JPS6358264B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electromagnetic pump with a boost delay device that can increase the pumping pressure at startup while appropriately delaying the pumping pressure. The present invention relates to an electromagnetic pump with a boost delay device that is effective for avoiding inconvenient phenomena such as combustion ignition noise in equipment and drooling of fuel oil from a nozzle.

[Prior art]

For gun type burners used in general household or commercial boilers, hot air heaters, etc.
The fuel oil from the nozzle is combusted in a spray state. When spraying fuel oil from the nozzle,
Since the discharge flow rate is proportional to the square root of the discharge pressure, if the ignition operation is performed at a low pressure, ignition will occur at a time when the discharge flow rate is low. If the discharge flow rate at the time of ignition is appropriate, the ignition noise should also be low. On the other hand, if the time from pump startup to steady pressure is extremely short, ignition will occur explosively and the ignition noise will be extremely loud. In order to deal with this situation, the fuel oil discharge pressure is lowered to the limit where an ignitable spray condition can be obtained.
The method used is to gradually bring the ignition to a steady state after ignition. According to such means, the ignition noise is reduced, which is preferable not only in terms of safety and durability of the combustion machine but also in terms of reducing noise pollution in areas with a large number of houses.

The rise curve of discharge pressure at the time of starting a normal electromagnetic pump without any countermeasures is shown in Figure 1 a.
It is known that the pressure rises rapidly, reaching steady pressure within a short time after the power is turned on. In this case, as mentioned above, steady pressure is reached in a very short time after startup, resulting in explosive combustion and the accompanying loud ignition noise.
Because it violates the requirements for quiet ignition or safe ignition,
This measure was desired.

Therefore, in recent combustor ignition technology, a method has been devised in which, for example, as shown in FIG. It has been used as an electromagnetic pump for silent ignition.

However, with such discharge pressure rise characteristics, a so-called sagging phenomenon occurs, in which the fuel oil discharged from the nozzle gradually flows into the combustion chamber even before it reaches an ignitable spray state, resulting in a fuel odor. However, under conditions where the combustion chamber is at a high temperature, such as when only a short period of time has passed after extinguishing the fire, it is difficult to avoid situations where explosive combustion occurs and a loud explosion sound is generated. It was hot.

[Problems to be solved by the present invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive and compact electromagnetic pump that can overcome the drawbacks of conventional electromagnetic pumps for silent ignition using a simple boost delay method.

[Structure of the invention]

The electromagnetic pump with a boost delay device according to the present invention includes:
As described in the claims, a controlled rectifier element connected in series with an electromagnetic coil of an electromagnetic pump;
a programmable unidirectional transistor for applying a variable timing control pulse to a control terminal of the control rectifying element; and an anode of the programmable unidirectional transistor for determining conduction timing of the programmable unidirectional transistor. a first resistor/capacitor series circuit connected to apply a capacitor potential to the current circuit; a transistor controlled by a resistance potential of a second resistor/capacitor series circuit supplied via a constant voltage diode, and as charging of the capacitor of the second resistor/capacitor series circuit progresses. It is characterized by comprising a step-up delay device that sequentially shortens the charging timing of the capacitor of the first resistor/capacitor series circuit from a predetermined time period after startup to a steady state by increasing the amplification degree of the transistor. do.

[Action of the invention]

In the electromagnetic pump according to the present invention, the electromagnetic coil is connected in series with a control rectifier to receive a half-wave alternating current, and the control terminal of the control rectifier has a pressure increase delay at the time of starting the discharge pressure of fuel oil. A control signal generated by the device is applied. This boost delay device has a two-stage rise characteristic that is effective for improving starting characteristics, and the change point and the slope of the rise characteristic can be easily adjusted.

〔Effect of the invention〕

According to the configuration of the present invention, when starting the electromagnetic pump, the rise characteristic of the discharge pressure of fuel oil is initially made steep until the pressure is suitable for ignition, and then the rise characteristic of the discharge pressure is made gradual until it reaches a steady state after ignition. By doing so, the drawbacks of the prior art can be overcome (see c in FIG. 1). moreover,
The points of change in the rise characteristics of the discharge pressure and their slopes can be adjusted as appropriate.
Therefore, depending on the characteristics of the equipment to be installed,
Optimal combustion conditions can be easily achieved.

〔Example〕

Hereinafter, the present invention will be explained with reference to the attached FIGS. 1 to 3.

FIG. 1 is a starting pressure increase characteristic curve of an electromagnetic pump in which the horizontal axis is the elapsed time t and the vertical axis is the discharge pressure P. In the case of a half-wave AC driven electromagnetic pump without any step-up delay, the step-up characteristic is as shown by curve a, which rises steeply in a short time after the power is turned on, as described above.

In addition, the main aim of improving the pressure rise characteristics in conventional pressure increase delay devices is to simply delay the time until a predetermined pressure is reached, as shown in Figure b, to make the slope of the pressure rise characteristic curve gentler. I had to do it. Even with such pressure rise characteristics, it is clear that the starting characteristics are improved in some sense than in the case of characteristic a, but as mentioned above, the so-called sagging phenomenon occurs,
There are many applications where such characteristics are undesirable.

Figure c discloses similar characteristics in the electromagnetic pump according to the present invention, which has two-step pressure increasing characteristics. Here, up to a discharge pressure of about 4 kgf/cm ² , which is generally considered suitable for ignition,
It shows a characteristic that it rises with a steep slope and then rises with a gentle slope until the steady pressure reaches 7 Kgf/cm ² . It was initially steep like this,
The reason for choosing a two-stage rise characteristic that becomes gradual after that is that the discharge flow rate is proportional to the square root of the discharge pressure, so the desired discharge pressure corresponding to the fuel oil discharge flow rate suitable for initial ignition can be reached in as short a time as possible. This is because it is necessary to increase the pressure, and once ignited, it is necessary to gradually increase the pressure by changing the pressure according to the characteristics of the applied equipment.

In each of FIGS. 2A to 2C, the driving voltage V of the electromagnetic pump is plotted on the vertical axis, and the elapsed time t is plotted on the horizontal axis. Figure A shows a half-wave AC waveform when no delay control is performed.

Figure B shows the driving voltage of the electromagnetic pump in the step-up delay device according to the prior art. By controlling the phase angle of the half-wave AC waveform so that it gradually increases, the voltage waveform applied to the electromagnetic pump changes. The graph shows that the pressure gradually increases and as the pressure approaches a steady state, the pressure is gradually controlled to become a normal half-wave AC waveform.

Figure C shows a driving voltage waveform in the electromagnetic pump with a boost delay device according to the present invention.
For a short time after the power is turned on, the voltage waveform remains the same and is controlled at a predetermined phase angle until it reaches the ignitable pressure of about 4 Kgf/cm ² , and then the voltage waveform remains the same until it reaches a steady pressure of about 7 Kgf/cm ² . The period between 1 and 2 indicates a state in which phase angle control is performed until a complete half-wave AC waveform is obtained in order to obtain a steady pressure while sequentially changing the control phase angle.

FIG. 3 shows a control circuit according to the present invention, which includes a rectification and constant voltage block 1 for performing half-wave rectification and generating a constant voltage for signals, and a phase control circuit for generating a phase angle control signal. An angle control signal block 2, a phase angle gradual increase block 3 for gradually increasing the phase angle of the generated control signal, and a phase angle gradual increase block 3 for controlling the passing current of the control rectifier SCR by variable control of the phase angle. The phase control block 4 receives current from an AC power source 5 via a switch 6.

The rectifier and constant voltage block 1 half-wave rectifies the alternating current using the rectifier D, divides a part of it through the resistor _R1 , makes it constant voltage through the constant voltage diode _ZD1 , and sends it to the phase angle control signal block 2. supply.

Phase angle control signal block 2 divides the signal constant voltage by resistors R ₂ and R ₃ and connects the programmable union transistor PUT (hereinafter referred to as PUT).
) is applied as a standard voltage to the gate G of the capacitor _C 1 through a resistor R ₄ , a variable resistor VR ₁ , and a resistor R ₅ . When the voltage of capacitor _C1 increases, the potential of anode A of PUT increases, and when it reaches the potential of gate G of PUT,
PUT turns ON and supplies a control signal to the gate G of the control rectifier SCR in the phase control block 4,
In response to this control signal, the control rectifier SCR is turned on. Therefore, when the resistance value of the variable resistor VR ₁ is decreased, the charging current of the capacitor C ₁ increases, the charging time is shortened accordingly, and as a result, the control phase angle is increased and the discharge pressure of the electromagnetic pump is increased. I can do it.

On the contrary, if the resistance value of the variable resistor VR ₁ is increased, the discharge pressure of the electromagnetic pump can be lowered. In this way, by controlling the resistance value of the variable resistor VR ₁ , a discharge pressure suitable for the combustor can be achieved.

The phase angle increasing block 3 includes a capacitor C ₂ , a variable resistor VR ₂ and a resistor R ₆ connected in series.
The emitter E of the transistor TR is connected to the positive (+) voltage line, and the collector C is connected to the midpoint of the series connection of the variable resistor VR ₁ and the resistor R ₅ in the phase control signal block 2. The base B of the transistor TR is connected between the capacitor C ₂ and the variable resistor VR ₂ via the constant voltage diode ZD ₂ .
When the capacitor _C2 is not charged, the emitter E and base B of the transistor TR are at the same potential, so the transistor TR is OFF, and the capacitor in the phase angle control signal block 2
The charging current of C ₁ is only current flowing through resistor R ₄ , variable resistor VR ₁ and resistor R ₅ . In this way, from turning on switch 6, capacitor C ₂
Until the charging potential of the electromagnetic pump reaches a predetermined value, the control phase angle remains at a predetermined value determined by the setting value of the variable resistor VR ₁ . This results in the achievement of boost characteristics.

As the charging of the capacitor _C2 progresses, the potential on the negative side of the capacitor _C2 decreases, and when the constant voltage diode _ZD2 reaches the Zener voltage, a current starts to flow between the emitter E and the base B of the transistor TR, and the voltage of the transistor TR increases. Emitsuta E/Collector C
Current will also flow between them. At this time, if the variable resistor VR ₂ and the resistor R ₆ are selected to have high resistance, the current flowing between the emitter E and the base B can be kept extremely low.
It is possible to keep the TR ON state in the critical state for a long time. During this time, the amplification degree of the transistor TR gradually increases, and the current flowing between the emitter E and the collector C also gradually increases. Thus, the current flowing between emitter E and collector C is added to the current flowing through resistor R ₄ , variable resistor VR ₁ and resistor R ₅ to gradually shorten the charging time of capacitor C ₁ . Along with this, the control phase angle of the control signal gradually increases, and the current passing through the electromagnetic pump P also increases, so that the discharge pressure in the electromagnetic pump P also gradually increases. In this case, increasing the resistance value of variable resistor VR ₂ will lengthen the time it takes to gradually increase from the ignition- _enabled pressure to the steady state pressure;
If the resistance value of is decreased, the time for gradual increase will be shortened.

The phase control block 4 has a controlled rectifying element SCR connected in series with the electromagnetic coil of the electromagnetic pump P, and conduction of the controlled rectifying element SCR is controlled by the output signal pulse of PUT. By controlling the generation time of the output signal pulse of this PUT, the current of the control rectifier SCR, and therefore the phase angle of the AC half-wave energized to the electromagnetic coil of the electromagnetic pump P, can be increased or decreased. As a result, the discharge pressure of the electromagnetic pump P can be adjusted. In addition, resistance
_R7 is the compensation resistance of the controlled rectifier SCR.

As described above, the electromagnetic pump with a boost delay device according to the present invention has a characteristic in which the pressure rises to a discharge pressure suitable for ignition is steep, and once ignited, the pressure rise characteristic is gradual to achieve quiet ignition and other desired starting characteristics. can be achieved. In this case, the discharge pressure at which ignition is possible is known to vary depending on the applicable combustion equipment, but this pressure can be easily adjusted, and furthermore, the subsequent gradual increase characteristic can also be easily adjusted. . Note that, since the circuit elements of the boost delay device according to the present invention are mainly composed of semiconductors, the device can be made small and inexpensive, and its durability and reliability can also be improved.

[Brief explanation of the drawing]

FIG. 1 shows the pressure increase characteristics at the time of starting the electromagnetic pump. Figure 2 A to Figure 2 C
shows the waveform of the driving voltage of the electromagnetic pump. FIG. 3 is a circuit diagram showing an example of a drive and control circuit in an electromagnetic pump with a boost delay device according to the present invention. The correspondence of the main reference symbols in the figure is as follows. 1: Half-wave rectification and constant voltage block, 2: Phase angle control signal block, 3: Phase angle gradual increase block,
4: Phase control block, 5: AC voltage, 6: Switch, SCR: Controlled rectifier (thyristor),
PUT: Programmable union transistor, VR ₁ , VR ₂ : Variable resistor, C ₁ , C ₂ : Capacitor, ZD ₁ , ZD ₂ : Constant voltage diode, R ₄ ,
_R5 , _R6 : Resistor, TR: Transistor.

Claims (1)

[Claims] 1. An electromagnetic pump driven by an alternating current half-wave current and used for hydraulically feeding fuel to combustion equipment, comprising: a controlled rectifying element SCR connected in series with an electromagnetic coil of the electromagnetic pump; A programmable unidirectional transistor PUT for applying a variable timing control pulse to a control terminal G of the control rectifying element; A first resistor/capacitor series circuit R ₄ connected to apply a capacitor potential to the anode A,
VR ₁ , R ₅ ; A current circuit is connected in parallel to C ₁ and at least a part of the resistance portion of the first resistor/capacitor series circuit, and is supplied via a constant voltage diode ZD ₂ Second resistor/capacitor series circuit C ₂ ;
a transistor TR controlled by the resistance potentials of VR _{2 and} R ₆ ;
It is characterized by comprising a step-up delay device that sequentially shortens the charging timing of the capacitor _C1 in the first resistor-capacitor series circuit from a predetermined time period after starting to a steady state by increasing the amplification degree of the circuit. electromagnetic pump. 2. The electromagnetic pump according to claim 1, wherein a variable resistor VR ₁ is disposed in a resistor portion connected in parallel with the transistor TR in the first resistor/capacitor series circuit of the boost delay device. 3. The electromagnetic pump according to claim 1, wherein a variable resistor VR ₂ is connected to the resistor portion of the second resistor/capacitor series circuit.