EP2667095B1

EP2667095B1 - Ignition device for oil burner

Info

Publication number: EP2667095B1
Application number: EP13275118.1A
Authority: EP
Inventors: Izuru NAKAMURA; Toshihiko Yamada; Toru Nakagaito
Original assignee: Toyotomi Kogyo Co Ltd; Toyotomi Co Ltd
Current assignee: Toyotomi Kogyo Co Ltd; Toyotomi Co Ltd
Priority date: 2012-05-22
Filing date: 2013-05-15
Publication date: 2019-05-01
Anticipated expiration: 2033-05-15
Also published as: KR102046836B1; CL2013001451A1; CN203336637U; JP6171539B2; EP2667095A3; ES2730853T3; JP2014001919A; KR20130130652A; EP2667095A2

Description

TECHNICAL FIELD

The present invention relates to an ignition device for an oil burner that is operable to ignite a combustion wick by means of electric discharge.

BACKGROUND ART

An early conventional ignition device for a wick-type oil burner generally utilized an ignition heater configured to be heated to a red heat. In recent years, a discharge-type igintion device, which employs a low-voltage dry-cell battery as a power source, has been put into practical use thanks to the improvements of an electrode mounting structure and a high-voltage generating circuit. (Refer to JP 06-241449 A .)
Documents JP H11 51317 A further discloses an ignition device for an oil burner, whereas documents JP 2007 330024 A , JP 2002 139786 A and JP S53 39661 U disclose devices with a manually-operated generator that is provided as a power source.

SUMMARY OF INVENTION

TECHNICAL PROBLEM

A discharge-type iginition device can be used over a long period of time merely by replacing a battery since a discharge electrode is not consumed. However, if a dry-cell battery is used as a power source, the following problem will be raised since an electric power obtainable from the dry-cell battery is small. If the dimension defined for the positional relationship between a combustion wick and a discharge electrode gets out of order, heat generated by means of spark discharge is directly used to vaporate an oil. As a result, a white oil voporizing gas is merely generated, and ignition fails. For this reason, it is necessary to accurately regulate the dimension defined for the positional relationshiop between the combustion wick and the discharge electrode.
The capacity of the dry-cell battery decreases as the battery is used, which leads to lowered voltage and weakened discharge spark. It is difficult to obtain expected ignition performance for a long period of time. This forces a user of the oil burner to replace the exhausted battery with a new battery in order to continue to use the oil burner. However, it is sometimes inconvenient to handle such oil burner. If a new battery is not available then, it will be inevitable to use a match to ignite the combustion wick until a new battery becomes available.
Putting aside the issue with the discharge electrode, the gap dimension between the combustion wick and the inginition electrode deviates from the initial setting due to a change in height of the combustion wick, wick thinning, and a change in surface condition of the combustion wick such as ahesion of tar to the surface of the wick. If the gap dimension is out of order, ignition performance will be lost in a short time although a certain level of ignition performance may be obtained for some time after starting the use of a new dry-cell battery.

SOLUTION TO PROBLEM

The present invention aims at improvements of an ignition device for an oil burner, the ignition device comprising a pair of discharge electrodes operable to give ignition spark to a combustion wick; a high-voltage oscillation circuit operable to periodically apply a high voltage to the pair of discharge electrodes; and a power surce circuit operable to supply an electric power for iginition to the high-voltage oscillation circuit. In the present invention, the power source circiut includes as a power source a generator capable of generating electricity by means of a manual operation. According to the present invention, it is possible to ignite the combustion wick of an oil burner without using a dry-cell battery. There is no need of worrying about deteriorated ignition performance due to consumption of the dry-cell battery. Stable ignition performance can be maintained even though the oil burner is used over a long period of time. If the generator is of a rotary type, a stable output of electric power can always be obtained by manually rotating the generator, thereby causing stable spark discharge between the pair of discharge electrodes.
In the main embodiment of the present invention, the power source circuit may include a power conversion circuit operable to convert an output from the generator to the electric power for ignition; and a power supply circuit operable to supply the electric power for ignition to the high-voltage oscillation circuit. If an output from the generator is AC (alternating current) power, the power conversion circuit works as a rectification circuit operable to convert AC power to DC (direct current) power or an AC-DC conversion circuit.
In one or more embodiments of the present invention, the power supply circuit may include a voltage comparing circuit operable to supply the electric power for ignition to the high-voltage oscillation circuit when an output voltage from the power conversion circuit exceeds a predetermined voltage. In such configuration as the voltage comparing circuit included in the power supply circuit, the electric power for ignition is supplied from the power source circuit to the high-voltage oscillation circuit after the output voltage from the power conversion circuit has reached a voltage required for electric discharge, thereby reliably causing ignition spark. Further, the power supply circuit may include an established voltage notifying circuit operable to notify an operator of the generator that the output voltage from the power conversion circuit exceeds the predetermined voltage when it is detected. In such configuration as the established voltage notifying circuit included in the power supply circuit, it is possible to notify the operator of the generator that an output voltage from the generator has reached a voltage required for ignition. As a result, the operator can know whether or not the operation (or rotation) of the generator is sufficient.
Alternatively, the power supply circuit may include an electricity storing means such as a capacitor; a charging circuit operable to charge the electricity storing means with an output from the power conversion circuit; and a discharge circuit operable to discharge electric charge from the electricity storing means to the high-voltage oscillation circuit. The output from the generator is stored in the electricity storing means in advance and the electric charge stored in the electricity storing means is then discharged to the high-voltage oscillation circuit. This allows a stable voltage to be supplied to the high-voltage oscillation circuit, thereby causing stable discharging. The discharge circuit may include an ignition switch operable to turn on when the ignition switch is operated by the operator. The discharge circuit may be configured to discharge electric charge from the electricity storing means to the high-voltage oscillation circuit when the ignition switch turns on. If such ignition switch is provided, it is possible to arbitrarily select the timing with which to discharge from the electricity storing means. The power supply circuit may preferably include a charging completion indicating circuit operable to indicate that charging is completed upon completion of charging. If such charging completion indicating circuit is provided, it is possible to notify the operator of the timing with which the operator can stop operating (or rotating) the generator, thereby avoiding wasteful operations of the generator.
The power source circuit may include a primary battery such as the dry-cell battery, and a selection circuit operable to selectively connect the electricity storing means or the primary battery to the discharge circuit. In such configuration, the primary battery may usually be used as a primary power source and a generator may be used as a power source for ignition if the primary battery becomes disabled. Thus, even if the primary battery cannot be replaced, the oil burner can be ignited.
In the main embodiment of the present invention, the high-voltage oscillation circuit may include a signal oscillating circuit operable to generate an oscillation signal so as to periodically oscillate; a switching circuit operable to turn on or off in response to an input of the oscillation signal; and a booster circuit operable to boost an output voltage from the power supply circuit according to a switching operation of the switching circuit. This configuration can facilitate circuit construction.
A drive force required to manually drive the generator, namely, a force applied by the operator to a rotor of the generator increases in proportion to an output current (or load) from the generator. In some cases, manual operation of the generator may impose a large burden on an operator who has weak strength. In order to alleviate the burden, a decelerating mechanism formed of a gear mechanism may be employed to increase a torque. In this case, however, another issue is raised. That is, it is necessary to increase the rotating speed of the decelerating mechanism. Then, the high-voltage oscillation circuit may preferably be configured such that an oscillation period and a non-oscillation period alternately occur. During the non-oscillation period, the load for the generator is zero. The load imposed on the generator can appropriately be alleviated by appropriately providing the non-oscillation periods, thereby reducing the force required for the manual operation of the generator. Of course, this configuration may be combined with an assistor formed of a gear mechanism.
Specifically, the high-voltage oscillation circuit includes a signal oscillating circuit operable to generate an oscillation signal so as to periodically oscillate; a switching circuit operable to turn on or off in response to an input of the oscillation signal; a booster circuit operable to boost an output voltage from the power supply circuit according to a switching operation of the switching circuit; and an oscillation period setting circuit operable to allow the oscillation signal to be input to the switching circuit during the oscillation period and disallow the oscillation signal to be input to the switching circuit during the non-oscillation period. In this main embodiment, it is possible to readily set the oscillation period and the non-oscillation period by adjusting the output from the oscillation period setting circuit.
In one or more embodiments of the present invention, the power source circuit may preferably include an external output terminal operable to externally deliver an output from the generator or the power conversion circuit. With such external output terminal, it is possible to utilize the output from the generator to operate various electrical equipment or charge secondary batteries of various electrical equipment in case of power failure or the like. The external output terminal may be in a form of a connector structure (or an output connector).
The ignition device may further include a timer means operable to count the time period from the start of operation of the high-voltage oscillation circuit till the stop of the operation thereof; and an alarm generating circuit operable to output an alarm of ignition error when the timer means counts a predetermined time period. In this configuration, it is possible to notify the operator that ignition is disabled due to some problem with the combustion wick condition.

BRIEF DESCRIPTION OF DRAWINGS

These and other objects and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

Fig. 1 is a vertical cross-sectional view of a major part of an oil burner according to embodiments of the present invention.
Fig. 2 is a traverse cross-sectional view of the major part of the oil burner according to the embodiments of the present invention.
Fig. 3 is a front view of the oil burner according to the embodiments of the present invention.
Fig. 4 is a circuit diagram of an example ignition device according to a first embodiment of the present invention.
Fig. 5 is a circuit diagram of an example high-voltage oscillation circuit configuration according to the first embodiment of the present invention.
Fig. 6 is a schematic signal waveform illustration to be used to explain how the high-voltage oscillation circuit of Fig. 5 is operated.
Fig. 7 is a circuit diagram of an ignition device according to a second embodiment of the present invention.
Fig. 8 is a circuit diagram of an ignition device according to a third embodiment of the present invention.
Fig. 9 is a circuit diagram of an ignition device according to a fourth embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

Now, embodiments of an oil burner or heater and an ignition device for an oil burner according to the present invention will be described below in detail with reference to the accompanying drawings. As illustrated in Figs. 1 to 3, an oil burner of the embodiments includes an inner combustion wick cylinder 1, an outer combustion wick cylinder 2, a combustion wick 3, an ignition electrode 4 comprised of a pair of discharge electrodes 4a and 4b, a high-voltage oscillation circuit 5, a generator 15, an oil tank 7, a combustion cylinder 8, a drive shaft 9 for moving the combustion wick 3 up and down for combustion, a bottom plate 10, a service tank 11, a housing 12, and a front panel 13. The housing 12 is fixed on the bottom plate 10. The oil tank 7 is also fixed on the bottom plate 10. The inner combustion wick cylinder 1 extends upward from a bottom plate of the oil tank 7. The outer combustion wick cylinder 2 extends upward from a top plate of the oil tank 7. The combustion wick 3 is disposed so as to freely move up and down in a gap formed between the inner and outer combustion wick cylinders 1 and 2. The combustion cylinder 8 is mounted on upper ends of the inner and outer combustion wick cylinders 1 and 2. A lower end of the combustion wick 3 extends into a fuel in the oil tank 7. An upper end of the combustion wick 3 faces a lower end of the combustion cylinder 8.
The drive shaft 9 is rotatably mounted to the oil tank 7. The drive shaft 9 is engaged with the combustion wick 3 to move the combustion wick 3 up and down. A knob 9a for rotating operation is fixed to an end portion, which projects from the front panel 13, of the drive shaft 9.
The ignition electrode 4 is formed of a pair of discharge electrodes 4a and 4b. The discharge electrodes 4a and 4b are disposed in the vicinity of the upper end of the combustion wick 3 to face the upper end of the combustion wick 3, the upper end projecting from the gap between the inner and outer combustion wick cylinders 1 and 2. When in use, at least one of the discharge electrodes 4a and 4b is caused to contact or bite into the combustion wick 3. One of the discharge electrodes is grounded.
Fig. 4 illustrates a basic circuit configuration of an ignition device according to the first embodiment of the present invention. The high-voltage oscillation circuit 5 is configured to periodically apply a high voltage to the pair of discharge electrodes 4a and 4b operable to give ignition spark to the combustion wick 3. The power source circuit 14 is operable to supply an electric power for ignition to the high-voltage oscillation circuit 5. The high-voltage oscillation circuit 5 is operated at a frequency of approximately 800 Hz to cause spark discharge at the ignition electrode 4. The power source circuit 14 includes as a power source the generator 15 capable of generating electricity by means of a manual operation. In the first embodiment, the generator 15 outputs AC (alternating current) power. Further, the power source circuit 14 includes a power conversion circuit 16 operable to convert an output from the generator 15 into the electric power for ignition; and a power supply circuit 17 operable to supply the electric power for ignition to the high-voltage oscillation circuit 5. The power conversion circuit 16 includes a rectifier circuit 16A operable to convert AC power output from the generator 15 into DC (direct current) power and a rectifying capacitor C. The rectifier circuit 16A is formed of a bridge circuit including six bridge-connected diodes. In place of the bridge circuit, of course, other AC-DC conversion circuits may be employed. The power supply circuit 17 includes an established voltage notifying circuit (R,18) and an ignition switch 19. The established voltage notifying circuit (R,18) is formed of a series circuit of a resistor R and a light-emitting diode 18 having Zener characteristics. When an output from the power conversion circuit 16 reaches a predetermined voltage, the light-emitting diode 18 turns on to notify voltage establishment to the operator of the generator 15. The ignition switch 19 is illustrated in Fig. 1. The ignition switch 19 of Fig. 1 works with the drive shaft 9 and is closed when the combustion wick 3 reaches the vicinity of a combustion position where the combustion wick 3 can be ignited. In other words, the ignition switch 19 is in an OFF state until the knob 9a for rotating operation is rotated to the combustion position, and gets into an ON state when the knob 9a for rotating operation is rotated to the combustion position.
As illustrated in Figs. 1 to 3, the generator 15 comprises a power generating section 15a including a rotor and a stator, not shown, a rotary handle 15b, and a decelerating mechanism 15c. The decelerating mechanism 15c includes an output shaft 15d fixed to one end of a rotary shaft on which the rotor of the power generating section 15a is fixedly mounted, an input shaft 15e to which the rotary handle 15b is fixed, and a gear mechanism disposed between the output and input shafts 15d and 15e. The power generating section 15a and the decelerating mechanism 15c are disposed inside the housing 12 of the oil burner. The rotary handle 15b is coupled to the input shaft 15e via a hinge mechanism. When the rotary handle 15b folded around the hinge mechanism and an operating knob 15f are received in an opening portion 13a of the front panel 13 of the housing 12, the rotary handle 15b is in a received condition. When the operating knob 15f is pulled out of the opening portion 13a and the rotary handle 15b is unfolded around the hinge mechanism, the rotary handle 15b is in an operable condition. Except for ignition operations, the rotary handle 15b should be folded and received in the opening portion 13a. For ignition purpose, the rotary handle 15b is pulled out of the opening portion 13a for rotation operation. Thus, in the present embodiment, the rotary handle 15b is received in the opening portion 13a not to disturb operations other than the ignition.
In the present embodiment, for the ignition operation, the drive shaft 9 is rotated to move the combustion wick 3 upward and bring the ignition switch 19 in an ON state. Next, when the rotary handle 15b, which has been set in an operable state, is rotated, rotation torque is amplified by the decelerating mechanism 15c and conveyed to the power generating section 15a to rotate the rotor of the power generating section 15a, thereby generating AC power. Then, the power supply circuit 17 supplies the electric power to the high-voltage oscillation circuit 5 and then the high-voltage oscillation circuit 5 is activated to cause spark discharge at the ignition electrode 4. After that, the drive shaft 9 is returned to the combustion position to turn off the ignition switch 19. Then, the power supply circuit 17 stops supplying the electric power, thereby stopping spark discharge. Thus, the oil burner gets into an ordinary combustion mode. In the present embodiment, the ignition switch 19 is provided, but DC power may directly be supplied to high-voltage oscillation circuit 5 without using the ignition switch 19.
A dry-cell battery has generally been used as a power source for an ignition device of a conventional oil burner. The ignition performance is affected by various factors such as deterioration of the combustion wick and changes in spark discharge due to voltage fluctuations. If the power source voltage is lowered due to the deteriorated dry-cell battery, discharge spark energy is weakened, thereby merely producing white oil vapor and failing in ignition. Thus, the ignition performance is worsened. Then, in the present embodiment, the ignition performance is improved by intermittently causing spark discharge or varying the oscillation frequency to cause spark to occur in different positions.
Fig. 5 illustrates an example high-voltage oscillation circuit configuration. The high-voltage oscillation circuit 5 of Fig. 5 includes a signal oscillating circuit 51, a switching circuit 52, a booster circuit 53, and an oscillation period setting circuit 54. The signal oscillating circuit 51 is formed of a multi-vibrator circuit or the like, and is operable to generate an oscillation signal so as to periodically oscillate, for example at a frequency of 800 Hz. The switching circuit 52 is formed of two transistors TR1 and TR2 and a resistor R1 and is operable to turn on or off in response to an input of the oscillation signal from the signal oscillating circuit 51. The booster circuit 53 is constituted from a voltage transformer formed of a primary winding W1 and a secondary winding W2 and a capacitor C1 connected to the primary winding W1 in parallel. When the transistors TR1 and TR2 of the switching circuit 52 are turned on, a current flows through the primary winding W1. In this state, when the transistors TR1 and TR2 of the switching circuit 52 are turned off, a high voltage, for example 8-9 V, is generated at the secondary winding W2 in a pulse form. The high voltage is generated according to the ratio for the number of windings of the primary and secondary windings W1 and W2. Fig. 6A schematically illustrates a high voltage generated in a pulse form. A high-voltage generated in a pulse form is repeatedly applied to the pair of discharge electrodes 4a and 4b, thereby repeatedly causing spark discharge to occur. The oscillation period setting circuit 54 includes a signal generating circuit 55 and a transistor TR3. The signal generating circuit 55 is operable to alternately generate a signal S1 and a signal S2 by a predetermined period, for example 25 ms. The signal S1 has a signal width TP1 corresponding to an oscillation period. The signal S2 has a signal width TP2 corresponding to a non-oscillation period. The signal generating circuit 55 may be formed of a multi-vibrator circuit or the like. Fig. 6C schematically illustrates these signals. During a period in which the signal S1 is input to a base of the transistor TR3 to turn off the transistor TR3, the transistors TR1 and TR2 repeatedly turn on and off in response to the oscillating signal from the signal oscillating circuit 51. During a period in which the signal S2 is input to the transistor TR3 to turn on the transistor TR3, the output from the signal oscillating circuit 51 is shortcut, thereby preventing the oscillating signal from entering into the transistors TR1 and TR2. In the example configuration illustrated in Fig. 5, the oscillation period setting circuit 54 is operable to allow the oscillation signal to be input to the switching circuit 52 during the oscillation period TP1 and disallow the oscillation signal to be input to the switching circuit 52 during the non-oscillation period TP2. In such configuration, the oscillation period and the non-oscillation period can readily be set, as illustrated in Fig. 6B, by adjusting the occurring period of the signals S1 and S2.
In proportion to an output current (or load) from the generator 15, a drive force required to drive the generator by a manual operation, in other words, a force to be applied to the rotor of the generator 15 by the operator of the generator increases. For this reason, in some cases, a large burden is imposed on an operator having weak strength when manually operating the generator 15. The decelerating mechanism 15c formed of a gear mechanism may be employed to increase a generated torque in order to alleviate the burden imposed on the operator. In this case, however, a new issue is raised, namely, the speed of rotation for the decelerating mechanism 15c must be increased. Then, in the present embodiment, the high-voltage oscillation circuit 5 of Fig. 5 is configured such that the oscillation period TP1 and the non-oscillation period TP2 alternately occur. In this configuration, the load for the generator 15 is zero during the non-oscillation periods. The load of the generator 15 may appropriately be alleviated by appropriately providing the non-oscillation periods TP2, thereby reducing the force required for the manual operation of the generator 15.
The oil burner according to the present embodiment does not utilize commercially available AC power, and works as an oil-fired space heater in the event of disaster or the like where the commercially available power is almost unavailable. To use a conventional ordinary oil burner in such situation, it is necessary to secure in advance a dry-cell battery to be used as a power source and some ignition means such as a match or a lighter. In contrast, the oil burner of the present embodiment does not require a dry-cell battery, a match, and a lighter. Once the oil burner is brought and installed in a site and a fuel is supplied to the oil burner, heating can readily be started. The oil burner of the present embodiment is very useful in the event of disaster or the like.
Fig. 7 illustrates an ignition device according to a second embodiment of the present invention. Parts of the second embodiment of Fig. 7 are allocated the same reference numerals and signs as counterparts of the first embodiment of Fig. 4, and explanations thereof are omitted. In the second embodiment, a power supply circuit 17 includes an electricity storing means 20 such as an electric double layer capacitor and a secondary battery; a charging circuit 21 operable to charge the electricity storing means 20 with an output from the power conversion circuit 16; and a discharge circuit 22 operable to discharge electric charge from the electricity storing means 20 to the high-voltage oscillation circuit 5. In the second embodiment, the output from the generator 15 is stored in the electricity storing means 20 and the stored electric charge is discharged, thereby supplying a stable voltage to the high-voltage oscillation circuit 5. The discharge circuit 22 includes an ignition switch 19' which turns on when operated by the operator of the ignition device. The ignition switch 19' is provided on the front panel of the oil burner. When the ignition switch 19' turns on, electric charge is discharged from the electricity storing means to the high-voltage oscillation circuit 5. The power supply circuit 17 includes an established voltage notifying circuit operable to notify the operator of voltage establishment by turning on the light-emitting diode 18 when a charged voltage of the electricity storing means 20 reaches a predetermined voltage. The established voltage notifying circuit is formed of a series circuit including a resistor R and a light-emitting diode 18 having Zener characteristics. The operator can activate the high-voltage oscillation circuit 5 with a necessary and sufficient electric power for ignition by turning on the ignition switch 19' after the light-emitting diode 18 has turned on. Such established voltage notifying circuit notifies the operator how long the operator should operate or rotate the generator, thereby avoiding wasteful operations of the generator. In the second embodiment, completion of charging is notified by turning on the light-emitting diode 18 disposed in the vicinity of the rotary handle 15b on the front panel 13 as illustrated in Fig. 3. The completion of charging may be notified by sounding a buzzer. When the light-emitting diode 18 turns on while the operator rotates the rotary handle 15b of the generator 15, the operator should confirm that the light-emitting diode 18 turns on, and stop rotating the rotary handle 15b of the generator 15 and operate the ignition switch 19' so as to be closed. Thus, the electric power is supplied from the electricity storing means 20 to the high-voltage oscillation circuit 5 which, in turn, is activated to cause spark discharge at the ignition electrode 4.
Fig. 8 illustrates an ignition device according to a third embodiment of the present invention. Parts of the third embodiment of Fig. 8 are allocated the same reference numerals and signs as counterparts of the first embodiment of Fig. 4, and explanations thereof are omitted. In the third embodiment, as with the first embodiment of Fig. 4, the power source circuit 14 converts AC power output from the generator 15 into DC power to obtain an electric power for ignition, and then supplies the electric power directly to the high-voltage oscillation circuit 5. The third embodiment is different from the first embodiment of Fig. 4 in that a voltage comparing circuit 24 is provided in the third embodiment. The voltage comparing circuit 24 is operable to supply the electric power for ignition to the high-voltage oscillation circuit 5 when an output voltage from the power conversion circuit 16 exceeds a predetermined voltage. The third embodiment is different from the first embodiment of Fig. 4 also in that a primary battery 26 formed of a dry-cell battery, a timer means 27 as described later, and an alarm means 28 are provided in the third embodiment. An amount of electric power generated by the generator 15 varies with an amount of rotation of the rotary handle 15b. If the rotary handle 15b is rotated slowly, an amount of rotation thereof is small, thereby generating a small amount of electric power. If the rotary handle 15b is rotated quickly, an amount of rotation thereof is large, thereby generating a large amount of electric power. A voltage detecting means 10 is provided to detect an output voltage from the generator 15. When the rotary handle 15b has been rotated by a predetermined amount of rotation and an output voltage from the power generating section 15a reaches a predetermined voltage, the voltage comparing circuit 24 gets into a conduction state and an output voltage from the power conversion circuit 16 is supplied to the high-voltage oscillation circuit 5.
In the third embodiment, even though the rotary handle 15b is operated, if an output voltage from the generator 15 does not reach a predetermined voltage since the amount of rotation is small, the high-voltage oscillation circuit 5 is not activated. Even if the rotary handle 15b is inadvertently rotated, ignition will not occur unless the rotary handle 15b is rotated by a predetermined amount of rotation. Thus, ignition of the combustion wick 3 is prevented from occurring due to an inadvertent operation, thereby securing safety.
Further, in the third embodiment, the operator of the ignition device can know that an output from the power conversion circuit 16 reaches a desired voltage when the operator notices that the light-emitting diode 18 turns on while the operator is rotating the rotary handle 15b. In the present embodiment, a reference voltage used by the voltage comparing circuit 24 is set to be equal to or lower than a voltage at which the light-emitting diode 18 turns on. When the light-emitting diode 18 turns on, the voltage comparing circuit 24 is in a conduction state and the high-voltage oscillation circuit 5 is in an operable state. The light-emitting diode 18 also works to indicate that the high-voltage oscillation circuit 5 is in an operable state when the light-emitting diode 18 turns on. It cannot be known how much rotation of the rotary handle 15b is required for spark discharge to properly occur at the ignition electrode 4 until the combustion wick 3 is ignited. In the third embodiment, however, if the operator rotates the rotary handle 15b until the light-emitting diode 18 turns on, an output voltage from the generator 15 reaches a predetermined voltage to activate the high-voltage oscillation circuit 5, and spark discharge properly occurs at the ignition electrode 4 to ignite the combustion wick 3. Thus, an amount of rotation of the rotary handle 15b can readily be known by the turning on of the light-emitting diode 18 even though the occurrence of discharge cannot directly be confirmed, thereby improving the operability of the ignition device.
In the third embodiment of Fig. 8, the generator 15 and the dry-cell battery (or primary battery) 26 are provided. The voltage comparing circuit 24 and the dry-cell battery 26 are selectively connected to the high-voltage oscillation circuit 5 via a selection switch 25 forming a selection circuit. In the present embodiment, the selection switch 25 is normally set to select the circuit for the generator 15 to connect it to the high-voltage oscillation circuit 5 and to disconnect the cry-cell battery 26 from the high-voltage oscillation circuit 5. In this selection, the drive shaft 9 is rotated to move the combustion wick 3 upward and then the rotary handle 15b of the generator 15 is rotated. An electric power generated by the generator 15 is supplied to the high-voltage oscillation circuit 5 to activate the high-voltage oscillation circuit 5 and then spark discharge occurs at the ignition electrode 4. In contrast with the present embodiment, the selection switch 25 may be set to select the dry-cell battery 26 to connect it to the high-voltage oscillation circuit 5 and to disconnect the circuit for the generator 15 from the high-voltage oscillation circuit 5. In this selection, the drive shaft 9 is rotated to move the combustion wick 3 upward and then the selection switch 25 is operated to select the dry-cell battery 26 to connect it to the high-voltage oscillation circuit 5. An electric power is supplied from the dry-cell battery 26 to the high-voltage oscillation circuit 5 to activate the high-voltage oscillation circuit 5 and then spark discharge occurs at the ignition electrode 4 to ignite the combustion wick 3.
According to the third embodiment, how to operate the ignition device may arbitrarily be selected. The dry-cell battery 26 may always be installed for use. In this case, the selection switch 25 is operated to ignite the combustion wick 3. If the capacity of the dry-cell battery becomes insufficient for ignition, the rotary handle 15b may be rotated to ignite the combustion wick 3. Thus, even when the exhausted dry-cell battery 26 cannot promptly be replaced with a new one, it is not necessary to find some other ignition means such as a match and a lighter, and the oil burner can be used. In the third embodiment, ease of operation has furthermore been improved since the generator 15 and the dry-cell battery 26 can selectively be used according to circumstances.
In the second embodiment shown in Fig.7, at the time of ignition, the ignition switch 19' should continuously be pressed down or the rotation of the rotary handle 15b should be continued until it can be confirmed that the combustion wick 3 is ignited. However, the combustion wick 3 becomes deteriorated. If the deterioration of the combustion wick 3 proceeds, it may take longer time or may be impossible to ignite the combustion wick 3 even though the spark discharge properly occurs at the ignition electrode 4. Then, in the third embodiment, the timer means 27 is provided. The timer means 27 is operable to start counting when an output from the generator 15 reaches a predetermined voltage to activate the high-voltage oscillation circuit 5 and to stop counting when the output from the generator 15 falls below the predetermined voltage to deactivate the high-voltage oscillation circuit 5. A reference numeral 28 designates an alarm means such as a buzzer or a lump. A predetermined period of time defined for the timer means 27 to continue counting is the upper limit of a period of time allowed for ignition of the combustion wick 3 by the spark discharge. In other words, the upper limit is a reference time to determine whether or not the combustion wick becomes deteriorated when ignition fails even though the spark discharge is continued. The predetermined period of time is learned from experience, and is set to 10 seconds in the present embodiment. When the timer means 27 continues counting for the predetermined period of time, an operation signal is output to the alarm means 28 to activate the alarm means 28. As a result, an output from the alarm means 28 works to warn that ignition is impossible due to the deterioration of the combustion wick 3 or the like. This may urge checking the time for maintenance or replacement of the combustion wick 3, thereby timely performing replacement of the combustion wick 3 or combustion for cleaning in such a manner that the combustion is continued until an oil in the oil tank 7 is exhausted.
Fig. 9 illustrates an ignition device according to a fourth embodiment of the present invention. The fourth embodiment is different from the third embodiment of Fig. 8 in that the fourth embodiment is provided with an output connector 29 in place of the dry-cell battery 26. The output connector 29 includes external output terminals 29a and 29b operable to externally deliver an output from the generator 15 or the power conversion circuit 16. In other aspects, the fourth embodiment is the same as the third embodiment of Fig. 8, and the explanations thereof are omitted. The output connector 29 is configured to receive a power plug of external equipment. Reference numeral 30 designates a selection switch operable to switch the output from the generator 15 or the power conversion circuit 16 between the high-voltage oscillation circuit 5 and the output connector 29. The selection switch 30 is normally connected to the side of the high-voltage oscillation circuit 5. When the external equipment is connected to the output connector 29, the selection switch 30 is switched to the output connector 29 and the rotary handled 15b is operated for rotation. Then, an electric power generated by the power generating section 15a is output to the output connector 29 via the power conversion circuit 16 and accordingly the electric power is supplied from the generator 15 to the external equipment connected to the output connector 29. The oil burner of the fourth embodiment can be used as a power source in the event of disaster or the like where power sources cannot readily be secured. For example, a mobile phone or a re-chargeable battery can be used in the event of disaster or the like by connecting the mobile phone or rechargeable battery to the output connector 29.
While certain features of the invention have been described with reference to example embodiments, the description is not intended to be construed in a limiting sense. Various modifications of the example embodiments, as well as other embodiments of the invention, which are apparent to persons skilled in the art to which the invention pertains, are deemed to lie within the scope of the invention.

INDUSTRIAL APPLICABILITY

According to the present invention, a combustion wick of an oil burner can be ignited without using a dry-cell battery. There is no need of worrying about lowered ignition performance due to the consumption of the dry-cell battery. Further, stable ignition performance can be maintained even when the oil burner is used for an extended period of time. If the generator is of a rotary type, stable output power may always be obtained by manually rotating the generator, thereby causing spark discharge to stably occur between a pair of discharge electrodes.

SEQUENCE LISTING

1: Inner combustion wick cylinder
2: Outer combustion wick cylinder
3: Combustion wick
4: Ignition electrode
5: High-voltage oscillation circuit
15: Generator
18: Light-emitting diode (notifying means)
19: Ignition switch
21: Charging circuit
24: Voltage comparing circuit
25: Selection switch
26: Dry-cell battery
27: Timer means
28: Alarm means
29: Output connector

Claims

An ignition device for oil burner comprising:
a pair of discharge electrodes (4a,4b) operable to give ignition spark to a combustion wick (3);

a high-voltage oscillation circuit (5) operable to periodically apply a high voltage to the pair of discharge electrodes (4a,4b); and

a power source circuit (14) operable to supply an electric power for ignition to the high-voltage oscillation circuit (5), characterized in that:
the power source circuit (14) includes:
as a power source a generator (15) capable of
generating electricity by means of a manual operation;

a power conversion circuit (16) operable to convert an output from the generator (15) into the electric power for ignition; and

a power supply circuit (17) operable to supply the electric power for ignition to the high-voltage oscillation circuit (5);

the high-voltage oscillation circuit (5) includes:
a signal oscillating circuit (51) operable to generate an oscillation signal so as to periodically oscillate;

a switching circuit (52) operable to turn on or off in response to an input of the oscillation signal; and

a booster circuit (53) operable to boost an output voltage from the power supply circuit (17) according to a switching operation of the switching circuit (52);

the high-voltage oscillation circuit (5) is configured such that an oscillation period (TP1) and a non-oscillation period (TP2) alternately occur;

and includes an oscillation period setting circuit (54) operable to allow the oscillation signal to be input to the switching circuit (52) during the oscillation period (TP1) and disallow the oscillation signal to be input to the switching circuit (52) during the non-oscillation period (TP2).
The ignition device for oil burner according to claim 1 wherein the power supply circuit (17) further includes a voltage comparing circuit (24) operable to supply the electric power for ignition to the high-voltage oscillation circuit (5) when an output voltage from the power conversion circuit (16) exceeds a predetermined voltage.
The ignition device for oil burner according to claim 1 wherein the power supply circuit (5) further includes:
a voltage comparing circuit (24) operable to supply the electric power for ignition to the high-voltage oscillation circuit (5) when an output voltage from the power conversion circuit (16) exceeds a predetermined voltage; and

an established voltage notifying circuit operable to notify an operator of the generator that the output voltage from the power conversion circuit (16) exceeds the predetermined voltage when it is detected.
The ignition device for oil burner according to claim 1, wherein the power supply circuit (17) includes:
an electricity storing means (20);

a charging circuit (21) operable to charge the electricity storing means with an output from the power conversion circuit; and

a discharge circuit (22) operable to discharge electric charge from the electricity storing means (20) to the high-voltage oscillation circuit (5).
The ignition device for oil burner according to claim 4, wherein the power supply circuit (17) further includes a charging completion indicating circuit operable to indicate that charging is completed upon completion of charging.
The ignition device for oil burner according to claim 4 or 5, wherein the discharge circuit (22) includes an ignition switch (19) to turn on when the ignition switch is operated by the operator, and is configured to discharge electric charge from the electricity storing means (20) to the high-voltage oscillation circuit (5) when the ignition switch (19) turns on.
The ignition device for oil burner according to claim 4, wherein the power source circuit (14) further includes:
a primary battery (26); and

a selection circuit (25) operable to selectively connect the electricity storing means (20) or the primary battery (26) to the discharge circuit (22).
The ignition device for oil burner according to claim 1, wherein the power source circuit (14) further includes external output terminals (29a,29b) operable to externally deliver an output from the generator (15) or the power conversion circuit (16).
The ignition device for oil burner according to claim 1, further comprising:
a timer means (27) operable to count a time period time from the start of operation of the high-voltage oscillation circuit (5) till the stop of the operation thereof; and

an alarm generating circuit (28) operable to output an alarm of ignition error when the timer means (27) counts a predetermined time period.
The ignition device for oil burner according to claim 1, wherein:
the generator (15) is capable of generating electricity by means of a manual rotating operation.
The ignition device for oil burner according to claim 10, further comprising an output connector (29) used to externally output an electric power generated by the generator (15) so as to be capable of externally supplying or charging the electric power to external equipment.