JP2005322515A - Discharge lamp lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device, having an ignitor with a transformer which can withstand a comparatively high voltage generated in a secondary coil, and thereby can prevent surface discharge and corona discharge. <P>SOLUTION: This discharge lamp lighting device has an ignitor 17, which carries out lighting of a high pressure discharge lamp by generating a high-voltage pulse by a transformer TR. The transformer TR is provided with a rod-shape core 2 having tapering in the axial direction, a primary coil 3a and a secondary coil 3b constructed on this rod-shape core 2 so that the secondary coil 3b is wound on the side of the smaller diameter of the rod-shape core 2, and a resin 4 filled between the primary coil 3a and the secondary coil 3b and the rod-shape core 2 so that the smaller diameter side of the rod-shape core is thicker than that of the larger diameter side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a discharge lamp lighting device for lighting a discharge lamp such as a headlight of an automobile, and more particularly to a structure of a transformer included in an igniter of the discharge lamp lighting device.

For example, as disclosed in Patent Document 1, a conventional in-vehicle discharge lamp lighting device converts the voltage of a DC power source to a high voltage by a DC / DC converter, and then converts it to an AC by a DC / AC converter. Thereafter, a higher voltage pulse voltage is generated by an igniter having a transformer and supplied to a discharge lamp such as an HID (High Intensity Discharge) bulb for discharging.
JP2003-203517A (5th page, FIG. 8, FIG. 9)

  As described above, an alternating current such as a rectangular wave is supplied to the primary winding of the transformer constituting the igniter to generate a high voltage in the secondary winding, but the voltage generated in the secondary winding is too high. As a result, creeping discharge or corona discharge may occur in this winding, and therefore the power supplied to the discharge lamp is naturally limited. Therefore, there has been a problem that a high voltage cannot be applied to the discharge lamp, and the lighting of the discharge lamp cannot be started easily and quickly.

  The present invention has been made in view of the problems of the conventional discharge lamp lighting device in which a relatively high pressure cannot be applied to the discharge lamp in order to prevent the creeping discharge and corona discharge of the igniter transformer as described above. It is an object of the present invention to provide a discharge lamp lighting device including an igniter having a transformer that can withstand a relatively high voltage generated in a side winding and therefore can prevent creeping discharge and corona discharge.

  According to claim 1 of the present invention, there is provided a discharge lamp lighting device having an igniter for generating a high voltage pulse by a transformer to light a high pressure discharge lamp, the transformer comprising: a rod-shaped core; and the rod-shaped core. On top of that, the primary winding and the secondary winding wound in one layer, and the gap between the secondary winding and the rod-shaped core is thicker than between the primary winding and the rod-shaped core. And a resin encapsulated between the primary and secondary windings and the rod-shaped core. A discharge lamp lighting device is provided.

  According to the present invention, a large amount of resin is sealed in the secondary winding, which can withstand a relatively high voltage generated in the secondary winding, and thus can prevent creeping discharge and corona discharge. There is an effect that a discharge lamp lighting device including an igniter having the above can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration example of one embodiment of the present invention. 1A to 1E show a configuration example of a transformer in a discharge lamp lighting device according to an embodiment of the present invention.

  1A shows the electrical configuration of the transformer TR, FIG. 1B shows the appearance of the transformer TR, FIG. 1C shows the transformer TR viewed from the direction A, and FIG. Is a sectional view of the transformer TR, and FIG. 1E is an enlarged sectional view of a winding portion.

  The transformer TR includes a rod-shaped core 2 having a taper, which will be described later, a primary winding 3a and a secondary winding 3b wound around the rod-shaped core 2, and a winding ratio of n1 to n2, and a primary side thereof. The winding 3a and the secondary winding 3b and the resin 4 enclosed between the rod-shaped cores 2 are composed of the primary winding 3a and the secondary winding 3b as shown in FIG. The rod-shaped core 2 has a flat plate shape in the cross-sectional direction, and is wound on the resin 4 of the rod-shaped core 2 in one layer.

  Regarding the dimensions, for example, the length d1 of the rod-shaped core 2 is 30.0 mm, the total length d2 of the primary side coil and the secondary side coil is 28.0 mm, and the primary side winding 3a and the secondary side winding 3b are wound. The ratio n1: n2 is, for example, 3 turns vs. 200 turns.

  The rod-shaped core 2 has a so-called taper shape in which the primary side winding 3a is thicker and the secondary side winding 3b is thinner, and the dimension thereof is, for example, a diameter φ1 of 8 at the end of the primary side winding 3a. 0.0 mm and the diameter φ2 of the end of the secondary winding 3b is 7.9 mm.

  It has been confirmed that good results can be obtained if the difference in diameter between the primary winding end and the secondary winding end in the rod-shaped core 2 is about 0.1 mm to 0.5 mm.

  In order to manufacture the transformer TR having the above structure, first, the rod-shaped core 2 having a predetermined taper is manufactured. Next, a coil including a primary side winding 3a and a secondary side winding 3b and having a predetermined diameter is manufactured. Next, the rod-shaped core 2 is fixed through the secondary winding 3b of the coil. The resin 4 is filled and sealed between the coil and the rod-shaped core 2 from the secondary winding side of the coil.

  If manufactured in this way, it is easy to pass the rod-shaped core 2 through the coil, and the resin is filled between the coil and the rod-shaped core from the secondary winding side having a relatively large space so that the resin can be filled. There is an advantage that a transformer which is easy and has an effect of effectively preventing discharge can be manufactured relatively easily.

  The transformer TR having the above-described structure is used, for example, in the igniter shown in FIG. 3 in the discharge lamp lighting device having the circuit shown in FIG.

  In FIG. 2, reference numeral 11 denotes a DC voltage source. This voltage source 11 is supplied to a DC / DC converter 12 where the voltage of the DC voltage source 11 is raised to, for example, about 360V to 400V. The boosted voltage is supplied to the DC / AC inverter 13, and a rectangular wave is generated by performing a switching operation of several hundred Hz in a full bridge circuit using four switching elements, for example. A control circuit 14 obtains power from the output current and voltage generated by the DC / AC inverter 13 and controls the power generated by the DC / DC converter 12 to be constant at 35 W, for example. The DC / DC converter 12, the DC / AC inverter 13, and the control circuit 14 constitute an inverter 15.

  The inverter 15 outputs DC voltages of 400 V and 1 kV, for example. The inverter 15 transmits 400 V to the igniter 17 using the power supply lines 161 and 162 and 1 kV using the power supply line 163. The power supply lines 161 to 163 are all shielded together, or the power supply lines themselves are shielded.

  Reference numeral 18 denotes a socket that is formed integrally with the igniter 17 and is fitted with, for example, the HID valve 19 to supply a high-voltage pulse voltage generated by the igniter 17.

  Next, the igniter 17 having the transformer TR described with reference to FIG. 1 will be described with reference to FIG.

  That is, 211 to 213 are connection terminals electrically connected to the power supply lines 161 to 163 taken out from the inverter 15, the connection terminal 211 is the power supply line 161, the connection terminal 212 is the power supply line 162, and the connection terminal 213. Are respectively connected to the feeder line 163. The connection terminal 211 is connected to one end of the capacitor C1, and is also connected to one end of the secondary winding of the open magnetic circuit type transformer TR formed of an elongated core having an end face.

  The connection terminal 212 is connected to the other end of the capacitor C1, and to one end of the primary winding of the capacitor C2 and the transformer TR. The connection terminal 213 is connected to the other end of the capacitor C2 and is connected to the other end of the secondary winding of the transformer TR through the discharge gap 22. The other end of the secondary winding of the transformer TR is connected to one electrode of the HID valve 19 via the socket 18, and the connection terminal 212 is connected to the other electrode of the HID valve 19 via the socket 18.

  The socket 18 of the igniter 17 has a shape that can be directly fitted into the base of the HID valve 19, and the transformer TR is disposed at the end of the socket 18. The inverter 15 is housed in a metal case and is magnetically shielded. The igniter 17 is magnetically shielded, for example.

  Next, the circuit operation of FIG. 3 will be described with reference to FIG. That is, a pulse voltage of 400 V as shown in FIG. 4 is applied from the output of the inverter 15 to the connection terminals 211 and 212 of the igniter 17, and a voltage of 1 kV is applied to the connection terminal 213. As a result, when charging of the capacitor C2 is started and the discharge breakdown voltage of the discharge gap 22 is reached, a current flows in the primary side winding of the transformer TR, and a pulse voltage of, for example, 20 kV is generated in the secondary side winding.

  This is because a voltage is generated on the secondary side of the transformer TR according to the ratio of the number n1 of the primary side windings and the number n2 of the secondary side windings. By setting the relationship of n2, a high voltage of, for example, 20 kV is generated in the secondary winding. This voltage is supplied to the HID bulb 19 and discharge of the HID bulb 19 is started.

  When the discharge of the HID bulb 19 is started, the voltage supplied to the connection terminals 211 and 212 becomes stable at a voltage around 43 V as shown in FIG. 4, and thereafter the output of the igniter 17 is also a low voltage. Thus, the HID bulb 19 is driven with this voltage and the lighting is continued.

  The capacitor C1 is for absorbing the initial voltage supplied to the connection terminals 211 and 212 so that the components of the igniter 17 are not destroyed.

  In the above embodiment of the present invention, the rod-shaped core 2 has a taper, and a higher voltage is induced toward the end of the secondary winding, but a greater amount of resin is encapsulated toward the end, Therefore, creeping discharge and corona discharge are unlikely to occur. In addition, the diameter of the primary side winding 13a of the rod-shaped core 2 is large, that is, a thick core is used in this portion, so that the inductance can be increased and a high voltage pulse can be easily generated. There is also.

  Moreover, since the coils of the primary side winding and the secondary side winding have a flat plate shape with respect to the cross-sectional direction of the rod-shaped core, the number of turns can be increased with respect to the length of winding of the coil. There is also an advantage that it is easy to generate a voltage pulse.

  In the igniter transformer used in the present invention, the resin encapsulated between the coil wound outside the core and the rod-shaped core does not have a taper on the rod-shaped core as described above. Should be enclosed thicker than the primary winding. FIG. 5A shows a cross-sectional view of another embodiment of a transformer used in the present invention. In this example, coils 52a and 52b of a primary side winding and a secondary side winding having a taper at least on the inner diameter are wound around a rod-shaped core 51 having the same diameter and having no taper. A resin 53 is enclosed between them.

  According to this embodiment, there exists an advantage which can use the rod-shaped core of the same diameter which is easy to manufacture.

FIG. 5B shows a cross-sectional view of still another embodiment of the transformer used in the present invention. In this example, taper-like primary winding and secondary-side winding coils 56a and 56b are wound around a taper-like core 55, and resin 57 is sealed between these coils and the rod-like core. It is what. According to this embodiment, it is possible to easily talk between the core and the coil on the secondary winding side, and thus a suitable transformer is obtained when a very large voltage is induced in the secondary winding. There are advantages.

  In the above-described embodiment, an example using a rod-shaped core having a columnar cross section has been described. Moreover, although the case where the HID bulb is used has been described in the above embodiment, the present invention can also be applied to other discharge lamps.

The figure for demonstrating the structural example of the transformer which has in the igniter of the discharge lamp lighting device of one Embodiment of this invention. The figure which shows the circuit structural example of the discharge lamp lighting device provided with the igniter which has the transformer shown in FIG. The figure which shows the circuit structural example of the igniter which has the trans | transformer shown in FIG. The figure for demonstrating operation | movement of the igniter shown in FIG. The figure for showing the structure of the transformer which has in the igniter of the discharge lamp lighting device of other embodiments of the present invention.

Explanation of symbols

TR ... Trance,
2, 51, 55 ... Rod-shaped core,
3a, 52a, 56a ... primary windings,
3b, 52b, 56b ... secondary winding,
4, 53, 57 ... resin,
11 ... DC voltage source,
12 ... DC / DC converter,
13 ... DC / AC inverter,
14 ... control circuit,
15 ... inverter,
17 ... igniter,
18 ... Socket,
19 ... HID valve,
161, 162, 163... Feeder line,
211, 212, 213... Connection terminals,
C1, C2 ... capacitors.

Claims (2)

A discharge lamp lighting device having an igniter for generating a high-voltage pulse by a transformer and lighting a high-pressure discharge lamp,
The transformer is
A rod-shaped core;
On the rod-shaped core, a primary winding and a secondary winding wound in one layer,
Between the primary winding and the secondary winding and the rod core so that the space between the secondary winding and the rod core is thicker than between the primary winding and the rod core. Encapsulated resin,
A discharge lamp lighting device comprising: A discharge lamp lighting device having an igniter for generating a high-voltage pulse by a transformer and lighting a high-pressure discharge lamp,
The transformer is
A rod-shaped core having an axial taper;
The primary side winding and the secondary side winding having a single layer on the rod-shaped core and having a flat plate shape with respect to the cross-sectional direction of the rod-shaped core, A coil configured to be wound;
Resin encapsulated between this coil and the rod-shaped core;
A discharge lamp lighting device comprising:

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