JPH0324415Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to the structure of the inlet pipe of a fuel tank, and in particular, to a fuel tank equipped with an inlet pipe having a complicated shape.
The present invention relates to a fuel tank inlet pipe structure suitable for reliably and smoothly separating fuel and air passing through a breather tube.

[Conventional technology]

The fuel tank 1 installed in a car etc.
For example, as shown in FIG. 3, an inlet pipe 3 for injecting fuel into the fuel tank body 2 is often connected at a position lower than the top surface 2A of the fuel tank body 2. Therefore, if the fuel tank body 2 is injected with fuel from the inlet pipe 3, the problem arises that the upper part 2B in the fuel tank body 2 cannot be effectively used as a fuel storage space. Therefore, as shown in FIG. 4, for example, the inlet pipe 3 has an upper part 2B in the fuel tank body 2 near the connection part 4 with the fuel tank body 2, straddling the connection part 4. A breather tube 5 is provided for communicating with. As a result, when fuel is injected from the inlet pipe 3, fuel and air pass through the breather tube 5 as the pressure inside the fuel tank main body 2 increases, and one end 5A of the inlet pipe 3 near the connection part 4. The fuel and air are discharged from the upper part 2 of the fuel tank body 2 because the fuel returns to the fuel tank body 2 and the air escapes upward.
This makes it possible to fill fuel up to B. A plate-shaped separator 6 is attached to the upper part of the inlet pipe 3 near the one end 5A of the breather tube 5 so as to cover the one end 5A, and the air discharged from the breather tube 5 is The fuel tank 1 can be smoothly removed from the fuel tank 1 without interfering with the incoming fuel. In FIG. 3, 7A is a sanction tube for taking out fuel from the fuel tank body 2, 7B is a return tube for returning the remaining fuel supplied to the engine into the fuel tank body 2, Reference numeral 8 indicates a gauge unit for detecting the amount of fuel in the fuel tank body 2, and in FIG. ing. However, in the structure of the inlet pipe of such a conventional fuel tank, since the plate or tube for the separator 6 is passed through the inlet pipe 3, the shape of the inlet pipe 3 has to be straight due to manufacturing. There was a problem that it was limited to nearby items. That is, due to constraints on the space for arranging the fuel tank 1 of a vehicle, it is often necessary to bend the inlet pipe 3 in a complicated manner.
This makes it impossible to pass the plate or tube for the separator 6 into the inlet pipe 3. Furthermore, since there are obstacles such as the separator 6 in the inlet pipe 3, there has been a problem in that fuel injection performance is deteriorated.

[Problem that the invention attempts to solve]

The present invention has been developed by focusing on the above-mentioned problems, and makes it possible to equip an inlet pipe with an integrated breather tube that has a complicated bending shape, and also makes it possible to remove obstacles such as separators from inside the inlet pipe. An object of the present invention is to provide an inlet pipe structure for a fuel tank that can eliminate this problem and greatly improve fuel injection performance.

[Means to solve the problem]

The present invention includes an airtight auxiliary chamber formed on the outside near the connection between the inlet pipe and the fuel tank body, and a breather tube for communicating the auxiliary chamber with the upper part of the fuel tank body. , a return hole formed in the auxiliary chamber at a lower position than the position where the breather tube is connected and for returning the fuel in the auxiliary chamber into the fuel tank body; The above object is achieved by providing an air tube for communicating the upper part of the inlet pipe through the outside of the inlet pipe.

[Effect]

The present invention forms an airtight sub-chamber outside near the connection between the inlet pipe and the fuel tank body, opens one end of the breather tube to the sub-chamber, and allows the fuel to pass through the breather tube. Discharging and separating the fuel and air that have come into the sub-chamber, and returning the fuel separated in the sub-chamber into the fuel tank main body through a return hole formed in the lower part of the sub-chamber;
On the other hand, similarly separated air is guided from a position higher than the position where the return hole is formed in the auxiliary chamber to the upper part of the inlet pipe through an air tube provided on the outside of the inlet pipe. Even if the inlet pipe has a complicated shape, the air in the fuel tank can be released smoothly, and since obstacles can be removed from the inlet pipe, fuel injection efficiency is greatly improved. can be improved.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. As shown in FIGS. 1 and 2, this embodiment includes an airtight auxiliary chamber 12 formed on the outer side near a connecting portion 4 between an inlet pipe 10 and a fuel tank body 2; A breather tube 16 for communicating the auxiliary chamber 12 and the upper part 2B in the fuel tank body 2 is formed at a position lower than the position where the breather tube of the auxiliary chamber 12 is connected. A return hole 14 for returning the fuel 13 into the fuel tank body 2 and a position higher than the return hole 14 in the auxiliary chamber communicate with the upper part of the inlet pipe 10 through the outside of the inlet pipe 10. Achieve 18 for,
It is equipped with the following. The inlet pipe 10 has a complicated shape in which it is difficult to insert the conventional separator 6, as the inlet pipe 10 is largely bent into a hook shape at approximately the center in the longitudinal direction. The subchamber 12 has a substantially hat-shaped cross section, and
By welding the flange portion to the outer circumferential surface of the inlet pipe 10 over the entire circumference, the connection portion 4 with the fuel tank body 2 on the outer circumference of the inlet pipe 10 is maintained airtight. It is installed on the outside near the The breather tube 16 is attached to the vicinity of the connection part 4 between the inlet pipe 10 and the fuel tank main body 2 by a retainer 20, and one end 16A thereof is opened at a position higher than the return port 14 of the subchamber 12. The other end 16B is opened to the upper part 2B inside the fuel tank main body 2. The entire air tube 18 has a shape that follows the outer shape of the inlet pipe 10. or,
One end 18A thereof is the return hole 14 of the subchamber 12.
The other end 18B is opened at a higher position than the
It is opened at the top of the inlet pipe 10. In addition, in FIG. 1, the reference numeral 22 indicates a welding material piled up at the welding location. In this embodiment, by having the above-mentioned configuration, when the fuel 13 is injected into the fuel tank body 2, the fuel 13 is injected into the inlet pipe 1.
0 and the fuel tank body 2, the fuel and air that entered from one end 16B of the breather tube 16 are caused by the pressure inside the fuel tank 2 to It will be pushed out from one end 16A.
As a result, the fuel 13 returns to the fuel tank 2 due to gravity from the return port 14 located below the one end 16A, but the air 15 exits from the one end 18A of the air tube 18 opened at the top of the subchamber 12. The fuel passes through the air tube 18 and is discharged outside the fuel tank 1 through the upper part of the inlet pipe 10, so that the fuel in the fuel tank 2 can easily rise to a specified level. . In addition, in the above embodiment, the subchamber had a hat-shaped cross section, but the subchamber in the present invention has a
The shape is not limited to this, and may be formed as appropriate depending on the shape of the vicinity of the connection between the inlet pipe and the fuel tank body.

[Effect of the idea]

Since the present invention has the above-mentioned configuration, even if the inlet pipe is complicatedly curved due to space restrictions for the fuel tank, it is possible to equip the inlet pipe with an integrated breather tube. At the same time, the fuel and air that have entered the breather tube can be separated well,
It has the advantage of being able to quickly return only the fuel into the fuel tank, and smoothly guide the air upwards into the inlet pipe without interfering with the injected fuel, allowing it to be released outside the fuel tank. Effects can be obtained. Also, since there are no obstacles inside the inlet pipe,
Another effect is that fuel injection efficiency is greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of the main part showing an embodiment of the inlet pipe structure of a fuel tank according to the present invention, Fig. 2 is a front view seen from the direction of the arrow in Fig. 1, and Fig. 3 is a conventional one. FIG. 4 is a perspective view showing an example of the structure of the inlet pipe portion of the fuel tank, and FIG. 4 is a sectional view taken along the line shown in FIG. 3. 1... Fuel tank, 2... Fuel tank body, 3, 10... Inlet pipe, 4...
... Connection part, 12 ... Sub-chamber, 13 ... Fuel, 14 ...
...Return hole, 15...Air, 18...Air tube.

Claims (1)

[Scope of utility model registration request] an airtight auxiliary chamber formed on the outside near the connecting portion between the inlet pipe and the fuel tank body; a breather tube for communicating the auxiliary chamber with the upper part of the fuel tank body; and the auxiliary chamber. A return hole is formed at a position lower than the position where the breather tube is connected and for returning the fuel in the sub-chamber into the fuel tank main body, and a return hole is formed at a position higher than the return hole of the sub-chamber and the inlet pipe. An inlet pipe structure for a fuel tank, comprising: an air tube for communicating with the upper part of the inlet pipe through the outside of the inlet pipe.