CN1696567A - Discharge lamp lighting device - Google Patents

Abstract

An embodiment of a discharge lamp lighting apparatus of the present invention includes a socket inserted with a discharge bulb, a transformer having a coil including a secondary side winding connected at one end to the socket, connected at the other end to a first drive wire, and a primary side winding connected at one end to a second drive wire, connected at the other end to a third drive wire through a discharge gap, a core inserted into the coil, and a resin filled between the core and the primary side winding, the secondary side winding, and a capacitor connected between the second drive wire and the third drive wire, wherein the transformer and the socket are aligned side by side.

Description

Discharge lamp lighting device

Cross-references for applications

This application is based on the benefit of priority of Japanese Patent Application No. 2004-139895 filed on May 10, 2004 and Japanese Patent Application No. 2005-115977 filed on April 13, 2005. The contents of the Japanese application are cited here and incorporated into this specification.

field of invention

The present invention relates to a lighting device for a discharge lamp whose depth and thickness are desired to be small, such as automobile headlights.

Background technique

In recent years, high luminance discharge lamps have been used in automobile headlights and the like. When high-intensity discharge lamps are used in automobile headlights, it is desirable that the thickness from the lamp holder of the discharge lamp in the depth direction be small in order to ensure space in the engine room.

However, in a high-intensity discharge lamp, the lamp holder of the discharge lamp is generally connected to an igniter, and the igniter requires a transformer that takes up a relatively large volume. Therefore, there is a problem that the lighting device including the socket and the igniter becomes thick.

Therefore, as shown in Japanese Patent Laid-Open No. 2004-206974, it is considered that the wiring for driving lines is led out toward the fitting surface of the socket, and the lighting device is made thin.

However, in doing so, the bulb of the discharge lamp exists in the direction in which the driving wires are drawn out, so that the drawn out driving wires need to be greatly bent, and there are problems in terms of operability and durability. Moreover, when the igniter uses a commonly used transformer, the voltage generated by the secondary coil may generate creeping discharge or corona discharge in the coil, which naturally limits the power supplied to the bulb of the discharge lamp. Therefore, a high voltage cannot be applied to the discharge lamp, and there is a problem that the discharge lamp cannot be easily and quickly turned on.

Contents of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide a discharge lamp lighting device suitable as an automobile headlamp. According to an embodiment of a discharge lamp lighting device of the present invention, a discharge lamp lighting device is provided, including a lamp socket into which a discharge lamp bulb is inserted, one end with a secondary coil connected to the lamp socket, the other end connected to the first driving line and the secondary One end of the primary coil is connected to the second drive line and the other end is connected to the coil composed of the primary coil of the third drive line through the discharge gap, and the magnetic core inserted into the coil and filled between the magnetic core and the primary coil and the secondary coil A resin transformer, and a capacitor connected between the second driving line and the third driving line; the transformers are arranged side by side next to the lamp socket.

Description of drawings

FIG. 1 is a diagram showing an example of a circuit configuration of a discharge lamp lighting device according to an embodiment of the present invention.

Fig. 2 is a diagram for explaining the structure of the igniter for the circuit configuration shown in Fig. 1 .

Fig. 3 is a perspective view showing the appearance of a lighting device according to an embodiment of the present invention.

Fig. 4 is a perspective view showing an internal structure of a lighting device according to an embodiment of the present invention.

Fig. 5 is a plan view showing the structure of a lighting device according to an embodiment of the present invention.

Fig. 6 is a diagram showing an A-A cross section of a transformer TR in the lighting device of Fig. 5 .

7 is a cross-sectional view showing the structure of a resin bobbin according to an embodiment of the present invention.

8 is a partially cutaway perspective view showing the structure of a resin bobbin according to an embodiment of the present invention.

9 is a partially cutaway perspective view showing the structure of a resin bobbin according to an embodiment of the present invention, viewed from another direction.

Fig. 10 is still another partially cutaway perspective view showing the structure of the resin bobbin according to the embodiment of the present invention viewed from another direction.

FIG. 11A is an electrical composition diagram showing a transformer TR of another embodiment of the present invention.

FIG. 11B is an external view of the transformer TR.

FIG. 11C is a view of the transformer TR seen from the direction A of FIG. 11B .

FIG. 11D is a sectional view of the transformer TR.

FIG. 11E is an enlarged sectional view of a coil portion of the transformer TR shown in FIG. 11D .

Fig. 12 is a diagram for explaining the operation of the igniter shown in Fig. 3 .

Fig. 13A is a cross-sectional view showing the structure of a transformer according to yet another embodiment of the present invention.

Fig. 13B is a cross-sectional view showing the structure of a transformer according to still another embodiment of the present invention.

Detailed ways

Embodiments of the present invention will be described with reference to the drawings. A feature of the invention, as described hereinafter, is the relationship of the socket into which the bulb of the discharge lamp is inserted and the transformer connected to the igniter of the socket. In order to facilitate the understanding of the present invention, before describing the features of the embodiments of the present invention in detail, the circuit of the discharge lamp lighting device will be described.

In FIG. 1 , 11 is a direct current voltage source, and the voltage of this voltage source 11 is supplied to a DC/DC (direct current/direct current) converter 12 . In the DC/DC converter 12, the voltage of the DC voltage source 11 is boosted to, for example, 360V to 400V. The boosted voltage is supplied to a DC/AC (direct current/alternating current) converter 13, and a switching operation of several hundred Hz is performed in a flip-flop circuit using, for example, four switching elements to generate a rectangular wave.

14 is a control circuit that obtains power from the output current I and voltage V generated by the DC/AC converter 13, and controls the power generated by the DC/DC converter 12 to be fixed at, for example, 35W. The DC/DC converter 12 , the DC/AC converter 13 , and the control circuit 14 constitute an inverter 15 .

The inverter 15 outputs DC voltages of, for example, 400V and 1kV. In the inverter 15, the DC/AC converter 13 supplies 400V of power to the igniter 17 through the driving lines 161 and 162. Further, the DC/DC converter 12 supplies power of 1 kV to the igniter 17 through the drive line 163 . The drive lines 161 to 163 are all shielded together, or the drive lines themselves are shielded.

Reference numeral 18 denotes a socket which is integrally formed with the igniter 17 and is fitted with, for example, an HID bulb 19 which is a discharge lamp bulb, and supplies high-voltage pulse voltage generated by the igniter 17 . FIG. 2 shows an example of a circuit diagram of the igniter 17 shown in FIG. 1 .

That is, 211 to 213 are connection terminals electrically connected to the drive lines 161 to 163 extracted from the inverter 15 , the connection terminal 211 is connected to the drive line 161 , the connection terminal 212 is connected to the drive line 162 , and the connection terminal 213 is connected to the drive line 163 . The connection terminal 211 is connected to one end of the capacitor C1 and also connected to one end of the secondary coil of the magnetic circuit open type transformer TR constituted by an elongated magnetic core having an end face.

The connection terminals 212 connect the other end of the capacitor C1, one end of the capacitor C2, and one end of the secondary coil of the transformer TR, respectively. The connection terminal 213 is connected to the other end of the capacitor C2 and also connected to the other end of the secondary coil of the transformer TR through the discharge gap 22 . The other end of the secondary coil of the transformer TR is connected to one electrode of the HID bulb 19 through the lamp holder 18 , and the connection terminal 211 is connected to the other electrode of the HID bulb 19 through the lamp holder 18 .

The socket 18 of the igniter 17 is formed in a shape capable of being directly fitted to the cap of the HID bulb 19 , and a transformer TR is disposed at an end of the socket 18 . The inverter 15 is housed in a metal box and magnetically shielded. The igniter 17 is magnetically shielded, for example.

FIG. 3 shows a perspective view of a composition example based on an embodiment of the present invention of the lamp holder 18 and the igniter 17 with a cover in FIG. 2 . In FIG. 3 , the drive lines 161 , 162 , and 163 are shown removed.

FIG. 4 shows the structure of the igniter 17 in FIG. 3 without the cover. Drive lines 161, 162, 163 are shown in FIG. 4 . FIG. 5 shows a plan view of the structure of the igniter 17 and the lamp holder 18 shown in FIG. 4 viewed from above, and FIG. 6 shows an A-A sectional view of the transformer TR shown in FIG. 5 .

As shown in FIG. 6 , the transformer TR has a structure in which a high voltage is generated at the upper end of the secondary coil n2 connected to the terminal on the lamp socket 18 side. The upper end has a structure in which the secondary coil n2 protrudes from the rod core 62 . Resin 63 is filled in recesses between the rod-shaped magnetic core 62 and the secondary coil n2 and above the secondary coil n2 and the rod-shaped magnetic core 62 . As a material of the resin 63, for example, gel, epoxy resin, silicon, polyurethane, or the like is used.

Actually, the primary coil and the secondary coil of the transformer TR are not laminated directly, but are laminated through a resin bobbin having a predetermined shape. FIG. 7 shows a cross-sectional view of such a resin bobbin 71 , and FIG. 8 shows a partially cutaway perspective view thereof. 9 and 10 also show the structure of such a resin bobbin. In FIGS. 7 and 8 , a central cavity 73 into which the rod-shaped magnetic core 62 and the secondary coil are inserted is provided at the center of a resin bobbin 72 . The central cavity 73 is axially provided with a plurality of ribs 74 protruding inwardly.

Reference numeral 75 is a bottomed coil cavity for inserting the primary coil n1 of the transformer TR, and reference numeral 76 is a groove for increasing the distance between circular surfaces.

Since the rib 74 is provided, a gap can be secured between the secondary coil and the inner side of the resin bobbin 72 even after the rod-shaped magnetic core 62 and the secondary coil n2 are inserted. Therefore, it is convenient to fill the gap with resin from the outside.

As a hard material of the above-mentioned primary coil n1, for example, a stainless steel material is used. When a hard material is used as the primary coil n1, the primary coil can be easily inserted into the coil cavity 75 .

The igniter 17 shown in FIG. 2 is constituted by the TR having the above structure, and the discharge lamp lighting device shown in FIG. 1 is constituted by this igniter 17 .

The operation of this lighting device will be described below. From the output of the inverter 15, a voltage of 400 V is applied to the connection terminals 211 and 212 of the igniter 17, and a voltage of 1 kV is also applied to the connection terminal 213. As a result, the charging of the capacitor C2 is started, and when the breakdown voltage of the discharge gap 22 is reached, a current flows through the primary coil of the transformer TR, so that the secondary coil generates a voltage of, for example, 20 kV.

This is because the secondary side of the transformer TR generates a voltage corresponding to the ratio of the number of coils n1 of the primary coil to the number of coils n2 of the secondary coil, and generates a high voltage ( eg 20kV). Applying this voltage to the HID bulb 19 causes the bulb 19 to start discharging.

When the HID bulb 19 starts to discharge, the voltage supplied to the connecting terminals 211 and 212 becomes stable at around 43V. After that, the HID bulb 19 is driven by the igniter 17 to continue lighting the bulb.

The capacitor C1 is used to prevent the high voltage generated on the secondary side of the transformer TR from flowing back to the inverter side through the connection terminal 212 . This capacitor C1 is provided on the side of the igniter 17 , but may also be provided in the inverter 15 .

As described above, the primary coil n1 of the transformer TR flows current only when starting the lighting of the discharge lamp, and the resistance is not required to be as low as that of the secondary coil. Therefore, from this point, a material having elasticity such as a spring material can also be used.

The resin bobbin 72 whose cross section is shown in FIG. 7 is used. The resin bobbin 72 has a structure in which a primary coil is provided on the outer peripheral portion of the secondary coil, and an opening for inserting the primary coil is provided on a side of the secondary coil where a high voltage is not generated.

As shown in FIG. 6, the transformer TR is thinned at the high-voltage-generating end of the secondary coil n2 of the rod-shaped magnetic core 62 and filled with thick resin to prevent corona discharge and creeping discharge. On the other hand, on the side below the secondary coil n2 shown in FIG. 6 , that is, on the side where no high voltage is generated, even if the diameter of the rod-shaped core is made larger, no discharge occurs and the maximum output can be ensured. This end is usually at ground potential, and corona discharge does not occur, so even if the secondary coil is exposed at this part, it will not become the starting point of creeping discharge.

As shown in Figure 6, the length of the rod-shaped magnetic core is shorter than the length of the secondary coil n2, and the cross-section becomes concave at the end where the high voltage is generated, so that the inner side of the coil can be fully filled with resin 63, thereby preventing creeping discharge and Corona discharge.

In the above-described embodiment, as shown in FIG. 6 , the secondary coil n2 has a constant diameter, and taper is provided on the rod-shaped magnetic core 62 . However, it is also possible to constitute the transformer TR by using an equal-diameter rod-shaped magnetic core, and using a secondary coil n2 of a structure having a larger diameter toward the side where the high voltage is generated. In short, as long as the gap between the secondary coil and the rod-shaped core can be filled with resin as the high voltage is generated, it is suitable as the transformer TR used in the present invention.

The transformer for the igniter of the lighting device of the above-described embodiment has a structure in which the primary coil is wound around the secondary coil. However, a configuration in which the primary coil and the secondary coil are arranged side by side may also be employed.

Another embodiment of the present invention employing a transformer of such a structure will be described below. 11A to 11E show a configuration example of a transformer of a discharge lamp lighting device according to an embodiment of the present invention.

Figure 11A shows the electrical composition of the transformer TR, Figure 11B shows the appearance of the transformer TR, Figure 11C shows a view of the transformer TR shown in Figure 11B from the direction A, Figure 11D shows a cross-sectional view of the transformer TR, Figure 11E An enlarged sectional view of a coil portion of the transformer TR shown in FIG. 11D is shown.

The components of this transformer TR include a rod-shaped core 112 having a taper as described later, a primary coil 113a and a secondary coil 113b wound on the rod-shaped core 112 with a coil ratio of n1:n2, and enclosed in these primary coils 113a and 113b. The resin 114 between the secondary coil 113b and the rod-shaped magnetic core 112, and the primary coil 113a and the secondary coil 113b have a flat plate shape to the cross-sectional direction of the rod-shaped magnetic core 112 as shown in FIG. .

Regarding the size, for example, the length d1 of the rod-shaped magnetic core 112 is 30.0mm, and the total length d2 of the primary coil and the secondary coil is 28.0mm; the coil ratio of the primary coil 113a and the secondary coil 113b is n1:n2, for example, 3 turns to 200 turns .

The bar core 112 is thicker at the side of the primary coil 113a and thinner at the side of the secondary coil 113b.

When manufacturing the transformer TR having the above-mentioned structure, first, a rod-shaped magnetic core with a predetermined taper is manufactured. Next, a coil composed of the primary coil 113a and the secondary coil 113b and having a predetermined diameter is manufactured. Next, from the side of the secondary coil 113b of this coil, it is fixed by the above-mentioned rod-shaped magnetic core 112 . Then, the resin 114 is filled and sealed between the coil and the rod-shaped core 112 from the secondary coil side of the coil.

In this manner, it is convenient to pass the rod-shaped magnetic core 112 through the above-mentioned coil. Furthermore, since the resin is filled between the coil and the rod-shaped magnetic core from the side of the secondary coil which has a relatively large margin in space, it is easy to fill the resin. There is also an advantage that a transformer capable of effectively preventing discharge can be manufactured relatively simply.

The transformer TR having the structure shown in FIG. 11A can be used for the igniter shown in FIG. 2 in the discharge lamp lighting device of the circuit shown in FIG. 1 .

Next, the circuit operation when the transformer TR having the structure shown in FIGS. 11B to 11E is used for the igniter shown in FIG. 2 will be described with reference to FIG. 12 . That is, a pulse voltage of 400 V shown in FIG. 12 was applied to the connection terminals 211 and 212 of the igniter 17 from the inverter 15 shown in FIG. 1 , and a voltage of 1 kV was also applied to the connection terminals. As a result, the charging of the capacitor C2 is started, and when the discharge breakdown voltage of the discharge gap 22 is reached, a current flows through the primary coil of the transformer TR, so that the secondary coil generates a pulse voltage of, for example, 20 kV.

This is because the secondary side of the transformer TR generates a voltage corresponding to the ratio of the number of coils n1 of the primary coil to the number of coils n2 of the secondary coil, and generates a high voltage ( eg 20kV). Applying this voltage to the HID bulb 19 causes the bulb 19 to start discharging.

When the HID bulb 19 starts to discharge, the voltage supplied to the connecting terminals 211 and 212 becomes stable at around 43V. After that, the HID bulb 19 is driven by the igniter 17 to continue lighting the bulb.

In the embodiment of the present invention, the rod-shaped magnetic core 2 has a taper, and the higher the voltage is induced toward the secondary coil end, but the more resin is sealed toward this end, it is difficult to generate creeping discharge and corona discharge. Moreover, since the diameter of the primary coil 13a of the rod-shaped magnetic core 2 is large, that is to say, the thick magnetic core is used for this part, the inductance can be increased, and the high-voltage pulse can be easily generated.

And because the cross-sectional direction of the coils of the primary coil and the secondary coil to the rod-shaped magnetic core is flat, the number of turns can be increased relative to the winding length of the coil, which has the advantage of easily generating high-voltage pulses.

In the transformer TR of the igniter used in the present invention, even if the rod-shaped magnetic core does not have a taper as shown in FIG. 11D, the resin sealed between the coil wound outside the magnetic core and the rod-shaped magnetic core can be filled so that the high-voltage side of the secondary coil is thicker than that of the primary coil. The low voltage side of the coil. Figure 13A shows a cross-sectional view of yet another embodiment of a transformer for use with the present invention. In this example, primary and secondary coils 132a and 131b with at least tapered inner diameters are wound around a non-tapered equal-diameter bar core 131, and resin 133 is sealed between these coils and the bar core.

According to this embodiment, there is an advantage that an equal-diameter rod-shaped core can be used which is easy to manufacture.

Figure 13B shows a cross-sectional view of another embodiment of a transformer for use with the present invention. In this example, tapered primary and secondary coils 136 a and 136 b are wound on a tapered rod core 135 , and a resin 137 is sealed between these coils and the rod core. According to this embodiment, since isolation between the magnetic core and the coil of the secondary coil can be facilitated, there is an advantage that a transformer suitable for a case where a very large voltage is induced at the end of the secondary coil can be obtained.

The relationship between the rod-shaped magnetic core and the coil shown in FIGS. 13A and 13B can also be used in the case of Embodiment 1 with the structure shown in FIG. 6 .

In the above-mentioned embodiment, the rod-shaped magnetic core is taken as a round rod with a circular cross-section, but a square or polygonal cross-section may also be used.

The present invention is not limited to the above-described embodiments, and various modifications can be made and implemented within the scope of the technical idea.

Claims (18)

1. A discharge lamp lighting device, characterized in that it comprises into the socket of a discharge lamp bulb, A coil composed of a primary coil with one end of the secondary coil connected to the lamp holder and the other end connected to the first drive line and one end of the secondary coil connected to the second drive line and the other end connected to the third drive line through the discharge gap, and inserted into the a core of the coil and a transformer filled with resin between the core and the primary and secondary coils, and a capacitor connected between the second drive line and the third drive line; The transformers are arranged side by side next to the lamp holders. 2. The discharge lamp lighting device according to claim 1, wherein: The transformer has a structure in which a primary coil is wound around a secondary coil. 3. The discharge lamp lighting device according to claim 2, wherein: The transformer has a structure in which the secondary coil protrudes from the magnetic core on a high voltage generating side, and the magnetic core and at least the high voltage generating side of the secondary coil are covered with resin. 4. The discharge lamp lighting device according to claim 1, wherein: The transformer is constituted by a coil frame made of resin, and the coil frame has a cavity in the center, an opening at the end of the secondary coil on a non-high-voltage generating side, and an opening for inserting the primary coil around the cavity. bottomed cavity. 5. The discharge lamp lighting device according to claim 3, wherein: The secondary coil is composed of stainless steel. 6. The discharge lamp lighting device according to claim 1, wherein: The transformer has a winding structure in which a secondary coil and a primary coil are arranged side by side. 7. A discharge lamp lighting device, characterized in that it comprises the socket into which the bulb of the discharge lamp is inserted, A coil composed of a primary coil with one end of the secondary coil connected to the lamp holder and the other end connected to the first drive line and one end of the secondary coil connected to the second drive line and the other end connected to the third drive line through the discharge gap, and inserted into the a core of the coil and a transformer filled with resin between the core and the primary and secondary coils, and a capacitor connected between the second drive line and the third drive line; The transformer has a bobbin around which the primary coil and the secondary coil are wound, a rod-shaped core inserted into the center of the bobbin, and a rod-shaped core filled between the rod-shaped magnetic core and the secondary coil that is closer to the connecting place. The resin in the gap is larger at one end of the lamp holder. 8. The discharge lamp lighting device according to claim 7, wherein: The transformer has a structure in which a primary coil is wound around a secondary coil. 9. The discharge lamp lighting device according to claim 8, wherein: The transformer has a structure in which the secondary coil protrudes from the magnetic core on a high voltage generating side, and the magnetic core and at least the high voltage generating side of the secondary coil are covered with resin. 10. The discharge lamp lighting device according to claim 7, wherein: The transformer is constituted by a coil frame made of resin, and the coil frame has a cavity in the center, an opening at the end of the secondary coil on a non-high-voltage generating side, and an opening for inserting the primary coil around the cavity. bottomed cavity. 11. The discharge lamp lighting device according to claim 10, wherein: The secondary coil is composed of stainless steel. 12. The discharge lamp lighting device according to claim 7, wherein: The transformer has a winding structure in which a secondary coil and a primary coil are arranged side by side. 13. A discharge lamp lighting device, characterized in that it comprises the socket into which the bulb of the discharge lamp is inserted, A coil composed of a primary coil with one end of the secondary coil connected to the lamp holder and the other end connected to the first drive line and one end of the secondary coil connected to the second drive line and the other end connected to the third drive line through the discharge gap, and inserted into the a core of the coil and a transformer filled with resin between the core and the primary and secondary coils, and a capacitor connected between the second drive line and the third drive line; The transformer has a bobbin having a predetermined diameter including winding the primary coil and a secondary coil, is inserted into the center of the bobbin, and has a diameter that becomes smaller closer to an end of the secondary coil connected to the lamp holder. The tapered rod core and the resin filled in the gap between the rod core and the bobbin. 14. The discharge lamp lighting device according to claim 13, wherein: The transformer has a structure in which a primary coil is wound around a secondary coil. 15. The discharge lamp lighting device according to claim 14, wherein: The transformer has a structure in which the secondary coil protrudes from the magnetic core on a high voltage generating side, and the magnetic core and at least the high voltage generating side of the secondary coil are covered with resin. 16. The discharge lamp lighting device according to claim 13, wherein: The transformer is constituted by a coil frame made of resin, and the coil frame has a cavity in the center, an opening at the end of the secondary coil on a non-high-voltage generating side, and an opening containing the primary coil embedded in the cavity around the cavity. The bottomed cavity of the coil. 17. The discharge lamp lighting device according to claim 16, wherein: The secondary coil is composed of stainless steel. 18. The discharge lamp lighting device according to claim 13, wherein: The transformer has a winding structure in which a secondary coil and a primary coil are arranged side by side.

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