JP6904107B2 - How to manufacture a discharge lamp - Google Patents

Description

Embodiments of the present invention relate to discharge lamps.

For example, in a semiconductor exposure process, a UV (ultraviolet) ink or UV paint drying process, a resin curing process, etc., a long arc type discharge lamp is used as a light source that emits ultraviolet rays in order to carry out a photochemical reaction by ultraviolet rays. There is.

An electrode shaft around which a coil is wound is arranged in the discharge space of this type of discharge lamp. The coil wound around the electrode shaft has a function of assisting the start of discharge at the start of discharge of the discharge lamp and a function of radiating heat so as to keep the electrode shaft at a desired temperature after the discharge lamp is lit. Therefore, in the discharge lamp, it is desirable that the coil is stably maintained at a predetermined position with respect to the axial direction of the electrode shaft.

U.S. Pat. No. 5,451,837 Japanese Unexamined Patent Publication No. 8-879777

By the way, in the manufacturing process of the discharge lamp, the electrode shaft into which the coil is fitted is handled in the step after the coil is fitted on the outer peripheral surface of the electrode shaft. Therefore, when handling the electrode shaft, there is a problem that the position of the coil is displaced with respect to the axial direction of the electrode shaft. As a countermeasure against this misalignment, a technique of welding the electrode shaft and the coil is known.

The electrode shaft and coil may recrystallize depending on the temperature at which the electrode shaft and coil are welded. For this reason, Patent Documents 1 and 2 aim to avoid recrystallization because damage to the electrode shaft and coil due to recrystallization may cause damage. In order to avoid recrystallization of the electrode shaft and the coil, Patent Documents 1 and 2 describe a technique for forming a recess into which a wire rod of the coil is fitted on the outer peripheral surface of the electrode shaft.

Further, in the techniques described in Patent Documents 1 and 2, the occurrence of coil misalignment is suppressed to some extent by forming a recess on the outer peripheral surface of the electrode shaft, but the coil and the electrode fitted in the recess of the electrode shaft The fitting strength with the shaft is insufficient, and the occurrence rate of misalignment is not sufficiently reduced.

Therefore, an object of the present invention is to provide a discharge lamp capable of suppressing the occurrence of misalignment of the coil with respect to the axial direction of the electrode shaft.

The discharge lamp according to the embodiment includes an arc tube having a discharge space, an electrode shaft provided in the discharge space, and a coil wound around the electrode shaft, and is provided on an outer peripheral surface of the electrode shaft. A recess is formed in which the wire of the coil is in contact, and the wire and the electrode shaft are recrystallized in the recess.

According to the present invention, it is possible to suppress the occurrence of misalignment of the coil with respect to the axial direction of the electrode shaft.

It is a schematic diagram which shows the discharge lamp which concerns on embodiment. It is a top view which shows the vicinity of the sealing part of the discharge lamp which concerns on embodiment. It is sectional drawing which shows the electrode shaft and coil of the discharge lamp which concerns on embodiment in an enlarged manner. It is a perspective view which shows the concave part of the electrode shaft of the discharge lamp which concerns on embodiment. It is a schematic diagram which shows the cross-sectional structure before the heat treatment about the electrode shaft of the discharge lamp which concerns on embodiment. It is a schematic diagram which shows the cross-sectional structure of the electrode shaft of the discharge lamp which concerns on embodiment after heat treatment. It is a figure for demonstrating the width of the concave part of the electrode shaft about the discharge lamp which concerns on embodiment. It is a figure for demonstrating the depth of the recess of the electrode shaft about the discharge lamp which concerns on embodiment. It is a figure for demonstrating the occurrence rate of coil misalignment, and the fitting strength of an electrode shaft and a coil with respect to the discharge lamp which concerns on embodiment.

The discharge lamp 5 according to the embodiment described below includes an arc tube 6, an electrode shaft 8, and a coil 9. The arc tube 6 has a discharge space 6a. The electrode shaft 8 is provided in the discharge space 6a. The coil 9 is wound around the electrode shaft 8. A recess 8a is formed on the outer peripheral surface of the electrode shaft 8. The wire rod 9a of the coil is in contact with the recess 8a. The wire rod 9a and the electrode shaft 8 are recrystallized in the recess 8a.

Further, in the discharge lamp 5 according to the embodiment described below, the diameter of the electrode shaft 8 is φR [mm], the wire diameter of the coil 9 is φr [mm], and the width of the recess 8a with respect to the axial direction of the electrode shaft 8 is W. When [mm] and the depth of the recess 8a with respect to the radial direction of the electrode shaft 8 is D [mm], φr ≦ W ≦ (φr × 1.5) and D ≧ (φr × 0.1) are satisfied.

Further, the recess 8a in the discharge lamp 5 according to the embodiment described below is located at the end of the coil 9 wound around the electrode shaft 8 in the axial direction of the electrode shaft 8.

(Embodiment)
Hereinafter, the long arc type discharge lamp (hereinafter, simply referred to as “discharge lamp”) according to the embodiment will be described with reference to the drawings. FIG. 1 is a schematic view showing a discharge lamp 5 according to an embodiment. As shown in FIG. 1, the discharge lamp 5 of the embodiment is attached to, for example, a mounting portion 3 included in the ultraviolet irradiation device 1 and is used to irradiate the irradiated body with ultraviolet rays. The mounting portion 3 has a pair of holding members 4 for holding the discharge lamp 5, and the pair of holding members 4 hold the pair of base members 13 described later that the discharge lamp 5 has.

(Discharge lamp configuration)
The discharge lamp 5 according to the present embodiment is a long arc type mercury lamp or a long arc type metal halide lamp, and is a so-called high intensity discharge lamp (HID: High Intensity Discharge lamp). As shown in FIG. 1, the discharge lamp 5 includes an arc tube 6, a base member 13, and a connecting line 14.

The arc tube 6 is formed in a cylindrical shape by quartz glass having transmitted light, and has a discharge space 6a inside. For example, argon gas and mercury having a high vapor pressure are sealed in the discharge space 6a, and in addition to these, metal halides such as iron, tin, and iodine are sealed.

As shown in FIG. 1, a pair of electrodes 7 are provided at both ends of the discharge space 6a of the arc tube 6. FIG. 2 is a plan view showing the vicinity of the sealing portion of the discharge lamp 5 according to the embodiment. As shown in FIG. 2, the electrode 7 has an electrode shaft 8 and a coil 9. One end of the electrode shaft 8 is directed toward the discharge space 6a, and one end is provided in the discharge space 6a. The other end of the electrode shaft 8 is welded and joined to the metal foil 10. The coil 9 is wound around the outer peripheral surface of one end of the electrode shaft 8 and is arranged in the discharge space 6a. The coil 9 has a wire rod 9a spirally wound around the electrode shaft 8. The electrode shaft 8 and the coil 9 are formed of a metal material containing tungsten as a main component. Details of the electrode shaft 8 and the coil 9 in this embodiment will be described later.

As shown in FIGS. 1 and 2, columnar sealing portions 11 for sealing the discharge space 6a are formed at both ends of the arc tube 6. As shown in FIG. 2, the entire metal foil 10 is covered inside the sealing portion 11, and the other end of the electrode shaft 8, the metal foil 10, and one end of the conducting wire 12 are sealed. The metal leaf 10 is formed in a rectangular shape by, for example, molybdenum. Further, one end of a lead wire 12 is joined to the other end of the metal foil 10. The other end of the conducting wire 12 is drawn out from the sealing portion 11. Further, as shown in FIG. 1, a cylindrical base member 13 is provided on the outer peripheral portion of the sealing portion 11. The base member 13 is joined to the sealing portion 11 of the arc tube 6 by an adhesive.

The connecting wire 14 is arranged outside the arc tube 6, and one end thereof is connected to the other end of the conducting wire 12 drawn from the sealing portion 11. One end of the connecting wire 14 and the other end of the conducting wire 12 are connected via, for example, a connecting portion (not shown) formed by welding. Then, when the discharge lamp 5 is mounted on the mounting portion 3 of the ultraviolet irradiation device 1, the base member 13 is held by the pair of holding members 4 provided on the mounting portion 3, and the connecting line 14 is connected to the power supply unit ( (Not shown) is connected.

FIG. 3 is an enlarged cross-sectional view showing the electrode shaft 8 and the coil 9 of the discharge lamp 5 according to the embodiment. FIG. 4 is a perspective view showing a recess of the electrode shaft 8 of the discharge lamp 5 according to the embodiment.

As shown in FIGS. 3 and 4, a recess 8a in contact with the wire rod 9a of the coil 9 is formed on the outer peripheral surface of the electrode shaft 8. The recess 8a is formed in a groove shape that extends along the longitudinal direction of the spirally wound wire rod 9a and extends in a direction slightly inclined with respect to the circumferential direction of the electrode shaft 8. Therefore, the coil is in contact with the recess 8a along the longitudinal direction of the wire rod. Therefore, the direction in which the recess 8a extends in a groove shape is appropriately set according to the winding state of the wire rod 9a of the coil 9 (the inclination of the wire rod 9a in the longitudinal direction with respect to the center line of the coil 9). The recess 8a may be formed in a groove shape extending along the circumferential direction of the electrode shaft 8.

As shown in FIG. 3, the recess 8a is formed in an arc shape in cross section in contact with the outer peripheral surface of the wire rod 9a, and an appropriate contact area with the wire rod 9a is secured. Further, the radius of curvature of the cross-sectional shape of the recess 8a is formed to be slightly larger than the radius of the wire 9a, so that the wire 9a can be easily fitted into the recess 8a and the wire 9a fluctuates in the recess 8a. Is suppressed. The cross-sectional shape of the recess 8a and the number of recesses 8a with respect to the axial direction of the electrode shaft 8 are not limited. The recess 8a may be formed in another cross-sectional shape such as a square groove shape, or the contact area between the recess 8a and the wire rod 9a may be adjusted.

Further, the recess 8a is located at the end of the coil 9 wound around the electrode shaft 8 in the axial direction of the electrode shaft 8. From the viewpoint of uniformly joining the entire coil 9 in the axial direction of the electrode shaft 8, recesses 8a may be formed at a plurality of locations in the axial direction of the electrode shaft 8, for example, both ends of the coil 9 and the center thereof. .. By having the plurality of recesses 8a, it is possible to improve the reliability of the joint state between the coil 9 and the electrode shaft 8 in the axial direction of the electrode shaft 8.

As described above, in the coil 9 wound around the electrode shaft 8, the wire rod 9a at the end of the coil 9 is fitted in the recess 8a, and the wire rod 9a and the electrode shaft 8 are recrystallized in the recess 8a. Has been done. That is, in the recess 8a, the wire rod 9a of the coil 9 and the electrode shaft 8 are diffused and bonded to each other by recrystallization.

(Joined state of electrode shaft and coil)
FIG. 5 is a schematic view showing a cross-sectional structure of the electrode shaft 8 of the discharge lamp 5 according to the embodiment before heat treatment. FIG. 6 is a schematic view showing a cross-sectional structure of the electrode shaft 8 of the discharge lamp 5 according to the embodiment after heat treatment. In the present embodiment, the electrode shaft 8 and the coil 9 are recrystallized by heating and pressurizing the electrode shaft 8 around which the coil 9 is wound to a predetermined temperature (recrystallization temperature) or higher (heat treatment). .. As shown in FIGS. 5 and 6, the electrode shaft 8 is recrystallized to generate polygonal crystal grains in the structure. In the present embodiment, for convenience, heating while pressurizing is referred to as heat treatment.

Here, the diameter of the electrode shaft 8 is φR [mm], the wire diameter of the coil 9 (diameter of the wire rod 9a) is φr [mm], the width of the recess 8a with respect to the axial direction of the electrode shaft 8 is W [mm], and the electrode shaft. When the depth of the recess 8a with respect to the radial direction of 8 is D [mm],
φr ≦ W ≦ (φr × 1.5) ・ ・ ・ (Equation 1)
D ≧ (φr × 0.1) ・ ・ ・ (Equation 2)
Meet.

When the width W of the recess 8a and the depth D of the recess 8a satisfy Equations 1 and 2, the wire rod 9a and the electrode shaft 8 are recrystallized in the recess 8a, and are fitted into the electrode shaft 8. The fitting strength of the coil 9 is 20 [N] or more, and the fitting strength can be appropriately secured. As a result, in the manufacturing process of the discharge lamp 5, it is possible to prevent the coil 9 from being displaced with respect to the axial direction of the electrode shaft 8. In other words, when the width W of the recess 8a does not satisfy the equation 1 and when the depth D of the recess 8a does not satisfy the equation 2, the coil 9 fitted in the electrode shaft 8 is fitted as described later. Since the strength is less than 20 [N], the misalignment of the coil 9 with respect to the axial direction of the electrode shaft 8 cannot be properly suppressed.

FIG. 7 is a diagram for explaining the width W of the recess 8a of the electrode shaft 8 with respect to the discharge lamp 5 according to the embodiment. The vertical axis in FIG. 7 indicates the fitting strength [N], and the target 20 [N] is indicated by a broken line. The horizontal axis in FIG. 7 indicates the width W [mm] of the recess 8a of the electrode shaft 8, and based on Equation 1, the width W [mm] of the recess 8a is multiplied by the wire diameter φr [mm] of the coil 9. Indicated by. FIG. 7 shows the relationship between the width W [mm] of the recess 8a and the fitting strength [N] when the depth D of the recess 8a is 0.2 [mm] and the recess 8a is recrystallized by heat treatment. ing.

As shown in FIG. 7, when the width W of the recess 8a is smaller than φr, the fitting strength becomes less than 20 [N]. This is because the contact area between the recess 8a and the wire 9a is insufficient. Further, when the width W of the recess 8a is larger than (φr × 1.5), the fitting strength becomes less than 20 [N]. This is because the position of the wire rod 9a is likely to fluctuate in the recess 8a. Therefore, when the width W of the recess 8a satisfies Equation 1, a fitting strength of 20 [N] or more can be obtained.

FIG. 8 is a diagram for explaining the depth D of the recess 8a of the electrode shaft 8 with respect to the discharge lamp 5 according to the embodiment. The vertical axis in FIG. 8 indicates the fitting strength [N], and the target 20 [N] is indicated by a broken line. The horizontal axis in FIG. 8 indicates the depth D [mm] of the recess 8a of the electrode shaft 8, and based on Equation 2, the depth D [mm] of the recess 8a is set to the wire diameter φr [mm] of the coil 9. It is shown by the magnification of. FIG. 8 shows the relationship between the depth D [mm] of the recess and the fitting strength [N] when the width W of the recess 8a is 1.2 [mm] and recrystallized by heat treatment. There is.

As shown in FIG. 8, when the depth D of the recess 8a is smaller than (φr × 0.1), the fitting strength becomes less than 20 [N]. This is because the contact area between the recess 8a and the wire 9a is insufficient. Therefore, when the depth D of the recess 8a satisfies Equation 2, a fitting strength of 20 [N] or more can be obtained.

FIG. 9 is a diagram for explaining the occurrence rate of misalignment of the coil 9 and the fitting strength between the electrode shaft 8 and the coil 9 with respect to the discharge lamp 5 according to the embodiment. The vertical axis in FIG. 9 indicates the fitting strength [N] and the occurrence rate [%] of the misalignment of the coil 9. The horizontal axis in FIG. 9 shows a combination of the presence / absence of the recess 8a, the presence / absence of heat treatment, and the presence / absence of recrystallization as a comparative form, and shows the occurrence rate of coil misalignment in each combination. Further, in FIG. 9, the wire diameter φr of the coil 9 is 1 [mm], the diameter φR of the electrode shaft 8 is 3 [mm], the width W of the recess 8a is 1.2 [mm], and the depth D of the recess 8a is 0. The rate of occurrence of misalignment of the coil 9 [%] and the fitting strength [N] when the value is set to .2 [mm] are shown. The occurrence rate [%] of the misalignment of the coil 9 was calculated using 100 samples.

As shown in FIG. 9, in the case of no recess 8a and no heat treatment, only 5 [N] of fitting strength was obtained, and the occurrence rate of misalignment of the coil 9 exceeded 15 [%]. When there is a recess 8a and no heat treatment is performed, the fitting strength is increased to 15 [N], but the occurrence rate of misalignment of the coil 9 still exceeds 5%. Further, when there is a recess 8a, there is heat treatment, and there is no recrystallization, the fitting strength is increased to about 15 [N], but the occurrence rate of misalignment of the coil 9 still exceeds 5 [%]. It was. On the other hand, in the case of the embodiment having the recess 8a, the heat treatment, and the recrystallization, the fitting strength is increased to about 25 [N], and the occurrence rate of the misalignment of the coil 9 is up to 0 [%]. lowered.

(Electrode assembly process)
The manufacturing process of the discharge lamp 5 configured as described above includes a processing step of processing a recess 8a on the outer peripheral surface of the electrode shaft 8 and an electrode assembly process of fitting the coil 9 on the outer peripheral surface of the electrode shaft 8. Have. In the process of assembling the electrode 7, the electrode shaft 8 is inserted into the inner peripheral portion of the coil 9 from one end side opposite to the other end side where the recess 8a is located, and the coil 9 is inserted from one end side of the electrode shaft 8 to the other. Move towards the edge. By moving the coil 9 to the other end side of the electrode shaft 8, the wire rod 9a at the tip in the traveling direction of the coil 9 is fitted into the recess 8a arranged on the other end side of the electrode shaft 8.

As described above, since the recess 8a is located on the other end side of the electrode shaft 8, the moving coil 9 is recessed while being moved from one end side to the other end side along the axial direction of the electrode shaft 8. The wire rod 9a is smoothly fitted into the recess 8a without being caught in the 8a. In addition, the wire rod 9a of the coil 9 is fitted into the recess 8a, so that the recess 8a positions the coil 9 moved along the axial direction of the electrode shaft 8. Therefore, the coil 9 can be easily positioned at a predetermined position with respect to the axial direction of the electrode shaft 8.

Next, the electrode shaft 8 and the coil 9 in which the wire rod 9a is fitted in the recess 8a are heated to a predetermined temperature (recrystallization temperature) or higher and pressurized in a vacuum heating furnace, for example, to form a recess. The wire rod 9a and the electrode shaft 8 are recrystallized in 8a. By this recrystallization, the wire rod 9a in contact with the recess 8a and the electrode shaft 8 are diffusion-bonded, so that a predetermined fitting strength can be obtained.

As described above, a recess 8a in contact with the wire 9a of the coil 9 is formed on the outer peripheral surface of the electrode shaft 8 in the discharge lamp 5 of the embodiment, and the wire 9a and the electrode shaft 8 are recrystallized in the recess 8a. Has been done. As a result, the fitting strength between the wire rod 9a and the electrode shaft 8 in the recess 8a can be appropriately obtained, and the occurrence of misalignment of the coil 9 with respect to the axial direction of the electrode shaft 8 can be suppressed.

Further, in the discharge lamp 5 of the embodiment, the diameter of the electrode shaft 8 is φR [mm], the wire diameter of the coil 9 is φr [mm], the width of the recess 8a of the electrode shaft 8 is W [mm], and the depth of the recess 8a. When the value is D [mm], φr ≦ W ≦ (φr × 1.5) ... (Equation 1) and D ≧ (φr × 0.1) ... (Equation 2) are satisfied. This makes it possible to secure the fitting strength between the wire rod 9a and the electrode shaft 8 in the recess 8a of 20 [N] or more, and the position of the coil 9 with respect to the axial direction of the electrode shaft 8 in the manufacturing process of the discharge lamp 5. The occurrence rate of deviation can be suppressed. That is, in the manufacturing process of the discharge lamp 5, the coil 9 can be stably maintained at a predetermined position with respect to the axial direction of the electrode shaft 8.

Further, the recess 8a of the electrode shaft 8 in the discharge lamp 5 of the embodiment is located at the end of the coil 9 wound around the electrode shaft 8 in the axial direction of the electrode shaft 8. As a result, when the wire rod 9a of the coil 9 is fitted into the recess 8a of the electrode shaft 8, the electrode shaft 8 is inserted into the inner peripheral portion of the coil 9 from the side opposite to the end where the recess 8a is located. The wire rod 9a can be smoothly fitted into the recess 8a without hindering the movement of the coil 9 with respect to the electrode shaft 8. Therefore, the workability of fitting the coil 9 into the electrode shaft 8 can be sufficiently ensured. In addition, by fitting the wire 9a of the coil 9 into the recess 8a, the coil 9 can be easily positioned with respect to the axial direction of the electrode shaft 8.

Although embodiments of the present invention have been described, the embodiments are presented as examples and are not intended to limit the scope of the invention. The embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. The embodiments and modifications thereof are included in the scope and gist of the present invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

5 Discharge lamp 6 Emission tube 6a Discharge space 7 Electrode 8 Electrode shaft 8a Recess 9 Coil 9a Wire rod 11 Sealing part D Depth R Diameter r Wire diameter W Width

Claims (4)

With an arc tube with a discharge space;
With the electrode shaft provided in the discharge space;
A method for manufacturing a discharge lamp including a coil wound around the electrode shaft;
The outer peripheral surface of the electrode shaft, a recess in which the wire before Symbol coils are in contact,
The coil is wound around the outer peripheral surface of the electrode shaft so that the wire rod is in contact with the recess.
By pressurizing with heating the electrode shaft which the coil is wound, recrystallizing said electrode axis and said wire in said recess, a discharge lamp production method of. With an arc tube with a discharge space;
With the electrode shaft provided in the discharge space;
A method for manufacturing a discharge lamp including a coil wound around the electrode shaft;
The outer peripheral surface of the electrode shaft, a recess in which the wire before Symbol coils are in contact,
The wire rod is fitted into the recess,
Said electrode axis and the coil and the wire is fitted in the recess in a vacuum heating furnace, by pressurizing with heating, recrystallizing said electrode axis and said wire in said recess, a discharge lamp Manufacturing method . [Phi] r [mm] the diameter of the pre-Symbol coil, W [mm] width of the recess with respect to the axial direction of the electrode axis, when the depth of the recess in the radial direction of the electrode axis was D [mm],
φr ≦ W ≦ (φr × 1.5)
(Φr × 0.1) ≦ D ≦ (φr × 0.3)
The electrode shaft and the coil satisfying the above conditions are used.
The method for manufacturing a discharge lamp according to claim 1 or 2 . The recess is formed so as to be located at the axial end of the electrode shaft of the coil wound around the electrode shaft.
The method for manufacturing a discharge lamp according to any one of claims 1 to 3 .

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