JP2005127674A - Discharge ignition system for combustor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge ignition system for a combustor capable of thinning a high voltage generator in comparison with a conventional one, and capable of corresponding to height reduction of the combustor. <P>SOLUTION: An ignition transformer 13 of the high voltage generator 2 has a bobbin 19 wound with a secondary coil 18 around an outer circumference part. In the bobbin 19, an outer circumferential shape hugging a winding direction of the secondary coil 18 is not round, but it is shaped in a flat substantially elliptic shape having a minor axis direction and a major axis direction. The bobbin 19 is arranged in an external casing 11 such that the minor axis direction matches with a thickness direction of the external casing 11. A center hole 20 of the bobbin 19 is shaped in a substantially elliptic shape, and a magnetic core 22 wound with a primary coil 21 and having a substantially elliptic outer circumferential shape is inserted through the center hole 20. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a discharge ignition device for a combustion appliance used in various combustion appliances such as a gas combustion appliance and an oil combustion appliance.

  In various combustion appliances such as a gas stove and a water heater, a discharge ignition device for a combustion appliance has been conventionally used as an ignition source. As such a discharge igniter for a combustion appliance, a device in which a high voltage generator having an ignition transformer that boosts a power supply voltage to a predetermined high voltage and an ignition plug installed in the vicinity of a gas burner or the like are generally used. Has been used. In the discharge ignition device for a combustion appliance having such a configuration, a gas burner or the like is ignited by generating a spark from the discharge electrode of the spark plug by the secondary side voltage boosted by the ignition transformer.

  The ignition transformer of the high-voltage generator has a structure in which a magnetic core with a primary winding wound is inserted into the center hole of a bobbin that is formed in a hollow cylindrical shape and has a secondary winding wound on the outer peripheral side. The transformer which has is used. The bobbin of the ignition transformer has a good balance of characteristics among engineering plastics, and is generally formed of a polyacetal resin that is particularly excellent in mechanical strength and rigidity. Such an ignition transformer is housed in an external housing together with a circuit unit and the like. Further, a resin sealing material is enclosed in the external housing, and these constitute a high voltage generator.

  Conventionally, the high voltage generator and the spark plug are electrically connected by using a high withstand voltage lead wire such as a high voltage cable with insulation coating. However, when such a high voltage cable is used, there is a problem in that a voltage drop is caused by a capacitance component generated between the high voltage cable and the device mounting surface (ground surface), thereby causing an ignition error. In addition, there is a problem in that noise occurs in the electronic circuit for controlling the combustion appliance, and the control by the electronic circuit is defective.

For this reason, the high voltage generator and the spark plug are directly connected without using a high voltage cable (see Patent Documents 1 and 2).
Japanese Patent Laid-Open No. 11-248155 (pages 3-4, FIGS. 1 and 4) JP 11-294766 A (page 3-4, FIG. 1)

  When the high voltage generator and the spark plug are directly connected as described above, the installation location of the high voltage generator in the combustion appliance is limited to the vicinity of the spark plug. For this reason, for example, in a water heater or the like, a high voltage generator is often arranged in a space between the burner portion and the front panel covering the burner portion.

  On the other hand, in recent years, in hot water heaters and the like, so-called low profile is being reduced to reduce the thickness of the entire hot water heater due to restrictions on the installation location. That is, by reducing the height in this way, the dimension protruding from the outer wall surface is made as small as possible when the water heater is fixed to the outer wall surface of the house. For this reason, the space between the burner part of the water heater and the front panel covering the burner part is being set to be very narrow.

  And as mentioned above, when the space between the burner part of a water heater and a front panel becomes narrow, in the conventional discharge ignition device for combustion appliances, the problem that a high voltage generator cannot be installed in this narrow space Occurs.

  The present invention has been made to address such problems. An object of the present invention is to provide a discharge ignition device for a combustion appliance that can make the high-voltage generator thinner than the conventional one and can cope with a reduction in the height of the combustion appliance.

(Claim 1)
A discharge ignition device for a combustion appliance according to the present invention includes a bobbin having a secondary winding wound on the outer periphery and a magnetic core inserted in the center hole of the bobbin and wound with a primary winding to boost the power supply voltage. A high-voltage generator including an ignition transformer and an external housing that houses the ignition transformer; and an ignition plug that is electrically connected to the high-voltage generator and generates a spark discharge. The outer peripheral shape along the winding direction of the secondary winding is a flat shape having a major axis direction and a minor axis direction shorter than the major axis direction, and the minor axis direction of the bobbin is The ignition transformer is arranged in the outer casing so as to face in the thickness direction.

  In the discharge ignition device for a combustion appliance according to the present invention, the outer peripheral shape of the bobbin of the ignition transformer along the winding direction of the secondary winding is not circular (the overall shape is substantially cylindrical), but the major axis direction and the major axis It is formed in a flat shape having a minor axis direction shorter than the direction. This makes it possible to reduce the thickness of the bobbin (ignition transformer) in the minor axis direction as compared with the case where it is circular. Then, by arranging the ignition transformer so that the direction of the minor axis direction of the bobbin coincides with the thickness direction of the outer casing, the thickness of the outer casing (thickness of the high voltage generator) is reduced. Can be made thin and low profile.

(Claim 2)
In one aspect of the discharge igniter for a combustion appliance of the present invention, the outer peripheral shape along the winding direction of the secondary winding of the bobbin is substantially oval. As a result, the secondary winding can be wound around the bobbin easily and mechanically.

(Claim 3)
In one aspect of the discharge igniter for a combustion appliance of the present invention, the outer peripheral shape along the winding direction of the secondary winding of the bobbin is substantially rectangular. This makes it possible to simplify the manufacturing process of the ignition transformer, particularly the manufacturing process of the magnetic core. This is because the magnetic core is manufactured as a large-sized substrate and then cut into a rectangular shape having a predetermined size.

(Claim 4)
In one aspect of the discharge igniter for a combustion appliance of the present invention, the ratio (a: b) of the minor axis direction length (a) of the bobbin to the major axis direction length (b) is 1: 1. The range is 2-1 to 4.0. As a result, the secondary winding can be easily wound around the bobbin and the height can be reduced efficiently while the balance between the thickness and the overall size is improved.

(Claim 5)
In one aspect of the discharge igniter for a combustion appliance of the present invention, the shape of the magnetic core is a flat shape corresponding to the shape of the bobbin. As a result, the height can be reduced efficiently. As an example of the flat shape here, the above-described substantially oval shape or substantially rectangular shape can be mentioned.

  According to the discharge ignition device for a combustion appliance of the present invention, the high voltage generator can be made thinner than conventional ones, and the combustion appliance can be reduced in height.

  Hereinafter, modes for carrying out the present invention will be described.

  1 and 2 show a configuration of a discharge igniter for a combustion appliance according to an embodiment of the present invention. A combustion appliance discharge ignition device 1 shown in these drawings includes a high voltage generator 2 and a spark plug 3. Such a discharge igniter 1 for a combustion appliance is used for various combustion appliances such as a gas combustion appliance such as a gas stove or a gas water heater, or an oil combustion appliance such as an oil fan heater or an oil water heater. .

  The high voltage generator 2 has an external housing 11 made of an insulating material such as resin. As shown in FIG. 2, the external housing 11 includes a mounting portion 12 for installing the high voltage generator 2 and thus the discharge ignition device 1 on the combustion appliance body.

  In the external housing 11, an ignition transformer 13 and a circuit unit 16 in which an electronic component 14 such as a diode or a resistor is mounted on a printed board 15 are housed. The circuit unit 16 is electrically connected to a power supply terminal 17 provided on the lower surface side of the external housing 11. Although not shown, a resin sealant such as urethane resin is sealed in the external housing 11.

  The ignition transformer (step-up transformer) 13 has a bobbin 19 around which a secondary winding 18 is wound on the outer periphery. The bobbin 19 is made of an insulating resin material such as polyacetal resin.

  The bobbin 19 is formed in a flat shape in which the outer peripheral shape along the winding direction of the secondary winding 18 is not circular but has a minor axis direction and a major axis direction as shown in FIGS. Yes. In the present embodiment, the bobbin 19 has a substantially elliptical shape (substantially elliptical shape) in which the ratio (a: b) of the minor axis length a to the major axis length b shown in FIG. 3 is about 1: 2. It is formed as follows. As shown in FIG. 1, the ignition transformer 13 is arranged in the outer casing 11 so that the minor axis direction (direction a) of the bobbin 19 coincides with the thickness direction of the outer casing 11. Yes.

  In other words, there is a limit to reducing the size of the ignition transformer 13 because of the relationship with the required electrical characteristics. For this reason, there has been a thickness of the ignition transformer 13 as one factor in which the thickness of the external casing 11 cannot be reduced conventionally.

  Therefore, in this embodiment, the bobbin 19 is formed in a flat shape instead of a circle, so that the thickness of the bobbin 19 (ignition transformer 13) in the minor axis direction is reduced compared to the case where the bobbin 19 is formed in a circle. Then, by arranging the direction of the minor axis direction of the bobbin 19 so as to coincide with the thickness direction of the outer casing 11, the thickness of the outer casing 11 (thickness of the high voltage generator 2) is reduced. I made it thin.

  Further, the center hole 20 of the bobbin 19 is formed in a substantially oval shape corresponding to the outer peripheral shape described above. A magnetic core 22 such as an iron core around which the primary winding 21 is wound is inserted into the center hole 20. The outer peripheral shape of the magnetic core 22 is also substantially elliptical to match the shape of the center hole 20. The bobbin 19 is provided with hook-shaped protrusions 90 at regular intervals.

  The thickness of the external casing 11 as described above is a conventional one using a circular bobbin, for example, about 20 mm. And in this embodiment, the thickness of the external housing | casing 11 can be about 18 mm-15 mm, for example.

  The shape of the bobbin 19 (and the magnetic core 22) may be a flat shape and is not limited to a substantially oval shape. For example, like the bobbin 119 shown in FIG. 4, the outer peripheral shape may be a polygonal shape such as a rectangle. In the case of the substantially rectangular bobbin 119 shown in FIG. 4, the major axis direction described above substantially coincides with the long side direction, and the minor axis direction described above coincides with the short side direction. In the bobbin 119 shown in FIG. 4, the center hole 120 is also rectangular according to the outer peripheral shape, and the magnetic core 122 is also rectangular according to this. When the magnetic core 122 having such a shape is used, the processing becomes easier than a circular core, and the manufacturing cost can be reduced. This is because, after the magnetic core is manufactured as a large substrate, it may be cut into a rectangular shape having a predetermined size. In FIG. 4, reference numeral 190 denotes hook-shaped protrusions provided on the bobbin 119 at regular intervals.

  Further, the ratio (a: b) between the minor axis direction length a and the major axis direction length b of the bobbin 19 is not limited to about 1: 2. The shorter the length a in the minor axis direction and the longer the length b in the major axis direction, and the greater the ratio, the lower the thickness and the lower the height. However, when the major axis length b increases, the area required for installation increases. For this reason, the ratio (a: b) of the minor axis direction length a to the major axis direction length b is preferably about 1: 1.2 to 1: 4.0, more preferably 1: 1. About 5 to 1: 3.0.

  In addition, the shape of the bobbin 19 and the ratio (a: b) between the minor axis direction length a and the major axis direction length b provide the electrical characteristics required for the ignition transformer 13, and the secondary It is necessary that the winding 18 can be wound mechanically without difficulty.

  In the ignition transformer 13, the power supply voltage is boosted to a predetermined high voltage based on the number of turns of the primary winding 21 and the secondary winding 18. Both ends of the primary winding 21 are connected to the power connection pins 23, 23. One end of the secondary winding 18 is connected to the output connection pin 24, and the other end is connected to the ground connection pin 25. ing. The ground connection pin 25 is grounded to the combustion appliance body. For each of these connection pins 23, 24, 25, for example, a mild steel wire with solder plating is used.

  The primary winding 21 of the ignition transformer 13 as described above is generally wound around the magnetic core 22 so that the number of turns is about 20 to 60 turns. For this reason, a resin-coated copper wire such as a urethane-coated copper wire having a wire diameter of about 0.3 mm is used for the primary winding 21. Both ends of the primary winding 21 are wound around the base portions of the power connection pins 23 and 23, respectively. The winding portions of the primary windings 21 are solder-dipped, whereby the primary winding 21 and the power connection pins 23 are electrically connected. The primary winding 21 is connected to the power supply terminal 17 via the power connection pin 23 and the circuit unit 16.

  On the other hand, the secondary winding 18 needs to be wound around the bobbin 19 so that the number of turns is about 2000 to 6000 turns. Therefore, a resin-coated copper wire such as a urethane-coated copper wire having a wire diameter of about 0.05 mm is used for the secondary winding 18. Such a secondary winding 18 is electrically connected by winding both ends of the secondary winding 18 around the output connection pin 24 and the ground connection pin 25, respectively, and further soldering the winding portion.

  On one side surface of the external housing 11 in which the ignition transformer 13 as described above is housed, a cylindrical convex portion 26 that is a mounting portion of the spark plug 3 is provided. The cylindrical convex portion 26 communicates with the inside of the outer casing 11. An output terminal 27 is disposed in the cylindrical convex portion 26. The output terminal 27 is electrically connected to the output connection pin 24 of the ignition transformer 13. The front end portion of the output terminal 27 is exposed from the external housing 11, and the front end exposed portion is a female connector.

  On the other hand, the spark plug 3 has a discharge electrode 30 made of a heat-resistant metal rod. One end of the discharge electrode 30 is installed in the vicinity of the burner of the combustion appliance, and is a spark discharge end 31 that generates a spark discharge. The other end of the discharge electrode 30 is a connection end 32 that is electrically connected to the high voltage generator 2. The outer periphery of the discharge electrode 30 is covered and protected by an insulator 33 so that the spark discharge end 31 and the connection end 32 are exposed. For the insulator 33, a heat-resistant and insulating ceramic material such as alumina is used. Further, a concave portion 34 constituting an attachment portion to the high voltage generator 2 is provided at an end portion of the insulator 33 on the connection end 32 side. The connection end 32 of the discharge electrode 30 is exposed in the recess 34.

  The connection end 32 of the discharge electrode 30 is used as a connection plug for directly connecting to the output terminal 27 of the high voltage generator 2, and the tip thereof is tapered. While the connection end 32 of the discharge electrode 30 is inserted and connected to the female connector of the output terminal 27, the recess 34 provided at the end of the insulator 33 is fitted into the cylindrical projection 26 of the high voltage generator 2. . With such a structure, the high voltage generator 2 and the spark plug 3 are mechanically coupled and electrically connected.

  As a result, it is possible to prevent the generation of a capacitance component due to a high voltage cable or the like for electrically connecting the high voltage generator 2 and the spark plug 3. Furthermore, the discharge electrode 30 and the output terminal 27 can be detachably connected, and their electrical connection reliability can be improved.

  In this embodiment, the case of the connection structure in which the connection end 32 of the discharge electrode 30 is inserted into the female connector provided on the output terminal 27 and the discharge electrode 30 and the output terminal 27 are directly connected has been described. However, the present invention is not limited to such a direct connection structure, and the discharge electrode 30 and the output terminal 27 can be directly connected using, for example, a compression-type or crimp-type connection terminal. Furthermore, the connection between the discharge electrode 30 and the output terminal 27 is not limited to the direct connection type, and the discharge electrode 30 and the output terminal 27 may be electrically connected by interposing a high voltage cable or the like.

  In such a combustion appliance discharge ignition device 1, the voltage input from the power supply terminal 17 is boosted to a predetermined voltage by the ignition transformer 13 of the high voltage generator 2, thereby generating a high voltage at the output terminal 27. . This high voltage is applied from the output terminal 27 to the discharge electrode 30 of the spark plug 3, and a spark is generated from the spark discharge end 31 of the discharge electrode 30. The discharge ignition device 1 ignites a gas burner, an oil burner, or the like by a spark generated at the spark discharge end 31 of the discharge electrode 30.

  As described above, according to the present embodiment, the thickness of the high voltage generator 2 can be reduced as compared with the conventional case. Therefore, the high voltage generator 2 can be installed in a narrow space between the burner portion of the water heater and the front panel. Thereby, it is possible to cope with a reduction in the height of a combustor such as a water heater.

It is sectional drawing which shows the structure of the discharge ignition device for combustion appliances of embodiment of this invention. It is a side view of the discharge ignition device for combustion appliances shown in FIG. It is a perspective view of the bobbin shown in FIG. It is a perspective view which shows other embodiment of a bobbin.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Discharge ignition device for combustion appliances, 2 ... High voltage generator, 3 ... Spark plug, 11 ... External housing, 13 ... Ignition transformer, 18 ... Secondary winding, 19 ... Bobbin, 20 ... Center hole, 21 ... Primary winding, 22 ... Magnetic core.

Claims (5)

An ignition transformer having a bobbin having a secondary winding wound around the outer periphery and a magnetic core inserted in the center hole of the bobbin and having a primary winding wound therein, and boosts the power supply voltage, and houses the ignition transformer A high voltage generator comprising an external housing;
A discharge ignition device for a combustion appliance, comprising a spark plug that is electrically connected to the high-voltage generator and generates a spark discharge,
The outer peripheral shape along the winding direction of the secondary winding of the bobbin is a flat shape having a major axis direction and a minor axis direction shorter than the major axis direction,
In addition, the ignition ignition device for a combustion appliance is characterized in that the ignition transformer is arranged in the outer casing so that the minor axis direction of the bobbin is directed in the thickness direction of the outer casing. The outer peripheral shape along the winding direction of the secondary winding of the bobbin is a substantially oval shape having a major axis direction and a minor axis direction shorter than the major axis direction,
2. The discharge for a combustion appliance according to claim 1, wherein the ignition transformer is disposed in the outer casing so that the minor axis direction of the bobbin is oriented in the thickness direction of the outer casing. Ignition device. The outer peripheral shape along the winding direction of the secondary winding of the bobbin is a substantially rectangular shape having a long side direction and a short side direction shorter than the long side direction,
2. The discharge for a combustion appliance according to claim 1, wherein the ignition transformer is disposed in the outer casing such that the short side direction of the bobbin is directed in the thickness direction of the outer casing. Ignition device.   The ratio (a: b) of the length (a) of the bobbin in the minor axis direction to the length (b) in the major axis direction is in a range of 1: 1.2 to 1: 4.0. The discharge ignition device for a combustion appliance according to any one of claims 1 to 3.   The discharge ignition device for a combustion appliance according to any one of claims 1 to 4, wherein a shape of the magnetic core is a flat shape corresponding to a shape of the bobbin.

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