JP3443858B2 - Tube and device using this tube - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a sealing portion at an end of an arc tube or an outer tube made of quartz glass, and seals a metal foil conductor joined to an inner lead wire to the sealing portion. And a device using the tube as a light source.

[0002]

2. Description of the Related Art Recently, the field of use of high-pressure metal vapor discharge lamps has been expanding, and it is becoming popular for indoor lighting such as buildings and stores by incorporating it into an optical system such as a reflecting mirror. Since such a discharge lamp is used by being housed in an instrument or a device together with the above optical system, downsizing of the lamp is required.

As an example of such a small discharge lamp, a case of a short arc xenon lamp will be described. Figure 3
Shows a short arc xenon lamp for direct current lighting, and in the figure, reference numeral 1 is an arc tube. The arc tube 1 is made of quartz glass having excellent heat resistance, forms an elliptical discharge space 2 in the center, and crushes and seals 3 at both ends.
3 is formed. Metal foil conductors 4 and 4 made of molybdenum are sealed to the crushed and sealed portions 3 and 3, respectively. An anode 5 and a cathode 6 are provided in the discharge space 1 so as to face each other, and the anode 5 and the cathode 6 each have an electrode shaft (corresponding to an internal lead wire) 7 made of tungsten. Electrode shaft (internal lead wire) 7,
The tip of 7 is guided to the crushing sealing portions 3 and 3 and joined to the metal foil conductors 4 and 4.

External lead wires 8 and 8 are joined to the metal foil conductors 4 and 4, and these external lead wires 8 and 8 are guided to the outside from the crushing sealing portions 3 and 3 and are crushing sealing portions. It is connected to the bases 9, 9 arranged at the ends of 3, 3. Further, the discharge space 1 is filled with xenon gas which reaches several tens of atmospheric pressure during lighting. Internal lead wire 7
When joining the end of the and the metal foil conductor 4, the internal lead wire
Since 7 is made of tungsten W and the metal foil conductor 4 is made of molybdenum Mo, both of which are refractory metals, it is difficult to weld them directly. Therefore, in the conventional case, as shown in detail in FIG. 4, the end portion of the internal lead wire 7 is carved out to form the flat portion 10, and the flat portion 10 is made to face one side surface of the metal foil conductor 4. A joining medium, for example, a brazing metal 11 made of platinum or the like is inserted between both surfaces,
The metal brazing material 11 is resistance-welded using a resistance welding machine to join the internal lead wire 7 and the metal foil conductor 4 to each other.
The metal brazing material 11 is, for example, in the form of a line or a strip, and
It is interposed between the flat portion 10 of the internal lead wire 7 and the side surface of the metal foil conductor 4.

Such a short arc xenon lamp is used by being housed in, for example, a reflector 20, as shown in FIG. The reflector 20 has a reflecting surface 21 on the inner surface formed of a rotating curved surface, and a cylindrical support portion 22 at the top of the inner part. In the lamp, the crushable sealing portion 3 on one side is inserted into the support portion 22 of the reflector 20 so that the reflector 2
0, where the centerline of the lamp is the reflector 20
Are arranged so as to coincide with the optical axis of. Then, the lamp is fixed to the reflector 20 by, for example, the position adjusting screw 23 screwed into the support portion 22. In addition, 25 is a feeder line connected to the base 9.

[0006]

In the case of the conventional short arc xenon lamp having such a structure, the lamp life is designed to be 1000 hours, and although the lamp is manufactured based on the lamp life, the lamp life is shortened. If it is less than half of the above, there is something that does not light up or rarely causes lamp damage.

When the cause of such a short life was examined, in many cases, foil breakage of the metal foil conductor 4 was observed. That is, in the case of conventional, FIG 4 (A) and (B)
As shown in FIG. 3, the metal brazing material 11 in the form of a wire or strip inserted between the flat portion 10 of the inner lead wire 7 and the side surface of the metal foil conductor 4 is connected to the center line OO of the inner lead wire 7. that they are arranged in a direction against orthogonal. However, in the case of a lamp having a long sealing portion 3, thermal expansion and contraction in the longitudinal direction of the sealing portion 3 becomes significantly larger than that in the width direction due to repeated lighting and extinction of the lamp. Thus as in the prior art, the internal metal brazing material 11
When arranged in a direction orthogonal to the center line O-O of the lead wire 7 , local fatigue occurs in the longitudinal direction of the metal foil conductor 4 due to expansion and contraction of the metal foil conductor 4, and cracks or cuts occur along the width direction. Is likely to occur.

Further, when arranged in a direction perpendicular to the metal brazing material 11 with respect to the center line O-O of the internal lead wire 7, is greater than the width of the flat portion 10 of the internal lead wire 7 the length of the brazing metal 11 Therefore, there is also a problem that the contact length of the metal brazing material 11 is restricted and the improvement of the bonding strength cannot be expected.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent cracking or cutting of a metal foil conductor even during long-term lighting, and to bond an internal lead wire and a metal foil conductor. The present invention intends to provide a tube and a device using the same, which can secure the property and can maintain a long life.

[0010]

In order to achieve the above object, the present invention forms a sealing portion at the end of a bulb made of quartz glass, and seals a metal foil conductor in the sealing portion. In a tube in which the metal foil conductor and the end portion of the inner lead wire are joined via a wire or strip-shaped joining medium, the joining medium is
The end of the inner lead that is parallel to the center axis of the inner lead
At the joint surface between the portion and the metal foil conductor, it is arranged so as to cross the center line of the internal lead wire obliquely.

[0011]

According to the present invention, the bonding medium is placed inside the inner lead wire.
The end of the inner lead wire and the metal foil conductor, which are parallel to the core axis
On the joining surface of the metal foil conductor, since it is arranged diagonally intersecting the center line of the internal lead wire, the joining medium is also joined diagonally intersecting the longitudinal direction of the metal foil conductor. It is possible to disperse the stress also in the width direction of the sheet and reduce foil breakage and cracks. Further, since the bonding medium contacts the internal lead wire and the metal foil conductor in a posture where the bonding medium and the metal foil conductor are obliquely intersected with each other, the energization area can be maintained at a predetermined size.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIG. FIG. 1 shows a joining structure between the anode 5 and the metal foil conductor 4 in the short arc xenon lamp described with reference to FIG. 3, which is a modification example to the case of FIG. In FIG. 1, each member has the same reference numeral as in FIG. In the present embodiment, the point different from the case of FIG. 4 is the joining attitude of the metal brazing material 11 as the joining medium.

That is, the metal brazing material 11 of this embodiment is
It is made of a platinum wire with a wire diameter of about 0.1 mm, and is inserted between the flat portion 10 of the inner lead wire 6 and the side surface of the metal foil conductor 4 as shown in FIGS. Has been done. In this case, the metal brazing material 11 is arranged in an oblique posture with a predetermined crossing angle θ (degrees) with respect to the center line OO of the inner lead wire 6. This intersection angle θ (degree) is 0 < θ ≦ 60 (1)

[0014]

The length of the metal brazing material 11 is a (mm),
When the width of the metal foil conductor 4 is L (mm), L ≧ a ≧ L / 2 (2).

According to such a configuration, the metal brazing material 11
Is obliquely arranged with respect to the center line O-O of the inner lead wire 7 , cracks and breaks in the metal foil conductor 4 are reduced. That is, as described above, the metal foil conductor 4 turns on the lamp,
By turning off the light, expansion and contraction are repeated in the longitudinal direction, and mechanical stress is generated in the joint portion with the metal brazing material 11 joining the metal foil conductors 4. Therefore, the metal brazing material 11 is internally
The bonding in the parallel direction can disperse the stress in the width direction of the metal foil conductor 4 rather than the bonding in the direction orthogonal to the center line O-O of the wire 7, and the bonding area is the same. However, the metal foil conductor 4 is less likely to be broken. For this reason,
Even if a local tensile stress is generated in the metal foil conductor 4 due to expansion and contraction of the metal foil conductor 4 due to repeated lighting and extinction of the lamp, it is possible to prevent cracking and cutting of the metal foil conductor 4.
It For this reason, in order to prevent foil breakage of the metal foil conductor 4 and to secure a current-carrying area between the inner lead wire 7 and the metal foil conductor 4, the metal brazing material 11 is used as the inner lead wire.
It is effective to arrange them obliquely with respect to the direction of the center line OO of 7 .

Meanwhile, the bonding strength and conductive properties of the internal lead wire 7 and the metal foil conductor 4 respectively, depends on the bonding area of the metal brazing material 11 to the internal lead wire 7 and the metal foil conductor 4. The bonding area is affected by the wire diameter and the length a of the metal brazing material 11, but the change of the length a has a larger effect than the change of the wire diameter. From this, it is desirable to increase the length a of the metal brazing material 11. When obtained by orthogonal metal brazing material 11 with respect to the center line O-O of the inner lead wire 7, the length of the brazing metal 11 can not be longer than the width of the flat portion 10 of the inner lead wire 7 On the other hand, if the metal brazing material 11 is arranged obliquely with respect to the center line OO of the inner lead wire 7 , the length of the metal brazing material 11 can be changed to the inner lead.
The width of the flat portion 10 of the line 7 can be made longer, which is also advantageous in terms of bonding strength and conductive performance.

Next, an experiment for deriving the equations (1) and (2) will be described. In the short arc xenon lamp shown in FIG. 3, the lamp power is 500 W,
When the lamp voltage is 20 V and the lamp current is 25 A, the inner lead wire 7 is made of tungsten having a wire diameter of 3 mm, and the flat portion 10 formed at the end has a width of 3 mm. The metal foil conductor 4 is made of molybdenum having a thickness of 0.026 mm and a width L of 5 mm, and a platinum wire having a wire diameter of 0.1 mm is used as the metal brazing material 11.

In the lamp having such a structure, the crossing angle θ between the metal brazing material 11 and the center line OO of the internal lead wire 7 is set.
(Degrees) and the length a (mm) of the metal brazing material 11 were variously changed, a repeated blinking test of lighting for 20 minutes and extinguishing for 20 minutes was performed, and a life test of 1000 hours was performed. Each lamp was tested by 5 lamps and evaluated. The results are shown in Table 1 below.

[0020]

[Table 1]

As a result of the above experiment, the length a of the metal brazing material 11 is
Of less than 2.5 mm and a crossing angle θ of more than 60 ° were not lit during the life of the lamp. Therefore, the length a (mm) of the metal brazing material 11 is preferably L ≧ a ≧ L / 2 when the width of the metal foil conductor 4 is L (mm), and the crossing angle θ
Is preferably in the range of 0 < θ ≦ 60. Further, if the crossing angle θ is less than 90 °, the brazing metal 11 is arranged obliquely crossing the center line of the metal foil medium 4, so that the metal brazing conductor 4 does not reach the above preferable range. It is possible to prevent cracking and cutting. It should be noted that also on the cathode 6 side shown in FIG. 3, the same effect can be obtained by the same configuration as above. Further, the present invention is not limited to the embodiment shown in FIG. That is, in the case of the above embodiment,
Although the metal foil conductor 4 and the inner lead wire 6 are joined using one metal brazing material 11, the present invention uses a plurality of metal brazing materials 11 as in the other embodiment shown in FIG. 4 and the internal lead wire 6 may be joined. Of course, also in this case, the metal brazing materials 11 and 11 are inclined. Further, the plurality of metal brazing materials 11 and 11 are not limited to being parallel to each other, and may be arranged in mutually opposite directions, for example, in a V shape or an X shape.

Further, the present invention is not limited to the short arc xenon lamp, but can be applied to the arc tube of other metal vapor discharge lamps such as small metal halide lamps, and of course the arc tube is housed. When the sealing part is formed on the outer bulb, it can also be applied to the sealing part of other incandescent light bulbs such as halogen bulbs, and the valve structure is not limited to both-ends sealed type but one-end sealed type. It can also be applied to a ball.

The shape of the sealing portion is not limited to the crushed sealing portion, and may be implemented with a sealing structure in which the sealing portion is drawn by a lathe while heating and softening the sealing portion. . Further, as the equipment, in addition to the lighting equipment, an ultraviolet irradiation equipment and the like can be used.

[0024]

As described above, according to the present invention, the bonding medium is parallel to the central axis of the internal lead wire.
At the joint surface between the end of the lead wire and the metal foil conductor, since it is arranged diagonally intersecting the center line of the internal lead wire, the joining medium is also joined obliquely to the longitudinal direction of the metal foil conductor. Therefore, the stress concentration due to the expansion and contraction of the metal foil conductor due to the lighting and extinction of the lamp can be dispersed in the width direction of the metal foil conductor. In addition, since the joining medium contacts the internal lead wire and the metal foil conductor in a posture where the joining medium obliquely intersects, the energizing area can be increased. Therefore, even if stress of expansion and contraction is applied to the metal foil conductor by repeating lighting and extinguishing, cracking and cutting of the metal foil conductor are prevented for a long period of time, and the bondability between the internal lead wire and the metal foil conductor is improved. Can be kept good, and long life and high reliability can be obtained.

[Brief description of drawings]

1A and 1B show a joining structure of an electrode and a metal foil conductor according to an embodiment of the present invention, in which FIG. 1A is a front view and FIG. 1B is a side view.

FIG. 2 is a front view showing a joint structure of an electrode and a metal foil conductor according to another embodiment of the present invention.

FIG. 3 is a sectional view showing an entire shoot arc xenon lamp used in a conventional example and an example of the present invention.

4A and 4B show a joining structure of an electrode and a metal foil conductor in a conventional case, where FIG. 4A is a front view and FIG. 4B is a side view.

FIG. 5 is a diagram showing an example of a device in which a shoot arc xenon lamp is incorporated in a reflector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bulb 2 ... Discharge space 3 ... Crushing sealing part 4 ... Metal foil conductor 5, 6 ... Electrode 7 ... Internal lead wire 10 ... Flat part 11 ... Metal brazing material 20 ... Reflector

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-82096 (JP, A) JP-A-53-45077 (JP, A) Real-life Sho 53-8783 (JP, U) Actual-open Sho 53- 55279 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01J 61/36

Claims (4)

(57) [Claims] 1. A sealing portion is formed at an end portion of a bulb made of quartz glass, and a metal foil conductor is sealed at the sealing portion, and the metal foil conductor and the end portion of an internal lead wire are connected to each other by a wire or a wire. In a tube joined via a band-shaped joining medium, the joining medium is parallel to the central axis of the inner lead wire,
At the joint surface between the end of the internal lead wire and the metal foil conductor,
A tube characterized in that it is arranged in an attitude that intersects diagonally with respect to the center line of this internal lead wire. 2. The tube according to claim 1, wherein an intersection angle θ (degree) between the joining medium and the center line of the inner lead wire is set to 0 <θ ≦ 60. 3. The bulb according to claim 1, wherein the bulb is a short arc type high pressure discharge lamp in which sealing parts are formed at both ends and electrodes are sealed in the sealing parts. 4. An instrument comprising the tube according to claim 1 and a reflector disposed in a positional relationship for reflecting the radiation emitted from the tube.