JPH041347Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a relatively small fuel supply pump device such as an automobile fuel pump, which has a switch part, and is particularly concerned with improving the gas vent passage provided in the switch part. be.

Conventionally, this type of electromagnetically driven reciprocating pump has been constructed as shown in FIG. 1, for example. That is, this type of pump is composed of an electromagnetic section A, a switch section B interlocked with the electromagnetic section A, and a pump C. The configuration of each part will be explained in detail below. First, in the electromagnetic part A, 1 is a cover, 2 is a pole fitted into the center of this cover 1, 3 is a coil wound concentrically around this pole 2, and 4 is arranged at a position facing the pole 2. plunger, 5 is cover 1
6 is a shaft fitted into the center of the plunger 4, a diaphragm 7 is fixed to one end of the shaft 6, and a first A spring 8 is provided. Next, the pump section C is composed of a suction chamber 9, an expansion chamber 10, and a discharge chamber 11. The suction chamber 9 has a built-in suction valve 13 pressed by a second spring 12, and the is the third spring 14
A discharge valve 15 that is pressed is built-in. Further, an inlet port 16 and a discharge port 17 are provided at the end of the pump portion C. The switch part B is composed of a switch 18 engaged with the shaft 6 and a protective cover 19 that houses the switch 18. A second passage 19B leading to
A grommet 21 is fitted into the surface measuring part, and a lead wire 2 is inserted in the center of the grommet 21.
2 is passing through.

When the switch 18 is energized from the coil 3, a magnetic path is formed between the cover 1, the pole 2, the plunger 4, and the magnetically conductive plate 5, whereby the plunger 4 is attracted to the pole 2, and the plunger 4 fitted on the shaft 6 moves up and down. At the same time, the diaphragm 7 attached to the lower tip of the shaft 6 is pulled upward, and fuel is sucked into the suction chamber 9 through the suction port 16, and the fuel also pushes up the suction valve 13, which is constantly pressed by the second spring 12. and flows into the expansion chamber 10. On the other hand, due to the operation of the plunger 4, the switch 18 engaged with the upper end of the shaft 6 opens, the magnetic path of the cover 1-pole 2-plunger 4-magnetic plate 5 disappears, and the first spring 8, the plunger 4 gradually moves downward from the plunger receiver 2. This operation is carried out by pushing down the diaphragm 7 and operating the discharge valve 15 which is pressed in one direction by the third spring 14, thereby directing the fuel in the expansion chamber 10 through the discharge chamber 11 to the discharge port 1.
Discharge from 7. During this operation, switch 18
An arc is generated between the contacts 20 due to the opening and closing operations of the contacts 20, and gas is generated. This gas is contact 2
There are problems such as forming an insulator in the switch 18, leading to poor conduction, and oxidizing the mechanical parts constituting the switch 18, causing functional failure. Therefore, for the purpose of venting this gas, a passage 19A is installed in the protective cover 19.
and 19B are provided.

In this way, the gas vent passage is connected to the atmosphere from the passage 19A to the passage 19B, but this is because this type of pump is often used in a highly flammable gas such as gasoline, and the switch 18 is turned off. The passage is relatively narrow and long so that even if an explosion occurs inside due to the spark (arc) generated between the contacts 20, the flame will not spread to the outside. Note that the lead wire 22 is for supplying current to the coil 3, and the grommet 21 is for making the space between the protective cover 19 and the lead wire 22 airtight.

The conventional device is constructed as described above, and the protective cover 19 of switch B is made of a thermoplastic resin molded product such as polypropylene, but as explained above, the gas venting passage is relatively narrow and long. Therefore, when molded into the shape shown in FIG. 1, for example, the mold is complicated, the cost is high, and the outside size is large, making it difficult to install.

This idea was made in order to eliminate the above-mentioned drawbacks of the conventional technology. By providing a gas vent passage in the grommet of switch part B, the shape of the protective cover can be simplified, and the resin molded product can be replaced with an iron plate. The aim is to supply electromagnetically driven reciprocating pumps that are inexpensive and highly reliable by making them into drawn products.

An embodiment of this invention will be described below with reference to FIG. In FIG. 2, except for 19A and 19B, numerals 1 to 22 represent the same parts as in FIG. 1, so their explanation will be omitted. That is, the gas vent passage in the present invention includes the grommet 21 and the grommet 21.
It consists of a passage 19C provided between the lead wire 22 and the lead wire 22 passing through the center thereof, and a penetration 19D extending downward from the end of this passage 19C.

Next, its operation will be explained. Note that the operations of the pump and switch are the same as described above, so a description thereof will be omitted. As mentioned above, when the contact 20 of the switch 18 engaged with the shaft is opened by the operation of the plunger 4, an arc is generated between the contacts 20, which has a negative effect on the function of the switch 18. Since this gas passes through the passage 19C→passage 19D provided in the grommet portion and is released into the atmosphere, the above-mentioned adverse effects caused by the gas do not occur. In addition, the gas vent passage of the present invention is arranged narrowly and long, so that even if the pump is used in a highly flammable gas concentration such as gasoline, and an explosion occurs inside the protective cover 19 due to a spark from the switch 18, The flame of the explosion is difficult to propagate to the atmosphere through the passages 19C and 19D.

As described above, according to this invention, the gas vent passage is provided in the grommet 21, so the shape is simple, the manufacturing cost of the protective cover 19 can be reduced, the explosion-proof performance is improved, and the gas vent passage is provided in the grommet 21. Since the outer end of the passage is bent and opened at the side surface of the grommet, it has the effect of making it difficult for water and dust to enter the protective cover from the outside.

[Brief explanation of the drawing]

FIG. 1 is a sectional front view showing a conventional electromagnetically driven reciprocating pump, and FIG. 2 is a sectional front view showing an embodiment of this invention. In the figure, 19 is a protective cover, 19C and 19D are gas vent passages, 21 is a grommet, and 22 is a lead wire. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] In an electromagnetically driven reciprocating pump that includes an electromagnet part, a switch part linked to the electromagnet part, and a pump part, and which takes in and discharges fuel, a through hole is formed in the protective cover of the switch part, and a grommet is installed in this through hole. A lead wire is inserted through the grommet, and a gas vent passage is formed around the lead wire's penetrating portion, and the outer end of the gas vent passage is bent and opened at the side surface of the grommet. An electromagnetically driven reciprocating pump characterized by: