JPH0227321Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Purpose of the Invention [Technical Field of the Invention] The present invention relates to a fuel control device for a combustion device such as an oil stove.

[Prior art and its problems]

FIG. 5 is a diagram showing a conventional pressure vaporization oil fan heater, in which the fuel pumped up from the fuel tank 1 by the pump P is routed from the vaporizer 2 to the nozzle 4 of the three-way solenoid valve V to the burner B. B, is atomized by nozzle 4, and burned. Burner B is equipped with an igniter and a flame detector (flame rod). When a fire is extinguished, the pump P stops first, but if the pump is stopped only, fuel gas will still be supplied to the burner due to the pulsation and vaporized kerosene pressure until the pump completely stops, resulting in incomplete combustion. and a foul odor.

FIG. 6 is a sectional view showing a conventional example of a three-way solenoid valve that performs such fuel control. This three-way solenoid valve energizes the excitation coil 7 to move the movable iron core 8 to the fixed iron core 9.
By drawing it to the side, the needle 3 connected to the movable iron core 8 is moved back, and the nozzle 4 is opened.
Fuel is supplied from the nozzle 4 to the burner. A heating tube 12 is wound around the heater 11 outside the needle storage tube 10 in a spiral manner, and one end of the heating tube 12 is connected to the needle storage tube 10 and the other end is connected to the fuel pump. Storage pipe 10
is supplied with fuel. Therefore, while the liquid fuel passes through the heating tube 12, it is heated by the heater 11 and gasified, and then sprayed from the nozzle 4 onto the burner section.

When extinguishing the burner, the excitation coil 7 is de-energized, and the movable core 8 is moved by the return spring 13 to the fixed core 9.
The needle 3 moves forward to the nozzle 4.
Close and stop oil supply to the burner section. at the same time,
When the movable core 8 separates from the fixed core 9, the valve port 14 opens, and the remaining gas in the needle storage pipe 10 is returned to the fuel tank via the return pipe 6.

However, with this configuration, the return spring 1
3 advances the needle 3 and closes the nozzle 4. That is, while the burner is in use, it is necessary to energize the three-way solenoid valve and open the nozzle 4, resulting in large power consumption.

In addition, when the movable core 8 returns to its original position and the nozzle 4 is closed, when the excitation coil 7 is energized to attract the movable core 8 as shown in the figure, the needle follows and starts suction at the same time as the movable core is attracted. I will do it. Therefore, a large force is required to attract the movable iron core 8, it is difficult to sufficiently increase the spring force of the return spring 13, and the ampere turns of the excitation coil 7 must be increased, resulting in an increase in the size of the excitation coil and Power consumption also increases, and together with the long energization time, the power consumption also increases.
If the spring force of the return spring 13 cannot be increased, not only will the nozzle 4 be insufficiently closed by the needle 3, but it will also be difficult to remove tar attached to the inner surface of the nozzle. That is, the return spring 13 moves the needle 3 to the nozzle 4.
By pressing the movable iron core 8 against the fixed iron core 9 and pulling the needle 3 away from the nozzle 4, tar adhering to the inner surface of the nozzle is removed. In order to remove this tar, it is necessary to press the needle against the inner surface of the nozzle with a stronger force, but if the return spring 13 is strengthened for this purpose, it will be able to overcome this force and attract the movable iron core 8 from the farthest position. The ampere-turn of the excitation coil 7 must be increased to enable this.

[Technical issues of the present invention]

The technical problem of the present invention is to eliminate such problems in conventional combustion devices, to reduce power consumption in the combustion device as much as possible, and to also make the three-way solenoid valve smaller.

(b) Structure of the invention [Technical means of the invention] The technical means of the invention taken to solve this technical problem consists of a needle connected to a movable core driven by an excitation coil, and a needle connected to a movable core driven by an excitation coil. It consists of a built-in needle storage tube and a needle valve that opens and closes a nozzle provided at the tip of the needle storage tube.A fuel supply tube is connected to the needle storage tube, and the back of the excitation coil is connected to the needle storage tube. There is communication between the return valve port and the needle storage pipe 3
In the two-way solenoid valve, a return spring is interposed between the fixed iron core and the movable iron core, a large diameter recess is formed in the cylindrical hole of the movable iron core, and the needle is attached to the rear end of the needle in the large diameter recess. In addition to loosely fitting a spring receiver, a bias spring is inserted to bias the needle toward the nozzle. Further, in the three-way solenoid valve, a fixed iron core is disposed at a position closer to the tip of the needle than the movable iron core, and a return valve port on the back side of the movable iron core is always closed.
The movable core is attracted to the fixed core and moves forward only when the excitation coil is energized, and the needle moves toward the nozzle to close the nozzle, thereby reducing power consumption.

[Effect of technical means]

According to this technical means, in a three-way solenoid valve, the movable core is normally pushed back to the opposite side of the nozzle by a return spring, and is separated from the fixed core.
When the excitation coil is energized, the movable iron core is attracted to the fixed iron core, and the needle advances toward the nozzle.
Close the nozzle. In the present invention, when the burner is extinguished, the pump stops, the timer means starts, the excitation coil of the three-way solenoid valve is energized, the nozzle is closed by the needle, and the fuel is supplied to the burner. Supply is cut off. The blowing fan operates until the remaining fuel in the burner is burned out, but the three-way solenoid valve is also energized and the nozzle remains closed at least until the fan stops.

Further, a spring receiver at the rear end of the needle is loosely fitted into a large-diameter recess formed in a cylindrical hole of the movable core, and a bias spring for biasing the needle, which is weaker than a return spring, is inserted. Therefore, whenever the nozzle is closed or opened, only the movable core moves first.
After the needle moves to a certain extent and the thrust becomes strong, the thrust is transmitted to the needle via the spring receiver, so the needle is reliably moved by the impact force at that time.

[Example of idea]

Next, how the fuel control device in a combustion device according to the present invention is actually implemented will be explained using an example. FIG. 1 is a diagram showing the entire structure of a liquid combustion device according to the present invention, and the same reference numerals are given to the same parts as in the conventional example shown in FIG. In the present invention, a timer means T is provided between the pump P and the three-way solenoid valve V. That is, when the pump P stops, the stop signal is input to the timer means T to start the timer means T, and is also input to the three-way solenoid valve V to energize the excitation coil of the three-way solenoid valve V. As a result, the movable core is attracted to the fixed core, the needle closes the nozzle, and fuel supply to the burner section is stopped. The set time of the timer means T is such that the fuel in burner B is completely combusted and 3
It is set to have enough margin so that the remaining fuel in the needle storage pipe of the solenoid valve can be completely returned to the fuel tank side. When the set time elapses and the timer T times out, the excitation coil of the three-way solenoid valve is de-energized, the needle returns to its original position, the nozzle opens, and the return valve closes. The timer means T is also used to stop the forced air fan F.
When a preset time has elapsed, the fan F can also be stopped.

FIG. 2 is a time chart showing the operational relationship between the three-way solenoid valve V and the pump P. First, prior to igniting the liquid combustion device, as shown in (a), the three-way solenoid valve V is energized and the nozzle is closed for a relatively short period of time, for example, 2 to 3 minutes. After the pump starts and fuel starts to be supplied, the energization of the three-way solenoid valve V is interrupted, the nozzle is opened, and fuel supply to the burner section is started.

When extinguishing the burner while the pump is operating and the burner section is burning, the pump is stopped and at the same time, the three-way solenoid valve is energized and the nozzle is closed. This state is maintained for about 6 to 8 minutes, for example, until the burner is completely extinguished and the remaining fuel in the needle storage pipe is completely returned.

Note that reliable operation is ensured by increasing the voltage applied to the excitation coil only for the first few seconds when the excitation coil of the three-way solenoid valve is energized.

FIG. 3 is a cross-sectional view showing an embodiment of a three-way solenoid valve suitable for closing the nozzle by energizing the nozzle only for a certain period of time after the pump is stopped. In the present invention, the fixed core 9 is disposed near the needle valve 5, and the movable core 8 is disposed close to the return valve port 14 on the return pipe 6 side. The needle 3 connected to the movable iron core 8 passes through the central through hole 15 of the fixed iron core 9 and extends into the needle storage tube 10. The tip of the needle 3 corresponds to the nozzle 4. A return spring 13 is interposed between the fixed core 9 and the movable core 8, and normally the return spring 13 is
The movable core 8 is pushed back from the fixed core 9. When the excitation coil 7 is energized, the movable iron core 8 is attracted to the fixed iron core 9 against the return spring 13, and the tip of the needle 3 is pushed into the nozzle 4 to close the nozzle. When the excitation coil 7 is de-energized in the closed state of the nozzle 4, the movable iron core 8 is pushed back from the fixed iron core 9 by the return spring 13, the needle 3 retreats, and the nozzle 4 is opened.

At the rear end of the guide sleeve 16 of the fixed iron core 9,
A return valve port 14 is provided at the connection port to the return pipe 6. On the other hand, the rear end of the movable iron core 8 is provided with a valve body 17 formed of a sealing member such as rubber.
Further, the needle 3 has a rectangular cross section, and the needle storage pipe 10 and the return valve port 14 on the back are in communication so that fuel can pass therethrough. Therefore,
The movable iron core 8 is attracted to the fixed iron core 9 and the needle 3
When the nozzle 4 is closed, the valve body 17 moves away from the return valve port 14 and opens, allowing fuel inside the needle storage pipe 10 and the like to pass to the return pipe 6 side. When the excitation coil 7 is de-energized, the movable core 8 returns, and the needle 3 retreats to open the nozzle 4, the return valve port 14 is closed by the valve body 17, and the fuel pumped by the pump P is transferred to the nozzle 4. It is supplied only to the side and cannot pass to the return pipe 6 side.

In the present invention, the following measures are taken to improve the driving characteristics of the needle 3. Fourth
The figure is an enlarged sectional view of the main parts inside the solenoid. The tip 81 of the movable iron core 8 has a conical shape, and the suction surface 91 of the fixed iron core 9 facing the movable iron core 8 has a conical recess so as to be parallel to the conical tip 81. There is. Then, when the conical inclination angle θ is extremely small and the movable core 8 has returned, the tip 82 of the conical portion of the movable core 8 and the edge 92 of the tip of the conical recess of the fixed core 9
are arranged so that the distance is the shortest.

Therefore, when the excitation coil 7 is energized with the movable core 8 in its restored state, a large amount of magnetic flux flows through the part with the lowest magnetic resistance between the conical part tip 82 and the edge 92 of the conical recess. The movable core 8 is attracted to the fixed core 9 with an extremely large force,
Start moving. As the movable core 8 is attracted and moved, the conical portion 81 of the movable core 8 enters the conical recess 91 of the fixed core 9, and the distance between them gradually becomes smaller, but the rate of change is lower than that of the conventional Extremely small compared to iron core structure. In other words, when the movable core 8 begins to be attracted to the fixed core 9, the tip 82 of the conical portion of the movable core 8 is extremely close to the edge 92 of the conical recess of the fixed core 9, so an extremely large suction force is generated. I decided to do it,
The ampere turns of the excitation coil can be made sufficiently small. Further, since the suction force is large, the spring force of the return spring 13 is also increased, and the needle 3 is separated from the nozzle 4 with a large force, thereby making it possible to reliably remove tar.

A spring receiver 18 such as an E-ring is attached to the rear end of the needle 3, and a cylindrical hole 83 of the movable iron core 8 is attached.
A large diameter recess 84 is formed by inserting a collar 86 therein. and the spring receiver 1
A bias spring 19 is interposed between the movable iron core 8 and a spring receiving portion 85 at the rear end of the movable iron core 8 .

In this configuration, when the movable core 8 has returned to its original position as shown in the figure, the needle 3 is pushed forward by the bias spring 19, but since the movable core 8 has returned, the tip of the needle is separated from the nozzle 4. The valves are opened at a distance.

When the excitation coil is energized now, the movable iron core 8 is attracted to the fixed iron core 9, but the needle itself does not follow the speed of the movable iron core 8 from zero, but after moving a certain distance z, the needle 3 in the stopped state
The tip of the collar 86 in the movable core 8 collides with the spring receiver 18 of the movable iron core 8 and follows the spring receiver 18 for the first time. This provides the needle 3 with the impact force of the movable core 8, that is, the hammer effect. Then, the nozzle 4 is closed at the tip of the needle 3 by a force several times the suction force of a normal movable iron core. In this way, when the nozzle 4 is in the closed state, the movable core 8 is in an excited state, so the spring receiver 18 is pressed by the tip of the collar 86 inside the movable core 8. However, when the excitation coil is de-energized, the movable core 8 8 begins to move back by the return spring 13. Then, the front end of the recess 84 of the movable iron core 8 collides with the front surface of the spring receiver 18 in the stopped state, and a backward force is instantaneously applied to the needle 3, causing the tip of the needle to be separated from the nozzle 4 by a hammer effect. Then, the movable core 8 is further pushed back by the return spring 13, resulting in the state shown in the figure.

(c) Effect of the invention As described above, according to the invention, when the excitation coil is energized, the needle itself does not follow the movable core at the same time, but follows the movable core only after it has moved a certain distance, so the hammer effect is produced. This eliminates the need to increase the size of the coil. In addition, a three-way solenoid valve is used in which the needle moves forward when the excitation coil is energized to close the fuel supply nozzle to the burner, and a timer means is provided so that the three-way solenoid valve is closed only for a certain period of time after the fuel pump has stopped. The nozzle of the electromagnetic valve is closed to stop the fuel supply to the burner section. Therefore, the excitation coil of the three-way solenoid valve only needs to be energized for a very short time, such as several minutes after the pump is stopped, and power consumption is significantly reduced.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the liquid combustion device according to the present invention. FIG. 1 is a diagram showing the entire structure of the liquid combustion device, FIG. 2 is a time chart showing the operation of the device, and FIG. The figure is a cross-sectional view of a three-way solenoid valve used in the same device, and FIG. 4 is an enlarged cross-sectional view of essential parts of the three-way solenoid valve. FIG. 5 is a diagram showing a conventional liquid combustion device, and FIG. 6 is a sectional view of a three-way solenoid valve used in the device. In the figure, P is the pump, B is the burner, and V is 3
1 solenoid valve, T is timer means, 3 is needle, 4
is a nozzle, 5 is a needle valve, 6 is a return pipe, 7 is an exciting coil, 8 is a movable iron core, 81 is a conical part, 82
9 shows the tip of the conical part, 9 the fixed core, 91 the conical recess, 92 the edge of the conical recess, 10 the needle storage pipe, and 14 the return valve opening.

Claims (1)

[Claim for Utility Model Registration] A needle connected to a movable iron core driven by an excitation coil, a needle storage tube in which the needle is built, and a nozzle provided at the tip of the needle storage tube with the tip of the needle. A three-way solenoid valve consisting of a needle valve that opens and closes, a fuel supply pipe is connected to the needle storage pipe, and a return valve port on the back and the needle storage pipe communicate within the excitation coil. A fixed iron core is disposed near the tip of the needle, a return spring is interposed between the fixed iron core and the movable iron core, a large diameter recess is formed in the cylindrical hole of the movable iron core, and a large diameter recess is formed in the large diameter recess. A spring receiver attached to the rear end of the needle is loosely fitted, and a bias spring weaker than the return spring is inserted to bias the needle toward the nozzle. The return valve port is closed, and only when the excitation coil is energized, the movable iron core is attracted to the fixed iron core side and moves forward, and the needle moves to the nozzle side to close the nozzle. Fuel control device in combustion equipment.