JP2002039057A - Electromagnetic pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage of liquid fuel into an electromagnetic pump regardless of the length of lifting height. SOLUTION: In the electromagnetic pump 1 equipped with a plunger 3 installed in the cylinder 2, and this plunger 3 is composed of continual magnetic generation by drive pulse signal supplying to an electromagnetic coil 5 and is reciprocated with vibration motion to the shaft center direction by antagonistic action of the first coil spring 22 power discharge fluid suck in suction port through fuel discharge hole 71f and equipped with a check valve 73 installed in the fuel discharge port 7 to control back-flow of fluid, the first coil spring 22 is installed in the bottom of the cylinder 2 to push the plunger 3 upward, and a shut off valve 8 is installed at the top of the plunger 3 to close the fuel path hole 72a by the first coil spring power under the circumstances that the supplying of drive pulse signal is stopping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic pump which can appropriately pump liquid fuel stored in a fuel tank irrespective of the height and length of a lift, and is particularly suitable for use as a pump. is there.

[0002]

2. Description of the Related Art Heretofore, a structure has been employed in which a plunger housed in a state of sliding contact with a cylinder is vibrated in an axial direction by a periodic change of a magnetic force to discharge fuel in a fuel tank toward a combustion device. Electromagnetic pumps are known. Such an electromagnetic pump is usually attached to a fuel tank of an oil heater used for heating, and discharges fuel toward a combustion device provided immediately above the fuel tank. Therefore, the head for sucking the fuel (the height difference between the liquid level in the fuel tank and the electromagnetic pump) is very short.

In recent years, such an electromagnetic pump has been interposed between a fuel tank and a combustion device provided in different places, respectively, and driven to pump fuel in the fuel tank toward the combustion device. It has been tried to be. It should be noted that a relay tank for temporarily storing the pumped fuel once between the electromagnetic pump and the combustion device is provided in many cases.

[0004] Pumps used for such purposes have hitherto been
It was common to employ a so-called rotary pump that sucks and discharges fuel by the rotation of fins and a reciprocating pump that sucks and discharges fuel by reciprocating pistons in cylinders.
These pumps have no difference in suction capacity (that is, suction pressure) depending on the type of the fluid to be sucked when the rotation speed and the stroke are constant. Therefore, when the oil level of the fuel tank is lower than that of the pump, which is a so-called minus head, and when this head is long, only the air filled in the pipe is sucked at the initial stage of driving, and the vacuum is generated until the fuel can be sucked in the pipe. In many cases, it is difficult to adjust the temperature, and it is necessary to introduce fuel into the pump in a priming manner (hereinafter referred to as priming), and the operation at the initial startup is very troublesome. Exists.

On the other hand, a so-called free piston in which the amplitude stroke length (stroke) of a plunger changes according to the viscosity of the fluid to be sucked, even if the applied energy (electric power) is the same, is used for the electromagnetic pump. Because
When low-viscosity air is targeted, the stroke length is longer than when high-viscosity fuel is targeted, which makes it possible to suction air appropriately and bring the inside of the pipe to a predetermined degree of vacuum. . Therefore, when the electromagnetic pump is used, it is possible to feed the fuel in the fuel tank to the combustion device without priming in the early stage of driving of the pump, and this applies the electromagnetic pump between the fuel tank and the combustion device. That is why it came to be.

The fuel pump is provided with a check valve which allows the liquid fuel to pass when the plunger is moved up and closes when the plunger is moved to prevent the liquid fuel from flowing back. This check valve normally closes the discharge opening by the biasing force of the coil spring, and when the plunger is moved upward, the discharge opening is opened by the upward movement by liquid pressure against the biasing force of the coil spring. When the plunger is moved downward, the plunger is moved downward by the urging force of the coil spring to prevent the liquid fuel from flowing back into the electromagnetic pump. With this mechanism, the liquid fuel sucked into the electromagnetic pump is discharged by the vertical movement of the plunger.

[0007]

However, when such an electromagnetic pump is used as a pump, the head pressure of the liquid fuel at the check valve in the electromagnetic pump becomes large due to the long head, so that the electromagnetic pump Is higher than the fuel tank, the liquid fuel once discharged may slip through the check valve when the electromagnetic pump is stopped and leak into the electromagnetic pump. In addition, the liquid fuel in the piping returns to the tank, which causes a problem in supplying fuel to the combustion device.

On the other hand, in the case of a so-called plus head in which the electromagnetic pump is provided lower than the fuel tank, when the electromagnetic pump is stopped, the liquid fuel in the fuel tank slips through the check valve and flows toward the combustion device. In some cases, there is a disadvantage that the fuel may overflow from the relay tank or the combustion device.

The present invention has been made in view of the above situation, and has been made to reliably prevent liquid fuel from leaking into the electromagnetic pump regardless of the length of the lift. An object of the present invention is to provide an electromagnetic pump suitable for use as a pumping pump capable of always properly feeding liquid fuel to a discharge destination.

[0010]

According to the first aspect of the present invention,
A plunger is provided in a cylinder having a fluid suction port at the bottom and a fluid discharge port at the top. The plunger resists the urging force of the urging means by generating a repetitive magnetic force by a drive pulse signal supplied to the electromagnetic coil. Reciprocatingly oscillating in the axial direction and discharging the fluid sucked from the fluid suction port from the fluid discharge port, and the fluid flows backward immediately before the fluid suction port or immediately after the fluid discharge port. In the electromagnetic pump provided with a check valve for regulating the pressure, the urging means is provided inside the cylinder so as to press one end of the plunger toward the other side, and the other end of the plunger is provided in the cylinder. A closing valve body for closing a fluid suction port or a fluid discharge port by the urging force of the urging means in a state where the supply of the drive pulse signal is stopped. That.

According to the present invention, the plunger in the cylinder draws the fluid or sucks the fluid against the urging force of the urging means when the driving pulse signal is supplied to the electromagnetic coil to generate a magnetic force. While moving in the direction
To return to the original position by the urging force of the urging means at the time of demagnetization,
Such reciprocation of the plunger is oscillatingly repeated by the supply of the drive pulse signal to the electromagnetic coil,
The fluid in the pump chamber is discharged from the fluid discharge port when the plunger is moved up, while the fluid is introduced into the electromagnetic pump when the plunger is moved down, and the fluid is pumped up from a predetermined fluid storage tank by reciprocating the plunger. And supplied to an external object.

The cylinder is provided with biasing means for pressing one end of the plunger toward the other side, and the supply of the drive pulse signal is stopped at the other end of the plunger. In this state, since the closing valve body that closes the fluid suction port or the fluid discharge port by the urging force of the urging means is provided, one end of the plunger is actuated by the urging force of the urging means when the drive of the electromagnetic pump is stopped. By being pressed, the closing valve body provided at the other end closes the fluid suction port or the fluid discharge port, and thereby the liquid fuel in the electromagnetic pump is closed by double closing with the conventional check valve. The distribution is interrupted.

Therefore, the conventional disadvantage that the liquid fuel, which is the fluid to be pumped, leaks into the electromagnetic pump and flows backward while the driving of the electromagnetic pump is stopped is solved.

The electromagnetic pump may be of a type that urges the plunger downward by the urging force of the urging means or a type that urges the plunger upward. In the case of an electromagnetic pump of the type that urges the plunger downward, a closing valve body is provided at the lower part of the plunger, while, in the case of an electromagnetic pump of the upward direction, a closing valve is provided at the upper part of the plunger. The body is attached.

The upwardly biasing type electromagnetic pump is used for the purpose of preventing the liquid fuel from leaking out of the system from the fluid discharge port when the operation is stopped. That is, during stoppage of the electromagnetic pump, the closing valve body closes the fluid discharge port while the plunger is pressed upward by the urging force of the urging means, so that the liquid fuel storage tank is higher than the electromagnetic pump. In the case of the plus head at the position, the pressure of the liquid fuel is added to the urging force of the urging means, and the liquid fuel pressure is applied to the closing valve body, so that the fluid discharge port is more reliably closed, and accordingly, the fluid from the storage tank is closed. The inconvenience of the liquid fuel flowing out toward the device to be supplied through the plunger and leaking from the device to be supplied is reliably avoided.

Further, the downwardly biasing type electromagnetic pump is
Even during the plus head, the downward biasing force of the biasing means can prevent the liquid fuel from flowing out to the outflow discharge port to some extent. In some cases, there is a restriction on the use, such as how far the safety factor should be viewed.

In the case of the upward biasing type, biasing means is provided at a lower portion of the plunger to bias the plunger upward, whereby the biasing means is provided in a space up to the upper check valve. It is possible to reduce the space above the plunger as compared with the case where the plunger is provided, and the compression ratio of the effective space (to be exact, the ratio of the original volume of the space to the reduced volume) Since the value of this ratio and the compression ratio of the internal air when there is no leakage have the same value, the term compression ratio is used for convenience in this specification. This is advantageous in increasing both the pressure and the suction pressure.

According to a second aspect of the present invention, in the first aspect, a pressure control circuit for controlling a pressure of a fluid discharged by driving the plunger by controlling a drive pulse signal supplied to the electromagnetic coil. Is provided.

According to the present invention, the pressure of the fluid discharged by the pressure control circuit can be reduced without changing the length of the valve body or taking hardware measures such as adjusting the urging force of the urging means. Can be electrically adjusted, so that it is possible to easily change the discharge pressure according to the installation status or use status of the electromagnetic pump.

According to a third aspect of the present invention, in the second aspect of the present invention, the pressure control circuit includes a diode incorporated so as to cut back electromotive force.

According to the present invention, for example, by providing a diode in parallel with the electromagnetic coil, it is possible to cut back electromotive force generated by supplying a drive pulse signal to the electromagnetic coil. By reducing the effect of increasing the return speed of the plunger due to the plunger, the plunger stroke is reduced, thereby reducing the discharge pressure.

Therefore, in a case where a relay container is interposed between the electromagnetic pump and the liquid supply device, and the liquid level of the relay container is controlled by the float, the discharge of the electromagnetic pump is controlled by the closing pressure of the float. If the pressure is higher, the liquid is supplied into the relay container by the drive of the electromagnetic pump, even though the inside of the relay container has reached the maximum allowable liquid level, whereby the liquid is transferred to the relay container. However, such a disadvantage can be avoided by a pressure control circuit incorporating a diode.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the plunger has a plurality of annular grooves recessed in an outer peripheral surface. Is what you do.

According to the present invention, the fluid on the compressed side during the forward / reverse movement of the plunger tends to move to the low pressure side through the gap between the outer peripheral surface of the plunger and the inner peripheral surface of the pump chamber. This fluid is turbulent by being diffused when it reaches the annular groove having a plurality of recesses formed on the outer peripheral surface of the plunger, and it becomes difficult to move through the gap due to an increase in flow resistance. The leakage of the fluid through the fluid is suppressed, whereby the decrease in the pressure of the discharged fluid is suppressed, and the degree of vacuum in the plunger during fluid suction is increased.

When the fluid is air, the temperature is -10.degree.
When the pressure falls below, the degree of vacuum (suction pressure) in the pump chamber of the plunger at the time of suction drops extremely, which makes it impossible to pump up liquid fuel in the fuel storage tank without priming at the beginning of operation of the electromagnetic pump. Inconveniences peculiar to the ground occur, but such an inconvenience is solved by providing the annular groove in the plunger. By the way, the temperature is -1
The reason why the degree of vacuum in the pump chamber of the plunger at the time of suction is reduced to 0 ° C. or less is not clear, but the viscosity of the air is likely to be small due to the fact that most of the moisture in the air is condensed. It is thought that it is from. Then, it is considered that when the viscosity of the air decreases, the air easily passes through the gap between the outer peripheral surface of the plunger and the inner peripheral surface of the pump chamber.

[0026]

FIG. 1 is a side sectional view showing a first embodiment of an electromagnetic pump according to the present invention. As shown in this figure, the electromagnetic pump 1 is provided with a cylindrical cylinder 2 and an axial direction in a state in which the electromagnetic pump 1 is housed in the cylinder 2 and supported by a biasing means (a first coil spring 22 described later). A swingable plunger 3, a cylindrical valve body 4 provided inside the plunger 3, an electromagnetic coil 5 provided around the cylinder 2, and a fuel suction portion 6 connected to a lower end of the cylinder 2.
A fuel discharge section 7 connected to the upper end of the cylinder 2;
When the drive is stopped, the fuel is attached to one end of the cylinder 2 (the upper end in the first embodiment).
And a closing valve body 8 for preventing the gas from flowing therethrough.

The electromagnetic coil 5 is formed by winding a predetermined wire around a coil bobbin 51 made of a cylindrical non-magnetic material. A flange is provided at each of the upper and lower ends of the coil bobbin 51, and the electromagnetic coil 5 is formed by winding a wire around the coil bobbin 51 between the flanges. The inner diameter of the coil bobbin 51 is set slightly larger than the outer diameter of the cylinder 2 so that an annular gap is formed between the coil bobbin 51 and the cylinder 2.

A cylindrical upper magnetic body 52 is fitted into the annular gap from the upper part, and a cylindrical lower magnetic body 53 is fitted from the lower part into the cylinder 2.
At the same time, a magnetic path is formed inside. Each magnetic body 52,
The length of the 53 is set so that each end thereof is separated by a predetermined length in a state of being externally fitted to the cylinder 2, whereby the urging means (the first coil spring A strong magnetic flux for lowering the plunger 3 against the urging force of 22) is generated.

A yoke 54 made of a magnetic material having a U-shape in a side view is fitted on each of the magnetic bodies 52 and 53. The yoke 4 forms an external magnetic path and plays a role as a structural material of the electromagnetic pump 1. The yoke 4 is a pair of upper and lower horizontal plates parallel to each other, and is mounted on these horizontal plates on one side surface. And a vertical plate portion extending vertically. At the center of the upper and lower horizontal plate portions, through holes are formed so as to be fitted to the upper and lower magnetic members 52 and 53. The cylinder 2 is fitted into these through holes via magnetic bodies 52 and 53, and the yoke 54 is
The distance between the upper and lower magnetic bodies 52 and 53 is determined in a state where the magnetic bodies 52 and 53 are mounted.

The upper and lower magnetic members 52 and 53 are provided with flanges 52a and 53a at opposite peripheral edges, respectively. The yoke 54 is mounted on the cylinder 2 via the magnetic members 52 and 53. Upper and lower flanges 52a, 5
3a.

The flange above the coil bobbin 51 is provided with a terminal block 55 projecting outward. Two connection terminals 56 protrude from the terminal block 55, and lead wires (not shown) for supplying a pulse-like drive signal from a drive device (not shown) are connected to the connection terminals 56. Two terminals of the coil wire are connected to the two connection terminals 56, respectively, and the electromagnetic coil 5 is intermittently excited by turning on a power switch (not shown).

The fuel suction section 6 includes a first suction cylinder 61 fitted and connected to the lower end of the cylinder 2 and a second suction cylinder 62 fitted and connected to the first suction cylinder 61. A cylindrical filter cylinder 63 having a bottom and being externally fitted to and connected to a lower end of the first suction cylinder 61 in the second suction cylinder 62; and a lower stopper externally fitted to an upper part of the first suction cylinder 61. And a plate 64.

The first suction cylinder 61 is dimensioned so that its outer diameter decreases gradually from the upper part to the lower part.
It has a three-stage structure including a large diameter portion 61a, a middle diameter portion 61b, and a small diameter portion 61c. On the top surface of the large diameter portion 61a, there is provided a two-stage circular hole 61d which is formed concentrically with the cylinder 2 and whose upper portion is larger in diameter than the lower portion. Such a two-stage circular hole 6
The small-diameter hole at the lower part of 1d is set to have a diameter that allows the small-diameter hole to be fitted to the cylinder 2 in a sliding state.

On the other hand, an annular seal member 65 made of an elastic material such as rubber is fitted on the lower end of the cylinder 2.
By fitting the lower end of the cylinder 2 into the two-stage circular hole 61d, the annular seal member 65 is elastically deformed, so that the gap between the inner peripheral surface of the upper large-diameter hole of the two-stage circular hole 61d and the outer peripheral surface of the cylinder 2 is increased. The cylinder 2 is fitted into the formed annular gap, whereby the inside of the cylinder 2 is sealed from the outside.

At the center of the first suction cylinder 61, a fuel suction hole 61e, which is smaller in diameter than the two-stage circular hole 61d and penetrates in the vertical direction, and is concentric with the cylinder 2, is formed. Further, the second suction cylinder 6 is provided at the middle diameter portion 61b of the first suction cylinder 61.
A male screw for screwing and connecting 2 is screwed.

The second suction cylinder 62 has a large-diameter portion 62a formed on the upper portion and having an outer diameter larger than that of the lower portion.
A small-diameter portion 62b is provided below the large-diameter portion 62a to form a two-stage structure. The small-diameter portion 62b is provided with an external thread for screwing a cap nut for connecting the suction-side tube. The second suction cylinder 62 has a through-hole that is vertically concentric with the first suction cylinder 61. This through-hole is formed by a screw hole 62c recessed from the top surface of the large diameter portion 62a.
, A filter mounting hole 62d concentrically communicating with the screw hole 62c, and a fuel suction hole 62e further communicating with the filter mounting hole 62d.

In the screw hole 62c, the first peripheral surface is formed on the inner peripheral surface.
While a female screw corresponding to the male screw of the middle diameter part 61b of the suction cylinder 61 is screwed, the medium diameter part 61 of the first suction cylinder 61 is screwed.
b, an annular groove 61f for fitting an annular sealing member 65 made of an elastic material is recessed at the upper end thereof, and a screw hole 62c is inserted into the first hole with the annular sealing member 65 fitted in the annular groove 61f. The annular seal member 6 in the annular groove 61f is screwed and fastened to the middle diameter portion 61b of the suction cylinder 61.
5 is compressed and elastically deformed, whereby the connection between the first suction cylinder 61 and the second suction cylinder 62 is sealed.

The length of the filter mounting hole 62d is set to be longer than the small diameter portion 61c of the first suction cylinder 61, and the inner diameter is set to be smaller than the outer diameter of the first suction cylinder 61. And the small diameter portion 6 of the first suction cylinder 61.
The size is set to be larger than the outer diameter of 1c. By doing so, the filter cylinder 63 is inserted into the filter mounting hole 62d in a state where the second suction cylinder 62 is mounted on the first suction cylinder 61.
Is formed so that a space can be formed.

The filter cylinder 63 is made up of a bottomed cylinder having through-holes formed on four sides, and a mesh material such as a fine mesh wire mesh attached to the through-hole of this cylinder from the inside. . In the filter cylinder 63, the inner diameter of the upper opening is set slightly smaller than the outer diameter of the small diameter portion 61c of the first suction cylinder 61, and the outer diameter is the inner diameter of the filter mounting hole 62d of the filter cylinder 63. The size is set smaller than the size, the upper opening of the filter cylinder 63 is press-fitted to the small-diameter portion 61c of the first suction cylinder 61, and then the second suction cylinder 62 is screwed to the first suction cylinder 61 and fastened. The filter tube 63 is set in a state of being mounted in the filter mounting hole 62d.

In the vicinity of the upper edge of the first suction cylinder 61, an annular groove 61g is formed, which is recessed over the entire circumference, while the lower stopper plate 64 is penetrated to the center. A hole is formed, and a C-ring 66 is fitted into the annular groove 61g in a state where the through-hole is externally fitted to the large-diameter portion 61a of the first suction cylinder 61. It is mounted on the part 61a.

Then, the first stop with the lower stop plate 64
With the suction cylinder 61 fitted on the cylinder 2, the yoke 54
The fuel suction unit 6 is connected to the cylinder 2 by being fixed to the horizontal plate below the bottom by bolts. Incidentally, the lower stopper plate 64 and the yoke 54
Since the portion in the direction perpendicular to the paper surface of FIG. 1 is bolted, the bolt for bolting does not appear on the paper surface of FIG.

The fuel discharge section 7 includes a fuel discharge cylinder 71 connected to the upper end of the cylinder 2, a valve receiving cylinder 72 provided inside the fuel discharging cylinder 71, and a cylindrical shape mounted on the valve receiving cylinder 72. , A second coil spring 74 for urging the check valve 73 in the valve closing direction, and a packing 75 made of an elastic material such as rubber laminated on the lower end surface of the valve receiving cylinder 72. It is provided with.

The fuel discharge cylinder 71 has a two-stage structure including a large-diameter portion 71a screwed onto the upper portion of the cylinder 2 and a small-diameter portion 71b integrally connected to the upper portion of the large-diameter portion 71a. The small diameter portion 71b is provided with a male screw for screwing a cap nut for connecting the discharge side pipe material. The fuel discharge cylinder 71 has a through-hole that is vertically concentric with the first suction cylinder 61. This through hole is concentrically communicated with a screw hole 71c recessed from the lower surface of the large diameter portion 71a, a valve receiving tube mounting hole 71d concentrically communicating with the screw hole 71c, and a valve receiving tube mounting hole 71d. Valve receiving cylinder mounting hole 71
The spring mounting hole 71e has a diameter smaller than that of the spring mounting hole 71e, and a fuel discharge hole 71f smaller than the spring mounting hole 71e communicated with the spring mounting hole 71e.

The inner diameter of the screw hole 71c is set to be substantially the same as the outer diameter of the cylinder 2, and a female screw is screwed on the inner peripheral surface.
A male screw 21 corresponding to the female screw is screwed on the upper portion of the cylinder 2. A screw hole 71 c is screwed into the male screw 21 and fastened, whereby the fuel discharge cylinder 71 is mounted on the cylinder 2.

The valve receiving cylinder 72 is provided with a valve receiving cylinder mounting hole 71.
The outer diameter is set so as to be fitted into d in a sliding contact state, and the inner diameter is set slightly smaller than the outer diameter of the check valve 73. A fuel passage hole 72 a concentric with the cylinder 2 is formed in the bottom of the valve receiving cylinder 72. Then, in a state in which the second coil spring 74 is fitted in the fuel discharge hole 71f, the valve receiving cylinder 72 on which the check valve 73 is mounted is fitted in the valve receiving cylinder mounting hole 71d.
The valve receiving cylinder 72 is mounted in the fuel discharge cylinder 71 with the check valve 73 pressed by the urging force of the second coil spring 74 closing the fuel passage hole 72a.

The thickness of the packing 75 is set such that the upper edge of the cylinder 2 is pressed against the lower surface of the packing 75 when the fuel discharge cylinder 71 is screwed onto the cylinder 2. Are securely sealed. The packing 75 has a valve receiving cylinder 7.
A fuel passage hole 75a having a diameter substantially the same as that of the second fuel passage hole 72a is formed.

FIG. 2 is a partially enlarged view of the electromagnetic pump 1 shown in FIG. 1 and is for explaining the plunger 3 and the closing valve body 8. As shown in this figure, the plunger 3
The length is set slightly longer than half the length of the cylinder 2 and the outer diameter is
The inner diameter of the cylinder 2 is slightly smaller than the inner diameter of the cylinder, whereby the cylinder can move up and down smoothly in the cylinder 2 and has a so-called free piston function in which the stroke length changes according to the load.

The plunger 3 is provided with a valve body mounting chamber 31 having a circular shape in plan sectional view, which is recessed so as to extend in the up-down direction at an axial center position of substantially the upper half, and has a valve body mounted in the lower half. A fuel suction hole 32 smaller in diameter than the chamber 31 is formed concentrically. The closing valve body 8 is press-fitted into an upper opening of the valve body mounting chamber 31 and is fixed to the cylinder 2.

The cylindrical valve element 4 is provided in the valve element mounting chamber 31 of the plunger 3.
Large-diameter portion 41 having a diameter slightly smaller than the inner diameter of No. 1
And an engaging portion 42 having a diameter smaller than the diameter of the large-diameter portion 41 protruding concentrically upward from the top surface of the large-diameter portion 41. The annular gap 3 formed between the outer peripheral surface of the engagement portion 42 and the inner peripheral surface of the valve element mounting chamber 31
4 so that the liquid fuel can be circulated.

In the valve body mounting chamber 31, a third coil spring 33 is housed in a compressed state. The third coil spring 33 has an upper end abutting against the bottom surface of the closing valve body 8 into which the cylinder 2 is press-fitted, while a lower end portion is fitted to the engaging portion 42 of the cylindrical valve body 4 and has a large diameter. Normally, the cylindrical valve element 4 is pressed against the third coil spring 33 to come into close contact with the bottom of the valve element mounting chamber 31, whereby the fuel suction hole 32 is closed. It has become.

The first coil spring 2 is provided in the cylinder 2.
2 are furnished. The first coil spring 22 is interposed between the bottom of the plunger 3 and the first suction cylinder 61 in a compressed state, and normally presses the plunger 3 upward, and the closing valve body 8 is moved. It comes into contact with the packing 75.

The lower end of the plunger 3 is provided with a circular projection 35 having an outer diameter substantially the same as the inner diameter of the first coil spring 22 projecting concentrically downward from the bottom surface. At the bottom of the two-stage circular hole 61d of the first suction cylinder 61, there is provided a circular concave portion 61h having an inner diameter substantially the same as the outer diameter of the first coil spring 22 concentrically recessed downward. The upper portion of the first coil spring 22 is externally fitted to the circular projection 35, while the lower portion is internally fitted to the circular concave portion 61h, so that the first coil spring 22 is stably mounted in the cylinder 2, and its outer periphery is expanded and contracted. The inconvenience of the surface sliding on the inner peripheral surface of the cylinder 2 is reliably avoided.

The closing valve body 8 has a cylindrical valve body 81 whose outer diameter is slightly larger than the inner diameter of the valve body mounting chamber 31 of the plunger 3, and is slightly lower than the vertical center of the valve body 81. And a T-shaped flow path 8 formed in the valve body 81 and having a T-shape in a side sectional view.
3 is provided. The three ends of the T-shaped channel 83 are respectively open to the outside. Then, the valve body 81 is pressed into the valve body mounting chamber 31 until the flange 82 of the valve body 81 comes into contact with the upper surface of the plunger 3, so that the closing valve body 8 is integrally fixed to the plunger 3.

The T-shaped flow path 83 comprises a vertical flow path 83a concentric with the plunger 3 and a horizontal flow path 83b extending horizontally in communication with the upper end of the vertical flow path 83a. The liquid fuel discharged from the valve body mounting chamber 31 due to the pressure reduction in the valve body mounting chamber 31 due to the downward movement flows into the upper part of the cylinder 2 from the left and right openings of the horizontal flow path 83b through the vertical flow path 83a. Become.

The pump chamber for sucking and discharging the liquid fuel by the vertical movement of the plunger 3 by the valve body mounting chamber 31, the T-shaped channel 83, and the space above the plunger 3 in the cylinder 2. 20 are formed.

The first coil spring 22 is in a state where no current is supplied to the electromagnetic coil 5 by properly setting the urging force, that is, the upper magnetic body 52 and the lower magnetic body 53 shown in FIG. In a state where no magnetic flux is generated therebetween, the urging force presses the plunger 3 upward, and the lower opening of the fuel passage hole 72a is closed by the contact of the upper surface of the closing valve body 8 with the packing 75. On the other hand, when the current is supplied to the electromagnetic coil 5, the plunger 3 moves down by the magnetic field formed between the magnetic members 52 and 53, and the fuel passage hole 72a is opened.

Further, in addition to the above-described operation, the first coil spring 22 operates within a stroke range where the closing valve body 8 does not come into contact with the packing 75 while a predetermined drive pulse signal is supplied to the electromagnetic coil 5. The biasing force is set so as to vibrate up and down in the cylinder 2.

The third coil spring 33 operates when the pressure in the pump chamber 20 is reduced by the downward movement of the plunger 3 due to the supply of the drive pulse signal to the electromagnetic coil 5 (the pump chamber 20 immediately before the downward movement is The fuel passage hole 72a of the receiving cylinder 72 is closed by the check valve 73, and the plunger 3
The fuel intake hole 32 is closed by the cylindrical valve body 4 to form an enclosed space.
(The pressure is reduced by the downward movement), the urging force is set so as to allow the cylindrical valve body 4 to move upward in the valve body mounting chamber 31.

In this embodiment, the cylinder 2
Has an inner diameter of 8.00 mm, whereas the plunger 3 has an outer diameter of 7.94 mm,
In this way, an annular gap having a radial gap of about 30 μm is formed between the inner peripheral surface of the cylinder 2 and the outer peripheral surface of the plunger 3 when both are set concentrically. By ensuring such a gap size, the gap size becomes 3
When the diameter is smaller than 0 μm, fine solid impurities in the liquid fuel are clogged and accumulated in the gap, and the inconvenience that the plunger 3 cannot move up and down in a short time is avoided.

Incidentally, if the mesh size of the mesh material provided in the filter cylinder 63 is set to 30 μm or less so that solid impurities having a particle size of 30 μm or less are not supplied into the cylinder 2, the gap size is further reduced. This makes it possible to reduce the leakage of fluid from the gap, but this causes a disadvantage that the mesh material is clogged in a short time, so that the gap dimension must be allowed to be at least 30 μm. Absent.

A plurality of labyrinth grooves 36 having a triangular cross section are formed in the outer peripheral surface of the plunger 3 in the annular groove. The labyrinth groove 36 is for preventing air from leaking from the gap even when a gap of 30 μm or more is formed between the inner peripheral surface of the cylinder 2 and the outer peripheral surface of the plunger 3. is there.

That is, the electromagnetic pump 1 of the present invention is used for pumping liquid fuel, and the liquid fuel is filled in the cylinder 2 during driving. Even if there is a gap of 30 μm between them, when the plunger 3 is vibrating up and down at a high speed, the liquid fuel does not leak from the gap due to its viscosity, and there is no particular inconvenience.

On the other hand, when the electromagnetic pump 1 has a so-called minus head, which is provided at a considerably higher level with respect to the liquid level in the fuel tank, the fuel tank and the electromagnetic pump 1 It is necessary to cause the electromagnetic pump 1 to suck the air in the pipe to be connected, and to pump the liquid fuel in the fuel tank to the cylinder 2 once by setting the pipe to a negative pressure.

However, air has a much lower viscosity than liquid fuel, and air leaks from the annular gap between the cylinder 2 and the plunger 3. Therefore, it is difficult to increase the degree of vacuum in the pump chamber 20. As a result, even if the plunger 3 vibrates at a high speed in the cylinder 2, the liquid fuel in the fuel tank is not sucked into the pump chamber 20. This tendency is remarkable in a cold region in winter when the temperature becomes −10 ° C. or less. In such a case, a priming process for filling the inside of the pipe with the liquid fuel is usually performed, but such operation is very troublesome.

To eliminate such inconvenience, a labyrinth groove 36 which is an annular groove is provided on the outer peripheral surface of the plunger 3. By providing such a labyrinth groove 36, the air in a laminar flow state leaking into the annular gap between the cylinder 2 and the plunger 3 reaches the labyrinth groove 36 and diffuses in the groove to be in a turbulent state. This increases the pressure loss and makes it difficult to move through the annular gap, so that the amount of air leaking into the annular gap is reduced.

Therefore, when the plunger 3 is lowered, the degree of vacuum in the pump chamber 20 is improved, and when the plunger 3 is raised, the degree of compression in the pump chamber 20 is increased. Since the air is efficiently sucked and removed, and the inside of the pipe has a high degree of vacuum, the liquid fuel in the fuel tank is pumped up by the electromagnetic pump 1 without priming.

Although the labyrinth groove 36 is provided in ten lines in the example shown in FIG. 2, the present invention is not limited to the labyrinth groove 36 having ten lines. One to twenty strips are recessed in accordance with the environment, the length of the plunger 3, and the like.

According to the electromagnetic pump 1 of the first embodiment, when the electromagnetic coil 5 is excited by a drive pulse signal (pulse current) to the electromagnetic coil 5 and a magnetic flux is generated between the magnetic bodies 52 and 53, the plunger 3 Receiving the first magnetic force
The closing valve body 8 is lowered from a state in which the closing valve body 8 is in contact with the packing 75 against the urging force of the coil spring 22, and a vacuum state appears in the pump chamber 20 due to the increase in the volume of the pump chamber 20 at this time. Since the pressure balance between the fuel suction hole 32 side of the plunger 3 and the pump chamber 20 side bordering on the valve body 4 is broken and the fuel suction hole 32 side becomes higher in the pump chamber 20, the cylindrical valve body 4 is Is pushed by the liquid fuel in the fuel suction hole 32 and rises in the valve body mounting chamber 31 against the urging force of the third coil spring 33 to cancel the valve-closed state. Is sucked into.

On the other hand, if the magnetic flux between the magnetic members 52 and 53 disappears due to the demagnetization of the electromagnetic coil 5 during the pulse pause period of the pulse drive signal, the plunger 3 is pushed upward by the urging force of the first coil spring 22. , Pump room 2
The liquid fuel in 0 presses the check valve 73 upward, and the liquid fuel is discharged from the fuel discharge hole 71f by opening the check valve 73 against the urging force of the second coil spring 74. .

When the plunger 3 moves upward, the frequency of the pulse drive signal and the frequency of the first coil spring 22 are applied so that current is supplied to the electromagnetic coil 5 until the closing valve body 8 contacts the packing 75. One of the powers,
Alternatively, since both are adjusted, the closing valve 8 does not collide with the packing 75 as long as the pulse drive signal is supplied to the electromagnetic coil 5. Such a plunger 3
Is repeated, and a predetermined amount of liquid fuel is sent out to the combustion device through the fuel discharge hole 71f.

As described above, the discharge of the liquid fuel when the liquid fuel has already been filled in the cylinder 2 has been described.
In the initial stage of the operation of the electromagnetic pump 1, when the liquid fuel has not reached the cylinder 2 and is filled with air, the only difference is that the inside of the cylinder 2 is air instead of the liquid fuel. In addition, air is sucked by the same operation as described above, and the pressure in the pipe provided between the fuel tank and the electromagnetic pump 1 is reduced, and the liquid fuel in the fuel tank is sucked into the cylinder 2.

When the supply of the pulse drive signal to the electromagnetic coil 5 is stopped, the plunger 3 is moved upward by the urging force of the first coil spring 22, whereby the closing valve body 8 is closed.
Abuts against the packing 75 to close the hole of the packing 75 on the upper surface of the closing valve body 8, so that the inside of the fuel discharge hole 71f and the inside of the pump chamber 20 communicate with each other so that the check valve 73 and the closing valve body 8 communicate with each other. And the fuel discharge hole 7 is double closed.
The flow of the liquid fuel between 1f and the pump chamber 20 can be reliably prevented.

Therefore, the backflow of the liquid fuel due to the fact that the side of the combustion device, to which the electromagnetic pump 1 is discharged, is installed at a level higher than the electromagnetic pump 1 is reliably prevented. The liquid fuel in the fuel tank is supplied to the combustion device via the stopped electromagnetic pump 1 in the case of a so-called plus head, and the combustion device is contaminated by the discharged liquid fuel. Such inconvenience is reliably prevented.

Since the biasing structure for biasing the plunger 3 employs a so-called one-spring biasing method using only the first coil spring 22, the conventional structure in which the plunger 3 is sandwiched between upper and lower coil springs. Compared to the so-called double spring biasing method, there is no need to secure a space for mounting a coil spring above the plunger 3 in the cylinder 2.
The capacity of the pump chamber 20 can be reduced.

Therefore, when the stroke amount of the plunger 3 is the same, the capacity ratio, which is the ratio between the minimum capacity and the maximum capacity of the pump chamber 20, can be increased as compared with the prior art. Since the compression ratio when air is present in the chamber 20 (the discharge force of the liquid fuel when the pump chamber 20 is full of liquid fuel) can be increased, the initial stage of the operation of the electromagnetic pump 1 can be increased. In addition to pumping the liquid fuel from the fuel tank without performing the priming process, the fuel tank may be provided at a considerably lower level than the electromagnetic pump 1, or in addition to the fuel tank and the electromagnetic pump 1, The liquid fuel can be pumped up with a stronger suction force even if the length of the pipe connecting the pipes is long.

FIG. 3 is a side sectional view showing a second embodiment of the electromagnetic pump 1a according to the present invention. The electromagnetic pump 1a of this embodiment is different from the first embodiment in that the valve body mounting chamber 31 is formed in a substantially lower half of the plunger 3a,
Check valve 67 corresponding to the check valve 73 of the first embodiment
Is provided in the first suction cylinder 610 of the fuel suction section 6a, which is different from the electromagnetic pump 1 of the first embodiment.

That is, the plunger 3a is provided with a valve body mounting chamber 31a at a lower position and a fuel discharge hole 32a at an upper position, and a closing valve body 8 is provided at an upper opening of the fuel discharge hole 32a. Is installed. A cylindrical lid 37 is press-fitted and fixed to the lower opening of the valve element mounting chamber 31a, and the cylindrical valve element 4 housed in the valve element mounting chamber 31a is supported by the cylindrical lid 37 to hold the valve element mounting chamber. 31a
Is pressed toward the cylindrical cover 37 by the third coil spring 33 provided inside the housing.

The fuel discharge cylinder 71 is not provided with the check valve 73,
Instead, a check valve 67 is provided in the first suction cylinder 610. Since the check valve 67 is mounted in the first suction cylinder 610, the structure of the first suction cylinder 610 is different from that of the first embodiment.

That is, the first suction cylinder 610 is provided with a three-stage circular hole 611 instead of the two-stage circular hole 61d.
An annular sealing member 6 similar to the above is provided in the first hole from the top.
5 is attached. A packing support cylinder 620 for supporting a rubber packing 612 (similar to the packing 75) is inserted into the upper hole of the second stage from the top, and the hole of the third stage is inserted into the hole. A check valve support cylinder 630 for supporting the check valve 67 (similar to the check valve 73) is fitted into the valve.

A spring mounting hole 622 for inserting a fourth coil spring 621 corresponding to the second coil spring 74 is formed in a lower portion of the packing support cylinder 620. In the lower part, a check valve support cylinder 6
An outer fitting hole 623 for externally fitting the spring mounting hole 623 is provided in the upper part of the check valve support cylinder 630.
22 is provided with a valve mounting hole 631 drilled corresponding to
With the check valve 67 fitted in the valve mounting hole 631,
By fitting the outer fitting hole 623 of the packing support cylinder 620 with the fourth coil spring 621 mounted in the spring mounting hole 622 so that the check valve 67 is mounted in the first suction cylinder 610. I have.

An annular groove 632 is formed at an appropriate position on the outer peripheral surface of the check valve support cylinder 630. The annular groove 632 is provided with an annular seal member 65 so that the annular groove 632 can be connected to the upstream side via the check valve 67. The seal with the downstream side is ensured. Further, a packing 75 is attached to a deep portion of the screw hole 71c of the fuel discharge cylinder 71.

Then, in a state where the first suction cylinder 610 is fitted to the lower part of the cylinder 2, the first coil spring 22 is interposed between the packing 612 and the cylinder lid 37 in the cylinder 2, Normally (ie, when current is not supplied to the electromagnetic coil 5) by the biasing force of the coil spring 22, the closing valve body 8 abuts the packing 75 to close the fuel discharge hole 71f. Other structures are the same as those of the electromagnetic pump 1 of the first embodiment.

According to the electromagnetic pump 1a of the second embodiment,
Only the installation positions of the valves (the cylindrical valve element 4, the closing valve element 8, and the check valve 67) are different from those of the first embodiment.
The same functions and effects as those of the electromagnetic pump 1 according to the embodiment can be obtained.

FIG. 4 is a side sectional view showing a third embodiment of the electromagnetic pump 1b according to the present invention. The electromagnetic pump 1b of the third embodiment has the same configuration of the plunger 3a as that of the second embodiment, except that a first coil spring 22 for urging the plunger 3a is provided above the plunger 3a. The point that the check valves 73 and 67 are provided in both the fuel discharge cylinder 71 and the first suction cylinder 610 and the point that the closing valve body 8 is provided in the lower part of the plunger 3a are electromagnetic waves of the second embodiment. It is different from the pump 1a.

That is, the electromagnetic pump 1b of the third embodiment
The structure of the plunger 3a is the same as that of the second embodiment, the structure of the fuel discharge unit 7 is the same as that of the first embodiment, and the structure of the fuel suction unit 6a is the same as that of the second embodiment. The same is true. The electromagnetic pumps 1 and 1a of the first and second embodiments are fundamentally different from the first and second embodiments in that the first coil spring 22 is disposed above the plunger 3a and the closing valve body 8 is disposed below the plunger 3a. It is provided that the plunger 3a is normally pressed downward by the urging force of the first coil spring 22 so that the closing valve body 8 abuts against the packing 612.

According to the electromagnetic pump 1b of the third embodiment,
Since the liquid fuel in the pump chamber 20 is discharged from the fuel discharge portion 7 when the plunger 3a moves upward by the excitation of the electromagnetic coil 5, by controlling the current value supplied to the electromagnetic coil 5, The point that the discharge pressure of the liquid fuel can be adjusted and the number of valves is four (the check valve 73, the cylindrical valve body 4, the closing valve body 8, and the check valve 67) and the case of the above embodiment. Since there is one more, it is excellent in that leakage of the liquid fuel can be more reliably prevented. Other functions and effects are the same as those of the previous embodiment.

FIG. 5 is an explanatory view showing an example of use of the electromagnetic pump according to the present invention. In this usage example, the fuel tank 90 is installed at a low level position such as a basement, whereas a combustion device 91 such as a stove or a water heater is arranged at a high level position on the first floor or the second floor or higher of a building. This is an example of use of the electromagnetic pump 1 in such a case. In such a case,
A relay tank 92 is provided on the floor where the combustion device 91 is installed, and the liquid fuel F in the fuel tank 90 is pumped up to the relay tank 92 via a pumping pipe 93 and temporarily stored therein. When the fuel pump 91 is used, the liquid fuel F stored in the relay tank 92 is sent out toward the combustion device 91 by driving the second electromagnetic pump 95. In such a fuel supply device, the electromagnetic pump according to the present invention is interposed at an appropriate position of the pumping pipe 93.

As the electromagnetic pump for such use, any of the above-described first to third embodiments can be adopted. However, the electromagnetic pump 1 of the first embodiment, in which the range of the volume change of the pump chamber 20 is large, is pumped. Therefore, the electromagnetic pump 1 of the first embodiment is preferably used.

The relay tank 92 has an oil level controller 94
The operation of the oil level controller 94 prevents the liquid fuel F in the relay tank 92 from overflowing.
The oil level controller 94 includes a valve member 94a attached to an upper end of the pumping pipe 93 that has entered the relay tank 92,
A float 94b is rotatably supported on the valve member 94a about a support shaft.

When the float 94b rises to a predetermined height due to the rise of the oil level in the relay tank 92, the on-off valve in the valve member 94a is closed to prevent the oil level from rising further. When the oil level is lowered by pumping the liquid fuel F in the relay tank 92 by driving the second electromagnetic pump 95, the float 94b is lowered and the valve member 9
The on-off valve in 4a is opened to supply the liquid fuel F.

An oil level sensor (not shown) for detecting the upper limit oil level and the lower limit oil level of the liquid fuel F is provided at an appropriate position in the relay tank 92. When the oil level sensor detects the upper limit oil level, the oil level sensor detects the oil level. When the drive of the electromagnetic pump 1 is stopped based on the detection signal, and the oil level sensor detects the lower limit oil level, the electromagnetic pump 1 is driven based on the detection signal. Therefore, in a state where an appropriate amount of the liquid fuel F is always stored in the relay tank 92,
Although the liquid fuel F in the relay tank 92 has reached the upper limit oil level, the oil level upper limit detection signal is not output to the switch circuit of the electromagnetic pump 1 due to, for example, a failure of the oil level sensor. It may be. In such a case, since the liquid fuel F continues to be discharged by driving the electromagnetic pump 1 continuously, for example, when the discharge pressure of the electromagnetic pump 1 is larger than the closing pressure of the on-off valve in the valve member 94a, The discharged liquid fuel F is supplied into the relay tank 92 by opening the closed on-off valve. When such a supply is performed, there is a problem that the liquid fuel F eventually overflows from the inside of the relay tank 92.

Therefore, in the present embodiment, the discharge pressure of the electromagnetic pump 1 is made smaller than the closing pressure of the on-off valve. Normally, the closing pressure of a commercially available on-off valve is 0.5 kg
/ Cm ² , the discharge pressure of the electromagnetic pump 1 is set to 0.4 kg in the present embodiment in consideration of safety.
/ Cm ² .

The discharge pressure can be adjusted by adjusting the urging force of the first coil spring 22 housed in the cylinder 2. In this embodiment, however, the discharge pressure can be adjusted.
This is achieved by reducing the value of the drive pulse signal (pulse current) supplied to the electromagnetic coil 5 by employing a control circuit as shown in FIG.

FIG. 6 is a diagram showing the principle of a circuit for driving an electromagnetic pump. As shown in this figure, a circuit for driving the electromagnetic pump includes a driving circuit 96 for outputting a driving pulse signal to the electromagnetic pump 1, a diode 97 having a cathode connected to the positive voltage side in parallel with the electromagnetic coil 5. Is formed.

As the diode 97, a flyback diode used for cutting (wearing) back electromotive force generated in the electromagnetic coil 5 is employed. The diode 97 circulates the current generated by the back electromotive force generated when the drive pulse signal is stopped, thereby shortening the stroke length of the plunger 3 against the urging force of the first coil spring 22. 3 functions to reduce the discharge flow rate of the liquid fuel F.

Instead of the flyback diode, a diode in which a Zener diode and a resistor are connected in series can be used. The discharge voltage of the liquid fuel F can be adjusted by adjusting the cut voltage by setting the zener voltage.

Although not shown, the fuel tank 90 is provided at a higher level than the electromagnetic pump 1.
In the case of the so-called plus head, a leakage phenomenon in which the liquid fuel F passes through the electromagnetic pump 1 due to a head when the operation of the electromagnetic pump 1 is stopped is likely to occur. However, in the present invention, in addition to the conventional check valve, a closing valve body is provided. The leakage of the liquid fuel F is unlikely due to the double closing action due to the provision of
Therefore, the disadvantage that the liquid fuel F flows back through the electromagnetic pump 1 toward the combustion device 91 can be reliably prevented.

[0098]

EXAMPLE In the circuit shown in FIG. 6, a confirmation test was conducted to confirm how much the discharge pressure and the discharge flow rate of the liquid fuel of the electromagnetic pump were reduced by providing the diode 97. As the test electromagnetic pumps, nine pumps were prepared by dividing the heads from those having a head of 0.0 m to those having a head of 4.0 m every 0.5 m. Each electromagnetic pump is designed in advance so as to have a specification according to the head distance, and is naturally set so that the discharge pressure and the discharge flow rate increase as the head increases (see Table 1).

Then, first, the discharge pressure and the discharge flow rate were measured using a circuit without the diode 97 while supplying a pulse drive signal from the drive circuit 96 to each electromagnetic pump. Subsequently, each electromagnetic pump was driven using the circuit provided with the diode 97, and the discharge pressure and the discharge flow rate were measured in the same manner.

For these measurements, a throttle valve is provided at the tip of the discharge-side pipe of the electromagnetic pump, and a pressure gauge is interposed in the pipe between the electromagnetic pump and the throttle valve to measure the pressure in the pipe. After the state, the electromagnetic pump is driven to suck the liquid fuel, and the discharge flow rate is obtained by measuring the amount of the liquid fuel discharged from the throttle valve in a state where the throttle valve is fully opened, and then setting the discharge rate of the electromagnetic pump. The pressure obtained by the pressure gauge in a state where the throttle valve was fully closed while driving was continued was defined as the discharge pressure.

FIG. 7 is a graph showing the test results, in which the horizontal axis indicates the head (m) and the vertical axis indicates the closing pressure (kg / cm ² ) and the discharge flow rate (ml / cm ² ). Each is graduated. As can be seen from this graph, the discharge pressure and the discharge flow rate of each of the electromagnetic pumps for the heads are lower when the diode 97 is used than when the diode 97 is not used. It was confirmed that the pressure and the discharge flow rate could be properly adjusted.

[0102]

According to the first aspect of the present invention, the cylinder is provided with a biasing means for pressing one end of the plunger toward the other side, and a driving pulse signal of the drive pulse signal is provided on the other end of the plunger. Since a closing valve body for closing the fluid suction port or the fluid discharge port with the urging force of the urging means in a state where the supply is stopped is provided, one end of the plunger is attached to the urging means when the operation of the electromagnetic pump is stopped. The closing valve provided at the other end closes the fluid suction port or the fluid discharge port by being pressed by the force, whereby the flow of the liquid fuel in the electromagnetic pump can be shut off. Therefore, it is possible to solve the conventional inconvenience that the liquid fuel, which is the fluid to be pumped, leaks into the electromagnetic pump and flows backward or forward when the operation of the electromagnetic pump is stopped.

According to the second aspect of the present invention, a spring mounting chamber extending in the axial direction of the plunger, a fluid suction hole formed in a lower part of the spring mounting chamber, and a fluid discharge hole formed in the upper part of the spring mounting chamber. Provided, a valve body facing the fluid suction hole or the fluid discharge hole in the spring mounting chamber, and a coil spring that presses the valve body so as to close the fluid suction hole or the fluid discharge hole. Since the outer diameter is formed by a cylindrical body having a slightly smaller diameter than the inner diameter of the pump chamber, the volume of the cylindrical body can be larger than that of a conventionally used spherical body as a valve body. Thus, even if the compression stroke of the plunger is the same as the conventional one, the compression ratio of the effective space can be increased by the increase in the volume of the valve element.

Therefore, when no liquid fuel is present in the pipe on the fluid suction side at the beginning of operation of the electromagnetic pump, the compression ratio of air in the effective space when the plunger is moved up is larger than that of the conventional electromagnetic pump. The higher-pressure air in the effective space is immediately discharged to the outside, and the lower the pressure in the effective space when the plunger moves down, the lower the pressure in the fluid suction-side pipe that communicates with the plunger. Thus, the liquid fuel can be quickly sucked into the pump chamber.

Further, the disadvantage of the conventional electromagnetic pump, in which the liquid cannot be pumped unless the priming oil is supplied to the fluid suction side pipe at the initial stage of the operation of the electromagnetic pump due to the minus head, is solved. A fuel tank for liquid fuel is installed in a low place such as a basement, while a combustion device is installed in a high place such as the second or third floor, and an electromagnetic pump is installed in the appropriate place of a fuel pipe connecting the two via a relay tank. Even if it is provided, the liquid fuel in the fuel tank is pumped up and supplied to the combustion device at a high place without performing a troublesome operation such as injecting the priming oil into the fuel pipe in the initial operation. be able to.

According to the third aspect of the present invention, the pressure control circuit for controlling the pressure of the fluid discharged by driving the plunger by controlling the drive pulse signal supplied to the electromagnetic coil is provided. The pressure of the fluid discharged by the pressure control circuit can be electrically adjusted without performing hardware operations such as changing the dimensions, and the discharge pressure can be adjusted according to the installation status and use status of the electromagnetic pump. Changes can be made easily.

According to the fourth aspect of the present invention, since the pressure control circuit is provided with the diode incorporated so as to cut back electromotive force, the diode is provided in parallel with the electromagnetic coil, so that the driving pulse signal is provided. Is supplied to the electromagnetic coil, it is possible to cut back electromotive force generated by this, and it is possible to reduce the discharge pressure by the plunger.

Therefore, in a case where a relay container is interposed between the electromagnetic pump and the liquid supply device, and the liquid level of the relay container is controlled by the float, the discharge of the electromagnetic pump is controlled by the closing pressure of the float. If the pressure is higher, the liquid is supplied into the relay container by the drive of the electromagnetic pump, even though the inside of the relay container has reached the maximum allowable liquid level, whereby the liquid is transferred to the relay container. However, such a disadvantage can be avoided by the pressure control circuit incorporating the diode.

According to the fifth aspect of the present invention, since a plurality of annular grooves are formed in the outer peripheral surface of the plunger, the fluid on the side compressed during the forward / reverse movement of the plunger can be moved between the outer peripheral surface of the plunger and the pump chamber. While trying to move to the low pressure side through the gap between the peripheral surface, the fluid becomes turbulent by being diffused when it reaches the annular groove formed in the outer peripheral surface of the plunger by a plurality of recesses, This makes it difficult to move through the gap due to an increase in flow resistance, which in turn suppresses leakage of fluid through the gap, thereby suppressing a decrease in pressure of the discharge fluid and also reduces the pressure in the plunger during fluid suction. The degree of vacuum can be increased.

When the fluid is air, the temperature is -10 ° C.
Below, the viscosity of the air becomes extremely small due to the moisture in the air being almost condensed, and the air easily passes through the gap between the outer peripheral surface of the plunger and the inner peripheral surface of the pump chamber. As a result, the degree of vacuum (suction pressure) in the pump chamber of the plunger is extremely reduced, which makes it impossible to pump up liquid fuel in the fuel storage tank without priming at the beginning of operation of the electromagnetic pump. Although inconvenience occurs, such an inconvenience can be solved by providing an annular groove in the plunger.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a first embodiment of an electromagnetic pump according to the present invention.

FIG. 2 is a partially enlarged view of the electromagnetic pump shown in FIG.

FIG. 3 is a side sectional view showing a second embodiment of the electromagnetic pump according to the present invention.

FIG. 4 is a side sectional view showing a third embodiment of the electromagnetic pump according to the present invention.

FIG. 5 is an explanatory view showing a usage example of the electromagnetic pump according to the present invention.

FIG. 6 is a principle diagram of a circuit for generating a drive pulse signal from an alternating current of a commercial power supply of 100 V, 50 to 60 Hz.

FIG. 7 is a graph showing a test result of the discharge pressure and the discharge flow rate of the liquid fuel, in which the horizontal axis indicates the head and the vertical axis indicates the closing pressure and the discharge flow, respectively.

[Explanation of symbols]

 1, 1a, 1b Electromagnetic pump 2 Cylinder 20 Pump chamber 21 Male screw 22 First coil spring 3, 3a Plunger 31 Valve body mounting chamber 32 Fuel suction hole 32a Fuel discharge hole 33 Third coil spring 34 Annular gap 35 Circular projection 36 Labyrinth groove 37 cylinder lid 4 cylindrical valve element 41 large diameter part 42 engaging part 5 electromagnetic coil 51 coil bobbin 52 upper magnetic body 53 lower magnetic body 54 yoke 55 terminal block 56 connection terminal 6, 6a fuel suction part 61, 610 first suction cylinder 61a Large-diameter portion 61b Medium-diameter portion 61c Small-diameter portion 61e Fuel suction hole 61f Annular groove 61g Annular groove 61h Circular concave portion 611 Three-stage circular hole 612 Packing 62 Second suction cylinder 62a Large-diameter portion 62b Small-diameter portion 62c Screw hole 62d Filter mounting hole 62e Fuel suction hole 620 Packing support cylinder 621 Fourth coil spring 6 2 Spring mounting hole 623 External fitting hole 63 Filter cylinder 630 Reverse support valve support cylinder 631 Valve mounting hole 632 Ring groove 64 Lower stop plate 65 Ring seal member 66 C ring 67 Check valve 7 Fuel discharge part 71 Fuel discharge cylinder 71a Large diameter part 71b Small diameter portion 71c Screw hole 71e Spring mounting hole 71f Fuel discharge hole 73 Check valve 74 Second coil spring 75 Packing 75a Fuel passage hole 8 Closing valve body 81 Valve body 82 Flange 83 T-shaped flow path 83a Vertical flow path 83b Horizontal flow Road 91 Combustion device 92 Relay tank 93 Pumping pipe 94 Oil level controller 94a Valve member 94b Float 95 Second electromagnetic pump 96 Drive circuit 97 Diode F Liquid fuel

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Keiji Kawanishi 2-7-15 Kita-Kamei-cho, Yao-shi, Osaka Inside Silver Co., Ltd. (72) Inventor Takeshi Sato 2-7-1 Kita-Kamei-cho, Yao-shi, Osaka No.15 Silver Co., Ltd. F-term (reference) 3H069 AA06 BB01 CC04 DD27 EE05 EE12 EE33 3H071 AA07 BB01 CC28 DD14

Claims (4)

[Claims] 1. A plunger is mounted in a cylinder having a fluid suction port at a lower portion and a fluid discharge port at an upper portion, and the plunger is biased by a repetitive magnetic force generated by a drive pulse signal supplied to an electromagnetic coil. Reciprocally reciprocates in the axial direction against the urging force of the fluid, and discharges fluid sucked from the fluid suction port from the fluid discharge port, immediately before the fluid suction port or immediately after the fluid discharge port. In the electromagnetic pump provided with a check valve for restricting the back flow of the fluid, the urging means is provided in the cylinder so as to press one end of the plunger toward the other side, and the other end of the plunger. A closing valve body for closing the fluid suction port or the fluid discharge port by the urging force of the urging means in a state where the supply of the drive pulse signal is stopped. And electromagnetic pump. 2. A pressure control circuit for controlling a pressure of a fluid discharged by driving the plunger by controlling a drive pulse signal supplied to the electromagnetic coil. Electromagnetic pump. 3. The electromagnetic pump according to claim 2, wherein the pressure control circuit includes a diode incorporated so as to cut back electromotive force. 4. The plunger according to claim 1, wherein the plunger has a plurality of annular grooves recessed in an outer peripheral surface.
An electromagnetic pump according to any one of claims 1 to 3.