JP4435598B2 - Discharge lamp lighting device - Google Patents

Description

  The present invention relates to a discharge lamp lighting device for reliably lighting a discharge lamp used for a headlight of an automobile.

A conventional in-vehicle discharge lamp lighting device discharges using an igniter that generates a high-voltage pulse voltage. The igniter's configuration circuit is completely magnetic except for the part that is connected to the outside so that radiated noise is not emitted to other in-vehicle electronic devices and other electronic devices and affects other electronic devices. Shielding is done. (For example, Patent Document 1)
JP 2003-203517 A (3rd page, FIGS. 1 and 2)

  In the technique of Patent Document 1 described above, in order to reduce the cost of the igniter, when an open magnetic circuit type core is used for the transformer, the magnetic flux is formed through the core material and the outer periphery. If there is a metal case that is a magnetic shielding material, the magnetic case absorbs the magnetic flux and the magnetic flux density is lowered, and there is a problem that the pulse voltage cannot be increased to a value that can light the discharge lamp.

  An object of the present invention is to provide a discharge lamp lighting device capable of reliably obtaining a pulse voltage for lighting a high pressure discharge lamp even when an igniter configured using a transformer having an open magnetic circuit type core is used. .

In order to solve the above-described problems, a discharge lamp lighting device according to the present invention is a discharge lamp lighting device for generating a high pulse voltage to turn on a high pressure discharge lamp, and is applied to the high pressure discharge lamp for discharge. An igniter that generates the high-pulse voltage, an insulating housing that houses the igniter so as to cover all directions of the igniter, and a main magnetic flux of a transformer that constitutes the igniter among the housings passes. to characterized by including a magnetic shielding material to shield the portions excluding portions.

  According to the present invention, a reliable high voltage pulse voltage for lighting a discharge lamp can be generated even with an igniter configured using an open magnetic circuit type core transformer.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a circuit configuration diagram of a discharge lamp lighting device used in the present invention. In FIG. 1, 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 voltage source 11 is boosted to about 360V to 400V, for example. 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, an HID (High Intensity Discharge) valve 19 to supply a high-voltage pulse voltage generated by the igniter 17.

  Next, the igniter 17 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 161 is the power supply line 211, the connection terminal 162 is the power supply line 212, and the connection terminal 163. Are respectively connected to the feeder line 213. The connection terminal 211 is connected to one end of the capacitor C1 and is 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 through the socket 18, and the connection terminal 212 is connected to the other electrode of the HID valve 19 through 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 by the present invention.

  Next, the operation of FIG. 2 will be described with reference to FIG.

  That is, a pulse voltage of 400 V as shown in FIG. 3 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 corresponding to the ratio of the number n1 of primary windings and the number n2 of secondary windings is generated on the secondary side of the transformer TR. 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 a stable voltage near 43 V as shown in FIG. 3, and thereafter the output of the igniter 17 also becomes a low voltage. The HID bulb 19 is driven with this voltage and 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.

  4A and 4B are explanatory views for explaining an embodiment of the present invention, in which FIG. 4A is a side view and FIG. 4B is a rear view.

  Reference numeral 41 denotes a housing in which the igniter 17 and the socket 18 are integrally formed. A portion indicated by a broken line indicates a portion where the transformer TR is disposed. Further, for example, a metallic magnetic shield material 42 (shaded portion) that shields magnetic flux is attached to the housing 41 excluding the portion where the transformer TR is disposed inside or outside the housing 41. The casing 41 is formed of a resin material in order to insulate the igniter 17. The magnetic shield material 42 may be any material having a magnetic shielding performance such as aluminum, iron, or copper.

  The magnetic shield material 42 is disposed only at a position excluding the transformer TR portion constituting the igniter 17, and at least absorption of the main magnetic flux can be suppressed by the magnetic shield material 42, so that a decrease in magnetic flux density can be suppressed. For this reason, the influence of the voltage resulting from the magnetic shield material 42 not being boosted to a desired value can be suppressed as much as possible. Thereby, a sufficiently high pulse voltage for lighting the HID bulb 19 can be obtained.

  FIG. 5 is an explanatory view for explaining another embodiment of the present invention, in which (a) is a side view and (b) is a rear view.

  In this embodiment, the magnetic shield material is also applied to the portion located on the side surface of the transformer winding which is not affected by the magnetic flux of the transformer. The same components as those in FIG. explain.

  That is, since the main magnetic flux of the transformer TR is generated in the direction shown by the one-dot chain line arrow in FIG. 5B, the position excluding the columnar bottom and top surfaces of the transformer TR that is not affected by the main magnetic flux as much as possible. The magnetic shield material 421 is also applied to the inside or the outside of the casing 42 that faces the surface.

  The present invention is not limited to the above-described embodiments. For example, the HID bulb may be a simple discharge lamp. In addition to the above-described materials, the magnetic shield material may be a method in which conductive plating is also applied to a portion having little influence on the main magnetic flux. In this case, the work process can be simplified as compared with the metallic material described above.

The system block diagram of the discharge lamp lighting device used for this invention. The block diagram for demonstrating the specific structure of the igniter of FIG. Explanatory drawing for demonstrating the operation | movement of FIG. Explanatory drawing for demonstrating one Example of this invention. Explanatory drawing for demonstrating the other Example of this invention.

Explanation of symbols

11 Power supply 15 Inverter 161-163 Feed line 17 Igniter 18 Socket 19 HID valve 211-213 Connection terminal TR Transformer 41 Cases 42, 421 Magnetic shield material

Claims (1)

In a discharge lamp lighting device for generating a high pulse voltage and lighting a high pressure discharge lamp,
An igniter that generates the high pulse voltage that is applied to the high-pressure discharge lamp to promote discharge;
An insulating housing that houses the igniter so as to cover all directions of the igniter;
The housing discharge lamp lighting apparatus characterized by including a magnetic shielding material to shield the main magnetic flux excluding a portion that passes part of the transformer constituting the igniter of.

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