JP2004026218A - Negative pressure eliminating mechanism of oil pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a pump from decreasing the suctional function by eliminating a negative pressure brought in the pump in the case that kerosene is sucked from a fuel tank by the oil pump. <P>SOLUTION: A negative pressure solving mechanism fitted to a pump body 10 fixed to a fuel tank 11 side is provided with air-tight connection sections 20, 25 air-tightly fixed to the fuel tank and an opening/closing valve 30 for the air-tight connection section to the outside air. The valve 30 is urged toward the closed position by a coil spring 32. When a negative pressure arises in the fuel tank, the valve is pushed by the outside pressure and moves to the opening position. In this way, the negative pressure of the fuel tank 11 is eliminated. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a refueling pump used to replenish fuel such as kerosene to a heating device such as an oil stove. More specifically, the present invention relates to a negative pressure canceling mechanism for preventing the pumping performance of the oil supply pump from being reduced due to the negative pressure generated in the tank.
[0002]
2. Description of the Related Art
In order to supply kerosene to a household oil stove, it is common to supply kerosene purchased in a plastic tank or the like to an oil stove (or to an attached cartridge) using a refueling pump. is there. An electric lubrication pump for easily supplying such kerosene has been conventionally known.
[0003]
In such a refueling pump, a suction mechanism having a built-in electric pump is inserted into a kerosene tank to suck up kerosene in the tank. At this time, the inside of the tank is often shut off from the outside air. If a negative pressure is generated in the tank, the suction function of the pump is reduced.
[0004]
[Means, actions and effects to solve the problem]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems in order to effectively solve a decrease in a pump suction function due to generation of a negative pressure. According to the present invention, there is provided a negative pressure eliminating mechanism for a refueling pump having the following features.
[0005]
The negative pressure elimination mechanism of the present invention includes a “airtight connection portion that hermetically engages a fuel tank (such as a plastic tank containing kerosene)” and an “open / close valve that opens and closes the airtight connection portion with respect to outside air”. The on-off valve is urged to the closed position by urging means such as a spring. When a negative pressure is generated in the fuel tank, the on-off valve is pushed by the external pressure and moves to the open position. As a result, the negative pressure can be eliminated by communicating with the outside air inside the fuel tank.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. First, an outline of the entire configuration of the refueling pump 1 will be described.
[0007]
Overall configuration of refueling pump 1 FIG. 1 is a front view and a side view showing an example of a refueling pump according to the present invention. The refueling pump 1 is configured by connecting the main body 10 and the nozzle operating unit 50 with the hose 3. As shown in FIG. 2, in the oil supply pump 1, the main body 10 is fixed to the kerosene tank 11 so that the suction mechanism 15 is submerged in kerosene, and the nozzle operation unit 50 is fixed to the oil stove side (for example, the cartridge 51). And used.
[0008]
The pump is driven by a battery, and the battery is built in the main body 10. FIG. 3 showing a cross section of a main part of the main body 10 shows a battery chamber 10b and a battery cover 10a. Note that an optical liquid level sensor (not shown) using a prism is disposed at the nozzle tip 61, so that an appropriate amount of kerosene can be supplied into the cartridge 51.
[0009]
The battery chamber 10b, the suction mechanism 15, and the liquid level sensor are electrically connected by electric wiring. When a slide-type on / off switch 55 provided on the nozzle operation unit 50 is operated, an impeller (not shown) in the suction mechanism unit 15 in the kerosene tank is rotated by a motor, whereby kerosene is sucked up and the cartridge is 51. The nozzle case 16 is used to hold the nozzle 60 when the refueling operation is interrupted while the pump body 10 is fixed to the kerosene tank 11.
[0010]
The pump body 10 includes a negative pressure eliminating mechanism, which will be described with reference to FIG. FIG. 3 shows a cross section of a main part of the main body 10.
[0011]
Structure of negative pressure elimination mechanism The main body 10 is fixed to the kerosene tank 11 side using a connection cap 20. The connection cap 20 is screw-engaged with the cylindrical portion 11a protruding from the upper part of the kerosene tank 11 (illustration of the screw engagement portion is omitted). This engagement is performed in a state close to an airtight state.
[0012]
An opening / closing valve 30 and a coil spring 32 are accommodated in a small chamber 25 provided near the connection cap 20. A vent opening 25a is formed in the upper part of the small chamber 25, and the opening / closing valve 30 is pressed and urged by a coil spring 32 in a direction in which the head 31 closes the vent opening 25a (a leaf spring or the like other than the coil spring). It is also possible to employ the urging means described above). An O-ring 33 is fixed to the valve head 31 to improve airtightness while the vent opening 25a is closed.
[0013]
As described above, when the cap 20 is connected to the kerosene tank 11, the space formed by the three elements of the tank 11, the connection cap 20, and the small chamber 25 is airtight with respect to the outside air. That is, the connection cap 20 and the small chamber 25 constitute an airtight connection to the tank 11. The opening / closing valve 30 opens and closes such an airtight space (sealed space) with respect to the outside air, and its principle will be described below.
[0014]
When the suction mechanism 15 operates and the amount of kerosene in the tank decreases, the pressure in the hermetic space decreases. Thereby, the inside of the space is in a negative pressure state with respect to the outside air. On the other hand, in the valve head 31 that closes the vent opening 25a, a portion exposed in the vent opening 25a communicates with the outside air. The exposed portion is located inside the pump main body 10, but the main body 10 is not completely sealed, so that the gap between the members (for example, the space between the battery lid 10 a and its peripheral portion) is provided. The exposed portion of the valve head communicates with the outside air through a gap or the like.
[0015]
Therefore, when a negative pressure is generated in the hermetic space, the exposed portion of the valve head 31 is pushed by the outside air, and as a result, the entire opening / closing valve 30 moves downward against the coil spring 32. Thereby, the vent opening 25a is opened, and the negative pressure in the tank 11 is eliminated. That is, it is possible to prevent the suction function of the pump from being reduced due to the negative pressure.
[Brief description of the drawings]
FIG. 1 is a front view and a side view showing a refueling pump according to the present invention.
FIG. 2 is an explanatory diagram showing a use state of the oil supply pump of FIG. 1;
FIG. 3 is a sectional view of a main part of a pump main body of the oil supply pump of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Refueling pump 3 Hose 5a, 5b Electric wiring 10 Pump main body 11 Kerosene tank 15 Suction mechanism 16 Nozzle case 20 Connection cap 25 Small chamber 25a Vent opening 30 Opening / closing valve 31 Valve head 32 Coil spring 33 O-ring 50 Nozzle operating part 51 Cartridge 55 ON / OFF switch 60 Nozzle 61 Nozzle tip

Claims (2)

A negative pressure eliminating mechanism provided on a pump body (10) fixed to the fuel tank (11) side,
The negative pressure eliminating mechanism includes a hermetic connection (20, 25) that hermetically engages the fuel tank, and an open / close valve (30) that opens and closes the hermetic connection (20, 25) with outside air. And
The opening / closing valve (30) is urged to the closed position by the urging means (32). When a negative pressure is generated in the fuel tank, the opening / closing valve (30) is pushed by the external pressure to move to the open position, and the fuel is moved to the open position. A negative pressure eliminating mechanism for eliminating negative pressure in the tank (11). The open / close valve (30) is biased to a closed position by a coil spring (32),
When a negative pressure is generated in the fuel tank (11), the valve head (31) receiving the outside air pressure compresses the coil spring (32), whereby the open / close valve (30) moves to the open position. The negative pressure eliminating mechanism according to claim 1, wherein

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