JP2001143882A - Discharge lamp socket shield cover - Google Patents

Abstract

(57) [Summary] [Problem] To provide an igniter circuit for starting a discharge lamp,
Since it generates a high voltage pulse, it is housed in the socket of the discharge lamp for the purpose of shortening the wiring distance. In addition, the igniter circuit has a pulse transformer that generates a high voltage. When the socket is shielded, an eddy current is generated in the shield and the output of the pulse transformer is attenuated, so that the shield cover cannot be attached. SOLUTION: A slit 11 is provided on a shield cover 10 covering an igniter circuit 31 near an extension of an axis of a pulse transformer 45 along a direction of a magnetic field line 98 of the pulse transformer 45 to increase resistance to an eddy current 99.
The eddy current 99 is reduced by the slit 11, and the shield cover 10 in which the output of the pulse transformer 45 is not attenuated can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a shield of a discharge lamp socket used for a headlight of an automobile, which has a built-in igniter circuit.

[0002]

2. Description of the Related Art Discharge lamps have begun to be widely used as headlights of automobiles because of their high luminous intensity compared to power consumption. However, the discharge lamp emits noise (electromagnetic noise) from the point that it is turned on using a high-voltage pulse power supply, and the point that it is necessary to apply a high-voltage pulse at startup, which is received by audio and radio in the car Therefore, there is a problem that unpleasant sound is generated, and various shielding methods have been proposed.

FIG. 6 is a diagram showing a structure of a discharge lamp device similar to that disclosed in Japanese Patent Application Laid-Open No. 10-302537.
FIG. 7 is a diagram showing the circuit configuration of FIG. 6 for explanation. In the figure, 1 is a discharge lamp used as a headlight,
M is an electrode part of the discharge lamp 1, R is a reflector for collecting light forward,
Reference numeral 30 denotes a socket connected to the electrode section M of the discharge lamp 1 and includes a connector (not shown) for holding and electrically connecting the discharge lamp 1 and a shield cable 60 connected to the igniter circuit section 31 and a power supply. Have been. A pulse transformer 45 generates a high-voltage pulse used in the igniter circuit 31. The discharge lamp socket 10 includes the socket 30, the igniter circuit 31, and the shielded cable 60.
0. 61 is a vehicle-mounted battery, 62 is a high-voltage power supply for converting the voltage of the battery 61 into a high-voltage AC (or pulse) voltage, and 63 is a connector connected to the high-voltage power supply 62.

The voltage output from the high voltage power supply 62 is several hundred volts
Although the frequency component is several hundred Hz, the voltage output by the igniter circuit 31 is around 20 kV, and the frequency component is a value on the order of several MHZ. Igniter circuit 31
The igniter circuit 31 is placed in the immediate vicinity of the socket 30 (or the socket 30 and the igniter circuit 31 are integrated) because the insulation of the circuit thereafter becomes difficult due to the high voltage.
Be composed. Now, the noise mainly comes from the wiring 60 from the high-voltage power supply 62 to the discharge lamp 1 and the igniter circuit 31.
And radiated from both. Among them, the shield line 60 is used for the wiring from the wiring 60, and the high voltage power supply 6
By taking measures such as accommodating 2 in a metal box, noise emission is sufficiently suppressed.

On the other hand, noise from the igniter circuit 31 can be reduced by attaching a metal cover that covers the socket 30 and the periphery of the igniter circuit 31.
The problem that occurs when the metal shield cover 10 is attached will be described with reference to FIG. In the figure, 1 is a discharge lamp used as a headlight, 30 is a socket into which the discharge lamp 1 is inserted, and has an igniter circuit unit 31 and a shielded cable 60 connected to a power supply. Reference numeral 45 denotes a pulse transformer for generating a high-voltage pulse built in the igniter circuit 31.

Reference numeral 10 denotes a shield cover virtually provided for explanation, and shields the socket 30 and the igniter circuit 31. The figure shows a socket 30 to help understand the structure.
Although the position of the igniter circuit 31 and the shield cover 10 are shifted from each other, the igniter circuit 31 is provided in contact with the socket 30, and
0 is put on the igniter circuit 31 and the socket 30. The description of the reflecting mirror R and the electrode portion M of the discharge lamp 1 is omitted. When the igniter circuit 31 is shielded by the metallic cover 10, since the frequency component of the pulse generated here is several MHZ as described above, the magnetic flux 9 of the pulse transformer 45
Where 8 crosses the metal plate 10 of the shield, eddy current 99 is easily generated in the metal plate of the shield, and the output of the pulse transformer is significantly attenuated. Therefore, shield cover 1
There is a problem that 0 cannot be added, and therefore, generation of noise cannot be suppressed.

[0007]

As described above, the conventional discharge lamp socket has a problem that it is difficult to suppress noise because the shield cover cannot be attached to the igniter circuit. In addition, in order to attach the shield cover so that the output of the pulse transformer does not attenuate, it must be installed far enough away that the shield cover does not intersect with the magnetic field lines of the pulse transformer. There was a problem to say.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a shield cover in which the output of a pulse transformer is not attenuated even if the shield cover is attached to a socket having a built-in igniter circuit.

[0009]

SUMMARY OF THE INVENTION A shield cover for a discharge lamp socket according to the present invention is an igniter circuit having a connector for holding a discharge lamp disposed at a front portion thereof and a pulse transformer disposed therein for generating a high voltage. And a discharge lamp socket having a cable with an exterior shield for drawing the output of the igniter circuit to the outside, and a non-magnetic metal case that covers at least the rear part of the discharge lamp socket and is provided with a slit along the magnetic field line of the pulse transformer. It is provided.

[0010] The slit is provided in the vicinity of an extension of the central axis of the winding of the pulse transformer crossing the shield cover.

The shield cover has a plurality of claws which engage with projections or recesses provided on the side surface of the socket, and the slit is provided between the claws.

[0012] The present invention further includes a grip for electrically connecting the shield cover and an outer shield of the cable and holding the shield cover.

[0013] The present invention further includes a conductive reflecting mirror disposed near the discharge lamp socket and reflecting light of the discharge lamp, and a shield cover electrically connected to the reflecting mirror.

[0014] Also, there is provided a connector for holding a discharge lamp disposed at the front, an igniter circuit having a pulse transformer for generating a high voltage disposed therein, and a cable with an exterior shield for extracting the output of the igniter circuit to the outside. A discharge lamp socket having an insulating case containing the conductive case, a conductive paint applied to the front or back surface of the insulating case,
Alternatively, the shield case is formed by plating on the front surface or the back surface of the insulating case, and has a shield surface provided with a slit along the line of magnetic force of the pulse transformer.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 shows a configuration of a shield cover of a discharge lamp according to the present invention. In the following drawings, the same or corresponding parts as those in the related art are denoted by the same reference numerals, and detailed description thereof will be omitted. In the figure, reference numeral 1 denotes a discharge lamp used as a headlight, 30 denotes a socket into which the discharge lamp 1 is inserted, and a connector (not shown) for holding and electrically connecting the discharge lamp 1, an igniter circuit unit 31, An external shielded cable 60 (hereinafter simply referred to as a shielded cable) is provided to draw the output (wiring) of the igniter circuit to the outside and connect it to a power supply (not shown). Numeral 45 denotes a pulse transformer for generating a high-voltage pulse built in the igniter circuit 31, whose magnetic path is not closed. The socket 30, the igniter circuit 31, and the shielded cable 60 constitute a discharge lamp socket 100.

10 is a socket 30 and an igniter circuit 31
And a shield cover for shielding FIG. 1 shows the socket 30, the igniter circuit 31, and the shield cover 10 in a displaced position for convenience of explanation, but these are assembled as one body, that is, the igniter circuit 3 is assembled.
1 is provided in contact with the socket 30. The shield cover 10 is made of a non-magnetic metal plate having a thickness of about 0.2 to 0.5 mm, and is a non-magnetic metal case covered over the igniter circuit 31 and the socket 30. That is, the shield cover 10 covers at least the rear part of the discharge lamp socket 100. Although the illustration of the reflecting mirror R and the electrode portion M of the discharge lamp 1 is omitted, they are used in the same manner as in the related art.

Reference numeral 11 denotes a slit (notch) provided in the shield cover 10, which is notched along the direction of the magnetic force line 98 extending from the pulse transformer 45 to the outside. Magnetic field line 9
Although the reference numeral 8 also exists inside the pulse transformer 45, the magnetic field lines 98 referred to in the present invention refer to magnetic field lines outside the pulse transformer 45. Since this slit 11 cuts off the electric circuit,
The eddy current generated in the shield cover 10 due to the change of the magnetic field lines 98 is reduced. The width of the slit 11 is, for example, 0.3 to
The number is about 1 mm, and the number is three in FIG. Further, if the slit 11 is extended to the end of the side surface, the shield cover 10 is separated apart. Therefore, the slit 11 is stopped in the middle of the side surface. End of the pulse transformer 45
A sufficient effect can be obtained if it reaches the side of.

FIG. 2 is an equivalent circuit diagram for explaining the operation principle of FIG. The plate of the metal case constituting the shield cover 10 operates as a single-turn coil 10a. If the slit 11 is not provided, the coil 10a is short-circuited and an eddy current flows. However, if the slit 11 is provided, the coil 10a is not short-circuited, and the performance of the pulse transformer 45 does not deteriorate much. Although the shield cover 10 is illustrated so as to cover the side surface and the rear surface of the igniter circuit 31, the effect is large even if the rear surface alone is used. Front (side with discharge lamp 1)
Only covers the side of the socket 30.
Further, a cutout for passing the shielded cable 60 may be provided as appropriate. The effect is increased as the number of the slits 11 is increased. However, if the number is too large, the strength is reduced structurally.

Although not shown in the figure, since the reflecting mirror R is located near the socket 30, the distance between the pulse transformer 45 and the reflecting mirror R is short and the reflecting mirror R is made of a conductive material. In some cases, a pulse current is induced in the reflecting mirror R to increase noise emission. It is desirable to electrically connect the shield cover 10 to the reflector R in order to reduce this radiation. When the distance is particularly short, it is effective to provide the slit 11 also at a portion near the socket 30 of the reflecting mirror R. Although the three slits 11 in FIG. 1 are described as being separated from each other at the extension of the axis of the pulse transformer 45, the eddy current reduction effect is larger when they are of course attached, but the strength is reduced. While confirming the effect, an appropriate slit length is set. Although the shield 10 of FIG. 1 has a structure that covers the side surface of the pulse transformer 45, the shield effect on the side surface is often not as effective as the ceiling portion, so the side surface portion is not necessarily required.

Embodiment 2 FIG. 3 shows a shield cover of a discharge lamp according to a second embodiment of the present invention. Reference numeral 12 denotes a claw provided on a side surface of the shield cover 10, and an igniter circuit 31.
Alternatively, the shield cover 10 is engaged with the concave or convex portion 15 provided on the side surface of the socket 30 to prevent the shield cover 10 from dropping off from the igniter circuit 31. In the case of FIG.
5 is provided at a position slightly deviated from the center of the igniter circuit 31, so that the slit 11
It is located off center above. That is, the slit 11
Is provided around the vicinity where the extension of the axis of the winding of the pulse transformer 45 intersects the shield cover 10.
Reference numeral 13 denotes a holding bracket (referred to as a holding unit) for electrically connecting the shield cover 10 to the shielded cable 60 and mechanically holding the shield cover 10. In FIG. 3, by providing the slit 11 between the claws 12,
It is devised not to impair the gripping effect of the nail. 13
Is a grip portion, which is secured to the surface of the outer shield of the shielded cable 60 by caulking, so that the shield cover 1
0 and an outer shield of the shielded cable 60, and a holding function of holding the shield cover 10 with respect to the shielded cable 60.

Embodiment 3 FIG. 4 shows a pulse transformer 45.
3 shows a case where the axial direction of the coil is arranged laterally when viewed from the direction in which the discharge lamp 1 is inserted. Slit 11
Are provided along the lines of magnetic force 98 (in the direction orthogonal to the eddy current 99), centering around the point where the extension of the axis of the coil of the pulse transformer 45 intersects the shield cover 10. As a result, the slit 11 is provided in a portion where the density of the magnetic field lines 98 is high, and the effect of reducing the eddy current is enhanced. In the case of FIG.
1 will be provided. In the drawing, the slit 11 is shown only on the side surface, but it goes without saying that the slit 11 may be extended to the upper surface portion in the drawing. A grip 13 has a connection function of electrically connecting the shield cover 10 and the outer shield of the shielded cable 60 and a holding function of holding the shield cover 10 to the shielded cable 60.

Embodiment 4 FIG. 5 shows a discharge lamp shield cover 10 according to the fourth embodiment. Igniter circuit 3
1 is housed in an insulating case. The shield cover 10 first forms a shield surface by applying a conductive paint to the front or back surface of the insulating case of the igniter circuit 31 or by performing plating. The coating or plating on the shield surface may be scraped off with a very thin (for example, 0.1 mm) slit (for example, a cut is made with a sharp blade) to form the slit 11, and the gap may be reduced to enhance the shielding effect. I can do it. In addition, since the insulating case has structural strength, the shield cover 10 does not need to be considered for maintaining strength, and the slit 11 is extended to the end of the shield cover 10 except for a portion for electrical connection (shown in the figure). 19) A better effect can be obtained by preventing the end from constituting the one-turn coil 10a. Although not shown, the coating or plating is brought into contact with the shield of the shield wire 60.

[0023]

The shield cover of the discharge lamp according to the present invention covers the outside of the socket containing the igniter circuit having the pulse transformer and has a slit along the magnetic field line of the pulse transformer, so that the output performance of the pulse transformer is improved. The igniter circuit can be shielded without dropping the igniter circuit.

Further, since the slit of the shield cover is provided in the vicinity of the extension of the center axis of the winding of the pulse transformer intersecting with the shield cover, the slit is provided in a portion of the pulse transformer where the magnetic field lines have a high density, The effect that the influence on the output of the transformer is small is obtained.

Further, since the slit of the shield cover is provided between the claws of the socket, there is obtained an effect that the holding force of the claws of the shield cover does not decrease.

Further, since the grip cover for electrically connecting and holding the shield cover to the outer shield of the cable is provided, an effect that the connection is reliable and the strength is high can be obtained.

In the case where there is a reflecting mirror made of a conductive material, the shielding effect is further enhanced because the shield cover is connected to the reflecting mirror.

The shield cover has mechanical strength maintained by the insulating cover of the socket, and the shield is made of a conductive paint applied to the front or back surface of the insulating cover or a plating applied to the front or back surface. Therefore, the slit can be arbitrarily and sufficiently long without restriction on mechanical strength.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a shield cover of a discharge lamp according to Embodiment 1 of the present invention.

FIG. 2 is an equivalent circuit diagram illustrating the operation of FIG.

FIG. 3 is a configuration diagram of a shield cover of a discharge lamp according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a shield cover of another discharge lamp according to the second embodiment.

FIG. 5 is a configuration diagram of a shield cover of a discharge lamp according to a third embodiment.

FIG. 6 is an explanatory diagram of a configuration of a conventional shield of a discharge lamp.

FIG. 7 is a circuit configuration diagram of the discharge lamp of FIG.

FIG. 8 is a diagram illustrating a problem when a shield cover is provided in the discharge lamp of FIG. 6;

[Explanation of symbols]

1 discharge lamp, 10 shield cover, 10a 1
Turn coil, 11 slits, 12 claws, 1
3 gripper, 19 slit reaching end, 30
Socket, 31 igniter circuit, 45 pulse transformer, 60 shielded cable, 98 lines of magnetic force,
99 virtual line of eddy current, 100 discharge lamp socket.

Claims (6)

[Claims] 1. An igniter circuit having a connector for holding a discharge lamp disposed at a front part thereof, a pulse transformer disposed therein for generating a high voltage, and a cable with an exterior shield for extracting an output of the igniter circuit to the outside. And a non-magnetic metal case that covers at least the rear part of the discharge lamp socket and is provided with a slit along the line of magnetic force of the pulse transformer. 2. The shield cover for a discharge lamp socket according to claim 1, wherein the slit is provided near an extension of a central axis of a winding of the pulse transformer of the shield cover. 3. A shield cover comprising a plurality of claws engaging with projections or recesses provided on a side surface of a discharge lamp socket, and a slit provided between said claws. Item 3. A shield cover for a discharge lamp socket according to item 1 or 2. 4. A grip portion having a connection function of electrically connecting a shield cover and the outer shield of the cable with an outer shield, and a holding function of holding the shield cover with respect to the outer shield. The shield cover for a discharge lamp socket according to any one of claims 1 to 3, wherein: 5. The apparatus according to claim 1, further comprising a conductive reflector disposed near the discharge lamp socket for reflecting light of the discharge lamp, and a shield cover electrically connected to the reflector. The shield cover of the discharge lamp socket according to any one of claims 1 to 4. 6. An igniter circuit having a connector for holding a discharge lamp disposed at a front part thereof, a pulse transformer for generating a high voltage disposed therein, and a cable with an exterior shield for extracting an output of the igniter circuit to the outside. And a discharge lamp socket having an insulating case housing the insulating case, formed by a conductive paint applied to the front or back surface of the insulating case, or by plating applied to the front or back surface of the insulating case. A shield cover for a discharge lamp socket, further comprising a shield surface provided with a slit along a line of magnetic force of the pulse transformer.