JPS6018874B2 - Combustion amount control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a combustion amount control device configured to control the combustion amount of a combustion appliance in accordance with the current flowing through an electromagnetic coil.

Conventional Structures and Problems Conventionally, electromagnetic valves have been widely used to control fluids such as gases, but unless they have a special structure, they can only perform on/off operations.

In other words, as shown in Fig. 1, the driving part of the solenoid valve is composed of a coil, a plunger 2, and a spring 3. When the coil 1 is energized, the plunger 2 is moved by a magnetic circuit 4 to overcome the force of the spring 3. direction to open the valve 5.
When the current is turned off, the plunger 2 is pushed down by the spring 3 and the valve 5 is closed. At this time, the force with which the coil attracts the plunger 2 acts in the A direction, but is also generated in the C direction at the same time, so when the small current changes, the plunger 2 is attracted to the inner wall of the coil 1, creating friction, and the force is generated in the A direction. Do not work. In order to operate this proportionally, the plunger 2 had to be held so as not to come into contact with the inner wall of the coil, making the structure complicated and causing concerns about longevity, reliability, etc. In addition, since the force in the C direction results in a loss, a large amount of coil current is required, and a large coil is also required, so a large amount of coil winding is used, resulting in a very high cost. OBJECTS OF THE INVENTION The present invention eliminates such conventional drawbacks by effectively utilizing electromagnetic force and continuously controlling the fuel in the combustor according to the signal from the temperature sensor. It is an object of the present invention to provide a combustion amount control device that can freely control the movement of a valve by mutually increasing and decreasing the current flowing through the coil.

Structure of the Invention In order to achieve the above object, the present invention provides a valve seat in a passage leading from a fuel inlet to an outlet of a combustor, and a valve seat that faces the valve seat and is normally biased by a spring to press against the valve seat. The valve is connected to the valve and is held movably in the axial direction, and has a bobbin around which a first coil is wound. A valve device that includes a second coil that forms a magnetic circuit that interacts with a direct current to make the gap between the valve and the valve seat variable steplessly, and detects the temperature of the heated part heated by the combustor. This configuration includes a control circuit that controls the current flowing through the first or second coil in accordance with the signal from the sensor, and can arbitrarily vary the current flowing through the other coil.

With this configuration, the combustion amount can be precisely controlled in a connected manner according to the signal from the temperature detection sensor, and since the current flowing to the other coil can be arbitrarily varied, the control characteristics of the valve device can be arbitrarily set. It has the effect of allowing fine-grained control according to the characteristics of the combustion equipment.

DESCRIPTION OF EMBODIMENTS The present invention eliminates these conventional drawbacks, and embodiments thereof will now be described with reference to the accompanying drawings.

In FIGS. 2 and 3, 6 is a fluid inlet, 7 is a fluid outlet, and there is a valve seat 8 in between, and a valve 9 made of an elastic material is disposed opposite to the valve seat 8.

The flow rate of the fluid is controlled by the gap between this valve seat 8 and a valve 9 that is driven up and down by a drive section to be described later. The drive section is the first
A bobbin 14 with a coil 13 wound thereon and a second coil 10
It consists of an iron core 11 equipped with.

The bobbin 14 is supported by flexible supports 15 and 16.
It is supported so as not to come into contact with the central protrusion 12 and side protrusion 12' of the DII.

The inner circumferences of the supports 15 and 16 are fixed to the bobbin 14, and the outer circumferences are fixed to the outer body 19, so that the bobbin 14 can move freely in the thrust direction (A in the figure) but not in the radial direction (C in the figure). has an immovable structure. Further, the bobbin 14 and the valve 9 are normally pressed against the valve seat 8 by a spring 17 to prevent fluid from leaking between the valve 9 and the valve seat 8 when the coils 10 and 13 are not energized.

Next, we will explain the operation.

When a current is passed through the second coil 10 attached to the iron core 11, a magnetic circuit like B is formed in the iron core 11. Therefore, magnetic flux B is also generated in the gap 18 formed by the central protrusion 12 and side protrusion 12' of the iron core 11 (see FIG. 3).
Here, if current is applied to the first coil 13 wound around the bobbin 14 and placed in the gap 18 from the front of the drawing toward the other side (counterclockwise when looking at the valve device from above), the gap 18 is Bobbin 14 according to Fleming's left hand rule
A force in the direction F is applied to the bobbin 14, which overcomes the force W of the spring 17, and pulls the bobbin 14 upwards, stopping it at a position where F and W are balanced. If the current flowing through the second coil 01 is increased or decreased, the magnetic flux E will also be increased or decreased, and the position where the forces F and W are balanced can be freely selected.

Alternatively, similar results can be obtained by changing the current flowing through the first coil 13. As mentioned above, the bobbin 14 has a valve 9.
Since the valve 9 is mounted, the valve 9 also moves as the bobbin 14 moves, changing the gap between the valve seat 8 and the valve seat 8, thereby controlling the flow rate of fluid. Note that the same effect can be obtained even if the supports 15 and 16 are made elastic and the spring 14 is omitted.

FIG. 4 shows an example of a proportional control circuit. Reference numeral 20 is an AC power source, and a DC power source is obtained by rectifying bridges 21, 22, 23, 24 and a capacitor 25.

In addition, the resistor 26 and Zener diode 27 provide a constant DC voltage, and this constant voltage section includes a variable resistance sensing element (e.g., a temperature-sensitive resistance element, a pressure-sensitive resistance element, etc., hereinafter referred to as a sensor).
28, a setting variable resistor 29, and resistors 30 and 31 form a bridge, and the midpoint potential is compared by a transistor 32. When the resistance value of the sensor 28 is large, the potential at point a is lower than the potential at point b, so the transistor 32 is energized and amplified by the transistor 33, causing current to flow through the second coil 10 of the valve device. When the resistance of the sensor 28 becomes 4.0, the potential at point a approaches the potential at point b, working in the direction of restricting the current in the coil 13. Further, when the resistance of the sensor 28 becomes smaller, the potential at point a becomes higher than the potential at point b, the transistor 32 is cut off and the coil 101 is no longer energized, and the valve 9 is suppressed by the valve seat 8 and closed. A constant current limited by a resistor 50 is applied to the first coil 13 .

Resistors 34 and 35 are the base resistance and emitter resistance of the transistor 33, and diodes 36 and 51 are the coils 10 and 1.
3 for preventing back electromotive force, and resistor 37 for inrush current protection. With the above circuit configuration, the current flowing through the coil 10' can be controlled in proportion to the resistance value of the sensor 28. Also resistance 2
9 allows the settings to be varied. Here, the characteristics of the valve device shown in FIG. 2 can be changed arbitrarily by changing the value of the resistor 50. Furthermore, the same effect can be obtained even if the coils 10 and 13 are reversed. FIG. 5 shows an example in which the present invention is applied to temperature control of a gas instant boiler.

38 is a gas inlet, passes through a valve device 39 of the present invention, and is burned in a gas burner 40.

41 is a water supply port, which is heated by a heat exchanger 42 and is connected to the water supply faucet 4.
It flows to 3.

Reference numeral 44 denotes a temperature sensor (herein, a negative temperature sensitive resistance element is used and hereinafter referred to as a thermistor) provided at the outlet of the heat exchanger 42. This thermistor 44 sends a signal to the control unit 45 and compares and amplifies the set temperature. and sends a current signal to the valve device 39.

For example, if the control circuit 45 uses the circuit shown in FIG.
Coil 1 so that the temperature of thermistor 44 reaches the set temperature.
Since the gas flow rate of the valve device 39 is controlled by changing the current of 3, hot water at a constant temperature is always supplied even if the load (for example, the amount of hot water supplied) is changed. Not only proportional control, but also two-position, multi-position,
Program control and the like can also be easily applied depending on the configuration of the control circuit section.

Next, the example shown in FIG. 6 will be explained.

In FIG. 6, parts having the same functions as those in FIG. 4 are given the same numbers. The transistor 33 controls the current flowing through the second coil 1 and at the same time controls the current flowing through the first coil 13.

50' is a resistor for limiting the current flowing through the second coil, 5
1' is a diode for preventing back electromotive force of the first coil 13.

With the above configuration, the gain of the control system is improved as shown in FIG. In other words, in Fig. 7, R is sensor 2
8 shows the resistance change, and X shows the displacement of the valve 9. If the G line is the characteristic when using the control circuit shown in Fig. 4, then in the case of Fig. 6 it becomes like the H line, and even if the change in resistance of the sensor 28 is the same, the displacement increases significantly (g and h ). If the gain required for the control system is the G line, the cost can be reduced by reducing the number of turns of the coils 10 and 13 or by reducing the current flowing through the coils 10 and 13. FIG. 8 shows another example in which a sensor 28, a variable resistor 29, and resistors 30, 31 form a first bridge, and a sensor 28, a variable resistor 29, and resistors 52, 53 form a second bridge.

The first bridge controls the current flowing through the coil 10,
The second bridge controls the current flowing through the coil 13.
In such a configuration, if the potentials at point b and point c are shifted, a curve that bends in the middle as shown in the characteristic in FIG. 10 can be obtained. This means that if the characteristics of R and × are straight lines like line J in Figure 9 A, the characteristics of valve displacement
Since it is not a straight line, the R and Q lines also look like the L line in FIG.

Therefore, by making the characteristics of R and × like the line 1 in Figure 9 A, R and Q
The controllability is improved by making the characteristic a straight line as shown in line M in FIG. 9C. FIG. 10 shows still another example, which is applied to combustion amount control of a gas instantaneous boiler.

Items with the same function as in Figure 5 are given the same numbers. In FIG. 10, gas flows in from inlet 38, passes through cock 57 and valve device 39, and is combusted in main burner 40.

A pilot flame 5 is branched from the middle between the valve device 39 and the main cock 57.
8 is provided. A thermocouple 59 that is heated by flame is arranged on the pilot flame 58. With the above configuration, the signal from the thermistor 44 is compared and amplified by the control circuit 45, and the valve device 39
The second coil 10' is energized.

The thermoelectric current generated by the thermocouple 59 is also applied to the first coil 13 of the valve device 39 . As a result, when the pilot flame 58 is extinguished for some reason during combustion, the thermal current in the thermocouple 59 disappears, so the first coil 13 is no longer energized, and even if the second coil 01 is energized, the main burner 4 The river will extinguish the fire.

Gas does not flow into the main burner 40 unless the pilot flame 58 at the time of ignition burns and the thermocouple 59 is heated. In other words, since the valve device 39 has a control function and a safety device function, no special pilot safety device is required.

Alternatively, the signal from the thermocouple 59 may be processed within the control circuit 45 to control the coil of the valve device 39. FIG. 11 shows an example in which the present invention is applied to a gas stove.

Gas enters through the inlet 60, passes through the valve device 39, and is ejected from the nozzle 61. It is mixed with air from the intake port 63 in the mixing pipe 62, burned in the gap 66 between the wire meshes 64 and 65, and exits from the exhaust port 67. 68 indicates glass, and 69 indicates a protective guard.

Here, 70 is an oxygen deficiency detection element (hereinafter referred to as an oxygen deficiency sensor) made of oxidized zirconia or the like, and its characteristics are shown in FIG. 12. The horizontal axis 0 indicates the oxygen concentration of the air, and the vertical axis V indicates the electromotive force. As shown in the figure, the oxygen deficiency sensor 70' has a constant concentration (approximately 1
(approximately 8 to 20%) or less, generating an electromotive force.
Further, 71 indicates a negative temperature sensitive resistance element for detecting room temperature (hereinafter referred to as a room temperature sensor), 45 indicates a control circuit, and 77 indicates a warning lamp. Next, the operation will be explained using an example of a control circuit. FIG. 13 is a circuit diagram thereof, which includes a room temperature control section N that controls the current flowing through the second coil 10' based on a signal from a room temperature sensor 71, a power supply section S, and an oxygen deficiency detection section P.

The operations of the room temperature control section N and the power supply section S have been described above, and will therefore be omitted here. The oxygen deficiency detection section S normally supplies current to the first coil 13 through the limiting resistor 72.

A thyristor 73 is connected in parallel to the coil 13.
The oxygen deficiency sensor 70 is connected between the gate 74 and the minus 75 of the thyristor 73. 76 is the gate resistance, 7
7 indicates a lamp made of a light emitting diode.

Now, when the oxygen concentration in the room decreases during combustion, the 12th
As shown in the figure, a voltage is generated from a certain point and the thyristor 73
A voltage is applied to the gate of the thyristor 73, and the thyristor 73 becomes conductive.

Therefore, the current flowing through the coil 13 is reduced to the thyristor 73.
, the current disappears and the aforementioned valve device 39
shuts off the gas. Further, since a lamp 77 made of a light emitting diode is connected in series with the thyristor 73, when a current flows through the thyristor 73, it emits light to warn of oxygen deficiency. Once the thyristor 73 operates, even if oxygen is introduced next time and the signal from the oxygen deficiency sensor disappears, the thyristor 73 is self-maintained and will not recover. To recover from this, a person must turn off the power switch 78 and start the ignition operation again, so safety is high.

Also, as shown in Figures 11 and 13, if one coil is controlled by the signal from the temperature controller and the other coil is controlled by the signal from the oxygen deficiency detection sensor, it can function as both a temperature controller and an oxygen deficiency safety device. It is also possible to add additional functions.

Effects of the Invention As described above, according to the present invention, the valve device has a simple configuration, and it is possible to continuously control fuel efficiently and smoothly without generating unnecessary suction force.

In addition, the operating characteristics of the valve device can be set arbitrarily by controlling the current flowing through coils other than the coil that controls the temperature, and it can be used with the optimal characteristics for the combustor, making it possible to achieve high-precision control. can.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional valve device, Fig. 2 is a sectional view of a solenoid valve showing an embodiment of the present invention, Fig. 3 is an enlarged view of the main part of Fig. 2, and Fig. 4 is a circuit diagram. FIG. 5 is an explanatory diagram showing an example in which the present invention is applied to temperature control of a gas instant boiler, FIG. 6 is a circuit diagram in another embodiment, and FIG. 7 is a diagram showing its control characteristics.
FIG. 8 is a circuit diagram of still another embodiment, FIG.
Figure 10 shows an example of its application to combustion amount control in a gas instantaneous water heater, Figure 11 shows its application to a gas stove, and Figure 12 shows an oxygen deficiency sensor. 13 is a circuit diagram of the stove shown in FIG. 11. 6... Fuel inlet, 7... Outlet, 8...
... Valve seat, 9... Valve, 10... Second coil, 13...
...First coil, 14...Bobbin, 17...Spring, 28, 44, 71...Temperature detection sensor, 3
9... Valve device, 40... Burner (combustor)
, 45... Control circuit, 59... Thermocouple (flame detection element)
, 70...Oxygen deficiency detection element, B...
Magnetic circuit, P...Oxygen deficiency detection section. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13

Claims (1)

[Scope of Claims] 1. It has an inlet and an outlet for fuel to be supplied to the combustor, a valve seat provided in a passage between them, and a valve seat that is usually pressed against the valve seat by a spring provided opposite to the valve seat. a bobbin connected to the valve and held movably in the axial direction; a first coil wound around the bobbin; and a first coil corresponding to the first coil. A valve device including a second coil configured to interact with a direct current flowing through the first coil to configure a magnetic circuit that allows the gap between the valve and the valve seat to be varied steplessly. and controls the current flowing through either the first coil or the second coil according to a signal from a temperature detection sensor of a heated part heated by the combustor, and controls the current flowing through the other coil. A combustion amount control device equipped with a control circuit that can arbitrarily vary the value of current applied to the combustion chamber. 2. The combustion amount control device according to claim 1, wherein the current value applied to the other coil is controlled by a signal from a flame detection element of the combustor. 3. The combustion amount control device according to claim 1, wherein the control circuit includes an oxygen deficiency safety circuit that controls the current value applied to the other coil based on a signal from an oxygen deficiency detection element of the combustor.