JPH0540309Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a reciprocating pump that sucks fluid through a suction valve and pumps it through a discharge valve by reciprocating a diaphragm.

[Conventional technology]

FIG. 3 is a cross-sectional view of a conventional reciprocating pump disclosed, for example, in Japanese Utility Model Application Publication No. 58-14467, and this pump is used, for example, as a fuel pump for two-wheeled vehicles. In the figure, 1 is a cylindrical yoke, and a plunger receiver 2 is fixed at the center of the yoke. 3 is an electromagnetic coil attached to the outer periphery of the plunger receiver 2; 4 is a magnetically conductive plate that is fitted and fixed to the inner circumference of the yoke 1 and receives the lower end of the electromagnetic coil 3; 5 is a magnetically conductive plate that allows the plunger receiver 2 to move up and down. With a movable shaft that passes through,
A plunger 6 facing the lower part of the plunger receiver 2 is fixed to an intermediate portion. The movable shaft 5 is supported in the radial direction by a lower bearing 10 fixed to the flange 9 and an upper bearing 11 fixed to the plunger bearing 2 so as to be movable up and down. 7 is a presser plate 34
A diaphragm is attached to the lower end of the movable shaft 5, and 8 is a cushioning member fitted into the lower part of the plunger receiver 2. 12 is a peripheral edge of the flange 9 between the yoke 1 and the yoke 1. The peripheral edge of the diaphragm 7 is clamped and fixed to the lower part of the pump base between the pump body 13 and the pump body 13. 14 is a compression spring installed between a spring receiver 15 provided on the diaphragm 7 and the flange 9.

The pump main body 13 has a bottom closed with a cover 16, a first pump chamber 17 and a third pump chamber 19 are formed in the lower part of the interior, and a second pump whose upper part is closed by the diaphragm 7 is formed in the upper part. room 18
is formed. The first pump chamber 17 is provided with a suction port 20, and the third pump chamber 19 is provided with a discharge port 21. At the bottom of the second pump chamber 18, a first
A suction valve 22 from the pump chamber 17 and a discharge valve 23 to the third pump chamber 19 are provided.The suction valve 22 is connected to a first compression spring 24, and the discharge valve 23 is connected to a second compression spring 25. Both are closed at all times.

In addition, the movable contact 27 of the switch 26 is connected to the fixed contact 28 at the portion where the movable shaft 5 protrudes on the yoke 1.
A switching mechanism 29 is provided to open and close the switch 26, and this switch 26 is connected in series to the electromagnetic coil 3. 30 is a protective cover that covers the switch 26.

The operation of the conventional reciprocating pump described above is as follows. First, when the switch 26 circuit is energized, the electromagnetic coil 3 is energized, and the plunger 6 is magnetically attracted to the lower end of the plunger receiver 2 and buffered by the buffer material 8 . The movable shaft 5 rises together with the plunger 6 against the pressure of the compression spring 14, and the diaphragm 7
deforms and moves upward, and the pressure in the second pump chamber 18 decreases. As a result, the liquid to be pumped enters the first pump chamber 17 from the suction port 20, and the compression spring 24
The suction valve 22 is pushed up against the
is inhaled.

Next, the switch switching mechanism 29 is reversed by the upward movement of the movable shaft 5, and the movable contact 27 of the switch 26 is separated from the fixed contact 28. As a result, the excitation coil 3 is de-energized and the magnetism disappears.
The spring pressure of the compression spring 14 pushes down the diaphragm 7 together with the movable shaft 5, and the pressure in the second pump chamber 18 increases. In this way, the liquid in the second pump chamber 18 presses down the discharge valve 23 against the compression spring 25, is sent to the third pump chamber 19, and is discharged under pressure from the discharge port 21.

Furthermore, the switching mechanism 29 is reversed and returned by lowering the movable shaft 5, and the movable contact 27 is closed to the fixed contact 28. As a result, the electromagnetic coil 3 is energized,
The pump action as described above is repeated.

By the way, in two-wheeled vehicles equipped with the pump, the fuel pump 32 is often located below the fuel tank 31, as shown in FIG. Become.

Further, even if the fuel pump 32 is located above the fuel tank 31, when the fuel in the fuel tank 31 evaporates and the pressure increases, a large pressure is applied to the fuel pump 32. In this way, if excessive pressure is applied to the fuel pump 32, the carburetor 33 to which fuel is pumped from the fuel pump 32 will overflow.

[Problem that the invention attempts to solve]

In the conventional reciprocating pump as described above, the suction valve 22 and the discharge valve 23 have a function of suppressing the discharge pressure in order to prevent overflow of the carburetor.
The compression springs 24 and 25 that press the are made to have a large spring pressure. However, the compression spring 24,
If the spring pressure of the fuel pump 25 is high, there is a problem in that the resistance of the flow path increases when the fuel is sucked in and discharged, and the flow rate decreases.

This invention was made to solve these problems, and it prevents excessive fluid pressure from being squeezed out from the discharge port due to excessive liquid pressure on the suction port side, and also prevents the amount of fluid being discharged from decreasing. The aim is to obtain a reciprocating pump that can supply an appropriate amount.

[Means for solving problems]

The reciprocating pump according to this invention has an auxiliary compression spring installed between the diaphragm receiving plate and the suction valve in addition to the compression spring that normally presses the suction valve to close it.

[Effect]

In this device, when the diaphragm is in the depressed state, the suction valve is pressurized by the support compression spring, and even if excessive fluid pressure on the suction port side is applied, the suction valve is reliably closed, and the diaphragm When the suction valve is pulled up, the pressure on the supporting compression spring is released, the suction valve can be opened easily, and fluid can be suctioned without any problem.

〔Example〕

FIG. 1 is a front view of the lower half of an embodiment of the reciprocating pump according to this invention, with the lower half sectioned.
7, 9, 10, 12-23, 25, 30, 34,
35 is the same as the conventional one mentioned above. The electromagnet means for vertically moving the movable shaft 5 and the opening/closing switch means for the electromagnetic coil are the same as those of the conventional device,
The explanation will be omitted. 40 is a first compression spring that presses the suction valve 22 and normally closes it, unlike the conventional compression spring 2.
The spring pressure is smaller than that of 4. Reference numeral 41 denotes a supporting compression spring installed between the receiving plate 35 of the diaphragm and the suction valve 22, which together with the compression spring 40 normally presses the suction valve 22 to forcefully close it.

In the reciprocating pump of the above embodiment, when the movable shaft 5 is raised by the electromagnetic means, the diaphragm 7 is deformed upward, and the fuel in the first pump chamber 17 is sucked into the second pump chamber 18 whose pressure has decreased due to the increase in volume. The valve 22 will be pushed up and the water will flow in. At this time, the movable shaft 5 is rising, the pressure of the compression spring 41 on the suction valve 22 is released, and the suction valve 22 is only pressed by the compression spring 40 whose pressing force is set to be relatively low. Fuel is easily drawn into the second pump chamber 18 from the pump chamber 17.

The pressure suppression function against excessive pressure on the fuel intake port 20 side ensures reliable performance because the movable shaft 5 is lowered when the engine is stopped and the intake valve 22 is strongly pressed by the compression springs 40 and 41. maintain. The pressing force of the compression spring 41 is set to 10 to 20 times the pressing force of the compression spring 40.
The pressing force is 1/2 to 1/2 compared to the conventional compression spring 24 mentioned above.
It is set to about 1/3, so that the flow path resistance during fuel intake is low, the pump performance is improved, and the ability to suppress excessive pressure on the fuel tank side is reliably achieved.

In the above embodiment, the reciprocating pump is used as a fuel pump for a two-wheeled vehicle, but it can be used not only for two-wheeled vehicles but also for a wide range of applications where excessive pressure is applied to the intake port.

Further, the fluid to be pumped is not limited to fuel, but other liquids or gases can also be used.

[Effect of idea]

As described above, according to this invention, in addition to the compression spring that normally presses and closes the suction valve and allows the suction valve to be opened by fluid pressure from the suction port, the diaphragm receiving plate and suction Since a support compression spring is installed between the valve and the valve, even if excessive fluid pressure is applied to the suction port side, an excessive amount of fluid is prevented from being squeezed out from the discharge port, and the amount of fluid discharged is reduced. It can be supplied in an appropriate amount without any problems.

[Brief explanation of the drawing]

Figure 1 is a front view of an embodiment of the reciprocating pump according to this invention, with the lower half shown in cross section, Figure 2 is a piping diagram showing the relationship between the fuel tank and the fuel pump, and Figure 3 is a conventional reciprocating pump. FIG. 5...Movable axis, 7...Diaphragm, 13...
Pump body, 17...first pump chamber, 18...second pump chamber, 19...third pump chamber, 20...suction port, 21...discharge port, 22...suction valve, 23...
...discharge valve, 25... second compression spring, 34... holding plate, 35... receiving plate, 40... first compression spring,
41...Support compression spring. Note that the same reference numerals in the same figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] a first pump chamber into which fluid flows from the suction port;
A second pump chamber into which fluid is sucked from the first pump chamber through a suction valve, and a third pump chamber into which fluid is pressurized from the second pump chamber through a discharge valve and are pumped out from the discharge port. A first pump body, which presses the suction valve so that it is normally closed, and which can be opened by fluid pressure from the suction port.
a second compression spring that presses the discharge valve so that it is normally closed and that allows the discharge valve to be opened by fluid pressure from the second pump chamber; a second compression spring that is disposed above the second pump chamber; A movable shaft is installed and reciprocated up and down, and the second pump chamber is stretched over and blocked by a movable shaft, the central part of which is sandwiched between a presser plate and a receiving plate and fixed to the lower end of the movable shaft, which reciprocates. In the pump, the pump includes a diaphragm that is moved to suck fluid from the first pump chamber into the second pump chamber and pressurize the fluid from the second pump chamber to the third pump chamber, the receiving plate of the diaphragm and the suction The reciprocating pump is equipped with a supporting compression spring which is installed between the valve and the suction valve, and which additionally presses and closes the suction valve when the movable shaft is lowered, and which releases the additional pressure when the movable shaft rises. .