seat 26 at radially opposite positions. Figure 3 、 Figure 7 As shown, the pair of minute notches 26 a and 26 a prevents the valve hole 25 from being completely blocked even when the back surface 91 of the regulating valve 90 abuts against the first valve seat 26 .

[0046] A second valve seat 27 projects downward from the periphery of the valve hole 25 on the valve chamber V side. The float valve 80 (here, the valve head 81 ) contacts and separates from the second valve seat 27 to close the valve hole 25 .

[0047] Furthermore, a housing portion 30 is provided protruding from the surface (surface) of the partition wall 23 on the ventilation chamber R side and the outer periphery of the first valve seat 26. The housing portion 30 surrounds and houses the regulating valve 90. Figures 3 to 6 As shown, the accommodating portion 30 of this embodiment has: a base portion 31 in a roughly circular frame shape, which rises to a specified height from the surface on the ventilation chamber R side of the partition wall 23; and an extension wall 33, which extends upward to a specified height from the inner peripheral edge of the upper end of the base portion 31.

[0048] Moreover, if Figure 5 As shown, when the accommodating portion 30 is observed from the axial direction of the regulating valve 90 (a direction along the direction of the pressure regulating valve rising and falling and consistent with the axial direction of the housing), as shown in FIG. Figure 3 As shown, a storage space R1 for accommodating the regulating valve 90 is formed inside the storage portion 30, and an outer space R2 is formed outside the storage space R1. In this embodiment, the cylindrical space formed inside the cover wall 43 described later becomes the outer space R2. Figures 6 to 8 As shown, the accommodation space R1 is a space surrounded by the surface of the partition wall 23, the inner peripheral surface of the accommodation portion 30, and the back surface 91 of the regulating valve 90. The accommodation space R1 is referred to as the "internal space" in the present invention.

[0049] In addition, if Figure 4 、 Figure 6As shown, the inner periphery of the accommodating portion 30 is provided with: a reduced diameter portion 35, located on the side of the partition wall 23, and set to a shape that matches the outer periphery of the regulating valve 90; and an expanded diameter portion 37, located above the reduced diameter portion 35, and set to a shape with a diameter larger than the outer periphery of the regulating valve 90.

[0050] In this embodiment, the reduced diameter portion 35 has a circular inner peripheral surface corresponding to the outer peripheral shape (circular shape) of the disc-shaped regulating valve 90, and the reduced diameter portion 35 is formed from the surface of the partition wall 23 on the ventilation chamber R side along the axial direction C of the housing 15 (refer to FIG. Figure 3 ) is formed with a fixed inner diameter. From the axial upper end 36 of the reduced diameter portion 35 (refer to Figure 4 ), a stepped portion 39 is formed, inclined so as to gradually increase the inner diameter of the accommodating portion, away from the partition wall 23. Furthermore, an expanded diameter portion 37 having a circular inner circumferential surface with a constant inner diameter is provided from the upper end of the stepped portion 39. Specifically, the expanded diameter portion 37 is provided across the stepped portion 39 from the upper end 36 of the reduced diameter portion 35.

[0051] In addition, if Figure 7 As shown, the height H of the upper end 36 of the reduced diameter portion 35 from the surface (surface) on the ventilation chamber R side of the partition wall 23 is aligned with the surface 92 of the adjustment valve 90 when the adjustment valve 90 is in contact with the first valve seat 26 (i.e., the back surface 91 of the adjustment valve 90 is in contact with the first valve seat 26). However, the height H of the upper end 36 of the reduced diameter portion 35 may be higher than the surface 92 when the adjustment valve 90 is in contact with the first valve seat 26. Figure 8 As shown, the regulating valve 90 is arranged so as to extend beyond the upper end 36 of the reduced diameter portion 35 when the regulating valve 90 is raised to the maximum due to an increase in the pressure in the fuel tank.

[0052] The housing portion 30 is provided with an opening 41 that allows the housing space R1 to communicate with the outer space R2. Figure 3 、 Figure 4 As shown in FIG. 1 , the opening 41 of this embodiment is in the shape of a slit extending in the axial direction C from the lower end to the upper end of the accommodating portion 30. Figure 5 As shown, in this embodiment, a plurality of openings 41 (here, four openings 41 are formed) are formed at equal intervals in the circumferential direction of the accommodation portion 30 .

[0053] Providing the opening 41 facilitates the release of fluid flowing into the storage space R1 to the outer space R when the pressure within the fuel tank rises, thereby increasing the valve closing pressure of the regulating valve 90. Furthermore, the opening 41 is in the form of a slit extending in the axial direction C. Therefore, regardless of the stroke position of the regulating valve 90 during its ascent, the fluid flowing into the storage space R1 is easily released to the outer space R2.

[0054] Moreover, if Figure 4 As shown, the opening width of the slit-shaped opening 41 is constant from the lower end of the reduced diameter portion 35 constituting the housing portion 30 (the portion abutting against the surface of the partition wall 23) to the middle of the step portion 39, and gradually expands from the middle of the step portion 39 toward the upper end of the housing portion. Figure 5 As shown, the radially inner portion of the accommodating portion 30 of the opening 41 is communicated with the accommodating space R1, and the radially outer portion of the accommodating portion 30 of the opening 41 is communicated with the cylindrical space forming the outer space R2, and, as shown Figure 6 As shown, the upper portion of the opening 41 is communicated with the ventilation chamber R.

[0055] In addition, if Figure 5 As shown, a cover wall 43 is disposed outside the accommodation space R1 and opposite to the opening 41. Both ends 44, 44 of the cover wall 43 are connected to the accommodation portion 30 on both sides of the opening 41.

[0056] To explain more specifically, Figure 4 、 Figure 5 As shown, the cover wall 43 of this embodiment protrudes to a specified height from the upper end surface of the base portion 31 located at the lower part of the extension wall 33 and at a position opposite to the opening 41, with an axial cross-section that is roughly arc-shaped, and its two ends 44, 44 are respectively connected to the outer periphery of the extension wall 33 and the two sides of the opening 41.

[0057] Furthermore, a cylindrical space is formed inside the cover wall 43, forming the outer space R2. The cylindrical space in this embodiment is a generally cylindrical space having a diameter larger than the fixed width portion of the slit-shaped opening 41. A portion of its inner circumference communicates with the accommodating space R1 via the narrow opening 41, and the upper portion is open to communicate with the ventilation chamber R.

[0058] Moreover, if Figure 4 As shown, a plurality of ribs 45 are provided in the expanded diameter portion 37. The plurality of ribs 45 extend from the step portion 39 in the axial direction of the expanded diameter portion 37 and are arranged at predetermined intervals in the circumferential direction of the expanded diameter portion 37. The radial inner end of each rib 45 is formed so as to be located at the same position as the inner circumferential surface of the reduced diameter portion 35 when the accommodating portion 30 is viewed from the axial direction (see FIG. Figure 5 ).

[0059] like Figure 4 、 Figure 5 As shown, the ribs 45 of this embodiment extend from the step portion 39 to the upper end of the expanded diameter portion 37 with a constant width, and their radial inner ends are in an arc-shaped shape with rounded corners and are arranged at equal intervals along the circumference of the expanded diameter portion 37. Figure 5As shown, a pair of ribs 45, 45 are arranged on both sides of the circumference of each opening 41, and a total of eight ribs 45 are provided. In addition, the arc-shaped end surface of the radial inner end of each rib 45 is flush with the inner circumference of the reduced diameter portion 35 (refer to Figure 4 ).

[0060] In addition, if Figure 3 、 Figure 7 As shown, a storage space R4 is formed between the outer periphery of the accommodating portion 30 and the inner periphery of the shell 15. The storage space R4 stores the fuel flowing into the breather chamber R. The upper end of the accommodating portion 30 is formed to be located below the fuel vapor exhaust port 61a provided in the shell 15 and connected to the outside of the fuel tank.

[0061] In this embodiment, a storage space R4 is formed between the upper surface of the base portion 31 constituting the lower portion of the accommodating portion 30, the outer surface of the extension wall 33 including the cover wall 43, and the inner surface of the peripheral wall 61 of the cover 60 constituting the shell 15. In addition, the upper end of the extension wall 33 is located below the fuel vapor exhaust port 61a.

[0062] It should be noted that the housing portion 30 of this embodiment has a generally circular frame shape as a whole. However, the housing portion may also be configured as a polygonal frame shape such as a quadrilateral, pentagon, or hexagon, or as a generally elliptical or oblong frame shape. However, it is preferred that the housing portion be shaped to conform to the outer peripheral shape of the pressure regulating valve.

[0063] In addition, the opening that connects the storage space and the outside space is in the form of a slit in the present embodiment, but the opening may also be a circular or square through-hole that connects the radial inside and radial outside of the storage portion, as long as the storage space and the outside space can be connected.

[0064] Furthermore, the shapes of the valve device of the present invention other than the accommodating portion and the opening of the housing are not limited to the above-described configuration.

[0065] Next, the effects of the valve device 10 of the present invention achieved by the above-described configuration will be described.

[0066] like Figure 3 As shown, when the fuel level in the fuel tank 1 has not risen and the float valve 80 is not immersed in the fuel, the float valve 80 descends in the valve chamber V, and the valve head 81 moves away from the second valve seat 27, opening the lower opening of the valve hole 25. In addition, when the pressure in the fuel tank 1 is below a specified value, the regulating valve 90 is urged toward the first valve seat 26 by its own weight, and the back surface 91 abuts against the first valve seat 26, closing the upper opening of the valve hole 25. At this time, the small notch 26a (see Figure 5), even if the back surface 91 of the regulating valve 90 abuts against the first valve seat 26, the valve hole 25 will not be completely blocked, so Figure 3 In the illustrated state, the valve chamber V and the breather chamber R communicate with each other via the valve hole 25 .

[0067] when Figure 3 The vehicle in the shown state is turning a curve, or driving on a bumpy road or a slope, or overturning due to an accident, causing the fuel in the fuel tank 1 to shake violently. When the fuel liquid level rises, the float valve 80 rises due to the force applied by the force spring 95 and the buoyancy of the float valve 80 itself, and the valve head 81 abuts against the inner peripheral edge of the second valve seat 27, closing the lower opening of the valve hole 25. Therefore, the fuel can be prevented from flowing into the ventilation chamber R through the valve hole 25, and the fuel can be prevented from leaking to the outside of the fuel tank 1.

[0068] Furthermore, when the fuel vapor increases in the fuel tank 1 due to the vehicle's running, etc., and the pressure in the fuel tank 1 increases, the fuel vapor and other fluids pass through the opening 71 of the cover 70, the valve chamber V, and the valve hole 25, and flow from the upper opening of the valve hole 25 into the vent chamber R (here, into the accommodation space R1 inside the accommodation portion 30). In this way, the fluid pushes the back surface 91 of the pressure regulating valve 90 that is in contact with the first valve seat 26. Therefore, as shown in FIG. Figure 8 As shown, the regulating valve 90 is pushed up and rises to the maximum extent until it contacts the position regulating portion 69 (full stroke).

[0069] At this time, in the valve device 10, as shown in FIG. Figure 4 、 Figure 6 As shown, a reduced diameter portion 35 having a shape that matches the outer periphery of the pressure regulating valve is provided on the inner periphery of the accommodating portion 30. Figure 7 As shown, the height of the upper end 36 of the reduced diameter portion 35 is consistent with the surface 92 of the regulating valve 90 when the regulating valve 90 abuts against the first valve seat 26, and as shown in FIG. Figure 8 As shown, the regulating valve 90 is arranged so as to extend beyond the upper end 36 of the reduced diameter portion 35 when the regulating valve 90 is raised to the maximum due to an increase in the pressure in the fuel tank.

[0070] Therefore, as described above, when the internal pressure of the fuel tank rises, the fluid flowing from the valve hole 25 into the accommodating space R1 (internal space) inside the accommodating portion 30 is restricted to flowing out from the accommodating space R1 of the accommodating portion 30 toward the side of the expanded diameter portion 37 until the regulating valve 90 rises to its maximum. Therefore, the pushing force generated by the fluid is easy to act on the back side 91 of the regulating valve 90, which can reliably make the regulating valve 90 rise to the maximum rising position (enabling the regulating valve to perform a full stroke).

[0071] In addition, the regulating valve 90 can be operated in full stroke as described above, so there is no need to increase the pressure-bearing area (the area that bears the pressure of the fluid) on the back side 91 of the regulating valve 90 (if the regulating valve 90 does not operate in full stroke, it is necessary to increase the outer diameter of the regulating valve 90 to ensure the pressure-bearing area), so the regulating valve 90 can be made compact and the valve device 10 can be prevented from becoming larger.

[0072] On the other hand, when the pressure within the fuel tank 1 drops, the regulating valve 90 descends due to its own weight toward the first valve seat 26. At this time, the accommodating portion 30 includes an opening 41 that connects the accommodating space R1 with the external space R2. Therefore, when the internal pressure of the fuel tank drops, fluids such as fuel vapor can be easily released from the accommodating space R1 to the external space R2 through the opening 41. As a result, the closing pressure of the regulating valve 90 (the pressure at which the raised regulating valve 90 descends, abuts the first valve seat 26, and closes the valve hole 25 again) can be increased. This reduces the difference between the opening and closing pressures, making it easier to close the regulating valve 90 even when the pressure within the fuel tank 1 is high.

[0073] Furthermore, as described above, when the pressure in the fuel tank 1 rises, the regulating valve 90 is pushed up by the fluid such as fuel vapor flowing into the accommodating space R1 from the valve hole 25 .

[0074] At this time, in this embodiment, if Figure 4 As shown, the expanded diameter portion 37 constituting the accommodating portion 30 is provided with a plurality of ribs 45, which extend from the step portion 39 in the axial direction of the expanded diameter portion 37 and are arranged at predetermined intervals in the circumferential direction of the expanded diameter portion 37. The radial inner end of each rib 45 is formed as follows. Figure 5 As shown, when viewing the accommodating portion 30 in the axial direction, it is located at the same position as the inner peripheral surface of the reduced diameter portion 35. Therefore, the plurality of ribs 45 configured as described above can guide the lifting action of the regulating valve 90, and the lifting action of the regulating valve 90 becomes stable.

[0075] In addition, if Figure 4 、 Figure 5 As shown, the cover wall 43 has its two ends 44 and 44 connected to the accommodating portion 3 on both sides of the opening 41 , and a cylindrical space is formed inside the cover wall 43 , which forms the outer space R2 .

[0076] Therefore, when the pressure within the fuel tank 1 decreases, the fluid flowing into the accommodating space R1 from the valve hole 25 is easily released from the accommodating space R1 into the cylindrical space forming the outer space R2. Furthermore, the two ends 44, 44 of the cover wall 43 are connected to the accommodating portion 30 on either side of the opening 41. This prevents the housing from deforming radially inward of the accommodating portion 30 during molding, maintains the accuracy of the width dimension of the opening 41, and prevents interference between the accommodating portion 30 and the regulating valve 90, thereby preventing the regulating valve 90 from being obstructed from raising and lowering. Furthermore, because the two ends 44, 44 of the cover wall 43 are connected to either side of the opening 41, the opening 41 is surrounded by the cover wall 43. Therefore, when the pressure within the fuel tank 1 increases, fluid such as fuel vapor flowing into the accommodating space R1 from the valve hole 25 is less likely to flow out of the accommodating space R1 into the outer space R2. This makes it easier to maintain the upward force of the fluid on the regulating valve 90, allowing the regulating valve 90 to be raised more easily.

[0077] In addition, in this embodiment, if Figure 3 、 Figure 7 As shown, a storage space R4 is formed between the outer periphery of the accommodating portion 30 and the inner periphery of the housing 15. This storage space R4 stores the fuel that has flowed into the breather chamber R. The upper end of the accommodating portion 30 is positioned below a fuel vapor discharge port 61a provided in the housing 15 and communicating with the exterior of the fuel tank. Therefore, fuel that has flowed into the breather chamber R from the valve hole 25 during fuel sloshing, for example, can be temporarily stored in the storage space R4, and the stored fuel can be prevented from flowing into the fuel vapor discharge port 61a.

[0078] Figures 9-12 Another embodiment of the valve device of the present invention is shown in . It should be noted that the same reference numerals are given to substantially the same parts as those in the above embodiment, and their description is omitted.

[0079] In the valve device 10 of this embodiment, the structure of the accommodating portion 30A is different from that of the above embodiment. Figure 9 、 Figure 10 As shown, the housing portion 30A in this embodiment includes a generally circular frame-shaped base portion 31 and an extension wall 33A extending upward from the inner circumferential edge of the upper end of the base portion 31 to a predetermined height. The extension wall 33A has circular inner and outer surfaces, forming a generally cylindrical shape that is continuous along the circumference. Specifically, the extension wall 33A lacks the opening 41 and cover wall 43 of the previous embodiment. It should be noted that the extension wall 33A extends further in the axial direction C of the housing 15 than the extension wall 33 in the previous embodiment.

[0080] Furthermore, a reduced diameter portion 35 is formed on the inner periphery of the accommodating portion 30A, near the partition wall 23. This reduced diameter portion 35 has a circular inner circumferential surface with a constant inner diameter, corresponding to the outer circumferential shape of the regulating valve 90. Furthermore, an expanded diameter portion 37A is provided on the inner periphery of the accommodating portion 30A, facing away from the partition wall 23, across an inclined step 39. This expanded diameter portion 37A has a circular inner circumferential surface with a constant inner diameter. This expanded diameter portion 37A extends longer than the expanded diameter portion 37 in the aforementioned embodiment.

[0081] Furthermore, a plurality of ribs 45A are provided on the expanded diameter portion 37A. Each rib 45A is formed into a tapered surface that gradually slopes radially inward from the two side surfaces 46, 46 of the rib 45A, and has a substantially trapezoidal cross-section, extending from the step portion 39 to the upper end of the expanded diameter portion 37A with a constant width. In addition, the radial inner end of each rib 45A is flat, but the inner end is flush with the inner circumference of the reduced diameter portion 35 (see FIG. Figure 9 ).

[0082] Moreover, if Figure 11 As shown in FIG. 1 , in this embodiment, the height H of the upper end 36 of the reduced diameter portion 35 from the surface of the partition wall 23 on the ventilation chamber R side is located above the surface 92 of the regulating valve 90 when the regulating valve 90 is in contact with the first valve seat 26. Figure 12 As shown, the regulating valve 90 is arranged so as to extend beyond the upper end 36 of the reduced diameter portion 35 when the regulating valve 90 is raised to the maximum due to an increase in the pressure in the fuel tank.

[0083] Moreover, in the valve device 10A, by adopting the above-mentioned structure, when the internal pressure of the fuel tank rises, the fluid flowing from the valve hole 25 into the accommodating space R1 (internal space) inside the accommodating portion 30A is restricted to flowing out from the accommodating space R1 of the accommodating portion 30A toward the side of the expanded diameter portion 37A until the regulating valve 90 rises to the maximum. Therefore, the pushing force generated by the fluid can easily act on the back side 91 of the regulating valve 90, enabling the regulating valve 90 to reliably perform a full stroke to the maximum rising position.

[0084] The present invention is not limited to the above-described embodiment, and various modified embodiments can be implemented within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention.

[0085] Example

[0086] For the example and comparative examples 1 to 3, the behavior of the pressure regulating valve when the pressure in the fuel tank increases was tested.

[0087] (Example)

[0088] Made with Figures 1 to 8This embodiment has a similar housing, housing, and opening to the valve device shown in the figure. Furthermore, when the pressure regulating valve is in contact with the first valve seat, the surface of the pressure regulating valve and the upper end of the reduced diameter portion coincide with each other. The flow path area (the area of the gap between the outer periphery of the pressure regulating valve and the inner periphery of the expanded diameter portion, measured along the entire circumference) is designated "a."

[0089] (Comparative Example 1)

[0090] like Figure 14 As shown in (a), a valve device according to Comparative Example 1 was manufactured, identical to the embodiment except that the inner periphery of the housing portion lacked a reduced diameter portion. The inner periphery of the housing portion was circular, with a constant diameter from its lower end to its upper end. Furthermore, if the flow path area (the area of the gap between the outer periphery of the pressure regulating valve and the inner periphery of the housing portion, measured along the entire circumference) is denoted by "b," then a < b.

[0091] (Comparative Example 2)

[0092] like Figure 15 As shown in (a), a valve device of Comparative Example 2 is manufactured, which has a reduced diameter portion and an expanded diameter portion on the inner periphery of the accommodating portion, but is configured so that when the pressure regulating valve abuts against the first valve seat, the surface of the pressure regulating valve is higher than the upper end of the reduced diameter portion.

[0093] (Comparative Example 3)

[0094] like Figure 16 As shown in (a), a valve device according to Comparative Example 3 was manufactured, which includes a reduced diameter portion and an expanded diameter portion on the inner circumference of the housing. When the pressure regulating valve is in contact with the first valve seat, the surface of the pressure regulating valve is lower than the upper end of the reduced diameter portion. However, when the pressure regulating valve is fully raised, the lower surface of the pressure regulating surface is located below the upper end of the reduced diameter portion. Furthermore, if the flow path area (the area of the gap between the outer circumference of the pressure regulating valve and the inner circumference of the expanded diameter portion) is represented by "c," then a < c.

[0095] (Test method)

[0096] The valve devices of the embodiment and comparative examples 1-3 described above were installed in fuel tanks. Air was blown into the fuel tanks at a predetermined flow rate from an air supply pipe (not shown) until the pressure reached a predetermined level or higher. The behavior of the pressure regulating valves in the valve devices of the embodiment and comparative examples 1-3 during this period was measured. Specifically, the change in tank internal pressure was measured when the pressure regulating valves were raised due to the blowing of air.

[0097] The results are as follows Figure 13 、 Figure 14 (b) Figure 15 (c) Figure 16(b) In each graph, the dashed line ("without valve") shows the relationship between pressure and flow rate when air is blown into the fuel tank without a pressure regulating valve installed (the common line in each graph). The solid line ("with valve") shows the relationship between pressure and flow rate when air is blown into the fuel tank with a pressure regulating valve installed in the embodiment and comparative examples 1 to 3.

[0098] like Figure 14 As shown in (b), in Comparative Example 1, as the flow rate increases, the pressure only rises at a roughly constant rate, and the pressure regulating valve does not rise to its maximum (does not fully stroke). This is probably because the flow path area is large, making it difficult for the fluid pushing up the pressure regulating valve to be released.

[0099] like Figure 15 As shown in (c), in Comparative Example 2, as the flow rate increases, the pressure rises and falls, and the pressure regulating valve repeatedly moves slightly up and down (when the pressure regulating valve rises, the valve hole opens and the pressure decreases; when the pressure regulating valve falls, the valve hole closes and the pressure increases). However, in this case, the pressure regulating valve does not rise to its maximum (does not fully stroke). This is probably because, although the pressure regulating valve rises slightly as the flow rate increases, the fluid is immediately released to the expanded diameter side, and the pressure regulating valve does not fully stroke.

[0100] like Figure 16 As shown in (b), in Comparative Example 3, as the flow rate increases, the pressure rises (see the peak on the right side of the lower graph), then decreases. It then rapidly rises, drawing a curve similar to the dashed line in a valveless state, and gradually rises, with the pressure regulating valve reaching its maximum stroke (full stroke). However, the solid line and dashed line on the upper side of the graph are far apart, indicating a large pressure loss. This is presumably because the back of the pressure regulating valve is located at the reduced diameter portion when the pressure regulating valve is fully raised, making it difficult for the fluid to diffuse toward the expanded diameter portion.

[0101] Compared with the above-mentioned Comparative Examples 1 to 3, Figure 13 In the illustrated embodiment, as the flow rate increases, the pressure rises (see the peak on the right side of the lower graph), then decreases. It then rapidly rises, describing a curve similar to the dashed line in a valveless state, and gradually rises, with the pressure regulating valve reaching its maximum stroke (full stroke). Furthermore, the solid line in the upper portion of the graph approximates the dashed line, indicating minimal pressure loss. This demonstrates that in this embodiment, the pressure regulating valve can reliably reach full stroke while minimizing pressure loss.

[0102] Description of reference numerals:

[0103] 1: Fuel tank; 10, 10A: Valve device; 15: Shell; 20: Shell body; 23: Partition wall; 25: Valve hole; 26: First valve seat; 27: Second valve seat; 30, 30A: Accommodation portion; 35: Reduced diameter portion; 36: Upper end; 37: Expanded diameter portion; 39: Step portion; 60: Cover; 70: Lid; 80: Float valve; 90: Pressure regulating valve (regulating valve); 91: Back side; 92: Surface; 95: Force spring; 97: Sealing ring; R: Vent chamber; R1: Accommodation space (internal space); R2: External space; R4: Storage space; V: Valve chamber.

Claims

1. A valve device, characterized in that: have: The housing has a valve chamber communicating with the inside of the fuel tank at its lower portion and a vent chamber communicating with the outside of the fuel tank at its upper portion, with a valve hole communicating with the valve chamber and the vent chamber formed in the partition wall. a float valve, housed in the valve chamber in a liftable manner to open / close the valve hole; and A pressure regulating valve for pressure regulation is housed in the ventilation chamber in a manner that allows it to be raised and lowered. A first valve seat is formed on the periphery of the valve hole on the ventilation chamber side so as to contact with or separate from the pressure regulating valve, and a second valve seat is formed on the periphery of the valve hole on the valve chamber side so as to contact with or separate from the float valve. A housing portion is provided protruding from the surface of the partition wall on the ventilation chamber side to surround and accommodate the pressure regulating valve, and an internal space of the housing portion is communicated with the valve hole. The inner periphery of the housing portion is provided with: a reduced diameter portion located on the partition wall side and having a shape that matches the outer periphery of the pressure regulating valve; and an expanded diameter portion located above the reduced diameter portion and having a diameter larger than the outer periphery of the pressure regulating valve. The height of the upper end of the reduced diameter portion from the surface of the partition wall on the ventilation chamber side is equal to or higher than the surface of the pressure regulating valve when the pressure regulating valve is in contact with the first valve seat. The pressure regulating valve is arranged so as to exceed the upper end of the reduced diameter portion when the pressure in the fuel tank rises to the maximum. The expanded diameter portion is provided across a step portion from the upper end of the reduced diameter portion. The expanded diameter portion is provided with a plurality of ribs, the plurality of ribs extending from the step portion in the axial direction of the expanded diameter portion and arranged at predetermined intervals in the circumferential direction of the expanded diameter portion. The radial inner end of each rib is formed so as to be located at the same position as the inner peripheral surface of the reduced diameter portion when the accommodating portion is viewed from the axial direction.

2. The valve device according to claim 1, characterized in that A storage space is formed between the outer periphery of the accommodation portion and the inner periphery of the housing, and the storage space stores the fuel flowing into the breather chamber. The upper end of the accommodating portion is formed to be located below a fuel vapor discharge port provided in the housing and communicating with the outside of the fuel tank.

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