JP4536611B2 - Float valve opening structure with single seal structure - Google Patents

Description

  The present invention is a float valve opening structure, for example, fuel evaporative gas in a fuel tank of an automobile or the like is caused to flow out into the canister and adsorbed by the adsorbent of the canister, or when the fuel oil level rises, The present invention relates to a valve-opening structure for a float valve that prevents flow into

  An automobile or the like is provided with a fuel tank that stores fuel to be supplied to an engine combustion chamber. The fuel tank is provided with a ventilation system so that air commensurate with the amount of fuel in the tank can enter and exit. This ventilation system communicates the inside of the fuel tank and the canister, but if the fuel tank becomes full or more, the overflowed fuel will be sent to the canister side, and the overflowed fuel will be sent to the canister side. The canister becomes wet and unusable, so when the fuel is full with a full tank control valve at the top of the fuel tank, the ventilation system is shut off so that air and fuel are not sent to the canister I have to.

  In addition to the full tank control valve, the fuel tank is provided with a fuel leakage prevention valve that is always open to the atmosphere to adjust the pressure fluctuation in the fuel tank and that closes when the automobile tilts or rolls over.

  The full tank control valve and the fuel leakage prevention valve are provided separately, but a float valve having both functions has already been proposed for reasons such as cost increase.

  The float valve is shown in FIG. This float valve 1 has a valve body 4 and a float body 5 housed in an internal space 3 formed by a case 2, and has an upper opening 8a above it and a lower opening 8b below it. 2 is inserted into the fuel tank 6 and is arranged in such a manner that a flange 7 formed horizontally on the upper outer peripheral wall of the case 2 is attached to the upper wall surface of the fuel tank 6.

  The float body 5 is a member that moves upward when the fuel in the fuel tank 6 enters the internal space 3 from the lower opening 8b, and a rod-like and small-diameter first valve 9 is formed on the upper surface thereof. The valve body 4 includes a valve receiver 4a and a ring-shaped and large-diameter second valve 4b supported by the valve receiver 4a. The valve body 4 is mounted above the float body 5 so as to be movable up and down.

  A small-diameter upper end opening 12 is formed at the center of the valve receiver 4a, and a first valve 9 having a small diameter of the float body 5 can be in contact with the lower end of the small-diameter upper end opening 12. A valve seat 10 is formed.

  A second valve seat 11 is formed at the lower end of the upper opening 8a. When fuel enters the internal space 3 from the lower opening 8b, for example, when fuel is supplied into the fuel tank 6, the float body 5 and the valve body 4 The first valve 9 having a small diameter of the float body 5 abuts on the first valve seat 10 of the valve receiver 4a to close the upper end opening 12 having a small diameter, and the second valve 9 has a second diameter. The valve 4b contacts the second valve seat 11 formed at the lower end of the upper opening 8a to close the large-diameter upper opening 8a, and the fuel passes through the communication passage 13 formed above the upper opening 8a. To prevent it from flowing into a canister (not shown).

  When the valve is closed, the force with which the first valve 9 with the small diameter comes into contact with the first valve seat 10 is considerably smaller than the force with which the second valve 4b with the large diameter comes into contact with the second valve seat 11, so that the fuel tank When the pressure in 6 decreases even slightly, the float body 5 moves down by its own weight, the contact between the small diameter first valve 9 and the first valve seat 10 is released, and fuel flows through the small diameter upper end opening 12. The inside of the tank 6 is opened to the atmosphere.

  As a result, the pressure in the fuel tank 6 decreases, the contact between the large diameter second valve 4b and the second valve seat 11 is immediately released, and the large diameter upper opening 8a is opened to the atmosphere. The pressure in the tank 6 drops rapidly.

  As described above, the conventional float valve has both functions of the full tank control valve and the fuel leakage prevention valve, and only one valve is required, so that it is excellent in cost and convenience (see Patent Document 1).

  By the way, in general, the resin seal structure requires high accuracy, and the production cost increases as the number of seal points becomes plural. As described above, the conventional float valve has a double seal structure using two valve bodies as described above. In addition, the sealing structure between the first valve 9 having the small diameter and the first valve seat 10 is made of resin.

Therefore, the conventional float valve has a limit in providing a high sealing effect. In addition, because of the double seal structure, there is a problem that the production cost increases accordingly.
JP 2004-257264 A

  The object of the present invention is to solve such a problem, and by using a single seal structure, the sealing performance is improved, the production cost is reduced, and the valve opening characteristics after the valve closing is not deteriorated. It is to provide a valve opening structure of a float valve.

  In order to achieve the above object, the present invention adopts the following configuration.

In the invention according to claim 1, a case, a float body provided in a space formed in the case so as to be movable up and down, an elastic valve body provided on an upper part of the float body, and an upper opening of the case And a valve opening member that can move up and down together with the float body, the valve opening member has a pressing portion that hangs downward, and the valve seat is Formed at the lower end of the cylindrical body, the valve-opening member has a cylindrical portion surrounding the cylindrical body, the pressing portion is formed at the lower end of the cylindrical portion, and the cylindrical portion is moves up and down along the outer peripheral surface of the body, during opening of the valve body, the pressing portion presses the portion of the valve body from above, a portion of the valve body forcibly deformed to press Configuration to open the valve.

  With such a configuration, when the fuel level in the fuel tank is slightly lowered after the valve body is closed, the float body moves down, and the pressing portion of the valve opening member that moves down together with the float body serves as the valve body. Press a part of. Then, the location of the valve body pressed by the pressing portion is forcibly opened, and as a result, the entire valve body is opened.

Their to, such a configuration, the cylindrical portion of the valve opening member is smoothly moved up and down along the outer periphery of the cylindrical body.

In the invention which concerns on Claim 2 , the said valve opening member is the structure formed in the said float body separately. Such a configuration facilitates the manufacture of individual members in addition to the operation of the invention according to claim 1 . Further, when the valve opening member is damaged during assembly of the float valve or the like, it can be dealt with only by replacing the valve opening member.

In the invention which concerns on Claim 3 , the structure which provides a notch in the location in which the press part of the upper wall surface of the valve receiver of the said valve body is located.

In the invention according to claim 1, after the valve body is closed, the float body moves down by its own weight only when the fuel level in the fuel tank is lowered slightly, and the pressing portion of the valve opening member that moves down together with the float body is provided with the valve. Since a part of the body is pushed down strongly, the valve body can be easily opened even if the internal pressure of the fuel tank is high. Moreover, since the seal part can be made in one place and the seal part can be made of rubber instead of the resin part, the sealing effect can be enhanced and the production cost can be reduced.

Moreover , since the cylindrical part of the valve opening member can be moved up and down along the outer periphery of the cylinder, the vertical movement can be smoothed and the valve body can be opened more reliably. .

In the invention according to claim 2 , by forming the valve-opening member separately from the float body, in addition to the effect of the invention according to claim 1, the manufacture of the valve body and the float body can be facilitated. Further, when the valve opening member is damaged during the assembly of the float valve or the like, it can be dealt with only by replacing the valve opening member, so that the production cost can be further reduced.

In the invention according to claim 3, by providing a notch at a position where the pressing portion of the upper wall of the receiving valve of the valve body is located, in addition to the effect of the invention according to claim 1 or 2, sufficient valve opening action Can play.

  1 is an overall cross-sectional view showing a closed state of a valve body of a float valve, FIG. 2 is an enlarged cross-sectional view showing a state in the vicinity of the valve body of FIG. 1, and FIG. FIG. 4 is an enlarged sectional view showing a state in which the entire valve body is opened, and FIG. 5 is an enlarged sectional view of the valve opening member. Indicates. The float valve of the present invention may be used for any application. In the following, the float valve used for an automobile fuel system will be described.

  The float valve 20 includes a case 30, a float body 50 disposed in the case 30, a valve body 60, a flange 41 that fixes the case 30 to the fuel tank 45, and the like.

  The case 30 is a cylindrical resin member having an open bottom, and an internal space 31 is formed. At the center of the upper wall surface 32 of the case 30, a cylindrical body 34 that communicates with the internal space 31 and has an upper opening 33 at the center is integrally formed. A valve body 60 described later is formed at the lower end of the cylindrical body 34. An abutting valve seat 35 is formed.

  A communication passage 36 is connected to the upper opening 33. The communication path 36 communicates with a canister (not shown), and discharges the fuel evaporative gas in the fuel tank 45 to the canister or introduces the atmosphere into the fuel tank.

  In the case 30, a plurality of ribs 37 are provided at equal intervals in the vertical direction along the inner wall surface, and the ribs 37 form a space between the inner wall surface of the case 30 and the side wall surface of the float body 50. It secures and forms passages, such as fuel evaporation gas, and guides up-and-down movement of float body 50 in the tip part.

  A bottom plate 38 is attached to the bottom of the case 30 by means such as heat welding. The bottom plate 38 has a plurality of bottom openings 39 through which fuel or the like enters the internal space 31. The bottom opening 39 is for allowing fuel to enter the internal space 31 when refueling or when the vehicle is in a tilted state or rolls over. The upper opening 33 is closed by a valve body 60, which will be described later, provided at the top of the float body 50 to prevent fuel from flowing out into the canister.

  Also, a plurality of vent holes 40 are provided in the upper side wall surface of the case 30, and fuel evaporative gas in the fuel tank 45 enters the internal space 31 through the vent holes 40, and the upper opening 33 and the communication path. It is discharged to a canister (not shown) through 36. Further, a flange 41 is integrally formed on the upper side wall surface of the case 30.

  Reference numeral 45 denotes a fuel tank. A mounting hole 46 is provided in the upper wall surface of the fuel tank 45. The case 30 is inserted into the mounting hole 46, and the flange 41 of the case 30 is fixed to the upper wall surface of the fuel tank 45. To do. As a result, the float valve 20 is attached in such a manner that it is inserted into the fuel tank 45 as shown in FIG.

  The float body 50 inserted and arranged in the case 30 is made of resin and has a generally hollow cylindrical shape that is open downward, and has a large-diameter cylindrical portion 51 formed below and a small-diameter cylindrical portion 52 formed above. The large-diameter cylindrical portion 51 has the same diameter and its outer peripheral portion moves up and down along the vertical rib 37 provided on the inner surface of the case 30. A small-diameter portion 55 having a slightly smaller diameter is formed on the outer periphery of the upper end of the large-diameter cylindrical portion 51, and an engagement protrusion 74 of a valve opening member 70 described later is fitted into the small-diameter portion 55. Indentation 56 is formed.

  A plurality of locking pieces 53 projecting in the radial direction are provided on the peripheral surface of the small-diameter cylindrical portion 52, and a rod body 54 having a columnar shape and a circular arc tip at the center of the upper surface of the small-diameter cylindrical portion 52. Established.

  Above the small-diameter cylindrical portion 52 of the float body 50, a valve body 60 including a valve receiver 61 and a valve 62 is disposed. The valve receiver 61 is made of a resin and is a substantially hollow cylindrical member that is open downward. A side wall surface of the valve receiver 61 includes a plurality of locking pieces 53 formed on the outer peripheral surface of the small-diameter cylindrical portion 52 of the float body 50. A plurality of engaging grooves 63 that can be engaged are provided.

  A concave fitting portion 64 into which the small-diameter rod body 54 on the float body 50 is fitted is formed at the center of the lower surface of the valve receiver 61, and the rod body 54 on the float body 50 is fitted into the concave fitting portion 64. Thus, the valve body 60 is pivotally supported on the upper part of the float body 50.

  In addition, a groove 65 recessed in a ring shape is formed on the upper outer peripheral side surface of the valve receiver 61, and a donut-shaped and rubber valve 62 is fitted in the groove 65. When the float body 50 moves up, the valve 62 abuts on a valve seat 35 formed at the lower end of the cylindrical body 34 of the case 30 to prevent the fuel or the like from flowing out to the upper opening 33 side. In this case, since the valve 62 is fitted with clearance in the front-rear and left-right directions, the valve 62 and the valve seat 35 are well adhered even when the float body 50 is inclined. The valve 62 may be made of any material as long as it has elasticity and can be deformed by the pressing portion 75 described later.

  The assembly of the float body 50 and the valve body 60 is performed as follows. First, the valve 62 is fitted into the groove portion 65 of the valve receiver 61 to complete the valve body 60. Next, the valve body 60 is placed on the upper part of the float body 50, and a force is applied from the upper part of the valve body 60 in the state as it is to move the valve body 60 downward. Then, the valve body 60 is pushed along the outer periphery of the small-diameter cylindrical portion 52 of the float body 50. Finally, the locking piece 53 provided on the outer periphery of the small-diameter cylindrical portion 52 enters the engaging groove 63, and both members Are forcibly engaged. As a result, the valve body 60 is connected so as to be movable up and down without being separated from the float body 50.

  Reference numeral 70 denotes a resin-made valve opening member. The valve opening member 70 has a cylindrical skirt portion 71, a horizontal upper wall surface 72, and a cylindrical body 73 that hangs downward at the center of the upper wall surface 72, and these are integrally formed.

  The outer diameter of the cylindrical skirt portion 71 is substantially the same as the outer diameter of the large-diameter cylindrical portion 51 of the float body 50, and an engagement protrusion 74 is formed on the inner peripheral surface of the lower end thereof. The valve opening member 70 is attached to the float body 50 by fitting the protrusion 74 into a recess 56 formed on the upper outer peripheral surface of the large-diameter cylindrical portion 51 of the float body 50.

  A cylindrical body 73 that hangs downward at the center of the upper wall surface 72 is attached so as to surround the cylindrical body 34 that forms the upper opening 33, and moves up and down along the outer peripheral surface of the cylindrical body 34 when the float body 50 moves up and down. Move. Therefore, when the float body 50 moves up and down, the upper end portion of the valve opening member 70 does not fluctuate, and the float body 50 moves smoothly up and down.

  Moreover, as shown in FIG. 5 which is a cross-sectional view seen from the AA line direction of FIG. 2, a pressing portion 75 extending downward is formed on a part of the lower end surface of the cylindrical body 73. As shown in FIG. 5, the pressing portion 75 has a rectangular cross section and a circular cross section, and is positioned slightly above the valve 62 when the valve shown in FIGS. 1 and 2 is closed.

  Next, when the fuel liquid level in the internal space 31 in the case 30 is slightly lowered, the float body 50 is lowered by its own weight. Press down as shown. Then, the valve 62 is forcibly opened, and the upper opening 33 and the internal space 31 are communicated. Therefore, the entire valve body 60 is opened as shown in FIG.

  FIG. 6 shows a modification of the pressing portion 75. In this device, the cylindrical body 73 is cut obliquely, and the portion having the longest downward length is used as the pressing portion 75. The thing of this example can raise the intensity | strength of the press part 75 since the base part of the press part 75 can be formed widely.

  In addition, although the skirt part 71 was demonstrated as a cylindrical thing, as long as intensity | strength is maintained, the several leg-like thing hung down at equal intervals may be sufficient.

  The assembly of the float valve 20 will be described. First, the valve 62 is fitted into the groove 65 of the valve receiver 61. Next, the locking piece 53 of the small-diameter cylindrical portion 52 is press-fitted into the engagement groove 63 of the valve body 60, and the float body 50 and the valve body 60 are engaged by force fitting. Thereafter, the valve opening member 70 is fitted to the float body 50 to form a float unit.

  Next, the case 30 is turned upside down, and the float unit assembled as described above is inserted into the inner space 31 upside down. In that case, the cylinder 34 at the top of the case 30 is fitted into the cylinder 73 of the valve opening member 70. Thereafter, the coiled spring 58 is inserted into the bottom space 57 of the float body 50.

  Next, the bottom plate 38 is fixed to the bottom of the case 30 by means such as adhesive or welding, and the lid is closed. At this time, the other end of the spring 58 is brought into contact with the upper surface of the bottom plate 38. After the float valve 20 is assembled, it is inserted into the fuel tank 45 in an upright state, and the flange 41 is fixed to the upper wall surface of the fuel tank 45 for use.

  Next, the operation will be described. Normally, the fuel evaporative gas generated in the fuel tank 45 enters the internal space 31 through the bottom opening 39 and the vent hole 40 and is sent to the canister via the upper opening 33 and the communication path 36. Even if the fuel tank 45 vibrates and the fuel closes the bottom opening 39, the vent hole 40 is provided above the case 30, so that the fuel evaporative gas can be discharged without any trouble.

  When fuel enters the internal space 31 from the bottom opening 39 during refueling or when the vehicle moves up and down or turns, the fuel that has entered the interior between the inner wall surface of the case 30 and the side wall surface of the float body 50 It tries to flow through the space 31 to the communication path 36 through the upper opening 33.

  However, the fuel entering the internal space 31 pushes up the float body 50, and buoyancy and urging force of the spring 58 are further applied to the float body 50. Therefore, the float body 50 immediately moves up together with the valve body 60, and the valve 62 contacts the valve seat 35.

  By the way, the force with which the valve abuts on the valve seat has a relationship that increases in proportion to the diameter of the valve. The valve 62 of the embodiment also has a relatively large diameter, and the force with which the valve 62 abuts on the valve seat 35 is large, so that the valve 62 does not move away from the valve seat 35 as the pressure in the fuel tank 45 is slightly reduced. .

  When the tank is full, the pressure in the fuel tank 45 is high, and the valve 62 receives the high pressure from below and is in contact with the valve seat 35 with a strong force, so that the pressure in the fuel tank 45 slightly decreases. However, the float body 50 is in contact with the valve body 60 in a small area between the rod body 54 and the recessed fitting portion 64, so that the fuel level in the fuel tank 45 can be reduced. Just by slightly lowering, the contact between the rod body 54 and the recessed fitting portion 64 is released, and the float body 50 falls by its own weight.

  Then, the pressing portion 75 of the valve opening member 70 integrated with the float body 50 comes into contact with a part of the valve 62, presses the contact portion of the valve 62 downward as shown in FIG. The upper opening 33 and the internal space 31 are communicated with each other by forcibly opening. Therefore, the high pressure in the fuel tank 45 immediately decreases, and as a result, the valve body 60 is completely opened as shown in FIG.

  A modification is shown in FIGS. In this example, a notch 67 is provided at a position where the pressing portion 75 of the upper wall surface 66 of the valve body 60 is located, and the rubber valve 62 fitted into the groove 65 of the upper wall surface 66 is pushed down by the pressing portion 75. Increase the amount.

  1 to 4, the upper wall surface 66 of the valve body 60 is flat, and a donut-shaped and rubber valve 62 is placed on the upper surface thereof. Therefore, when the location where the valve 62 is to be pressed is pressed downward by the pressing portion 75 of the valve opening member 70, the descending distance is such that the location where the valve 62 is pressed down is as shown in FIG. The distance comes into contact with the upper wall surface 66. Therefore, even if the vertical length H of the engagement groove 63 is sufficiently secured, if the distance between the valve seat 35 and the valve 62 is shorter than the vertical length of the engagement groove 63, a sufficient valve opening action is achieved. There are cases where you cannot expect.

  In this example, as shown in FIG. 8, the upper wall surface 66 of the valve body 60 is the same as that shown in FIGS. 1 to 4, and a notch 67 is provided at a position below the pressing portion 75 of the valve opening member 70. At the same time, the size of the notch 67 is set such that the pressing portion 75 can penetrate downward.

  The valve opening operation will be described. When the valve opening member 70 is lowered together with the float body 50 at the time of valve opening, the pressing portion 75 of the valve opening member 70 comes into contact with the upper surface of the valve 62 and then pushes the valve 62 downward. Since the notch 67 is formed in the upper wall surface 66 of the valve body 60 below the pressing portion 75, the pressing portion 75 can be lowered to the vertical length H of the longest engagement groove 63. As a result, as shown in FIG. 7, the distance h between the valve seat 35 and the valve 62 can be made longer than that shown in FIGS. 1 to 4, and a sufficient valve opening action can be achieved. .

  It should be noted that the present invention is not limited to the configuration of the above-described embodiment, and the design can be changed as appropriate without departing from the gist of the invention.

Whole sectional view in which the valve element of the float valve of the present invention shows a closed state FIG. 1 is an enlarged cross-sectional view showing the state in the vicinity of the valve body The expanded sectional view which shows the state by which a part of valve body of this invention was forcibly opened by the press part of the valve opening member The expanded sectional view which shows the state by which the whole valve body of this invention was opened A valve opening member of the present invention, which is a cross-sectional view taken along line AA in FIG. Sectional drawing of the other valve opening member of this invention The expanded sectional view of the modification which shows the state by which a part of valve body of this invention was forcibly opened by the press part of the valve opening member The perspective view of the valve body used in the modification of this invention Cross-sectional view of a conventional float valve

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Float valve 30 ... Case 31 ... Internal space 32 ... Upper wall surface 33 ... Upper opening 34 ... Cylindrical body 35 ... Valve seat 36 ... Communication path 37 ... Rib 38 ... Bottom plate 39 ... Bottom part opening 40 ... Vent hole 41 ... Flange 45 ... Fuel tank 46 ... Mounting hole 50 ... Float body 51 ... Large diameter cylindrical part 52 ... Small diameter cylindrical part 53 ... Locking piece 54 ... Rod body 55 ... Small diameter part 56 ... Depression 57 ... Bottom space 58 ... Spring 60 ... Valve body 61 ... Valve receiver 62 ... Valve 63 ... Engaging groove 64 ... Recessed fitting portion 65 ... Groove portion 66 ... Upper wall surface 67 ... Notch 70 ... Valve opening member 71 ... Skirt portion 72 ... Upper wall surface 73 ... Cylindrical body 74 ... Engaging protrusion 75 ... Pressing part

Claims (3)

Case and
A float body provided in a space formed in the case so as to be movable up and down;
A valve body having elasticity provided at an upper portion of the float body;
A valve seat formed in the upper opening of the case and freely contactable with the valve body;
A valve opening member that can move up and down together with the float body,
The valve-opening member has a pressing part that hangs downward,
The valve seat is formed at a lower end of a cylindrical body, the valve opening member has a cylindrical portion surrounding the cylindrical body, the pressing portion is formed at a lower end of the cylindrical portion, and the cylindrical portion Moves up and down along the outer peripheral surface of the cylinder ,
When the valve body is opened, the pressing portion presses a part of the valve body from above, and forcibly deforms a part of the valve body to be pressed to open the valve body. Float valve opening structure. The float valve opening structure of a single seal structure according to claim 1, wherein the valve opening member is formed separately from the float body. The float valve opening structure of a single seal structure according to claim 1 or 2 , wherein a notch is provided at a position where the pressing portion of the upper wall surface of the valve body of the valve body is located.

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