JPS5927395Y2 - fuel tank cap - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a fuel tank cap.

The cap of the fuel tank of an internal combustion engine always communicates the inside of the tank with the atmosphere and can release it to the outside when the pressure inside the liquid tank increases, and vice versa. In this case, the tank is constructed so that atmospheric air can be drawn into the tank from the outside.

However, this type of fuel tank cap has a complicated structure, and if the vehicle itself temporarily tilts or falls over, there is a risk that the fuel in the tank may leak to the outside.

The present invention was devised in consideration of the above points, and has a simple structure that enables ventilation in two directions. To provide a fuel tank cap that prevents fuel in the fuel tank from leaking to the outside even if the fuel tank falls over.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Reference numeral 1 designates a cap body, and on the inside of the cap body 1, an annular protrusion 2 having a protruding center portion is formed, an atmospheric pressure chamber 3 is formed on the inside of the protrusion, and an annular groove 4 is formed on the outside of the protrusion.

Reference numeral 5 denotes a valve holder that covers the opening of the atmospheric pressure chamber 3 and is attached to the annular protrusion 2, and is formed with a cylindrical cavity 6 and a first ventilation hole 7 communicating from the cylindrical cavity 6 to the atmospheric pressure chamber 3. A valve seat 8 is formed at the entrance of the first ventilation hole 7.

9 is a disc-shaped retainer, and has a circular recess 9a that opens inward.
An annular recess 9b that opens outward is formed in the center part and an annular recess 9b that opens outward on the outer periphery. A latch piece 10 that is latched to the tank body is fixed to the recess 9a with a rivet 11, and the recess 9a holds the valve holder 5. The recess 9b covers the annular groove 4 through the gasket 12, and the groove formed inside the cap body 1 and the gasket 12 or the retainer 9 form a ventilation path 13 communicating with the atmosphere. .

Reference numeral 14 denotes a holding member having a cylindrical portion 15 that communicates with the inside of the tank.
and is screwed and fixed to the annular protrusion 2 via the valve holder 5.

Reference numeral 18 denotes a cap-shaped slit valve that is movable up and down inside the cylindrical cavity 6, and has a slit 19 at its upper end and a ventilation groove 20 at its side wall.

This slit-type valve 18 is pushed upward by the spring 21, and the shoulder portion 23 of the slit-type valve 18 constantly contacts the valve seat 8 to close the first ventilation hole 7.

Reference numeral 24 denotes a second ventilation hole that communicates between the cylindrical cavity 6 and the inside of the tank, and a hole 25 in the circular recess 9a of the retainer 9 and the latch piece 10.
The holes 26 are overlapped and communicated with each other with a step.

The second vent hole 24 is formed at a position away from directly below the slit 19 to prevent the fuel in the tank from rippling due to vibrations of the vehicle body and reaching the slit 19 directly.

27 is a seal fitted into the annular recess 9b of the retainer 5.

Next, to explain the operation of the present invention, when the fuel in the liquid tank decreases and the inside of the tank becomes negative pressure, the slit type valve 18 moves downward against the spring 21 due to the atmospheric pressure to connect the valve seat 8 and the slit type valve 18. A gap is created between the tank and the shoulder 23, and the atmospheric pressure chamber 3 and the cylindrical cavity 6 are communicated through the ventilation groove 20, and the atmosphere is replenished into the tank through the second ventilation hole 24 and the cylinder 15. On the other hand, when the fuel in the tank vaporizes and the pressure inside the tank increases, the slit 19 opens and the pressure is released to the outside, making it possible to maintain atmospheric pressure inside the fuel tank at all times.

The fuel in the tank ripples due to vibrations from the vehicle body, etc.
Even if the fuel passes through the second vent hole 24, the second vent hole 2
4 is formed at a position further away than directly below the slit 19, so that it does not directly reach the slit 19, and leakage of fuel due to ripples can be prevented.

Further, even if the vehicle overturns or the fuel tank is tilted, the fuel in the liquid tank is blocked by the slit valve 18 and will not leak to the outside.

Since the present invention is constructed as described above, it has a simple structure and can reliably provide ventilation in two directions.It also prevents the liquid level in the fuel tank from undulating due to vibrations of the vehicle body, or causing the vehicle to temporarily tilt. It is a device with great practical benefits, such as being able to reliably prevent the fuel in the fuel tank from leaking to the outside even if the fuel tank falls over or falls over.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is a front view taken along the line II in FIG. 2, FIG. 2 is a bottom view, and FIG. 3 is shown in FIG. It is a sectional view of III. 1 is the cap body, 3 is the atmospheric pressure chamber, 5 is the valve holder, 6 is the cylindrical cavity, 7 is the first ventilation hole, 8 is the valve seat, 9 is the retainer, 18 is the slit type valve, and 1 is the slit. , 20 is its ventilation groove, 23 is its shoulder, 21 is a spring, and 24 is a second ventilation hole.

Claims (1)

[Scope of utility model registration request] A cap body having a ventilation passage and an atmospheric pressure chamber communicating with the ventilation passage, a cylindrical cavity, a first ventilation hole communicating the cylindrical cavity and the atmospheric pressure chamber, and a valve seat formed in the first ventilation hole. A slit-type valve that opens when the pressure inside the tank becomes high is attached to the valve seat with an elastic member so that the slit-type valve opens when the pressure inside the tank becomes low, and is moved away from the valve seat by atmospheric pressure when the pressure inside the tank becomes low. A cap for a fuel tank, characterized in that a second vent hole communicating with the inside of the tank is formed at a position away from directly below the slit.