KR19990067962A - Metering type electromagnetic pump - Google Patents

Abstract

An object of the present invention is to accurately control the discharge amount at the frequency of the pulsed current applied to the electromagnetic coil. The electromagnetic pump according to the present invention includes an electromagnetic solenoid 13, a plunger 18 driven by the electromagnetic solenoid, and a check valve 2 disposed downstream of the plunger 18 and driven by the electromagnetic solenoid 13. And an intake valve 17 provided in the plunger 18 and a discharge valve 8 provided in the inner yoke 6, when the pulsed current energizing the solenoid 13 is turned on. The check valve 2 is opened, and the plunger 18 is configured to be discharged.

Description

Metering Electronic Pumps {METERING TYPE ELECTROMAGNETIC PUMP}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metering type electronic pump for supplying liquid fuel, and in particular, it is necessary to easily and accurately control the discharge flow rate, and to provide an on-off valve between the pump and a device to which liquid fuel is supplied. A metering electronic pump which does not.

There are two types of electronic pumps for supplying liquid fuel, such as metering and pressure control. The metering type electric pump determines the discharge amount by the excluding volume of one stroke of the plunger, and the pressure controlling type electric pump reciprocates the plunger at a constant speed to maintain a constant discharge pressure by a pressure adjusting mechanism such as a diaphragm type. It is to make it.

Metered electronic pumps control the flow rate by the number of times the plunger is driven. In the pressure-controlled electromagnetic pump, the flow rate is controlled by an orifice or a relief valve. Since the pressure-controlled electromagnetic pump requires orifice replacement when changing the flow rate, it is cumbersome to control the flow rate. In general, an electromagnetic pump requires an on-off valve for stopping the supply of fuel or the like.

An example of a conventional metered liquid fuel supply electronic pump is shown in FIG. As shown in the figure, the sleeve 4 is fitted to the end yoke 1 and the outer yoke 10, and the inner yoke 6 is fixed in the sleeve 4. The shock absorbing sheet 19 is attached to the lower end of the inner yoke 6. The plunger 18 is slidable with the sleeve 4 and is biased downward by the compression coil spring 20 mounted between the ring 19 and the lower flange and pressed against the packing 22. In addition, the coil diameter is reduced in the lower portion of the compression coil spring 20.

The outer side of the sleeve 4 is sealed with the O-ring 15. An electromagnetic coil 13 is disposed inside the outer yoke 10, and current flowing through the electromagnetic coil 13 is directed to the outer yoke 10, the end yoke 1, the inner yoke 6, and the plunger 18. Magnetic flux is generated in the formed magnetic circuit.

The discharge valve seat 28 is fixed to the lower part of the hole formed in the center of the inner yoke 6. The intake valve 17 is biased to enter the recess provided in the upper end surface of the plunger 18 by the compression coil spring 16. The discharge valve 27 is slidably arranged in a hole formed in the center of the inner yoke 6, and is biased so as to be press-contacted to the discharge valve seat 28 by the compression coil spring 7. In addition, grooves are formed around the discharge valve 27 to form a flow path.

A nipple 26 is fitted to the lower end of the outer yoke 10, and an O-ring 24 for sealing is mounted therebetween. The filter 25 is fixed to the outer yoke 10 and the nipple 26. The nipple 26 is formed with a fuel intake 26a. In addition, a fuel discharge port 6a is formed in the inner yoke 6.

In the above configuration, when the electromagnetic coil 13 is not energized, the plunger 18 is pressed against the packing 22 as shown by the elasticity of the compression coil spring 20, and the shock absorbing sheet ( The liquid fuel is filled in the space between 12) and the upper surface of the plunger 18 and the suction valve 17.

When the electromagnetic coil 13 is energized, magnetic flux is generated in the magnetic circuit formed by the outer yoke 10, the end yoke 1, the inner yoke 6, and the plunger 18, and the plunger 18 and the inner yoke ( 6) The plunger 18 rises against the elasticity of the compression coil spring 20 due to the suction force in the magnetic gap therebetween, and the pressure of the liquid fuel generated at this time causes the discharge valve 27 to be compressed coil spring. Resistant to the elasticity of (7), liquid fuel lifts the hole in the center of the discharge valve seat 28, the gap between the discharge valve seat 28 and the discharge valve 27, and the groove around the discharge valve seat 27. It flows out from the fuel discharge port 6a of the center hole of the inner yoke 6 through it.

When the energization of the electromagnetic coil 13 is stopped, the plunger 18 is pushed out by the elasticity of the compression coil spring 20. At this time, a negative pressure is generated between the plunger 18 and the inner yoke 6, and the discharge valve 27 is pushed down by the elasticity of the compression coil spring 7 to close the discharge valve seat 28. do.

In addition, the intake valve 17 generates a gap between the intake valve 17 and the plunger 18 due to the negative pressure generated between the plunger 18 and the inner yoke 6, and through the gap, the fuel inlet ( The liquid fuel flowing from 26a) is filled with a space between the shock absorbing seat 12 and the upper surface of the plunger 18 and the suction valve 17.

Thus, the liquid fuel of the exclusion volume of the plunger 18 is sent out by an electromagnetic pump by applying a pulse type electric current to the electromagnetic coil 13. The discharge amount of the fuel can be controlled by the frequency of the pulsed current applied to the electromagnetic coil 13.

An example of a pressure controlled electromagnetic pump is disclosed in Japanese Patent Laid-Open No. 52-38243. The electromagnetic pump is an electromagnetic piston driven by an electromagnetic coil to which a current applied by half-wave rectification of a spring and a commercial power source is an electromagnetic piston pump in which a pressure piston is driven, and an electromagnetic movable piece which is biased by a spring is provided in the liquid passage. . The electron moving piece normally closes the liquid passage, but opens when a half-wave rectified current is applied to the electron coil. Since the electromagnetic pump is pressure-controlled, the discharge pressure is constantly controlled by a pressure regulating mechanism provided on the pump discharge side. The pressure regulating mechanism controls the flow regulating valve by the diaphragm so that the pressure in the constant pressure chamber is constant.

In the conventional metered electromagnetic pump shown in Fig. 2, it is necessary to provide an on-off solenoid valve or a manual on-off valve that closes the fluid passage when the energization of the electromagnetic coil is stopped, and there is a problem that the overall equipment cost becomes high. In addition, there is a problem that a so-called blow-by phenomenon occurs in which the actual flow rate increases from the theoretical discharge flow rate of the pump.

The blow-by phenomenon occurs because the intake valve is opened by the inertia of the fluid of the pulsating flow generated by the pump action, and in theory, the fluid flows in the discharge direction through the intake valve when the intake valve is closed. When the blow-by phenomenon occurs, the flow rate changes due to the pressure on the suction side, which makes it difficult to accurately control the pump discharge amount.

In the electromagnetic pump disclosed in Japanese Patent Application Laid-open No. 52-38243, since the liquid flow path is closed by the electromagnetic movable piece when no current is supplied to the electromagnetic coil, the opening / closing solenoid valve or the manual switching valve is not necessary. Since it is a pressure-controlled electromagnetic pump, as mentioned above, there existed a problem that flow volume was controlled by an orifice, a relief valve, etc., and flow volume control becomes cumbersome.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and its object is to provide a metered electromagnetic pump which is simple in flow control and does not require the installation of an on / off solenoid valve or a manual on / off valve for closing the fluid passage. .

1 is a cross-sectional view showing a metered electronic pump as an embodiment of the present invention.

2 is a cross-sectional view showing a conventional example of a metered electronic pump.

Explanation of symbols for main parts of the drawings

1. End yoke 2. Check valve

3. Compression coil spring 4. Sleeve

5. O-ring 6. Inner yoke

7. Compression coil spring 8. Discharge valve

9. Discharge valve seat 10. Outer yoke

11.O-shaped ring 12.Shock absorbing seat

13. Electronic coil 14. Spacer

15. O-shaped ring 16. Compression coil spring

17. Suction valve 18. Plunger

19. Ring 20. Compression coil spring

21.Nipple Base 22.Packing

23. Stopper 24. O-shaped ring

25.Filter 26.Nipple

27. Discharge valve 28. Discharge valve seat

The metered electromagnetic pump of the present invention includes an electromagnetic solenoid, a plunger driven by the electromagnetic solenoid, a check valve disposed downstream of the plunger and driven by the electromagnetic solenoid, a suction valve installed in the plunger, The discharge valve is provided in the inner yoke, and the check valve is opened when the pulsed current passing through the electromagnetic solenoid is turned on, and the plunger is discharged.

Moreover, in each said metering electromagnetic pump, it is comprised so that discharge flow volume may be controlled by the frequency of the pulse electric current which energizes said electromagnetic solenoid.

Hereinafter, the electronic pump for metered liquid fuel supply of the present invention will be described by way of example with reference to the drawings. 1 is a cross-sectional view showing an electronic pump for metered liquid fuel supply as an embodiment of the present invention. The sleeve 4 shown in the figure is fitted to the end yoke 1 and the nipple base 21, and the inner yoke 6 is fixed to the central portion thereof. The shock absorbing sheet 12 is adhered to the lower end of the inner yoke 6. The plunger 18 is slidably received in the sleeve 4 and is deflected downward by a compression coil spring 20 mounted between the ring 19 and the lower flange and supported by the stopper 23. 22) is pressed in. In addition, the coil diameter is reduced in the lower portion of the compression coil spring 20.

The outer side of the sleeve 4 is sealed with the O-ring 15 and the O-ring 5. The electromagnetic coil 13 is disposed inside the outer yoke 10 through the spacer 14, and the current flowing through the electromagnetic coil 13 is the outer yoke 10, the end yoke 1, and the check valve 2. The magnetic flux is generated in the electronic circuit formed by the inner yoke 6, the plunger 18 and the nipple base 21.

The check valve 2 is slidably guided along the sleeve 4 and has a hole for acting as a fluid passage, and an upper end of the check valve 2a for closing the fuel outlet 1a formed in the end yoke 1. ) Is formed. The check valve 2 is normally press-contacted to the seat surface formed on the end yoke 1 by the compression coil spring 3, and closes the fuel discharge port 1a.

The discharge valve seat 9 is fixed to the lower portion of the hole formed in the center of the inner yoke 6. In addition, the periphery of the inner yoke 6 is sealed by the O-ring 11. The suction valve 17 is pressurized by the compression coil spring 16 to enter the recess formed in the upper surface of the plunger 18.

The discharge valve 8 is slidably arranged in a hole formed in the center of the inner yoke 6, and is biased so as to be press-contacted to the discharge valve seat 9 by a compression coil spring 7. In addition, grooves are formed around the discharge valve 8 to form a flow path.

The nipple 26 is fitted in the lower end of the nipple base 21 fixed to the outer yoke 10, and an O-ring 24 for sealing is mounted therebetween. The filter 25 is fitted to the nipple base 21 and the nipple 26 and fixed. The nipple 26 is formed with a fuel inlet 26a.

In the above configuration, when the electromagnetic coil 13 is not energized, the plunger 18 is pressed against the packing 22 by the elasticity of the compression coil spring 20, and the shock absorbing sheet 12 ) And a liquid fuel is filled in the space between the plunger 18 and the upper surface of the intake valve 17. At this time, the check valve 2 is pressed against the seat surface formed in the end yoke by the elasticity of the compression coil spring 3, and closes the fuel discharge port 1a.

When energized by the electromagnetic coil 13, magnetic flux is formed in the magnetic circuit formed of the outer yoke 10, the end yoke 1, the check valve 2, the inner yoke 6, the plunger 18 and the nipple base 21. And the suction force generated in the magnetic gap between the plunger 18 and the inner yoke 6 rises in response to the elasticity of the compression coil spring 20, and the pressure of the liquid fuel generated at this time. Lifts the discharge valve 8 against the elasticity of the compression coil spring 7 so that the liquid fuel is discharged from the hole in the center of the discharge valve seat 9, between the discharge valve seat 9 and the discharge valve 8, and discharged. It flows into the hole of the check valve 2 through the groove around the valve 8.

At this time, with the suction force generated in the magnetic gap between the check valve 2 and the inner yoke 6, the check valve 2 is lowered against the elasticity of the compression coil spring 7, and the fuel discharge port 1a is opened. The liquid fuel is discharged from the hole of the check valve 2 through the fuel discharge port 1a.

When the energization of the electromagnetic coil 13 is stopped, the plunger 18 is pushed out by the elasticity of the compression coil spring 20. At this time, a negative pressure is generated between the plunger 18 and the inner yoke 6, and the discharge valve 8 is pushed down by the elasticity of the compression coil spring 7 to close the discharge valve seat 9.

In addition, the intake valve 17 generates a gap between the intake valve 17 and the plunger 18 due to the negative pressure generated between the plunger 18 and the inner yoke 6, and through the gap, the fuel intake port 26a. The liquid fuel flowing from the top fills the space between the shock absorbing seat 12, the plunger 18, and the upper surface of the suction valve 17.

When the energization of the electromagnetic coil 13 is stopped, the check valve 2 is pushed up by the elasticity of the compression coil spring 3 to close the fuel discharge port 1a. In the suction stroke of the liquid fuel, the fuel discharge port 1a is closed, so that the generation of the blow-by phenomenon described in the conventional example is suppressed. In the suction stroke, both the check valve 2 and the discharge valve 8 are closed, but since the discharge valve 8 has a small mass, it is quickly pressed against the discharge valve seat 9 so that a negative pressure is generated and the intake valve 17 is closed. Since it is open, the back flow of the suction stroke which arises when the suction valve 17 is closed is prevented.

Thus, the liquid fuel of the exclusion volume of the plunger 18 is sent out by an electromagnetic pump by applying a pulse type electric current to the electromagnetic coil 13. As described above, since there is no blow-by phenomenon, the discharge amount of fuel can be precisely controlled by the frequency of the pulsed current applied to the electromagnetic coil 13. In addition, when the electric current is not applied to the electromagnetic coil 13, the check valve 2 closes the fuel discharge port 1a, so that it is not necessary to provide an on-off solenoid valve or a manual on-off valve that closes the fluid passage.

According to the metering electromagnetic pump of the present invention, the discharge amount can be accurately controlled at the frequency of the pulsed current applied to the electromagnetic coil. In addition, since the fuel discharge port is closed when no current is applied to the electromagnetic coil, there is no need to provide an on-off solenoid valve or a manual on-off valve that closes the fluid passage.

Claims (2)

An electromagnetic solenoid, a plunger driven by the electromagnetic solenoid, a check valve disposed downstream of the plunger and driven by the electromagnetic solenoid, an intake valve formed in the plunger, and a discharge valve formed in the inner yoke; And the check valve is opened and the plunger is discharged at the time of turning on a pulsed current that energizes the electromagnetic solenoid. The metered electronic pump according to claim 1, wherein the discharge flow rate is controlled by a frequency of a pulse current which energizes the electromagnetic solenoid.