JPS5834305Y2 - liquid pump - Google Patents

Description

[Detailed description of the invention] This invention is a means to prevent noise caused by the flow of liquid (pulsating flow) in relatively small liquid pumps, such as electric fuel pumps installed in automobiles or goldfish tank pumps. It is related to.

Generally, low noise is a particularly important performance requirement for small liquid pumps such as those mentioned above, but even rotary pumps as well as reciprocating pumps produce pulsating flow in the discharged liquid. The noise caused by this pulsating flow may be unexpectedly large.

A diaphragm type gas damper is generally used as this soundproofing means.

That is, in FIG. 1, 1 is a motor-type silent pump driven by a vane pump sound motor, and is provided with an inlet 2 and an outlet 3.

4 is a gasoline passage, and gasoline flows in the direction of the arrow and is discharged from the discharge port 3.

A soundproof damper 7 is held like a diaphragm between the discharge chamber 5 and the damper chamber 8 via a packing 6 to form a gas chamber 9.

Further, the discharge chamber 5 is fixed to the pump body via a packing 10.

In the fuel pump configured as described above, the damper 7 absorbs pulsations caused by the flow of gasoline to prevent noise and fluctuations in gasoline discharge pressure.

Conventional liquid pumps are constructed as described above, but there is a risk of gasoline leaking from the gasket 6 and damper 7, the soundproofing effect will be lost if the damper 7 is damaged, and the gas chamber is closed in response to the discharge pressure. There are problems in that it is necessary to adjust the gas pressure in the gas chamber 9, and the internal pressure in the gas chamber 9 changes due to changes in the temperature of the pump or gasoline, reducing the damper effect.

Furthermore, there are problems that are difficult to solve with the conventional single damper 7.

In other words, in the case of automobile fuel pumps, the operating speed of the pump changes depending on the rotational state of the engine, so either the pulsation frequency that occurs in the flow of gasoline changes, or the change in pulsation frequency is absorbed by one type of damper. It was difficult to achieve a soundproofing effect by doing so.

The purpose of this invention is to provide a liquid pump that eliminates the above-mentioned problems by using a plurality of simple gas dampers 4. An embodiment of this invention will be described below with reference to the drawings.

That is, Fig. 2 and Fig. 3 show an embodiment for an automobile fuel pump, in which 1 is the fuel pump body, 2 is the suction port, and 3 is the fuel pump body.
1 is a discharge port, and 4 is a gasoline passage, which are similar to the fuel pump shown in FIG.

5 is a discharge chamber, which is connected to the pump body 1 through a gasket 10.
is fixed to.

Reference numerals 7A, 7B, and 7C are gas dampers which are essential parts of this invention, and are constructed as described later, and are each installed in the discharge chamber 5 in a loosely fitted state.

In FIG. 2, the gas damper IC is not shown.

The gas dampers 7A, 7B, and 7C are divided into three parts, as shown in a partially cutaway view in FIG. 3, each having a flexible button and gasoline resistance. Form into a balloon shape using different synthetic resin films.

In other words, materials with different film thicknesses, materials with different film hardnesses, or materials with different materials such as fluorinated ethylene film, vinyl fluoride film, nylon 6 film, and synthetic rubber sheets are selected and used. to form a balloon shape.

As shown in Fig. 3, the balloon shape can be formed by bonding a bulging film and a flat film by heating or ultrasonicating only the pan-shaped linear portion, and by bonding the film into a bag-like shape. Alternatively, there is a method of forming it into a tube shape and sealing the opening.

According to the fuel pump equipped with gas dampers 7A, 7B, and 7C'r as described above, each gas damper 7
A, 7B, and 7C absorb the pulsation caused by the flow of gasoline, but since they are made of different materials, the frequencies that are easily absorbed by the gas dampers 7A, 7B, and 7C are different.

Therefore, the gas dampers 7A, 7B, and 7C sequentially absorb changes in the pulsation frequency due to changes in the operating speed of the pump.

Furthermore, even if the temperature of the pump or gasoline changes, the gas dampers 7A, 7B, 7C are divided into small parts, so the change in internal pressure is relatively small. The inward tilting ensures optimal conditions for pulsation absorption.

However, in the case of a single gas damper, the internal pressure changes as the temperature changes, making it difficult to absorb pulsating frequencies.

On the other hand, if a plurality of gas dampers having different internal pressures are installed, the internal pressure of each gas damper changes in accordance with temperature changes.

Therefore, among the plurality of gas dampers, the changed internal pressure becomes an appropriate internal pressure for absorbing the pulsation frequency,
Ensure conditions for pulsation absorption.

In addition, in the above explanation, three gas dampers were shown, but two
The number may be four or more, or four or more may be used.

Alternatively, it may be provided on the suction port side.

As described above, according to this invention, a plurality of gas dampers made of different materials are installed in the fluid passageway in a loosely fitted manner, so that many effects are achieved as described below.

(1) Since it can absorb the pulsating sound of liquid in a wide frequency band, it has a great soundproofing effect and also has a great effect of preventing pulsation of discharge pressure.

(2) If many types of gas dampers are installed, the internal pressure can be determined without any special relationship with the pulsation frequency.
Since any one of many types of gas dampers absorbs pulsation, it is easy to manufacture.

(3) Since there is no need for a seal part (such as a seal) to be installed inside the gas damper, the risk of gasoline leakage is reduced.

(4) The fact that the seal portion is not required means that the number of parts is small, assembly is easy, and manufacturing is possible at low cost.

(5) Since it can be easily installed in the liquid passage, there are few restrictions on the installation position of the suction port and discharge port.

(6) Even if one or two of the gas dampers are damaged, the remaining gas dampers can be expected to provide the same level of soundproofing effect and discharge pressure pulsation prevention effect.

[Brief explanation of drawings]

Figure 1 is a partially cutaway side view of a conventional liquid pump;
2 and 3 show an embodiment of this invention, with FIG. 2 being a partially cutaway side view and FIG. 3 being a partially cutaway perspective view of the gas damper. In the figure, 2 is an inlet, 3 is a discharge port, and 4 is a liquid passage. 7A, 7B, and 7C are gas dampers. The same buttons and the same reference numerals in the figures indicate the same or corresponding parts, respectively.

Claims (1)

[Scope of utility model registration request] A liquid pump characterized in that a plurality of balloon-shaped gas dampers made of synthetic resin films of different thicknesses and materials are loosely fitted in a liquid passage within the pump.