JP2005276686A - Method of manufacturing lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a lamp capable of reducing tension strain caused in a glass tube nearby a flare portion. <P>SOLUTION: This method of manufacturing a lamp includes a step in which a structure having a flare stem 2 and an exhaust pipe 3 and a glass tube 1 are held so that their longitudinal directions are almost perpendicular to the direction of gravity, and while a flare portion 2a and the glass tube 1 nearby it are heated from the side of the flare portion in the condition that an end face of the glass tube 1 contacts with an exterior surface of the flare portion 2a, the flare portion 2a heated is pushed to an end face of the glass tube 1 to join the glass tube 1 to the flare portion 2a. When the upper half 1c of the glass tube held is an upper portion 1c and the lower half is an lower portion 1d, in the foregoing step, while at least the upper portion 1c of the glass tube 1 nearby the flare portion is covered with a shield member 6 arranged not to contact with the glass tube 1, the flare portion 2a and the glass tube 1 nearby it are heated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to various discharge lamps and methods for manufacturing lamps such as light bulbs.

  In a conventional lamp manufacturing method, a vertical method and a horizontal method are known as methods for joining a glass tube and a flare stem. In the vertical method, the structure in which the flare stem is provided with the exhaust pipe and the glass tube are held so that their longitudinal directions are parallel to gravity. In the horizontal method, the glass tube and the structure are held so that their longitudinal directions are substantially orthogonal to the direction of gravity.

In particular, in recent years, horizontal systems that are advantageous for high-speed production have become mainstream, and a joining apparatus used in the horizontal system has also been disclosed (for example, see Patent Document 1). In the horizontal method, the flare portion and the glass tube in the vicinity thereof are heated from the flare portion side in a state where the end surface of the glass tube and the outer surface of the flare portion of the flare stem are in contact with each other, thereby softening the flare portion. Next, the flare portion softened by the plate for batting is pressed against the end of the glass tube to join the glass tube and the flare stem. Heating is performed by a burner having an annular flame outlet. The flame outlet is disposed so as to face the end surface of the glass tube and the inner surface of the flare portion, and the flame is ejected in the horizontal direction.
JP 2002-289138 A

  However, in the horizontal method described above, the flame outlet is disposed opposite to the end surface of the glass tube and the inner surface of the flare portion, so that the flame ejected from the flame outlet is upward due to the influence of the air current and the like. May shake. Therefore, the ambient temperature in the vicinity of the joined portion between the glass tube and the flare portion becomes non-uniform, and the temperature on the outer surface of the glass tube near the flare portion also becomes non-uniform. As a result, a strong tensile strain remains in the glass tube in the vicinity of the flare portion, and this tensile strain has caused the glass tube to be damaged during the post-process and lamp use. When the upper half of the glass tube held by the joining device is the upper part and the lower half is the lower part, a large tensile strain is observed particularly in the vicinity of the flare part of the glass tube to which the flare part is joined. It was.

  The lamp manufacturing method of the present invention is a lamp manufacturing method including a glass tube and a flare stem provided with a flare portion fixed to an end of the glass tube, and includes the flare stem and an exhaust tube. The structure and the glass tube are respectively held so that the longitudinal direction thereof is substantially orthogonal to the direction of gravity, and the flare portion and the glass tube in a state where the end surface of the glass tube and the outer surface of the flare portion are in contact with each other. While heating the glass tube in the vicinity from the flare portion side, the heated flare portion was pressed against the end surface of the glass tube to hold the glass tube and the flare portion and held. When the upper half of the glass tube is an upper portion and the lower half is a lower portion, in the step, at least the upper portion of the glass tube in the vicinity of the flare portion is disposed so as not to contact the glass tube. In covered state by member, characterized by heating said flared portion and said glass tube in the vicinity.

  In the present invention, since at least the upper part of the glass tube in the vicinity of the flare part is covered with a shielding member arranged so as not to contact the glass tube, the flare part and the glass tube in the vicinity thereof are heated. The tensile strain generated in the glass tube can be reduced.

  The present inventor, when the upper half of the glass tube held by the joining apparatus in the lamp manufacturing method is the upper part, and the lower half is the lower part, in the vicinity of the flare part of the glass tube to which the flare part is joined, It was discovered that a large tensile strain was generated especially in the upper part. Based on this discovery, the present inventor has arrived at a method for manufacturing the lamp of the present invention.

  Next, an example of the manufacturing method of the lamp | ramp of this invention is demonstrated using FIGS. In the lamp manufacturing method of the present embodiment, for example, a joining apparatus as shown in FIG. 1 is used.

  As shown in FIG. 1, the joining device has a first holding part 8 for holding the glass tube 1, a second holding part 9 for holding the structure 4, and the shape of the flame outlet 7 a. An annular burner 7, an annular pressing portion 5, and a driving portion 10 that can advance and retract the pressing portion 5 in the horizontal direction 12 are provided. The second holding portion 9 has a lumen into which the exhaust pipe 3 of the structure 4 can be inserted, and the second holding portion 9 is inserted into the lumen so that the second holding portion 9 is structured 4. Can be held. Examples of the drive unit 10 include an air cylinder.

  Moreover, in the joining apparatus, the burner 7 and the pressing part 5 are arrange | positioned in this order on the outer side of the 2nd holding | maintenance part 9 centering on the 2nd holding | maintenance part 9. FIG.

  The structure 4 includes a flare stem 2 and an exhaust pipe 3, and the flare stem 2 has a support portion 2 b that supports a lead wire 13 and a flare portion 2 a.

  The distance L1 between the end surface 5a on the burner 7 side of the pressing portion 5 and the outer surface 7b of the burner 7 facing the end surface 5a is, for example, 0.5 mm. By setting L1 to be, for example, 0.5 mm, air is easily supplied around the flame outlet 7a, and oxygen shortage is suppressed.

  Further, the joining device includes a shielding member 6 having a cylindrical shape. The inner diameter of the shielding member 6 is larger than the outer diameter of the straight portion 1 a of the glass tube 1. The shielding member 6 is integrated with, for example, the pressing portion 5, and is provided on the side of the pressing portion 5 that faces the flare portion 2 a when the structure 4 is held by the second holding portion 9. .

  The length L4 in the longitudinal direction of the shielding member 6 is preferably equal to or longer than the sum of the movement distance L2 of the pressing portion 5 and the length L3 in the longitudinal direction of the flare stem 2, for example. If L4 is equal to or longer than the sum of L2 and L3, the pressing portion 5 may be disposed at any location within the moving range with the flare portion 2a and the end face of the glass tube 1 in contact with each other. The glass tube 1 can be covered with the shielding member 6 so that the flare stem 2 cannot be seen.

  The inner diameter of the shielding member 6 may be set so that, for example, the difference between the half of the inner diameter of the shielding member 6 and the half of the outer diameter of the straight portion 1a of the glass tube 1 is 1 mm or more and 20 mm or less.

  As shown in FIG. 1, in the lamp manufacturing method of the present embodiment, for example, a glass tube 1 for a straight tube fluorescent lamp has a first holding portion 8 such that its longitudinal direction is substantially perpendicular to the direction of gravity. Hold on. The glass tube 1 includes a straight portion 1a and a reduced diameter portion 1b which is provided at both ends of the straight portion 1a and has an outer diameter smaller than that of the straight portion 1a, but holds the straight portion 1a with the first holding portion 8. . On the other hand, the structure 4 is inserted into the lumen of the second holding part 9 and the structure 4 is held by the second holding part 9 so that the longitudinal direction of the structure 4 is substantially perpendicular to the direction of gravity. .

  Next, as shown in FIG. 2, the flare stem 2 is inserted into the glass tube 1 so that the outer surface of the flare portion 2 a and the end surface of the glass tube 1 are brought into contact with each other. Subsequently, the flame 11 is ejected from the flame outlet 7a, and the flare portion 2a and the glass tube 1 in the vicinity thereof are heated until the flare portion 2a is softened. At this time, the pressing portion 5 is kept waiting at a position away from the flare portion 2a so as not to hinder heating. However, the flare portion 2a and the glass tube 1 in the vicinity thereof are heated in a state of being covered by the shielding member 6 arranged so as not to contact the glass tube 1.

  In the lamp manufacturing method of the present embodiment, the flare portion 2a and the glass tube 1 in the vicinity thereof are heated with the shielding member 6 covering the entire circumference of the glass tube 1 in the vicinity of the flare portion 2a. It is desirable to adjust the supply amount of oxygen so that oxygen around the flame outlet 7a does not become insufficient.

  Next, as shown in FIG. 3, the driving unit 10 is driven to move the pressing unit 5 to the flare part 2 a side, and the flare part 2 a heated by the pressing unit 5 is pressed against the glass tube 1, and the flare part 2 a The glass tube 1 is joined. The pressing by the pressing unit 5 may be performed a plurality of times at regular time intervals. The pressing by the pressing part 5 is performed while heating the flare part 2a and the glass tube 1 in the vicinity thereof.

  Thus, the shielding member 6 arranged so as not to contact the glass tube 1 covers the glass tube 1 in the vicinity of the flare portion 2a, and in this state, the flare portion 2a and the glass tube 1 in the vicinity thereof are connected to the flare portion 2a. When heated by the burner 7 from the side, the flame 11 ejected from the flame ejection port 7 a exists in the space between the shielding member 6 and the glass tube 1. Therefore, it is suppressed that the flame 11 is fluctuated upward due to the influence of the air flow, etc., the uniformity of the temperature around the glass tube 1 near the flare portion 2a is increased, and the uniformity of the temperature distribution on the outer surface of the glass tube is also improved. Rise. As a result, the tensile strain of the glass tube 1 can be reduced.

  In particular, in the example described with reference to FIGS. 1 to 3, the entire circumference of the glass tube 1 in the vicinity of the flare portion 2 a is covered with the shielding member 6, so that the ambient temperature uniformity around the glass tube 1 in the vicinity of the flare portion 2 a is And the uniformity of temperature distribution on the outer surface of the glass tube is also high. As a result, the tensile strain of the glass tube 1 can be effectively reduced.

  Further, in the lamp manufacturing method of the present embodiment, as shown in FIG. 2, when the glass tube 1 is viewed from the upper part 1c side, the shielding member 6 prevents the flare stem 2 from being seen, so that the flare portion 2a is near. It is preferable to heat the flare portion 2a and the glass tube 1 in the vicinity thereof while covering the glass tube 1. Large tensile strain is likely to occur in the glass tube upper portion 1c, particularly in the portion immediately above the flare stem 2 in the glass tube upper portion 1c. Accordingly, if the flare portion 2a and the glass tube 1 in the vicinity thereof are heated from the flare portion 2a side in a state where the glass tube 1 is covered with the shielding member 6 so that the flare stem 2 is not visible, the tensile strain of the glass tube 1 Can be reduced more effectively. In addition, let the upper half of the hold | maintained glass tube 1 be the upper part 1c, and let the lower half be the lower part 1d.

  As shown in FIG. 3, the distance L5 between the outer surface of the straight portion of the glass tube 1 and the inner surface of the shielding member 6 depends on the straightness of the straight portion and the holding accuracy of the first holding portion and the second holding portion. Usually, it is preferably 1 mm or more and 20 mm or less. If the distance L5 is too short, the glass tube 1 may come into contact with the shielding member 6 and breakage. If the distance L5 is too long, the uniformity of the temperature around the glass tube cannot be sufficiently improved. If the distance L5 is 1 mm or more and 20 mm or less, the uniformity of the temperature can be sufficiently increased without bringing the shielding member 6 and the glass tube 1 into contact with each other.

  In the example described with reference to FIGS. 1 to 3, the entire circumference of the glass tube 1 in the vicinity of the flare portion 2 a is covered by the cylindrical shielding member 6, but is not necessarily limited thereto. The tensile strain is particularly noticeable in the upper portion 1c of the glass tube, and further in the region immediately above the flare stem 2 in the upper portion 1c of the glass tube (see FIG. 2). Therefore, as shown in FIG. 4, when the upper half of the held glass tube 1 is the upper portion 1c and the lower half is the lower portion 1d, only the upper portion 1c of the glass tube 1 near the flare portion 2 is covered with the shielding member 6. Even if the flare portion and the glass tube 1 in the vicinity thereof are heated in the state, the tensile strain generated in the glass tube 1 can be reduced. 4 is a cross-sectional view taken along the line AA ′ of FIG. 2, but a flare stem and the like disposed inside the glass tube 1 are omitted.

  In the lamp manufacturing method of the present embodiment, the process after the flare portion 2a and the glass tube 1 are joined is the same as the conventional process. For example, the glass tube 1 to which the flare is bonded is transferred to an exhaust device by a transfer device, and the glass tube 1 is evacuated and cleaned, and then the enclosed gas (rare gas) and a small amount of mercury are put into the glass tube 1. To fill. Next, the exhaust pipe is sealed and the exhaust pipe is cut.

  Below, an example of the manufacturing method of the lamp | ramp of this invention by an Example is demonstrated more concretely, referring FIGS. 1-4. However, in the following examples and comparative examples, the manufacturing process after joining the flare portion of the flare stem and the glass tube is omitted.

  A glass tube 1 for a straight fluorescent lamp mainly composed of soda lime, and a structure 4 made of lead glass including a flare stem 2 and an exhaust pipe 3 were prepared. The straight portion 1a of the glass tube 1 has an outer diameter of 28 mm and an inner diameter of 26.4 mm. The length L3 in the longitudinal direction of the flare stem 2 constituting the structure 4 is 20 mm. Subsequently, the glass tube 1 is held by the first holding portion 8 so that the longitudinal direction thereof is substantially orthogonal to the direction of gravity, and the structure 4 is held so that the longitudinal direction thereof is substantially orthogonal to the direction of gravity. 2 holding part 9 (see FIG. 1).

  Next, the flare stem 2 of the structure 4 was inserted into the glass tube 1, and the end surface of the contracted portion of the glass tube 1 and the outer surface of the flare portion 2 a of the flare stem 2 were brought into contact with each other. In this state, the entire circumference of the flare portion 2a and the glass tube 1 in the vicinity thereof is covered with a cylindrical shielding member 6, and the flare portion 2a and the glass tube 1 in the vicinity thereof are heated by the burner 7 from the flare portion 2a side. The flare portion 2a was softened (see FIG. 2). The burner 7 is supplied with a mixed gas composed of fuel gas, air, and oxygen (oxygen different from oxygen contained in the air), and the mixing ratio is fuel gas: air: oxygen = 4: 3: 0. About 5.

  Since the shielding member 6 is made of stainless steel and has an inner diameter of 36 mm, the length L5 is 4 mm (see FIG. 3). The length L4 in the longitudinal direction of the shielding member 6 is 25 mm, and the distance L1 between the end surface 5a of the pressing portion 5 and the outer surface 7b of the burner 7 facing the end surface 5a is 0.5 mm ( (See FIG. 1).

  Subsequently, while heating the flare portion 2a and the glass tube 1 in the vicinity thereof, the softened flare portion 2a was pressed against the end surface of the glass tube 1 by the pressing portion 5 to join the glass tube 1 and the flare portion 2a. The pressing force by the pressing portion 5 was performed a plurality of times (for example, three times) (see FIG. 3). Thereafter, the flare portion 2a and the glass tube 1 in the vicinity thereof were further heated. In addition, the moving distance L2 of the pressing part 5 was 5 mm.

Instead of the shielding member 6 used in Example 1, the flare portion 2a and the glass tube 1 in the vicinity thereof were heated while covering the upper portion 1c of the glass tube using the shielding member 6 shown in FIG. 2). Except for the above, the flare portion 2 and the glass tube 1 were joined in the same manner as in Example 1.
(Comparative example)

  The flare portion 2 and the glass tube 1 were joined in the same manner as in Example 1 except that the flare portion and the glass tube in the vicinity thereof were heated without covering the glass tube with the shielding member.

  Next, the maximum value of the tensile strain was measured for the glass tube 1 to which the flare stem was joined obtained in Examples 1 and 2 and the comparative example. For the measurement of tensile strain, “Polarimeter SFII” manufactured by Shinko Seiki Co., Ltd. was used. The unit of tensile strain is an angle, and the larger the angle, the greater the degree of strain.

  As a result of measuring the tensile strain, Examples 1 and 2 and Comparative Example all showed the largest tensile strain at the top of the glass tube, which was 20 ° in Example 1, 28 ° in Example 2, In the comparative example, it was 33 °. From this result, in Examples 1 and 2, it was confirmed that the tensile strain generated in the glass tube near the flare portion was reduced as compared with the comparative example.

  The lamp manufacturing method of the present invention is useful as a lamp manufacturing method because it can reduce the tensile strain generated in the glass tube in the vicinity of the flare portion. The lamp manufacturing method of the present embodiment can be applied to a straight tube fluorescent lamp, a round fluorescent lamp, a fluorescent lamp in which a plurality of glass tubes arranged in parallel to each other are connected by a bridge, and the like.

The fragmentary sectional view explaining 1 process of the manufacturing method of the lamp | ramp of this invention The fragmentary sectional view explaining 1 process of the manufacturing method of the lamp | ramp of this invention The fragmentary sectional view explaining 1 process of the manufacturing method of the lamp | ramp of this invention AA 'sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass tube 1a Straight part 1b Reduced diameter part 1c Upper part 1d Lower part 2 Flare stem 2a Flare part 3 Exhaust pipe 4 Structure 5 Press part 6 Shielding member 7 Burner 7a Flame outlet 8 1st holding part 9 2nd holding part 10 Drive unit

Claims (4)

A lamp manufacturing method comprising a glass tube, and a flare stem having a flare portion fixed to an end of the glass tube,
The structure including the flare stem and the exhaust pipe and the glass tube are held so that the longitudinal direction thereof is substantially perpendicular to the direction of gravity, and the end surface of the glass tube and the outer surface of the flare portion are in contact with each other. While heating the flare part and the glass tube in the vicinity thereof from the flare part side, the heated flare part is pressed against the end surface of the glass tube, and the glass tube and the flare part are Including the step of joining,
When the upper half of the glass tube held is the upper part and the lower half is the lower part,
In the step, the flare portion and the glass tube in the vicinity thereof are heated in a state where at least the upper portion of the glass tube in the vicinity of the flare portion is covered with a shielding member arranged so as not to contact the glass tube. A method of manufacturing a lamp characterized by the above.   In the step, the flare portion and the glass tube in the vicinity thereof are heated in a state where the glass tube is covered with the shielding member so that the flare stem is not visible when the glass tube is viewed from the upper side. Item 2. A method for manufacturing a lamp according to Item 1.   The manufacturing of the lamp according to claim 1 or 2, wherein in the step, the flare portion and the glass tube in the vicinity thereof are heated in a state where the entire circumference of the glass tube in the vicinity of the flare portion is covered with the shielding member. Method. The glass tube includes a straight portion and a reduced diameter portion provided at both ends of the straight portion and having a smaller outer diameter than the straight portion,
The manufacturing method of the lamp according to any one of claims 1 to 3, wherein in the step, a distance between an outer surface of the straight portion and an inner surface of the shielding member is 1 mm or more and 20 mm or less.

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