JP7553365B2 - Valve mechanism - Google Patents

Description

This invention relates to an improvement to a valve device that is attached to a fuel tank of an automobile, motorcycle, etc., and is used to connect the ventilation passage of the fuel tank to the fuel tank.

Patent documents 1 and 2 show connectors or fuel shutoff valves that are attached to a fuel tank and used to connect the fuel tank's ventilation flow path to the fuel tank.

In the devices shown in Patent Documents 1 and 2, a communication hole is formed in the partition wall separating the lower and upper chambers, and when fuel flows into the lower chamber, a float in the lower chamber rises and closes the communication hole.

In addition, in the devices shown in Patent Documents 1 and 2, a cover is provided above the communication port in Patent Document 1, and a blowback section is provided in Patent Document 2, in order to prevent as much as possible the situation where fuel in the lower chamber sprays up and enters the air flow path connected to the upper chamber just before or just after the float closes the communication port.

However, in both of the devices shown in Patent Documents 1 and 2, although the cover and blowback section create a gap between them in the vertical direction and the communication port, they are large enough to hide the entire communication port in a plan view. For this reason, the devices shown in Patent Documents 1 and 2 cause excessive pressure loss when the valve is opened.

Patent No. 5841784 JP 2019-27352 A

The main problem that this invention aims to solve is how to effectively prevent the inflow of fuel into the ventilation passage while minimizing pressure loss in this type of valve device.

In order to achieve the above object, the present invention provides a valve device , comprising a partition wall separating an upper chamber having a vent portion to the outside of a fuel tank from a valve chamber formed below the upper chamber, the partition wall having a valve opening portion that is opened and closed by a float body that is housed in the valve chamber so as to be movable up and down,
The float body comprises a main body portion and a main valve body interposed between the main body portion and the partition wall so as to be movable up and down, and the main body portion is provided with a sub-valve body for a vent hole formed in the main valve body,
a blocking portion having an outer diameter smaller than the diameter of the valve orifice portion for blocking fuel from spraying up through the air hole, which is supported at a position directly above the air hole and below the air portion, such that a gap is formed between an outer surface of the blocking portion and the rim of the valve orifice portion at any position around the center of the valve orifice portion in a plan view, thereby forming an annular air vent gap in a plan view ;
The ventilation section is formed by a tubular section protruding from the side of the upper chamber onto the partition wall, and the inner end of the tubular section is positioned directly above the blocking section.

In this way, by supporting a blocking portion that blocks fuel from blowing up from the vent hole at a position directly above the vent hole and below the vent portion so as to form an air gap between the outer surface of the blocking portion and the rim of the valve orifice portion, it is possible to ensure communication between the upper chamber and the valve chamber through the valve orifice portion while minimizing pressure loss. Also, when the main body portion descends and the sub-valve body of the main body portion separates from the vent hole of the main valve body, and the upper chamber and the valve chamber are in communication within the range of the vent hole of the main valve body, even if fuel remaining in the valve chamber is blown out from the vent hole, it can be blocked by the blocking portion and returned to the valve chamber, preventing it from entering the vent portion.

One aspect of the invention is to support the blocking portion on the valve opening portion by a support piece having one end integrated with the bulkhead and the other end integrated with the blocking portion.

In one aspect of the invention, the blocking section is in the shape of a container with a top and sides, an open bottom, and a ventilation area on the side.

Another aspect of the invention is to form a space between the ventilation section and the partition wall to serve as a fuel reservoir.

According to this invention, the blocking section can effectively block fuel blown into the upper chamber from flowing into the ventilation section while minimizing pressure loss.

FIG. 1 is a perspective view showing a valve device according to an embodiment of the present invention as viewed from below. FIG. 2 is a cutaway perspective view of a main part of the valve device. FIG. 3 is a vertical cross-sectional view of the valve device, showing the valve open state with the float body lowered. FIG. 4 is a vertical cross-sectional view of the valve device, showing the valve closed state with the float body raised. FIG. 5 is a vertical cross-sectional view of the valve device, showing an intermediate state in which the main valve body constituting the float body is seated on the valve opening portion, but the main body part constituting the float body has descended to open the air hole of the main valve body. FIG. 6 is an enlarged cross-sectional view of a main portion of FIG. FIG. 7 is a cross-sectional view taken along line AA in FIG.

A typical embodiment of the present invention will be described below with reference to Figures 1 to 7. The fuel tank valve device V according to this embodiment is attached to a fuel tank T of an automobile or motorcycle, and is used to connect the ventilation passage P of the fuel tank T to the fuel tank T.

This valve device V is formed by forming a valve opening 3a in a horizontal partition wall 3 that separates an upper chamber 1 with a vent 1a to the outside of the fuel tank T from a valve chamber 2 formed below the upper chamber 1, and the valve opening 3a is opened and closed by a float body 4 that is housed in the valve chamber 2 so that it can move up and down.

In the illustrated example, the valve device V is formed by combining a case 11 with the lower part of a main body 10. The top part 12a of the upper case 12 described below serves as the partition wall 3, the upper chamber 1 is formed inside the main body 10 above this partition wall 3, and the interior of the case 11 below this partition wall 3 serves as the valve chamber 2.

The main body 10 is a short cylinder with a closed upper end and an open lower end. An outer flange 10a is formed at approximately the middle of the main body 10 in the vertical direction.

The side 10b of the main body 10, located between the upper end of the cylinder and the outer flange 10a, i.e., the side of the upper chamber 1, is provided with a tubular portion 10c that is integrated with the main body 10 so that the tube axis is perpendicular to the central axis of the main body 10. The tubular portion 10c has an outer end 10d located on the outside of the side 10b of the main body 10 and an inner end 10e located on the inside of the side 10b of the main body 10, and the middle portion is integrated with the side 10b of the main body 10. Both the outer end 10d and the inner end 10e are open. In this embodiment, the ventilation portion 1a is constituted by the tubular portion 10c. The inner end 10e of the tubular portion 10c is located above the valve opening portion 3a, more specifically, directly above it.

In the illustrated example, the vent passage P is connected to the fuel tank T via the valve device V by connecting a tube or the like that constitutes the vent passage P to the tubular portion 10c.

The case 11 is made up of an upper case 12 and a lower case 13. Both the upper case 12 and the lower case 13 are cylindrical.

The lower end of the upper case 12 is open. On the other hand, the upper end of the upper case 12 has a top portion 12a that serves as the partition wall 3 and has the valve opening portion 3a in the center.

Directly above the valve opening 3a on the top portion 12a, which forms the bulkhead 3 of the upper case 12, a fuel blow-out prevention portion 14, which will be described later, is supported.

A positioning portion 12b is formed on the outside of the side of the upper case 12, approximately in the middle in the vertical direction. In the illustrated example, the upper case 12 and the main body 10 are combined by fitting the upper part of the upper case 12 into the main body 10 until the lower end of the cylinder of the main body 10 abuts against the positioning portion 12b of the upper case 12, and engaging the engagement protrusion 10f of the main body 10 with the engagement window 12c of the upper case 12. In this combined state, the upper chamber 1 is formed between the top part 12a, which becomes the partition wall 3 of the upper case 12, and the upper end of the cylinder of the main body 10. The reference numeral 15 in the figure denotes a seal ring that is located between the top part 12a and the positioning portion 12b of the upper case 12 and seals between the inner surface of the main body 10 and the outer surface of the upper case 12.

The lower case 13 has an open upper end and is provided with a support 13a for the float body 4 and the additional float body 9 (described later) inside. In the illustrated example, the lower case 13 and the upper case 12 are combined by fitting the lower part of the upper case 12 into the lower case 13 and fitting the engagement protrusion 12d formed on the outside of the upper case 12 into the engagement window 13b of the lower case 13. In the illustrated example, the space inside the case 11 formed by the lower case 13 and the upper case 12 becomes the valve chamber 2. The valve chamber 2 is configured to communicate with the inside of the fuel tank T at each open part 13c on the lower end side of the cylinder of the lower case 13 and a window part 12e formed on the side of the upper case 12 that communicates with a window part 10g formed in the side part 10b of the main body 10.

In the illustrated example, the case 11 is configured to be thick enough to fit into the mounting hole Ta that is provided through the fuel tank T, and the outer diameter of the portion of the body 10 where the outer flange 10a is formed is configured to be large enough not to fit into the mounting hole Ta. The valve device V is then attached to the fuel tank T by welding the outer flange 10a to the outer surface of the fuel tank T with the lower part of the outer flange 10a inserted into the fuel tank T through the mounting hole Ta.

In the illustrated example, the valve device V has the valve opening portion 3a on one side of the center of the partition wall 3 that connects the valve chamber 2 and the upper chamber 1, and an additional communication portion 3b on the other side of the center of the partition wall 3 that connects the valve chamber 2 and the upper chamber 1.

In addition, a float body 4 is housed in the valve chamber 2 directly below the valve opening portion 3a so that it can move up and down, and an additional float body 9 is housed in the valve chamber 2 directly below the additional communication portion 3b so that it can move up and down.

As shown in FIG. 7, the valve chamber 2 has a substantially circular cross-sectional contour. The upper case 12 is formed with a vertical partition wall 12f that divides the inside of the valve chamber 2 into a main valve chamber 2a that houses the float body 4 and an auxiliary valve chamber 2b that houses the additional float body 9. The valve opening portion 3a communicates with the main valve chamber 2a, and the additional communication portion 3b communicates with the auxiliary valve chamber 2b.

In the illustrated example, when the fuel level in the fuel tank T reaches the bottom end of the main valve chamber 2a, fuel enters the main valve chamber 2a, causing the float body 4 to rise and close the valve opening 3a, thereby increasing the pressure in the fuel tank T and raising the fuel level in a filler pipe (not shown), causing the sensor of the fuel gun inserted into this filler pipe to detect a full tank. In other words, the valve opening 3a, main valve chamber 2a, and float body 4 form a full tank detection valve (Fuel Limit Vent Valve/FLVV).

In addition, in the illustrated example, ventilation between the inside and outside of the fuel tank T can be ensured through the windows 10g, 12e, the sub-valve chamber 2b, the additional communication part 3b, and the ventilation part 1a even when the fuel level in the fuel tank T reaches the bottom end of the sub-valve chamber 2b, and the additional communication part 3b can be closed by the additional float body 9 housed in the sub-valve chamber 2b in the event that fuel flows from the additional communication part 3b into the upper chamber 1. In other words, the additional communication part 3b, the sub-valve chamber 2b, and the additional float body 9 form a roll over valve (ROV).

In the illustrated example, a conical valve body 9a is formed on the upper part of the additional float body 9, with the lower end of the additional communication part 3b serving as the valve seat. The reference numeral 16 in FIG. 3 denotes a compression coil spring that applies a constant biasing force to the additional float body 9 toward the upper chamber 1.

In the illustrated example, the additional communication section 3b contains a cylindrical upper valve body 17 with both upper and lower ends open, which is biased by a spring 18 toward the valve chamber 2 and presses its outer surface against the inner wall of the flow path of the additional communication section 3b, and a lower valve body 19 biased by a spring 20 toward the upper chamber 1 and pressed against the lower end of the upper valve body 17. When the pressure inside the fuel tank T becomes higher than a certain value, the upper valve body 17 moves upward against the bias and separates from the inner wall of the flow path, allowing ventilation through the additional communication section 3b. Conversely, when the pressure inside the fuel tank T becomes lower than the outside by a certain value, the lower valve body 19 moves downward against the bias and separates from the lower end of the upper valve body 17, allowing ventilation through the additional communication section 3b.

In the illustrated example, when looking up at the bulkhead 3 from below (FIG. 7), the inside of the upper case 12 is provided with an outer baffle 12g that intersects with an imaginary straight line L connecting the windows 10g, 12e and the additional communication section 3b on the window 10g side, and an inner baffle 12h that intersects with the straight line L on the inside of the outer baffle 12g. The outer baffle 12g is integrated with the inner surface of the side of the upper case 12, and the inner baffle 12h is integrated with the side of the vertical bulkhead 12f that faces the auxiliary valve chamber 2b. As a result, even if fuel and gas enter together through the windows 10g, 12e, the path they take to reach the additional communication section 3b is no longer linear, so gas-liquid separation is achieved and fuel does not enter the additional communication section 3b.

The float body 4 is composed of a main body 5 and a main valve body 6 that is vertically movable between the main body 5 and the partition wall 3, and the main body 5 is provided with a sub-valve body 5a for a vent hole 6a formed in the main valve body 6.

In other words, the float body 4 has the main valve body 6 placed on the main body 5. In this placed state, the distance from the main valve body 6 to the lower end of the main body 5 is smaller than the distance between the bulkhead 3 and the support portion 13a, and a gap is formed between the outer surface of the float body 4 and the inner surface of the upper case 12. As a result, when the float body 4 is in a descending state with its lower end in contact with the support portion 13a, the gas in the fuel tank T flows from the open portion 13c into the main valve chamber 2a, and through the gap, flows from the valve opening portion 3a into the upper chamber 1 (Figures 2 and 3/open valve state).

When the fuel level in the fuel tank T rises and fuel flows into the main valve chamber 2a through the open portion, the main body 5 rises together with the main valve body 6, and the main valve body 6 seats on and blocks the valve opening 3a, and the sub-valve body 5a of the main body 5 seats on and blocks the air hole 6a of the main valve body 6 (Figure 4/valve closed state).

When fuel flows out of the main valve chamber 2a, the main body 5 descends and the sub-valve body 5a of the main body 5 separates from the vent hole 6a of the main valve body 6, thereby connecting the upper chamber 1 and the main valve chamber 2a (valve chamber 2) within the range of the vent hole 6a of the main valve body 6 (Figs. 5 and 6/intermediate state), and then the main valve body 6 drops, connecting the upper chamber 1 and the main valve chamber 2a through the valve opening 3a.

In the illustrated example, a compression coil spring 21 is interposed between the main body 5 and the support portion 13a, so that a constant biasing force is applied to the main body 5 toward the upper chamber 1.

In the illustrated example, the main valve body 6 is composed of a seal body 7 and a linking member 8 for the main body portion 5. The seal body 7 has a vent hole 6a in the center and has an outer diameter larger than the valve opening portion 3a. A short cylindrical portion 7a is formed on the underside of the seal body 7, the inside of which is connected to the vent hole 6a. The sub-valve body 5a of the main body portion 5 is designed to seat on the lower end of the short cylindrical portion 7a. The linking member 8 has a hole 8a in the center into which the short cylindrical portion 7a of the seal body 7 is fitted, and is equipped with legs 8b extending downward from the outer edge. A claw 8c is formed at the lower end of the leg 8b.

The main body 5 is composed of a seal body 5b that serves as the sub-valve body 5a, and a cylindrical body 5d with a flange portion 5c on the upper side that supports the seal body 5b from below.

The main valve body 6 and the main body 5 are assembled together so that the claws 8c of the legs 8b of the main valve body 6 are positioned between the flange portion 5c of the main body 5 and the upper end of the body portion 5d.

In addition, in this embodiment, a blocking portion 14 that blocks fuel from blowing up from the vent hole 6a is supported at a position directly above the vent hole 6a and below the vent portion 1a so that a ventilation gap 22 is formed between the outer surface of this blocking portion 14 and the rim of the valve orifice portion 3a at any position around the center of the valve orifice portion 3a. In other words, the blocking portion 14 is disposed within the upper chamber 1. The ventilation gap 22 is annular around the blocking portion 14 (see FIG. 7).

The blocking portion 14 is supported on the valve opening portion 3a by a support piece 23, one end of which is integrated with the bulkhead 3 and the other end of which is integrated with the blocking portion 14.

The blocking section 14 has a top section 14a and a side section 14b, is container-shaped with an open bottom, and has a ventilation area 14c on the side section 14b.

In the illustrated example, the blocking portion 14 is a short cylinder with the upper end of the cylinder closed to form the top portion 14a, and the lower end of the cylinder open.

The outer diameter of the blocking portion 14 is larger than the outer diameter of the circular vent hole 6a, but smaller than the diameter of the circular valve opening portion 3a.

In the illustrated example, the blocking portion 14 is supported at the center of the valve orifice 3a by a support piece 23 formed between the side of the blocking portion 14 and the rim of the valve orifice 3a so as to form the ventilation gap 22 between the lower end of the tube and the valve orifice 3a. In the illustrated example, the support pieces 23 are provided at three locations with equal intervals between adjacent support pieces 23 in the direction around the tube axis of the blocking portion 14. In the illustrated example, each support piece 23 is plate-shaped with its plate surface aligned in the vertical direction, and is curved at a substantially right angle between the connection point to the bulkhead 3 and the connection point to the blocking portion 14, so that it does not impede ventilation from the valve orifice 3a to the upper chamber 1.

In addition, on the side of the blocking portion 14 facing the inner wall of the upper chamber 1 on the side where the tubular portion 10c is formed, a notch is formed by notching the side of the blocking portion 14 from below, and this notch forms the ventilation area 14c.

In this embodiment, the blocking portion 14 that blocks the fuel from blowing up from the vent hole 6a is supported at a position directly above the vent hole 6a and below the vent portion 1a so as to form a vent gap 22 between the outer surface of the blocking portion 14 and the rim of the valve orifice portion 3a, so that the communication state between the upper chamber 1 and the valve chamber 2 through the valve orifice portion 3a can be ensured while minimizing pressure loss. In addition, when the main body portion 5 descends and the sub-valve body 5a of the main body portion 5 separates from the vent hole 6a of the main valve body 6, and the upper chamber 1 and the valve chamber 2 are in communication within the range of the vent hole 6a of the main valve body 6, even if the fuel remaining in the valve chamber 2 blows out from the vent hole 6a, it can be blocked by the blocking portion 14 and returned to the valve chamber 2, so that it does not enter the vent portion 1a.

In addition, in this embodiment, a space 24 that serves as a fuel pool is formed between the ventilation section 1a and the partition wall 3. In the illustrated example, there is a blocking section 14 on the partition wall 3, and the inner end 10e of the tubular section 10c is positioned directly above the blocking section 14, so that even if fuel does enter the upper chamber 1, the fuel remains in the space 24 between the partition wall 3 and the inner end 10e of the tubular section 10c and does not enter the ventilation section 1a.

In addition, in this embodiment, the vent point 14c of the blocking section 14 is located closer to the inner wall of the upper chamber 1 than the inner end 10e of the tubular section 10c, that is, closer to the outer end 10d of the tubular section 10c. As a result, the path between the valve chamber 2 and the vent section 1a is meandering rather than linear, as shown by the arrow in Figure 3, so that gas-liquid separation is achieved and the intrusion of fuel into the vent section 1a is prevented as much as possible.

The main body 10, the case 11, the float body 4, and the main parts of the additional float body 9 can typically be easily and appropriately constructed from molded synthetic resin parts.

Naturally, the present invention is not limited to the embodiments described above, but includes all embodiments that can achieve the object of the present invention.

V: valve device T: fuel tank 1: upper chamber 1a: vent portion 2: valve chamber 3: bulkhead 3a: valve mouth portion 4: float body 5: main body portion 5a: sub-valve body 6: main valve body 6a: vent hole 14: blocking portion 22: vent interval

Claims (4)

A valve device comprising a partition wall separating an upper chamber having a vent portion to the outside of a fuel tank from a valve chamber formed below the upper chamber, the partition wall having a valve opening portion that is opened and closed by a float body that is housed in the valve chamber so as to be movable up and down,
The float body comprises a main body portion and a main valve body interposed between the main body portion and the partition wall so as to be movable up and down, and the main body portion is provided with a sub-valve body corresponding to an air hole formed in the main valve body,
a blocking portion having an outer diameter smaller than the diameter of the valve orifice portion for blocking fuel from spraying up through the air hole, which is located immediately above the air hole and below the air portion, is supported between an outer surface of the blocking portion and the rim of the valve orifice portion so that a gap is formed at any position around the center of the valve orifice portion in a plan view, thereby forming an annular air gap in a plan view ;
The vent portion is formed by a tubular portion protruding from a side portion of the upper chamber onto the partition wall, and the inner end of the tubular portion is positioned directly above the blocking portion. The valve device according to claim 1, wherein the blocking portion is supported on the valve opening portion by a support piece having one end integral with the bulkhead and the other end integral with the blocking portion. The valve device according to claim 1 or 2, wherein the blocking portion is in the shape of a container having a top and sides with an open bottom, and has a ventilation area on the side. The valve device according to any one of claims 1 to 3, in which a space for fuel accumulation is formed between the vent and the partition.

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