JPH0343409Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a fuel supply pump device that supplies fuel by driving an electric pump submerged in, for example, a fuel tank of a vehicle.

[Conventional technology]

3 and 4 are cross-sectional views showing a conventional fuel feed pump device disclosed in, for example, Japanese Utility Model Publication No. 52-55555. In the figures, A is a motor such as a DC commutator motor, and the armature 1, a permanent magnet 2, a commutator 3, a brush 4, a shaft 5, a bearing 6 that supports one end of the shaft 5, a motor case 7 that houses these, and a motor case 7 whose open end is closed. A bracket 8 supports the other end of the shaft 5 and also serves as a part of a pump case, which will be described later. Reference numeral B designates a pump unit such as a peripheral type pump, which is composed of an inlet port 9, a discharge port 10, a pump case 11 having the discharge port 10, and a blade wheel 12 fixed to the shaft 5. The electric motor A and the pump section B constitute a pump main body P. Reference numeral 13 represents a fuel excess element provided at the intake port 9.

Next, the operation will be explained. When installing the pump body P in the fuel tank T, as shown in FIG. It is fixed so as to be suspended from the upper surface _T1 of the fuel tank T via c. This lid c is provided with a power supply relay terminal d and a connecting pipe e for connecting a fuel supply hose. The discharge port 10 of the pump section B and the connecting pipe e are connected by a rubber pipe f, and a relief valve g is provided as a pressure regulating device in the middle of the rubber pipe f. In addition, the power supply relay terminal d and the power supply terminal of the pump body P are connected by a conductor h, and the lengths of the support plate b and the rubber tube f are adjusted so that the pump body P approaches the bottom surface _T2 of the fuel tank T. It has been done.

[Problem that the invention attempts to solve]

In the conventional fuel feed pump device as mentioned above,
There is no problem if the pump body P is completely immersed in the fuel (gasoline), but if the gasoline level in the fuel tank T drops and the current collector is exposed to the atmosphere, it becomes extremely flammable. Since the operation is performed in a strong gas atmosphere, there is a possibility that the brush sparks will ignite the gas and cause an explosion within the fuel tank T. However, if the gas ignites at the current collector, the flame will ignite from motor A.
The fuel flows from the inside into the pump part B, passes through the suction port 9, enters the fuel over-element 13, and attempts to exit into the fuel tank T. As the flame passes while being dispersed, the ignition energy is reduced and the combustion temperature is lowered, thereby preventing the flame from escaping into the fuel tank T. However, in the unlikely event that the fuel overload element 1
There was a problem in that safety was low in the event that 3 was damaged and a hole was formed or the connection to the suction port 9 became disconnected.

This invention was made to solve the above-mentioned problems, and the purpose is to provide a fuel feed pump device that has a simple structure and can ensure high safety.

[Means for solving problems]

The fuel feed pump device according to this invention includes an end cover attached to a lower surface of a pump portion so as to form a fuel passage between the lower surface and the lower surface, and an end cover that is opened on the lower surface of the pump portion so as to open to the fuel passage. The suction port is smaller than the suction port opened at a position of the end cover away from the suction port so as not to overlap with the suction port, and the total hole area thereof is larger than the hole area of the suction port. The end cover includes a plurality of small holes, and an over-element attached to the lower surface of the end cover so as to cover each of the small holes.

[Effect]

In this design, the flame that comes out from the inlet of the pump collides with the end cover, is bent at right angles, moves through the fuel passage, and tries to exit into the over-element through the small hole in the end cover. The energy is reduced by colliding with the cover or being squeezed by a small hole, so it no longer comes out into the over-element.

[Example of idea]

1 and 2 show an embodiment of this invention, in which A, B, P, f, 1 to 8 and 12 are exactly the same as the conventional device described above. A pump case 14 has a discharge port 15 and a suction port 16 opened on the bottom surface of the case. An end cover 17 is formed to maintain a fuel passage E between the end cover and the lower surface of the pump case 14. Reference numeral 18 denotes a plurality of small holes opened in the end cover 17, and each small hole 18 is located at a position separated from the suction port 16 by an appropriate distance R so as not to overlap with the suction port 16, as shown in FIG. The holes are smaller than the suction port 16 and have a total hole area larger than the hole area of the suction port 16. Reference numeral 19 denotes a fuel over-element, which is made of a flexible synthetic fiber mesh or soft wire wire mesh, and its open end is attached to the outer periphery of the motor case 7 with a band 20 and is connected to the lower surface of the end cover 17 at an appropriate distance. It is set up to maintain F.

When the fuel feed pump device configured as described above is operated by submerging it in a fuel tank as shown in FIG. Needless to say, it is sucked in through the suction port 16 of the pump case 14, pressurized by the impeller 12, and fed from the discharge port 15 to the internal combustion engine via the rubber pipe f.

In this invention, the pump case 14 is covered with an end cover 17, and the outer side of the end cover 17 is covered with a fuel excess element 19.
Since the fuel tank is covered with gas, even if the gas ignites at the current collecting part, it will prevent the flame from escaping into the fuel tank, making it possible to obtain a safer pump device. This is based on the concept of a narrow explosion-proof structure, which prevents the gas from igniting in the current collector from spreading into the fuel tank. By making the holes that serve as passageways as small as possible, and by bending the flame passageway as much as possible to form a maze, increasing the creepage distance as much as possible and narrowing the flame passageway, Reduce the flame energy as much as possible by cooling or dispersing the flame,
This reduces the combustion temperature and prevents the flame from escaping.

That is, when gas is ignited in the current collector, the flame moves from inside the electric motor into the pump section, passes through the air inside the pump section, and exits from the suction port 16 to the outside of the pump section. This flame collides with the end cover 17, is bent at right angles, moves through the fuel passage E, and tries to exit from each small hole 18 to the space F, but it collides with the end cover 17 and is constricted by each small hole 18. As the energy decreases, it does not come out from each small hole 18. This is an explosive flammability test (JIS-C0904,
This was confirmed by forcibly igniting the inside of an electric motor using hydrogen gas (class 1 explosion class), which has higher ignitability than gasoline vapor (class 1 explosion class) using the explosion-proof structure test method for general electrical equipment.

In addition, the explosion-proof performance varies depending on the size of each small hole 18 in the end cover 17 and the positional relationship between the inlet port 16 of the pump case 14 and each small hole 18 in the end cover 17. This has been confirmed based on the results of explosion and flammability tests in which the height and the relative position of both holes were varied. In the case of a fuel supply pump device that supplies fuel to an internal combustion engine such as a vehicle, if the size of each small hole 18 is too large, the explosion-proof performance will be lost, and if it is too small, the liquid resistance will increase and the pump discharge performance will deteriorate. descend. Therefore, each small hole 1
The hole diameter of 8 is smaller than the hole diameter of the suction port 16 of the pump case 14.
6, it has explosion-proof performance by providing it at positions separated by an appropriate distance R, and by providing a plurality of holes and making the total hole area larger than the hole area of the suction port 16, there is less liquid resistance during suction. Pump performance will no longer deteriorate.

[Effect of idea]

As explained above, this idea has a simple structure in which an end cover with multiple small holes is provided between the pump case and the fuel over-element, which prevents holes from forming when the fuel over-element is damaged and the fixing band This has the effect of providing a high level of safety in that even if the current collector ignites in a state where the fuel tank has come off and fallen off, the flame will not escape into the fuel tank.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of this invention, Fig. 2 is a sectional view taken along the line - in Fig. 1, Fig. 3 is a sectional view of a conventional device, and Fig. 4 is a usage state diagram of Fig. 3. It is. In the figure, A is the electric motor, B is the pump section, P is the pump body, E is the fuel passage, 14 is the pump case,
15 is a discharge port, 16 is an intake port, 17 is an end cover, 18 is a small hole, and 19 is a fuel overflow element.

Claims (1)

[Scope of utility model registration request] In a fuel feed pump device in which a pump body including an electric motor and a pump unit driven by the electric motor and combined with the lower part of the electric motor is sunk in a fuel tank to supply fuel, this pump body is provided on the lower surface of the pump unit. an end cover attached to form a fuel passage between the end cover and the lower surface; an inlet opening on the lower surface of the pump part so as to open into the fuel passage; a plurality of small holes that are smaller than the suction port and have a total hole area larger than the hole area of the suction port, and the end cover is arranged to cover each of the small holes; A fuel feed pump device characterized by comprising an over-element attached to the lower surface of the fuel supply pump device.