阅读说明：本技术 燃料箱用通气控制阀 (Ventilation control valve for fuel tank ) 是由 杉山晃也 武笠雄辅 田所卓也 于 2018-11-09 设计创作，主要内容包括：设置在连通箱(2)的内部与外部的通气道中的一种燃料箱用通气控制阀(3)。燃料箱用通气控制阀包括漂浮在燃料液面上并上下移动的浮子(54)。燃料箱用通气控制阀,还包括阀机构(23),该阀机构与浮子联动而将通气道的通道截面积切换为开放状态、以及通道截面积比开放状态更受限制的限制状态。浮子在与第三壳体(53)之间具有容积与浮子的上下移动联动而大小变化的容积室(61)。在浮子的筒状壁(54a)与壳体的筒状壁(53c)之间形成有作为流量调节机构的控制间隙(67)。通过控制间隙,容积室作为阻尼器发挥作用。(A fuel tank ventilation control valve (3) provided in a ventilation passage that communicates the inside and outside of the tank (2). The fuel tank ventilation control valve includes a float (54) that floats on the fuel liquid surface and moves up and down. The fuel tank ventilation control valve further includes a valve mechanism (23) that switches the passage cross-sectional area of the ventilation passage to an open state and a restricted state in which the passage cross-sectional area is restricted more than the open state in conjunction with the float. The float has a volume chamber (61) between the third casing (53) and the float, the volume of which changes in size in conjunction with the vertical movement of the float. A control gap (67) as a flow rate adjusting mechanism is formed between a cylindrical wall (54a) of the float and a cylindrical wall (53c) of the housing. By controlling the gap, the volume chamber functions as a damper.)

1. A vent control valve for a fuel tank, provided in a vent passage that communicates the inside and outside of the fuel tank, comprising:

a valve mechanism (23) which has a float (54) that floats on the liquid surface of the fuel and moves up and down, and which switches the passage cross-sectional area of the air duct to an open state and a restricted state in which the passage cross-sectional area is restricted more than the open state in conjunction with the float;

a volume chamber (61) whose volume changes in size in conjunction with the vertical movement of the float; and

a flow rate adjusting mechanism (66, 67) that sets an outflow of a fluid from inside to outside of the volume chamber to a first state and an inflow of the fluid from outside to inside to a second state different from the first state,

the volume chamber includes:

fixed pistons (53c, 53e) provided on the housing; and

and a movable cylinder (54a) that is provided on the float and that relatively movably houses the fixed piston.

2. The ventilation control valve for a fuel tank according to claim 1, wherein the flow rate adjustment mechanism is provided with a control clearance (67) between the fixed piston and the movable cylinder.

3. The ventilation control valve for a fuel tank according to claim 1 or 2, wherein the fixed piston has a gas reservoir (65) that stores gas, and a through hole (66) that supplies gas from the gas reservoir to the volume chamber.

4. A vent control valve for a fuel tank, provided in a vent passage that communicates the inside and outside of the fuel tank, comprising:

a valve mechanism (23) which has a float (54) that floats on the liquid surface of the fuel and moves up and down, and which switches the passage cross-sectional area of the air duct to an open state and a restricted state in which the passage cross-sectional area is restricted more than the open state in conjunction with the float;

a volume chamber (61) whose volume changes in size in conjunction with the vertical movement of the float;

a flow rate adjustment mechanism (67) that sets an outflow of fluid from the inside to the outside of the volume chamber to a first state, and sets an inflow of fluid from the outside to the inside to a second state different from the first state;

a gas reservoir (65) for storing gas; and

and a through hole (66) that penetrates from the gas reservoir to the volume chamber and supplies gas from the gas reservoir to the volume chamber.

5. The ventilation control valve for a fuel tank according to claim 4, wherein the flow rate adjustment mechanism includes a control gap (67) provided between a cylindrical wall (54a) provided on the float and a cylindrical wall (53c) provided on the housing.

6. The ventilation control valve for a fuel tank according to any one of claims 1 to 5, wherein the flow rate adjustment mechanism restricts outflow of the fuel from the inside to the outside more than outflow of the gas from the inside to the outside.

7. A vent control valve for a fuel tank, provided in a vent passage that communicates the inside and outside of the fuel tank, comprising:

a valve mechanism (23) which has a float (54) that floats on the liquid surface of the fuel and moves up and down, and which switches the passage cross-sectional area of the air duct to an open state and a restricted state in which the passage cross-sectional area is restricted more than the open state in conjunction with the float;

a volume chamber (61) whose volume changes in size in conjunction with the vertical movement of the float; and the number of the first and second groups,

and flow rate adjusting means (66, 67) for setting an outflow of the fluid from the inside to the outside of the volume chamber to a first state and setting an inflow of the fluid from the outside to the inside to a second state different from the first state.

8. The ventilation control valve for a fuel tank according to claim 7, further comprising a cylindrical housing which forms a ventilation passage communicating an inside and an outside of the fuel tank, has openings (53f, 53g) for introducing the fuel at a lower portion, and forms an air chamber in the fuel tank;

the float is responsive to a level of the fuel within the interior of the housing.

9. The ventilation control valve for a fuel tank according to claim 7 or 8, wherein the flow rate adjustment mechanism includes a control gap (67) provided between a cylindrical wall (54a) provided on the float and a cylindrical wall (53c) provided on the housing.

10. The ventilation control valve for a fuel tank according to any one of claims 7 to 9, wherein the flow rate adjustment mechanism restricts outflow of the fuel from the inside to the outside more than outflow of the gas from the inside to the outside.

Technical Field

The present disclosure relates to a ventilation control valve for a fuel tank.

Background

Patent documents 1 and 2 disclose a float valve provided in a fuel tank vent passage. The float valve is used as an oil feed control valve for one of its uses. The fuel feed control valve is also called a top-up control valve for controlling a top-up (a state where fuel is added to an upper limit of a fuel tank) operation. When the liquid level reaches the float, the device closes the passage by floating the float on the fuel. When the passage is closed, the liquid level of the filler pipe rises, facilitating automatic shutoff of the oil feeder. The disclosures in the prior art documents cited as background art are incorporated by reference into the present application as descriptions of technical elements in the present specification.

Disclosure of Invention

The float valve moves according to the fuel level. Meanwhile, the float valve sometimes moves according to the flow of gas and/or liquid. For example, the sub float valve closes the fuel passage in accordance with the fuel level to realize the first automatic shutoff. At the same time, however, the fuel vapor may move according to the flow of the fuel vapor. For example, when the negative pressure of the steam processing device pulsates, the sub float valve may move up and down in a vibrating manner. The movement of the float valve may cause the float valve to collide with other members. Such collisions can produce undesirable sounds. In the above-described point or other points not mentioned, further improvement of the ventilation control valve for the fuel tank is demanded.

An object of the present invention is to provide a fuel tank ventilation control valve having a desired responsiveness.

Another object of the present invention is to provide a fuel tank ventilation control valve having response that is easy to close and difficult to open.

The present disclosure provides a fuel tank ventilation control valve provided in a ventilation passage communicating between the inside and the outside of a fuel tank. A fuel tank ventilation control valve includes: a valve mechanism (23) which has a float (54) that floats on the fuel liquid surface and moves up and down, and which switches the channel cross-sectional area of the air duct to an open state and a restricted state in which the channel cross-sectional area is restricted more than the open state in conjunction with the float; a volume chamber (61) whose volume changes in size in conjunction with the up-and-down movement of the float; and flow rate adjusting mechanisms (66, 67) for setting the outflow of the fluid from the inside to the outside of the volume chamber to a first state and setting the inflow of the fluid from the outside to the inside to a second state different from the first state. The volume chamber includes a fixed piston (53c, 53e) provided on the housing and a movable cylinder (54a) provided on the float and movably housing the fixed piston.

According to the disclosed ventilation control valve for a fuel tank, the volume chamber functions as a damper that restricts the valve closing operation and/or the valve opening operation of the float. The flow rate adjusting mechanism sets the outflow of the fluid from the inside to the outside of the volume chamber to a first state, and sets the inflow of the fluid from the outside to the inside to a second state different from the first state. The volume chamber has a fixed piston provided on the housing and a movable cylinder provided on the float and relatively movably accommodating the fixed piston. As a result, a volume chamber is formed which functions as a damper for restricting the movement of the float.

The present disclosure provides a fuel tank ventilation control valve provided in a ventilation passage communicating between the inside and the outside of a fuel tank. A fuel tank ventilation control valve includes: a valve mechanism (23) which has a float (54) that floats on the fuel liquid surface and moves up and down, and which switches the channel cross-sectional area of the air duct to an open state and a restricted state in which the channel cross-sectional area is restricted more than the open state in conjunction with the float; a volume chamber (61) whose volume changes in size in conjunction with the up-and-down movement of the float; a flow rate adjustment mechanism (67) which sets the outflow of the fluid from the inside to the outside of the volume chamber to a first state and sets the inflow of the fluid from the outside to the inside to a second state different from the first state; a gas reservoir (65) for storing gas; and a through hole (66) that penetrates from the gas reservoir to the volume chamber and supplies gas from the gas reservoir to the volume chamber.

According to the disclosed ventilation control valve for a fuel tank, the volume chamber functions as a damper that restricts the valve closing operation and/or the valve opening operation of the float. The flow rate adjusting mechanism sets the outflow of the fluid from the inside to the outside of the volume chamber to a first state, and sets the inflow of the fluid from the outside to the inside to a second state different from the first state. Since the gas reservoir stores gas, even if liquid enters the float, the buoyancy of the float can be supplemented by supplying gas from the through-hole. Therefore, the valve opening operation is given a damping action without impairing the responsiveness of the valve closing operation.

The present disclosure provides a fuel tank ventilation control valve provided in a ventilation passage communicating between the inside and the outside of a fuel tank. A fuel tank ventilation control valve includes: a valve mechanism (23) which has a float (54) that floats on the fuel liquid surface and moves up and down, and which switches the channel cross-sectional area of the air duct to an open state and a restricted state in which the channel cross-sectional area is restricted more than the open state in conjunction with the float; a volume chamber (61) whose volume changes in size in conjunction with the up-and-down movement of the float; and flow rate adjusting mechanisms (66, 67) for setting the outflow of the fluid from the inside to the outside of the volume chamber to a first state and setting the inflow of the fluid from the outside to the inside to a second state different from the first state.

According to the disclosed ventilation control valve for a fuel tank, a valve mechanism is provided in a ventilation passage. The valve mechanism performs a valve opening operation and a valve closing operation. The valve mechanism is provided with a volume chamber and a flow rate adjustment mechanism. The float moves up and down to provide a valve closing operation and a valve opening operation. The volume chamber functions as a damper that restricts the movement of the float. Therefore, the volume chamber functions as a damper that restricts the valve closing operation and/or the valve opening operation of the float. The flow rate adjusting mechanism sets the outflow of the fluid from the inside to the outside of the volume chamber to a first state, and sets the inflow of the fluid from the outside to the inside to a second state different from the first state. For example, the flow rate adjustment mechanism adjusts the valve closing operation and/or the valve opening operation to be slow. When the valve closing operation is adjusted to be slow, the energy at the time of valve closing is suppressed. When the valve opening operation is adjusted to be slow, the stroke amount for opening the valve can be suppressed without impairing the responsiveness of the valve closing operation, and the energy at the time of the next valve closing can be suppressed. As a result, it is possible to prevent the occurrence of an undesired collision.

The various modes disclosed in the present specification adopt different technical means to achieve respective purposes. The parenthesized reference signs described in the claims and claims are merely exemplary in correspondence with the corresponding portions of the embodiments described below, and are not intended to limit the scope of protection. The objects, features and effects disclosed in the present specification will become more apparent by referring to the following detailed description and accompanying drawings.

Drawings

Fig. 1 is a sectional view showing a system provided by the first embodiment.

Fig. 2 is a sectional view showing the operation of the valve with respect to a change in liquid level.

Fig. 3 is a sectional view showing the operation of the valve with respect to a change in liquid level.

Fig. 4 is a cross-sectional view showing the operation of the valve with respect to a change in liquid level.

Fig. 5 is a sectional view showing the operation of the valve with respect to a change in liquid level.

Fig. 6 is a cross-sectional view showing the operation of the valve with respect to a change in liquid level.

Fig. 7 is a sectional view showing the operation of the valve with respect to a change in the liquid level.

Fig. 8 is a sectional view showing the operation of the valve with respect to a change in the liquid level.

Fig. 9 is a cross-sectional view showing the operation of the valve with respect to a change in liquid level.

Fig. 10 is a sectional view showing the operation of the valve with respect to a change in liquid level.

Fig. 11 is a cross-sectional view showing the operation of the valve with respect to a change in liquid level.

Fig. 12 is a sectional view showing the volume chamber in the second embodiment.

Detailed Description

The embodiments are described with reference to the drawings. In each embodiment, functionally and/or structurally corresponding portions and/or associated portions are sometimes denoted by the same reference numerals or by reference numerals differing only in digits of more than one hundred digits. Corresponding parts and/or associated parts may refer to the description in the other embodiments.

First embodiment

(System)

In fig. 1, a fuel storage device 1 includes a fuel tank 2, an oil supply control valve 3, and a vapor processing device (EVCS) 4. The storage device 1 is mounted on a vehicle. The storage device 1 provides a system for a vehicle. The storage device 1 may include a fuel supply device that supplies liquid fuel to an internal combustion engine mounted on a vehicle. The fuel tank 2 is a container for storing liquid fuel. The fuel tank 2 has a complicated shape so as to provide a predetermined capacity while being able to be mounted in a vehicle. In the following description, unless otherwise specified, the term fuel refers to liquid, and the term gas refers to a mixture of air and fuel vapor in the fuel tank 2.

The fuel feed control valve 3 is provided on the fuel tank 2. The refueling control valve 3 provides a tank ventilation control valve. The oil feed control valve 3 may also be provided on a fuel supply device provided in the fuel tank 2, such as a pump module. The fuel tank float valve is provided to the oil control valve 3. The fuel feed control valve 3 is provided in a vent passage for ventilation between the fuel tank 2 and the vapor treatment device 4. The vent is used to vent gases from the fuel tank 2 into the vapor treatment device 4. The airway is also referred to as a ventilation channel or a breathing channel. The oil feed control valve 3 opens and closes the air passage. The fuel feed control valve 3 is provided on a wall surface of an upper portion of the fuel tank 2.

The fuel feed control valve 3 allows fuel feed from the fuel feed port by allowing ventilation between the fuel tank 2 and the steam processing device 4. The fuel feed control valve 3 causes the fuel feed from the fuel feed port to be stopped by shutting off the air flow between the fuel tank 2 and the steam processing device 4. The oil feed control valve 3 raises the fuel liquid surface in the direction of the oil feed port by cutting off the ventilation. As a result, an automatic stop mechanism (also referred to as an Auto stop mechanism) of the oil feeder automatically stops the oil feeding from the oil feeder in response.

The vapor treatment device 4 includes a canister (canister) for trapping fuel vapor (vapor) contained in gas discharged from the fuel tank 2. The steam processing device 4 includes a purge mechanism. The purge mechanism treats the fuel vapor captured by the canister by supplying the fuel vapor to the internal combustion engine to be combusted when a predetermined condition is established.

(oil feed control valve)

The oil feed control valve 3 is mounted on a flange 6 provided at an upper portion of the fuel tank 2. The flange 6 is made of resin or metal. The flange 6 is a member that covers the opening of the fuel tank 2. The flange 6 may be provided by a dedicated member for mounting to the oil control valve 3, or a member for mounting other tank accessories. The oil feed control valve 3 is disposed in the fuel tank 2 via a flange 6. The fuel feed control valve 3 is suspended from the flange 6 into the fuel tank 2. The flange 6 defines a passage 7 that forms between the fuel tank 2 and the vapor treatment device 4. The oil feed control valve 3 and the flange 6 are connected by a connection mechanism such as a snap mechanism. A seal member 8 is provided between the oil feed control valve 3 and the flange 6. The oil feed control valve 3 is provided: when the vehicle is in a horizontal state, that is, when the fuel tank 2 is placed in a horizontal state, the fuel feed control valve 3 is in the illustrated state.

The fuel feed control valve 3 has a cylindrical shape that depends downward from the upper portion of the fuel tank 2 and extends. The oil control valve 3 is provided with a tube 3a having a cylindrical shape, and the tube 3a is defined by members 31, 34, 51, 53 as a housing. When the fuel level is about to reach the upper end of the fuel tank 2, the pipe 3a can raise the fuel level in the pipe 3a while ensuring an air space outside the pipe 3a (the upper portion of the fuel tank 2). The tube 3a may also be referred to as a siphon or an air chamber forming tube. The upper end of the pipe 3a communicates with the passage 7, and the lower end thereof opens at a position slightly lower than the upper end of the fuel tank 2. The pipe 3a hangs down from the upper portion of the fuel tank 2, thereby defining a vent passage. The fuel feed control valve 3 opens and closes a communication state between the fuel tank 2 and the passage 7, that is, opens or closes a vent passage, in response to the fuel level in the pipe 3 a.

The housings 31, 34, 51, and 53 form a ventilation passage that communicates the inside and the outside of the fuel tank 2. The housings 31, 34, 51, and 53 have openings 53f, 53g for introducing fuel at the lower portions. The housings 31, 34, 51, and 53 have a cylindrical shape so that an air chamber is formed in the fuel tank 2 even if fuel is introduced inside.

The oil feed control valve 3 has a main float valve 21, a fuel holder 22, a sub float valve 23, and a relief valve 24.

(Main float valve)

The main float valve 21 is disposed in the pipe 3 a. When there is no fuel in the pipe 3a, the main float valve 21 opens the air passage. The main float valve 21 floats on the fuel in the arrival pipe 3a to close the air passage. The main float valve 21 opens and closes the air passage in response to the fuel level (first liquid level) in the relatively upper portion of the pipe 3 a.

The fuel holder 22 provides a fuel chamber for regulating the responsiveness of the main float valve 21. The fuel holder 22 is also a responsiveness adjusting mechanism for preventing frequent opening and closing such as reopening in a short time after the main float valve 21 is once closed. The fuel holder 22 holds the main float valve 21 in the closed state for a period of time that is assumed to be a period in which the fueling operator recognizes that the fuel tank 2 is full, and stops the fueling operation.

(auxiliary float valve)

The sub-float valve 23 controls fuel to reach the main float valve 21. Even if the fuel level rises temporarily, the sub-float valve 23 prevents the fuel from reaching the main float valve 21. Further, when a continuous fuel level rise occurs, the sub-float valve 23 allows the fuel to reach the main float valve 21. The sub float valve 23 is disposed at a position further inside the pipe 3a than the main float valve 21 on the fuel tank 2 side. The sub float valve 23 is disposed in the lower portion of the pipe 3a, i.e., in the vicinity of the inlet. When there is no fuel in the pipe 3a, the sub float valve 23 opens the air passage. The sub float valve 23 floats on the fuel in the arrival pipe 3a to close the air passage. Thereby, the sub float valve 23 restricts the fuel from reaching the main float valve 21. The sub float valve 23 opens and closes a passage inside the pipe 3a, i.e., opens and closes a gas passage between the inlet of the pipe 3a and the main float valve 21, in response to the fuel level at the inlet of the pipe 3 a.

(Overflow valve)

And a relief valve 24 for controlling the pressure in the fuel tank 2. The relief valve 24 is provided at the uppermost portion of the oil feed control valve 3, in other words, at the uppermost portion of the pipe 3 a. The relief valve 24 is provided on the upper wall of the first housing 31. The relief valve 24 has a valve seat 24a, a float 24b, and a spring 24 c. The relief pressure is set by float 24b and spring 24 c. The relief valve 24 opens the valve when the pressure in the fuel tank 2 becomes excessively high, and discharges the gas in the fuel tank 2 into the passage 7.

(first case)

The main float valve 21 has a first housing 31. The first housing 31 has a cylindrical shape. The upper end of the first housing 31 is connected to the flange 6. An opening portion for communicating the inside of the fuel tank 2 and the passage 7 is provided at the upper end of the first casing 31. The opening portion is surrounded and defined by the first valve seat 32. An open end communicating with the fuel tank 2 is provided at a lower end of the first housing 31. A sub float valve 23 is provided at the lower end of the first housing 31. The lower end of the first housing 31 is opened and closed by the sub float valve 23. At a predetermined position of the upper portion of the first housing 31, a through hole 33 is provided. The through hole 33 communicates the inside and outside of the first housing 31. The through-holes 33 make it possible to discharge fuel from the upper portion of the first housing 31 and/or supply air to the upper portion of the first housing 31.

(inner cup)

The main float valve 21 and the fuel holder 22 have an inner cup 34. The inner cup 34 is housed in the first housing 31. The inner cup 34 has a cup shape capable of storing fuel. The inner cup 34 defines a fuel cavity in the first housing 31. The upper end opening 35 of the fuel chamber provided by the inner cup 34 is located at almost the same height as the through hole 33. The inner cup 34 is formed to introduce and store fuel from the upper end opening 35. The inner cup 34 is held by being sandwiched between the first housing 31 and a second housing 51 described later.

The inner cup 34 has a through hole 36 provided in the side wall and a through hole 37 provided in the bottom wall. The through holes 36 enable the discharge of fuel from the fuel chamber in the inner cup 34. The through holes 36 slowly discharge the fuel. The through hole 36 is set small to allow a slow leakage of fuel over a longer period of time in which it is expected that the operator of the oil feeding device will give up continuing the oil feeding. The bottom wall of the inner cup 34 is formed to provide a funnel-shaped bottom surface to the interior. And a through hole 37 opened at the lowermost position of the bottom wall. The through-hole 37 is formed relatively large to rapidly discharge the fuel. The inner cup 34 provides a member that forms a fuel chamber that stores fuel to keep the main float valve 21 in a closed valve state.

(sphere)

The fuel holder 22 has a ball 38. The ball 38 may block the through hole 37. Also, the ball 38 can roll to open the through hole 37 by sensing shaking. Of course, various members such as a roller, a sheet, etc. capable of sensing shaking may be used instead of the ball 38. The inner cup 34 and the ball 38 provide the fuel holder 22. The inner cup 34 and the ball 38 provide a discharge valve for discharging the fuel in the inner cup 34 during a period after the oil feeding operation is completed. The ball 38 rolls by sensing the roll of the fuel tank 2, that is, the roll accompanying the travel of the vehicle. The through holes 36, 37 and the ball 38 provide a discharge mechanism for discharging fuel from the fuel chamber provided by the inner cup 34. And a discharge mechanism that retains fuel to prevent excessive oil feeding in a single oil feeding operation and is capable of re-feeding oil after the end of the oil feeding operation. The through hole 37 and the ball 38 provide a mechanism for discharging fuel upon judging the end of the oil feeding operation.

(float of main float valve)

The main float valve 21 has a movable valve body 39. The movable valve body 39 is a float for the main float valve 21. The movable valve body 39 is housed in the first housing 31. The movable valve body 39 is housed in the inner cup 34. The movable valve body 39 is housed so as to be movable in the axial direction, i.e., the vertical direction, within the first housing 31 and the inner cup 34.

The movable valve body 39 is arranged to float on the fuel when there is fuel in the inner cup 34. The movable valve body 39 has a float 41. The float 41 is housed in the inner cup 34. The movable valve body 39 has a holder 42. The retainer 42 is disposed on the float 41. The retainer 42 is coupled to the float 41 by a coupling mechanism 43. The coupling mechanism 43 is provided by a projection provided on the float 41 and a hook provided on the holder 42, the hook having an elongated groove in the height direction that receives the projection. Play is allowed as the protrusion is to move in the groove of the hook. The coupling mechanism 43 couples the float 41 and the retainer 42 so that they are separated by a predetermined amount in the axial direction.

The holder 42 is for holding a seal member 44. The seal member 44 is an annular plate. The seal member 44 is tightly fitted in the cylindrical portion of the holder 42. When the movable valve body 39 is seated on the valve seat 32, that is, when the seal member 44 is seated on the valve seat 32, the retainer 42 and the seal member 44 shut off the communication between the fuel tank 2 and the passage 7. The sealing member 44 is seated on the valve seat 32, thereby providing a closed valve state of the main float valve 21. The sealing member 44 is separated from the valve seat 32, and the main float valve 21 is opened.

A pilot valve 45 for assisting the opening of the main float valve 21 is formed between the float 41 and the retainer 42. The float 41 has a hemispherical convex portion. The holder 42 has a seat surface for receiving the convex portion. By means of the play provided by the linkage 43, the pilot valve 45 can be opened or closed. When the seal member 44 is seated on the valve seat 32, the pressure inside the fuel tank 2 becomes higher than the pressure in the passage 7. When the float 41 descends due to a decrease in the fuel level, the link mechanism 43 allows the float 41 to move away from the cage 42. As a result, the pilot valve 45 is opened. When the pilot valve 45 is opened, the pressure difference between the front and rear of the sealing member 44 is reduced, and the sealing member 44 is easily separated from the valve seat 32.

The float 41 is guided in the inner cup 34 in the up-and-down direction, i.e. in the axial direction. The inner cup 34 provides an inner and outer cylinder for guiding the float 41. Further, a guide mechanism 46 is provided between the holder 42 and the first housing 31. The guide mechanism 46 is provided by a small-diameter cylindrical portion provided on the holder 42 and a large-diameter cylindrical portion provided in the first housing 31. By disposing the small-diameter cylindrical portion in the large-diameter cylindrical portion, the holder 42 is guided to be movable in the axial direction without being displaced in the radial direction. A spring 47 in a compressed state is disposed between the inner cup 34 and the float 41. The spring 47 may push the movable valve body 39 upward. The spring 47 compensates for the buoyancy of the movable valve body 39.

The first housing 31, the inner cup 34, the float 41, and the retainer 42 are made of resin. The ball 38 is made of resin. The sealing member 44 is made of rubber.

(second case)

The sub float valve 23 has a second housing 51. The second housing 51 has a cylindrical shape. The second housing 51 is mounted on the lower end opening of the first housing 31. The first housing 31 and the second housing 51 are connected to each other. In the present embodiment, the first housing 31 and the second housing 51 are coupled by the coupling mechanism 26. The connection mechanism 26 is provided by an engagement mechanism utilizing elastic deformation of the first housing 31 and the second housing 51. The coupling mechanism 26 is also referred to as a snap mechanism.

(third case)

The sub float valve 23 has a third housing 53. The third housing 53 has a shallow plate shape. The third housing 53 is mounted on the lower end opening of the second housing 51. The second housing 51 and the third housing 53 are coupled by a coupling mechanism 27. The connecting mechanism 27 is provided by an engaging mechanism utilizing elastic deformation of the second housing 51 and the third housing 53. The coupling mechanism 27 is also referred to as a snap mechanism.

The third housing 53 has an opening formed at the lower end of the second housing 51, and a housing chamber for the float 54 is formed between the second housing 51 and the third housing 53. The receiving chamber communicates at a lower end with the inside of the fuel tank 2 through a plurality of large openings. Therefore, the fuel in the fuel tank 2 can freely enter at least the chamber defined by the second housing 51 and the third housing 53.

The third housing 53 provides a guide portion that guides the float 54. The third housing 53 has a shape that may be referred to as a disk. The third housing 53 has a plurality of elastic engagement pieces 53a on the radial outer side. These elastic engagement pieces 53a are coupled to the lower end portion of the second housing 51.

The third housing 53 has an outer cylinder 53b for housing the float 54. The outer cylinder 53b is cylindrical. The outer cylinder 53b has an inner diameter larger than an outer diameter of the float 54 to receive the float 54. A sufficiently large gap through which the liquid fuel and the gas pass is formed between the outer cylinder 53b and the float 54.

The third housing 53 has an inner cylinder 53 c. The inner cylinder 53c is cylindrical. The inner cylinder 53c has an outer diameter smaller than an inner diameter of the float 54 to be inserted into the inside of the float 54. A control gap 67 described later is formed between the inner tube 53c and the float 54.

The third housing 53 has a bottom wall 53 d. The bottom wall 53d connects the lower end of the outer cylinder 53b and the lower end of the inner cylinder 53 c. The bottom wall 53d is annular. The bottom wall 53d may contact the lower end of the float 54.

The third housing 53 has a partition wall 53 e. The partition wall 53e is a wall extending across the inner cylinder 53 c. The partition wall 53e is also an end wall located at an end of the inner cylinder 53 c. A cap-shaped member formed by the inner cylinder 53c and the partition wall 53e provides a fixed piston provided on the housing. The fixed piston is movable relative to a movable cylinder described later.

The partition wall 53e provides a wall having a convex shape at the center portion. The partition wall 53e causes the fuel to flow toward the radially outer edge. The partition wall 53e allows fuel to flow into a control gap 67 described later. Thereby, the air flow rate through the control gap 67 is suppressed.

The partition wall 53e may contact the float 54 in an internal cavity of the float 54. A plurality of ribs arranged radially are provided between the inner cylinder 53c and the partition wall 53 e. The plurality of ribs are triangular having sides extending along the inner cylinder 53c and sides extending along the partition wall 53 e.

The third housing 53 has a plurality of openings as described above. These openings allow fuel to enter around the float 54. And a third housing 53 having a plurality of openings 53 f. The opening 53f extends from the lower portion of the inner cylinder 52c to the bottom wall 53 d. The fuel can enter the inside of the outer cylinder 53b through the opening 53 f. And a third housing 53 having a plurality of openings 53 g. The opening 53g expands between the second housing 51 and the outer cylinder 52 b. The opening 53g extends between the plurality of elastic engagement portions 53 a. The fuel can enter the inside through the opening 53g beyond the upper end of the outer cylinder 53 b. The fuel can be introduced from the opening 53f before the liquid surface FL passes over the upper end of the outer cylinder 53 b. Thereby, when the liquid level rises, the float 54 can be made to respond quickly.

(float of sub-float valve)

The sub-float valve 23 is provided in a vent passage communicating between the inside and the outside of the fuel tank 2. The secondary float valve 23 provides a valve mechanism. The valve mechanism has a float 54 that floats on the liquid surface FL of the fuel and moves up and down. The valve mechanism switches the passage cross-sectional area of the air duct to an open state and a restricted state (a closed state) in which the passage cross-sectional area is more restricted than the open state (an open state) in conjunction with the float 54. The float 54 is also referred to as a movable valve body. The float 54 has a flat cylindrical shape. The float 54 also has a flat cap shape. The buoy 54 may define a cavity therein that may temporarily or permanently store gas when submerged. The float 54 is housed between the second case 51 and the third case 53.

The second housing 51 has a second valve seat 52 for the sub float valve 23. The second valve seat 52 is formed opposite to the float 54. The second valve seat 52 is positioned on the upstream side of the first valve seat 32 in the air flow direction in the oil feed control valve 3. In other words, the second valve seat 52 is located further inside the fuel tank 2 than the first valve seat 32. The opening defined by the second valve seat 52 is larger than the opening defined by the first valve seat 32. The float 54 can be seated on the second valve seat 52 or separated from the second valve seat 52 by floating on the fuel in the fuel tank 2.

The float 54 has a first member 54a and a second member 54 b. The first member 54a provides a cylindrical outer wall of the float 54. The first member 54a provides a movable cylinder. The first member 54a, i.e., a movable cylinder, is provided on the float 54 and relatively movably houses a fixed piston. The first member 54a may also be referred to as an outer member (outer member) or a link member (link member). The first member 54a is cylindrical. The first member 54a has a cap shape having a lower end opening at a lower end. The first member 54a has a through hole on the upper wall. The through hole opens into an opening portion surrounded by the second valve seat 52.

The second member 54b provides a central portion of the float 54. The second member 54b may also be referred to as a center member (centermeber) or a cap member (cap member). The second member 54b has a disc shape. The second member 54b is configured to close the through hole in the center of the first member 54 a.

The first member 54a and the second member 54b are made of resin. The first member 54a and the second member 54b can be connected by various connection methods such as pressing, bonding, welding, and the like. The first member 54a and the second member 54b are connected by a snap mechanism utilizing resin elasticity.

The float 54 has a sealing member 54 c. The sealing member 54c is disposed on the upper surface of the float 54. The sealing member 54c is fixed between the first member 54a and the second member 54b as the forming members. The sealing member 54c may be seated on the second valve seat 52 or away from the second valve seat 52. When the float 54 floats on the fuel to move upward, the seal member 54c is seated on the second valve seat 52. The sealing member 54c closes the air passage by seating on the second valve seat 52. The sealing member 54c, when moved downward due to the float 54 sinking into the fuel or as the liquid level of the fuel drops, leaves the second valve seat 52. The sealing member 54c moves away from the second valve seat 52, thereby opening the air passage. The movement of the float 54 in the radial direction is restricted by the third housing 53. The float 54 is movable in the up-down direction, i.e., axially, guided by the third housing 53.

(volume chamber of sub-float valve)

Between the float 54 and the third housing 53, a volume chamber 61 is defined and formed. The volume chamber 61 is also referred to as a float chamber. The volume of the volume chamber 61 changes with the position of the float 54. The volume of the volume chamber 61 changes in size in conjunction with the up-and-down movement of the float 54. When the float 54 is positioned at the lowermost position (valve-open position), the volume of the volume chamber 61 is minimum. When the float 54 is positioned at the uppermost position (valve-closing position), the volume of the volume chamber 61 is maximized. The volume chamber 61 is also referred to as a volume chamber. The volume chamber 61 is filled with fuel and/or gas. The ratio of fuel to gas in the volume chamber 61 regulates the buoyancy of the float 54.

The volume chamber 61 has a dual chamber (dual chamber)62 and a gas chamber 63. The dual chamber 62 may be filled with fuel and/or gas. The gas chamber 63 is closed upward and is opened only downward. The gas chamber 63 is provided mainly for storing gas. The float 54 can float on the fuel by the buoyancy of the gas stored in the volume chamber 61. The volume chamber 61 provides a buoyancy chamber for floating the float 54 on the fuel when the fuel reaches the float 54.

The double chamber 62 is disposed in a radially central portion of the float 54. The double chamber 62 is configured to occupy a radially central portion of the float 54. The double chamber 62 is disposed at an upper portion of the float 54.

The double chamber 62 provides a buoyancy reducing mechanism that gradually reduces the buoyancy applied to the float 54 with the passage of time after the fuel reaches the float 54. The float 54 has a through hole 64. The through hole 64 provides a buoyancy reducing mechanism that gradually reduces the buoyancy of the float 54. The through-holes 64 allow air to be discharged from the dual chamber 62 and fuel to be introduced from the lower portion of the dual chamber 62. As a result, the buoyancy reducing mechanism gradually sinks the float 54 into the fuel. The through hole 64 provides a mechanism for adjusting the buoyancy of the float 54 after the sub-float valve 23 sinks below the liquid level FL. The sub float valve 23 is easily opened or transited to an opened state after being submerged through the through hole 64.

The gas chamber 63 is disposed radially outward of the float 54. The gas chamber 63 is configured to surround at least a portion of the double chamber 62. The gas chamber 63 is arranged in a ring shape. The gas chamber 63 is arranged annularly along the second valve seat 52. The gas chamber 63, does not have a buoyancy reducing mechanism such as the through hole 64. The gas chamber 63 has a plurality of small cavities. These multiple small cavities are distributed in the radial direction. In other words, the plurality of small annular cavities are concentrically arranged. The plurality of small chambers may store air independently of each other. The gas chamber 63 may be divided into a plurality of small chambers arranged in a dispersed manner in the circumferential direction.

(damping mechanism of sub-float valve)

A damping mechanism is formed between the float 54 and the third housing 53. The damping mechanism is provided by a volume chamber 61 formed between the float 54 and the third housing 53, and a flow rate adjusting mechanism that controls the flow of fluid (including fuel and gas as liquid) between the volume chamber 61 and the outside. In the present embodiment, the flow rate adjustment mechanism is provided by the through hole 64, the through hole 66, and the control gap 67. The through holes 64 and 66 provide relief ports primarily for gas flow. The control gap 67 is provided between the first member 54a, which is a cylindrical wall provided on the float 54, and the inner wall 53c of the cylindrical wall provided on the third housing 53.

The control gap 67 exhibits less resistance to the flow of gas and greater resistance to the flow of fuel. In the present embodiment, the inflow of fuel into the volume chamber 61 and the outflow of fuel from the volume chamber 61 are controlled by forming the narrow control gap 67 that restricts the degree of flow of fuel. The control gap 67 restricts the outflow of the fuel from the inside to the outside of the volume chamber 61 less than the outflow of the gas from the inside to the outside of the volume chamber 61.

The flow rate adjusting mechanism sets the outflow of the fluid from the inside to the outside of the volume chamber 61 to a first state, and sets the inflow of the fluid from the outside to the inside to a second state different from the first state. The first state is, for example, a blocking state, i.e., an off state. The second state is, for example, an allowed state, i.e., an open state. The first state is provided by, for example, the flow path resistance in the control gap 67 in a state where fuel is present in the control gap 67. The second state is provided by, for example, flow path resistance in a state where fuel is not present in the control gap 67. Further, the second state is provided by supply gas from a gas reservoir 65 described later. This is because the floating speed of the float 54 becomes fast by supplying gas from the gas reservoir.

In this embodiment, a phase difference is provided between the fluctuation of the liquid surface FL outside the oil feed control valve 3 and the fluctuation of the float 54. The damping mechanism delays the operation of switching from the closed valve state to the open valve state by restricting the discharge of the fuel from the volume chamber 61. The damping mechanism intentionally reduces the responsiveness of the float 54 as a float. This can suppress excessive opening and closing of the sub float valve 23. Further, the sound generated by the sub float valve 23 can be suppressed.

(gas reservoir of sub-float valve)

Further, the third housing 53 is defined by the inner cylinder 53c and the partition wall 53e and forms a gas reservoir 65. The gas reservoir 65 is open to the bottom with a large opening, and does not store fuel. The gas reservoir 65 stores gas below the liquid level FL. A gas reservoir 65 is defined above the upper edge of the opening 53 f.

The partition wall 53e has a through hole 66. And a through hole 66 opened at a lower portion of the dual chamber 62 where the through hole 64 is opened. The position of the through hole 66 is offset from the position of the through hole 64 in the direction of the axis AX.

The through hole 66 penetrates from the gas reservoir 65 to the volume chamber 66. The through hole 66 supplies gas from the gas reservoir 65 to the volume chamber 61. The size and length of the through-hole 66 are set to adjust the gas supply rate. When the liquid surface FL rises rapidly and the float 54 is about to float, the volume chamber 61 sucks up the gas from the through hole 66. At this time, the volume chamber 61 attempts to suck up the fuel from the control gap 67, but the fuel exhibits higher resistance than the gas, so the volume chamber 61 sucks up the gas from the through hole 66. The gas is supplied from the gas reservoir 65 via the through hole 66, and the floating speed of the float 54 is increased as compared with the floating speed obtained by controlling only the gap 67. Thus, even if the control gap 67 is provided between the float 54 and the inner cylinder 53c, the valve closing response required when the liquid level FL rises can be obtained.

It is also believed that the through-hole 66 can regulate the rate of rise of the float 54. The through hole 66, for example, suppresses the rising speed of the float 54. Therefore, even if the liquid surface FL abruptly rises, the impact when the float 54 is seated on the second valve seat 52 can be reduced.

(operation of the sub-float valve)

Fig. 2 to 11 are sectional views showing the sub float valve 23 in a model form. Referring to fig. 2 to 11, the operation of the sub float valve 23 with respect to the fluctuation of the liquid surface FL will be described.

Fig. 2 shows a state where the liquid level FL is sufficiently lower than the sub float valve 23. The float 54 is located at the lowest position due to its own weight. The sub float valve 23 is in an open state.

Fig. 3 shows a state after the liquid surface FL reaches the lower portion of the float 54. The arrow of the liquid level FL indicates that the liquid level FL is in the process of rising. The float 54 is located at the lowest position or slightly starts to float due to its own weight. The gas reservoir 65 stores gas.

Fig. 4 shows a state where the liquid surface FL floats the float 54. The float 54 floats completely on the liquid surface FL. At this time, it is difficult for the fuel to pass through the control gap 67 due to viscosity and surface tension. The gas stored in the gas reservoir 65 is gradually supplied into the volume chamber 61. As a result, the fuel gradually enters the gas reservoir 65.

Fig. 5 shows a state after the liquid surface FL rises to such an extent that the sub float valve 23 is closed. The float 54 is seated on the second valve seat 52. Therefore, the sub float valve 23 is in a closed valve state. The gas of the gas reservoir 65 moves completely to the volume chamber 61 via the through hole 66. The gas in the volume chamber 61 gradually flows out from the through hole 64. As a result, the volume chamber 61 is gradually filled with fuel.

If the sub float valve 23 is submerged below the liquid level FL for a long time, the buoyancy for maintaining the closed valve state is lost. Shortly after the double chamber 62 is filled with fuel, the float 54 sinks. As a result, the sub float valve 23 is opened.

Fig. 6 shows the open state of the sub float valve 23 below the liquid level FL. The float 54 is located below the liquid level FL, lowermost as in fig. 2.

Fig. 7 shows a state where the liquid surface FL is lowered from the state of fig. 5. In this case, the fuel in the volume chamber 61 is intended to flow out from the through hole 66 and the control gap 67. At this time, the flow rate flowing through the control gap 67 is restricted. As a result, the lowering of the float 54 is suppressed. The float 54 slowly descends. Therefore, even if the liquid surface FL abruptly fluctuates up and down, the excessive reaction of the float 54 can be suppressed. As a result, collision between the second valve seat 52 and the float 54 is suppressed.

Fig. 8 shows a case where the liquid surface FL is lowered in a state where the fuel remains in the volume chamber 61. When the liquid surface FL falls below the upper end of the opening 53f, the fuel in the gas reservoir 65 immediately flows down. Thus, the gas reservoir 65 is filled with gas. The fuel in the volume chamber 61 flows out from the through hole 66 and the control gap 67. At this time, the fuel also exhibits higher resistance than the air, decelerating the descent speed of the float 54. At this time, the partition wall 53e having an upward convex shape guides the fuel to the control gap 67. Soon after all the fuel has flowed out of the volume chamber 61, the float 54 returns to the initial state shown in fig. 2.

Fig. 9 shows a case where the liquid surface FL rises again in a state where the fuel remains in the volume chamber 61. In this case, the gas is stored in the gas reservoir 65 again. The gas in the gas reservoir 65 is gradually supplied to the volume chamber 61 via the through hole 66. Thereby, the float 54 again makes the sub-float valve 23 flat.

Fig. 10 shows a case where the negative pressure supplied from the steam processing device 4 fluctuates in the case of fig. 4. In a state where the float 54 is slightly separated from the second valve seat 52, the negative pressure supplied from the steam processing device 4 may fluctuate as indicated by a thick arrow. For example, when the rotation speed of the internal combustion engine that draws fuel vapor varies, the negative pressure varies. In this case, the float 54 sometimes collides against the second valve seat 52. When the float 54 collides with the second valve seat 52, an undesirable sound is generated. For example, when the negative pressure decreases, the float 54 may descend. In this case, the control gap 67 restricts the flow of fuel and gas. Therefore, the abrupt lowering of the float 54 is suppressed, and even if the float 54 collides with the second valve seat 52 thereafter, the energy at the time of collision is suppressed.

Fig. 11 shows a case where the negative pressure supplied from the steam processing device 4 fluctuates in the case of fig. 5. Even after the float 54 is seated on the second valve seat 52, if the negative pressure fluctuates, the float 54 tends to separate from the second valve member 52. Even in this case, the control gap 67 restricts the flow of fuel and gas. Therefore, the abrupt lowering of the float 54 is suppressed, and even if the float 54 collides with the second valve seat 52 thereafter, the energy at the time of collision is suppressed.

According to the above embodiment, the volume chamber 61 functions as a damper that restricts the valve closing operation and/or the valve opening operation of the float 54. The control gap 67 sets the outflow of the fluid from the inside to the outside of the volume chamber 61 to a first state, and sets the inflow of the fluid from the outside to the inside to a second state different from the first state. For example, the control gap 67 adjusts the valve closing operation and/or the valve opening operation to be slow. When the valve closing action is adjusted to be slow, the energy at the time of valve closing is suppressed.

When the valve opening operation is adjusted to be slow, the stroke amount for opening the valve can be suppressed without impairing the responsiveness of the valve closing operation, and the collision energy at the time of the next valve closing can be suppressed. As a result, it is possible to prevent generation of an undesired sound.

Second embodiment

This embodiment is a modification of the previous embodiment. In the above embodiment, the gas reservoir 65 is defined between the inner cylinder 53c and the partition wall 53 e. Instead, a structure in which the gas reservoir 65 is not provided may be employed.

Fig. 12 is a sectional view showing the sub float valve 23 in a model form. The partition wall 253e is provided at the lower end of the inner cylinder 53 c. In this embodiment, there is no gas reservoir 65. In this embodiment, the control gap 67 also restricts the flow of fuel or gas from the inside to the outside of the volume chamber 61.

Other embodiments

The invention disclosed in the specification and the drawings is not limited to the illustrated embodiments. The present disclosure includes the embodiments listed and variations thereof that would occur to those skilled in the art. For example, the present disclosure is not limited to the combinations of components and/or elements disclosed in the embodiments. The present disclosure may be implemented in various combinations. The present disclosure may also have an additional portion that can be added to the embodiments. The present disclosure also includes embodiments in which components and/or elements of the embodiments are omitted. The present disclosure encompasses permutations and combinations of parts and/or elements between one embodiment and other embodiments. The technical scope of the disclosure is not limited to the description of the embodiments. The technical scope of the present disclosure is defined by the description of the claims, and all changes that come within the meaning and range of equivalency of the claims are to be embraced therein.

In the above embodiment, the damping mechanism is provided in the sub float valve 23 of the so-called top-up control valve. Alternatively, a damping mechanism may be provided in the main float valve 21. In addition, in the case where a single float valve is provided, a damping mechanism may be provided for the single float valve.

In the above embodiment, the operation of the float and the opening and closing of the valve mechanism are in a fixed relationship. That is, the up and down of the float corresponds to the closing and opening of the valve mechanism. In contrast, the up and down of the float may correspond to the opening and closing of the valve mechanism. In addition, the cylinder and piston may be reversed. For example, in the above embodiment, the fixed piston provided on the third housing 53 and the movable cylinder provided on the float 54 are movable relative to each other. Alternatively, a fixed cylinder provided in the third housing 53 and a movable piston provided in the float 54 may be movable relative to each other. In the above embodiment, a cylindrical piston is used. In contrast, the piston may have a cylindrical shape.

In the above embodiment, the control gap 67 is provided between the inner cylinder 53c as the fixed cylinder and the outer wall of the first member 54a as the movable piston. Alternatively, a seal mechanism may be provided between the inner cylinder 53c and the outer wall. For example, a rubber O-ring that prevents the outflow of gas and liquid may be provided.