JPH11329359A - Lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lamp that can eliminate the eccentricity of electrodes and the eccentricity of filament coils and employs a closing part structural body to which an air exhaust process can efficiently be performed in a lamp manufacturing process in relation to a lamp such as a discharge lamp or an incandescent bulb which employs a closing part structural body made of a functionally gradient material. SOLUTION: Each lamp closing part structural body 4 to weld and seal a closing tube part 3 continuously formed on a lamp arc tube part 2 is formed from a generally post-like functionally gradient material which is formed from a conductive inorganic substance constituent and an insulating inorganic substance constituent, and in which a conductive region and an insulating region are formed by gradiently changing the concentration of the conductive inorganic substance constituent along tire axial direction, and when it is assumed that the maximum diameter of a part at which the lamp closing part structural body 4 is welded and sealed is (d) and the inside diameter of the closing tube part to be welded is D, a relationship of 0.60D<=(d)<=0.94D should be satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp such as a mercury lamp, a xenon lamp, or a metal halide lamp, wherein a lamp closing structure for closing a closing tube connected to an arc tube is made of a functionally graded material. Alternatively, the present invention relates to a lamp such as an incandescent lamp such as a halogen lamp or a halogen heater.

[0002]

2. Description of the Related Art Recently, a closing structure for a lamp for sealing a closing tube portion connected to an arc tube portion of a discharge lamp in which a pair of electrodes are arranged opposite to each other in a lamp, for example, an arc tube portion made of silica glass. As such, functionally graded materials have begun to be used.
The closed part structure made of functionally graded material has one side rich in insulating inorganic substance components such as silica, and the proportion of conductive inorganic substance components such as molybdenum increases continuously or stepwise toward the other side. Is what you do.

[0003] Therefore, in the case of a closure structure using a functionally gradient material composed of, for example, silica and molybdenum,
One side of the closed part structure is insulative and has a coefficient of thermal expansion equal to or close to the coefficient of thermal expansion of the silica glass of the arc tube material, and the other side is electrically conductive and has a coefficient of thermal expansion of the electrode. It has a characteristic that it is close to the coefficient of thermal expansion of tungsten or molybdenum as the material of the core rod. This property is suitable as a lamp closing structure.

[0004] Further, among the incandescent lamps such as halogen lamps and halogen heaters having a filament coil as a light emitting / heating element, the arc tube portion is made of silica glass, so that the end portion of the arc tube portion is formed. This functionally graded material can be used as a lamp closing portion structure for closing a continuous blocking tube portion.

FIG. 1 is a sectional view showing an example of a conventional discharge lamp using a functionally graded material as a closing structure of the discharge lamp. The arc tube portion 2 and the closed tube portion 3 of the discharge lamp are made of an insulating inorganic material component (for example, silica glass), and a pair of electrodes 5 facing each other inside the arc tube portion 2 are arranged. The two electrodes are located at the tips of the electrode core rods 6, and the electrode core rods 6 are inserted up to the conductive region 41 of the closing part structure 4 and shrink-fit when the closing part structure 4 is sintered. Reference numeral 7 denotes an external lead, which is shrink-fitted like the electrode core rod. In some cases, the external lead 7 and the electrode core rod 6 may be integrated and shrink-fitted through the closing portion structure 4.

The closed part structure 4 has a substantially cylindrical shape, usually has a uniform outer diameter in the axial direction, and has an insulating inorganic material component (eg, silica) and a conductive inorganic material component (eg, molybdenum).
One side (the inner side of the arc tube portion) of the closed portion structure 4 is an insulating region 40 rich in an insulating inorganic substance component, and the other side (the outer side of the arc tube portion) is conductive. The conductive region 41 is rich in a conductive inorganic substance component. The insulating inorganic material component side end face is disposed so as to face the discharge space of the arc tube part 2 of the discharge lamp 1, and the obstruction tube sections 3 formed at both ends of the arc tube section 2 are closed. Is hermetically welded and sealed in the insulating region 40.

[0007] In a discharge lamp, when a closed structure is welded to a closed tube, the welding is performed as shown in FIG. That is, as shown in FIG. 2A, a bulb 1 having a closed tube portion 3 formed at an end of an arc tube portion 2 is prepared,
The closing part structure 4 is inserted into the closing pipe part 3 of the valve.
Next, as shown in FIG. 2 (b), the outer end of the closed pipe portion 3 of the valve 1 is heated and melted and sealed. Then, in a state where a negative pressure is applied to the inside of the valve 1, the portion of the closed tube structure 3 where the insulating region 40 of the closed portion structure 4 is located is heated from the outer periphery in the direction of the arrow, thereby obtaining the state shown in FIG. ), The closed tube portion 3 is melted and deformed to reduce the diameter,
The sealing portion 10 is formed by hermetically welding the closing tube portion 3 to the peripheral surface of the insulating region 40 of the closing portion structure 4. FIG. 2 (d) shows a state in which the closed portion structure is welded to the closed portion and the closed portion outside the welded end is removed. The discharge lamp shown in FIG. 1 is obtained by cutting the outer end of the closed tube portion and attaching the base 13 after the step shown in FIG. The diameter (inner / outer diameter) of the closed tube before welding is maintained in the closed tube outside the welded end.

If the maximum diameter d of the welded sealing portion M of the closing portion structure 4 (the maximum diameter of the portion for welding and sealing the closing tube portion) is much smaller than the inner diameter D of the closing tube portion 3 to be welded, the sealing is performed. If the electrodes 5, 5 of the lamp after the stoppage are eccentric, or if the maximum diameter d of the welded sealing portion M of the closing portion structure 3 is too close to the inner diameter D of the closing tube portion 3, the blocking will occur. It is difficult to insert the partial structure 4 itself into the closed tube portion 3, and the conductance is deteriorated during the evacuation in the lamp manufacturing process.

FIG. 3 is a schematic view showing a case where the maximum diameter d of the portion of the closed portion structure to be welded and sealed is largely different from the inner diameter D of the closed tube portion. In the case of a discharge lamp, the amount of deviation (eccentricity) Δ between the centers of both electrodes 5A and 5B is 0.5% of the diameter D corresponding to 50% of the inner diameter D of the closed tube portion, and the maximum diameter d is the inclination. When the closure structure made of a functional material is used, the maximum deviation causes a 0.5D electrode eccentricity.
If D = 4 mm, the eccentricity Δ becomes 2.0 mm. If there is such a deviation, when the outer diameter of the anode is 3 mm, the eccentricity Δ greatly exceeds the 1.5 mm radius of the anode, so that the discharge arc is considerably inclined.

When the discharge lamp is used together with an optical system such as a concave reflecting mirror, the optical axis is deviated, and the efficiency of the optical system is significantly reduced. The electrodes wear out,
It is not preferable because the blackening of the arc tube portion occurs. Although the above is an extreme example, the eccentricity of the electrode is a major problem in effectively utilizing the light emission of the lamp.

On the other hand, when the maximum diameter d of the portion to be welded and sealed of the closing portion structure is close to the inside diameter D of the closing tube portion, it becomes difficult to insert the closing portion structure into the closing tube portion. In addition, as described in FIG. 2, in order to exhaust the entire lamp, it is necessary to provide a gap between the closed structure and the inner wall of the closed pipe to such an extent that the exhaust can be performed. For example, in the case of d = 0.94D, the cross-sectional area shows that 1
There is only a gap corresponding to a cross-sectional area of 2%, and the exhaust conductance drops to a maximum of about 12%.

After the block structure is inserted into the block tube as shown in FIG. 2A, both ends of the block tube are connected to each other as shown in FIG.
After the sealing as described above, the gas is exhausted from the exhaust chip tube portion (not shown) of the arc tube portion, and then the welding and sealing are performed. The remaining impurity gas comes into contact with the heated electrode part, thereby contaminating the electrode surface.

Further, in a chipless lamp in which the discharge tube portion has no exhaust chip tube portion and both ends of the closed tube portion are sealed, the inside of the discharge tube portion is finally exhausted through one closed portion structure. If the gap between the closed part structure and the inner wall of the closed pipe part is small, exhaust will be insufficient. That is, H ₂
O and the like cannot be sufficiently removed and remain as impurities in the arc tube portion, which causes problems such as blackening of the arc tube portion.

[0014]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an eccentricity of an electrode and an eccentricity of a filament coil in a lamp such as a discharge lamp or an incandescent lamp using a closed structure for a lamp made of a functionally graded material. By eliminating the core and defining the relationship between the outer diameter of the closed structure and the inner diameter of the closed pipe to be welded so that the evacuation process can be performed efficiently in the lamp manufacturing process, the evacuation during lamp manufacturing can be achieved. SUMMARY OF THE INVENTION An object of the present invention is to provide a lamp which has no problem and has less eccentricity of electrodes.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a lamp closure structure for welding and sealing a closure tube portion connected to an arc tube portion, comprising a conductive inorganic material component. And a substantially columnar functionally graded material in which a conductive region and an insulating region are formed by gradiently changing the concentration of the conductive inorganic material component along the axial direction. When the maximum diameter of a portion of the lamp closing portion structure for sealing and sealing the closed tube portion is d, and the inside diameter of the closed tube portion to be welded and sealed is D, 0.60D ≦ d ≦
The lamp has a relationship of 0.94D.

[0016]

(Embodiment 1) The diameter of the light emitting space in the light emitting tube portion is 11.0 mm, and the distance in the tube axis direction is 11.0 mm.
mm, the distance between the electrodes is 1.5 mm, 40 mg of mercury as a luminescent substance, 0.4 mg of Dy.Nd.Cs iodide and 0.3 mg of indium bromide are enclosed, and 4 × 10 ⁴ Pa of argon is used as a buffer gas. A sealed short arc metal halide lamp having a rated lamp power of 150 W was manufactured. The electrode size is 0.5 mm cathode diameter,
The anode diameter is 3 mm. The inner diameter of the closed pipe is 3.3 m.
In the case of m, five types (No. 1 to No. 5) of short arc metal halide lamps in which the electrode was eccentric were manufactured by changing the maximum diameter d of the functionally graded material in the range shown in Table 1. Maximum eccentricity delta _max of the electrode were as shown in Table 1. The degree of blackening in the arc tube portions of these lamps at the time of lighting for 1000 hours was compared. In each case, the test was performed by vertical lighting with the anode facing upward.

[0017]

[Table 1]

In the results of Table 1, No. 1 and No. 5
In the lamp of No. 5, the blackening of the arc tube portion was so severe that the lamp was no longer usable after lighting for 1000 hours. No. In the case of No. 1, it is considered that blackening occurred due to the effect of residual gas due to insufficient exhaust during lamp production. In addition, No. In No. 5, the eccentricity of the electrode is large due to the large difference between the inside diameter D of the closed tube portion to be welded and the maximum diameter d of the portion of the closed portion structure where the closed tube portion is welded and sealed. It is considered that the blackening of the arc tube portion was biased, and the degree of the blackening was increased. No. 2, No. 3, No. In the lamp of No. 4, the degree of blackening of the arc tube part also reached a medium level at the time of lighting for 1000 hours, and the lamp was continuously usable thereafter.

Example 2 Next, a halogen lamp as shown in FIG. 4 was manufactured, and the effect of the present invention was verified. In FIG. 4, 1 is a bulb made of quartz glass, 2 is an arc tube part, and 3 is a closed tube part. Reference numeral 4 denotes an obstruction portion structure made of a functionally gradient material, reference numeral 40 denotes an insulating region, and reference numeral 41 denotes a conductive region. 11 is an internal lead, 8 is a filament coil, and 7 is an external lead, which is connected to the metal contact 9 via a caulking member 12. A quartz glass tube having an outer diameter of 10 mm, an inner diameter of 6 mm, and an emission length of 127 mm was used. The power consumption is 500 W in design value.

The inner diameter of the closed tube portion was 6 mm, and the filament coil was eccentric by changing the maximum diameter d of the portion of the closed portion structure made of a functionally graded material for welding and sealing the closed tube portion within the range shown in Table 2. Five types of halogen lamps (No. 6 to No. 1)
0) These lamps were manufactured, and the degree of blackening in the arc tube part at the time of lighting for 1000 hours was compared. Maximum eccentricity value Hderuta _max filament coil 8 were as shown in Table 2.

[0021] Here, the maximum eccentricity value Hderuta _max filament coil 8 a pair of perpendicular directions of the mutual positional deviation to the tube axis at the tip of inner lead 11 connected to the filament coil 8 ends is maximized It is the value of time.

The filament coil 8 is connected in advance to an internal lead 11 projecting from the closure structure 4 made of a functionally graded material. The closed part structure 4 is set in a quartz glass tube, one end of the glass tube is closed, and air is exhausted from the other end of the glass tube. Both ends of the glass tube are heated while the inside of the glass tube is kept at a negative pressure, and the glass tube is sealed with the closing structure 4 made of a functionally graded material.

The maximum eccentricity value HΔ of the filament coil 8
_max is in the range shown in Table 2. When the eccentricity of the filament coil increases, the temperature of the glass tube wall at a portion remote from the filament coil decreases, and crystallization easily occurs on the glass tube wall at a portion close to the filament coil.
Further, if the maximum diameter d of the portion to be welded and sealed of the closed portion structure is too close to the inner diameter D of the glass tube (closed tube portion inner diameter), blackening occurs due to insufficient exhaustion.

[0024]

[Table 2]

In the results in Table 2, 6 and no. 1
In the case of a lamp of 0, blackening of the arc tube portion easily occurs. No. 6
Is considered to be the effect of residual gas due to insufficient exhaust during lamp production. In addition, No. 10 shows that the difference between the maximum diameter d of the portion to be welded and sealed of the closed portion structure with respect to the internal diameter D of the closed tube portion becomes large, thereby causing the influence of the eccentricity of the filament coil and causing the blackening to be remarkable. Conceivable.

From the results of Examples 1 and 2 above, the maximum diameter of the portion of the lamp closure structure for welding and sealing the closure tube is d, the inner diameter of the closure tube before welding and sealing. When D is set to D, the relationship of 0.60D ≦ d ≦ 0.94D is satisfied, so that in the discharge lamp, the eccentricity of the electrode is reduced without leaving any impurity gas at the time of exhaustion during manufacture, and the arc tube is reduced. It can be seen that a lamp in which the degree of blackening of the portion is suppressed can be obtained.

In the first embodiment, a study was conducted with a DC discharge lamp. However, even in an AC discharge lamp as shown in FIG. 1, a high temperature portion of the arc emits light due to the electrode eccentricity. The temperature balance inside the arc tube part is broken by approaching the inner surface of the arc tube part, and problems such as blackening of the arc tube part easily occur. Therefore, the above numerical limitation 0.60D ≦ d ≦
0.94D is also effective for AC discharge lamps.

Also, in the case of an incandescent lamp such as a halogen lamp, 0.60D ≦ d
By setting the relationship of ≦ 0.94D, it is possible to obtain a lamp in which the eccentricity of the filament coil is reduced and the degree of blackening of the arc tube part is suppressed.

[0029]

According to the present invention, when the maximum diameter of the portion of the lamp closing portion structure for welding and sealing the closed tube portion is d and the inside diameter of the closed tube portion to be welded and sealed is D, By defining the range of d, the sealing position can be stabilized. In the completed lamp, the electrode is not eccentric, the exhaust at the time of sealing can be sufficiently performed without eccentricity of the electrode, and the eccentricity of the electrode can be improved. Also, blackening of the arc tube due to insufficient exhaust is unlikely to occur. In a halogen lamp or a halogen heater, the eccentricity of the filament coil can be suppressed.

[Brief description of the drawings]

FIG. 1 shows a diagram of a discharge lamp using a closure structure made of a functionally graded material.

FIG. 2 is a view for explaining a step of welding a closed part structure to a closed pipe part.

FIG. 3 is a conceptual diagram in a case where the outer diameter of the closing portion structure is smaller than the inner diameter of the closing tube portion.

FIG. 4 shows a view of a halogen lamp using a closure structure made of a functionally graded material.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 bulb 2 arc tube part 3 closed tube part 4 closed part structure 40 insulating region 41 conductive region 5 electrode 5A cathode 5B anode 6 electrode core rod 7 external lead 8 filament coil 9 metal contact 10 sealing part 11 internal lead 12 Caulking member 13 Base M Welding sealed part Δ Eccentricity

Claims (1)

[Claims] A lamp closure structure for welding and sealing a closure tube portion connected to an arc tube portion is made of a conductive inorganic material component and an insulating inorganic material component, and is provided with a conductive material along an axial direction. It is made of a substantially columnar functionally graded material in which a conductive region and an insulating region are formed by gradiently changing the concentration of an inorganic substance component, and welds the closed tube portion of the lamp closing structure. A lamp characterized by a relationship of 0.60D ≦ d ≦ 0.94D, where d is the maximum diameter of the portion to be sealed and D is the inner diameter of the closed tube portion to be welded and sealed.