JP2004014326A - Fluorescent lamp and manufacturing method of fluorescent lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent lamp of which the closed part at the glass tube top end portion is changed into a shape having no risk of strength deterioration and its manufacture can be made easily, and in which bulb strength and work performance can be improved, and a manufacturing method of this fluorescent lamp. <P>SOLUTION: This is the fluorescent lamp L that comprises a glass tube 2 which has fluorescent film 25 on the inner surface and in which a closed part 3 having a thick protrusion 31 protruding to the outside in the center is formed at least at the end face on one end side, a bent-shaped bulb 1 in which a discharge path 6 is formed by connecting plural pieces of this glass tube 2 in series, a stem 4 which is sealed at the furthest top end of the glass tube 2 at the end portion of the discharge path 6 of this bent-shaped bulb 1, an electrode 5 installed on this stem 4, and a discharge medium filled in the bent-shaped bulb 1, and a manufacturing method of this fluorescent lamp L is provided. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp of a bulb shape or a compact type having a bulb formed by connecting a plurality of straight glass tubes and being bent, and a method of manufacturing a fluorescent lamp.
[0002]
2. Description of the Related Art In a bulb-type fluorescent lamp and a compact fluorescent lamp, the ends of a plurality of straight glass tubes are formed so that a bulb constituting a discharge path has a bent shape such as a substantially H shape or a substantially W shape. It is formed by connecting the parts near each other.
[0003]
The ends of the discharge path of the bent bulb are hermetically sealed via a stem having electrodes, but the end of each straight glass tube in the middle of the bulb is generally blocked by the following. It is done in such a way.
[0004]
The middle part of the straight glass tube is heated with a burner flame, and after softening and melting, it is moved in the opposite direction of the tube axis, sealed and closed, and the closed part is further heated and melted with a burner flame to adjust the tip shape. .
[0005]
In this method, the phosphor formed on the inner surface of the glass tube enters the glass by being heated by the burner. Cracks may be caused by such foreign matter.
[0006]
When the heating of the glass tube 2 continues, as shown in FIG. 5 (a), the outer surface side of the closed portion 9 becomes smooth, but the fluorescent material also gathers at the central portion on the inner surface side and protrudes inward. The convex portion 91 is formed and the periphery becomes thin. When the pressure inside the glass tube 2 is increased to avoid this, as shown in FIG. 5B, the outer surface side becomes a smooth hemispherical surface, but the thick convex portion 91 remains at the center of the inner surface. 5 and the periphery of the closed portion 9 becomes thin, and those shown in FIG. 5 have a problem of strength reduction that the closed portion 9 is easily damaged when an impact is applied to the closed portion 9 or the vicinity of the closed portion 9. is there.
[0007]
To cope with such a decrease in strength, for example, there is a method described in Japanese Patent Publication No. 4-58137 or Japanese Patent Application Laid-Open No. 2001-357782.
[0008]
In other words, this bulb is formed by heating and fusing a central portion of a single straight glass tube having a phosphor film formed on the inner surface to close the heating portion to form two glass tubes having substantially the same shape of a closed portion. Is made by heating the vicinity of both closed portions to blow out and pierce, and using a glass projecting from the pierced portion or through a separate glass tube to hermetically connect the two pierced portions, for example, A U-shaped valve has been obtained.
[0009]
According to the description of the former publication, after the fusing of the glass tube, the end wall, which is the closed portion, is bent substantially at right angles to the straight portion wall and the transition portion (from the straight portion to the closed portion (end wall)). The thickness of the glass is 0.4 to 0.8 times the straight portion.
[0010]
By adopting such a configuration, mixing of the phosphor into the glass at the time of heating for forming the end wall can be suppressed, and a uniform phosphor film can be obtained on the inner surface of the end wall and the strength of the transition portion can be increased. is there.
[0011]
However, in the case of the former publication, the transition portion from the straight portion to the closing portion is substantially perpendicular, so that the thickness of the glass becomes thin, so that the strength may be weakened. However, there is a problem that a special type (abutment) member is required and the manufacturing apparatus becomes complicated and expensive.
[0012]
Also, in this publication, it is described that the glass at the center of the end wall of the bulb becomes thick, but in this case, since the outer surface of the end wall is flat, the glass is formed to protrude inward of the bulb. Therefore, there is a problem that the fluorescent substance easily accumulates on the inner convex portion, and the glass in this portion is easily cracked.
[0013]
Further, according to the description of the latter publication, at the time of fusing division of the glass tube, the closing portion has a hemispherical shape, and the closing portion of the valve is blown by gas so that the inner and outer wall surfaces and the straight portion wall surface of the closing portion do not form a right angle. Has formed.
[0014]
By adopting such a configuration, the inner and outer surfaces of the closed portion have a spherical curved surface shape, and the thickness distribution is uniform and the strength can be improved with an appropriate thickness to maintain safety. is there.
[0015]
However, in the case of this latter publication, it may be possible if conditions such as glass tube, heating means such as a burner and gas blowing are constant, but it is well known that each has an allowable variation range and variation. In addition, it is extremely difficult to obtain a hemispherical closed portion having a uniform thickness due to a change due to the material and adjustment.
[0016]
In order to form and form the closed portion at the end of the glass tube, when the flat surface is used as described above, the appearance is good, but the transition portion becomes thin and the strength may be reduced. .
[0017]
In addition, when the closed portion has a hemispherical shape, the appearance is good, but in order to obtain a uniform shape and thickness, a high-precision material and a manufacturing apparatus are required, which may be expensive.
[0018]
SUMMARY OF THE INVENTION The present invention provides a fluorescent lamp with improved bulb strength and workability, and a method for manufacturing the fluorescent lamp, which can change the shape of the closed portion at the end of the glass tube into a shape having no risk of lowering the strength and can easily manufacture the same. The purpose is to:
[0019]
According to a first aspect of the present invention, there is provided a fluorescent lamp having a phosphor film on an inner surface, and a thick projection having a central portion projecting outward at least on one end surface. A glass tube in which a closed portion having a closed end is formed, a bent tube in which a plurality of glass tubes are connected in series to form a discharge path, and a glass tube at the end of the discharge path at the end of the discharge path of the bent tube. It is characterized by comprising a mounted stem, an electrode provided on the stem, and a discharge medium sealed in the bent bulb.
[0020]
The thickness of the portion from the straight portion to the closing portion of the glass tube is increased, and the thickness of the glass is increased at each portion, with the central portion being a thick convex portion protruding outward. In addition, the fluorescent substance formed on the inner surface of the glass tube is less likely to collect in the thick central portion when the glass is melted, and the fluorescent substance is not diffused to make the inside look transparent.
[0021]
In the present invention and the following inventions, the definitions and technical meanings of terms are as follows unless otherwise specified.
[0022]
The fluorescent lamp to which the present invention can be applied is formed by connecting a plurality of glass tubes to form a meandering one discharge path, and having an outer shape formed by connecting a straight glass tube to a bent glass tube assembly. And so-called compact fluorescent lamps and compact fluorescent lamps. The bulb is formed by connecting a plurality of straight tubular glass tubes into a bent shape such as a U-shape, a W-shape, a WU-shape or a WW-shape.
[0023]
The glass tube forming the bulb is applicable to soda lime glass or lead glass having an outer diameter of 10 to 20 mm and a wall thickness of about 0.8 to 1.2 mm.
[0024]
The discharge medium sealed in the bulb is mercury or a rare gas such as argon or xenon. When mercury is sealed, liquid mercury, amalgam of mercury and indium, tin, bismuth or lead, mercury and zinc, etc. It may be a mercury-releasing alloy with titanium or titanium, or a mercury pellet impregnated with mercury in a porous substrate formed of ceramic or glass. Further, a lamp which emits noble gas without mercury may be used.
[0025]
Further, the electrode is not limited to a hot cathode such as a filament coil, and may be a cold cathode, and the arrangement position may be inside or outside the bulb.
[0026]
The stem to be sealed to the end of the glass tube at the end of the discharge path is a flare stem, button stem or bead stem (mount) provided with the above electrodes, and the sealing form is burned down, butted or crushed. A stop can be applied. It is to be noted that the electrode may be provided on the glass tube in the middle part forming the bulb.
[0027]
Further, a protective film such as alumina or a transparent conductive film may be formed between the inner surface of the glass tube and the phosphor film.
[0028]
In the fluorescent lamp according to claim 2 of the present invention, the thickness of the protruding portion at the center of the closed portion of the end face is 1.5 times or more and the thickness of the periphery of the closed portion is 0.8 times the thickness of the glass tube. It is characterized by the above.
[0029]
A glass tube for forming a bulb having a normal thickness of 0.8 to 1.2 mm is used. The thickness of the convex portion at the center of the closed portion on the end face is 1.5 times or more, and the thickness around the closed portion is 0. The same effect as described in the first aspect is achieved by making the glass tube straight portion having a thickness of at least 0.8 times or more.
[0030]
In the method for manufacturing a fluorescent lamp according to the third aspect of the present invention, a stem having an electrode is sealed in a bent bulb in which a plurality of glass tubes each having a phosphor film formed on an inner surface thereof are connected in series to form a discharge path. And a method of manufacturing a fluorescent lamp in which a discharge medium is enclosed therein, wherein the glass tube constituting the bent bulb is a step of externally heating and melting a portion to be cut of the straight glass tube, and at least one of the glass tube Moving the side in a reciprocal direction along the tube axis, fusing from the portion to be cut to form a closed portion, and heating the blown tip side of the glass tube closed portion to form a glass lump; A step of shrinking the closing portion while moving the heating position from the distal end side to the base end side of the blown glass tube to form a closing portion having a thicker outwardly projecting central portion, Gradually cool the closed part of the glass tube Characterized in that it comprises the that step.
[0031]
The molten glass is heated and melted from the tip side of the stretched part to reduce the change on the inner surface side of the straight glass tube to form a molten mass, and this molten mass is left in the center and solidified to form a thick convex portion. Therefore, the influence on the inner surface side is small, and it is possible to prevent the fluorescent substance in the molten portion from gathering in a narrow range or diffusing into the molten glass.
[0032]
Also, in the process after the division, the heating of the division was performed while being moved from the center of the tip toward the straight part, and then from the transition to the center at a temperature lower than the heating in the opposite direction to the above. By performing the movement while licking the glass, the glass can be moved from the central part to the transition part and the surface can be made smooth.
[0033]
In the present invention, the configuration of the closed portion is such that a transition portion from the straight portion of the glass tube to the closed portion is gradual, and the thickness is thicker, preferably equal to or more than the thickness of the straight portion, The central portion is formed as a thick projection protruding outward, so that the glass thickness of each portion is made thicker than the material.
[0034]
Further, the working process of the present invention can be performed by a rotary or conveyor type equipment that rotates continuously or intermittently.
[0035]
DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional front view in which a part of a compact fluorescent lamp L having a substantially H-shaped bulb shape is cut away, for example, and FIGS. 2A to 2G sequentially show steps of forming a closed portion on the end face of a glass tube. It is an explanatory (front) figure shown later.
[0036]
In the drawing, reference numeral 1 denotes a bent valve having a substantially H-shape, which is formed by connecting a straight glass tube 2 or 2 made of soda lime glass or lead glass through a connecting tube 21 near one end thereof. A closing part having a convex part 31 shown in FIG. 2 (f) or (g) whose central part protrudes outward by means to be described later on the top end surface of one end side of both glass tubes 2 and 2. 3 are formed.
[0037]
In addition, a sealing portion 22 (only one side is shown) hermetically attached to a stem 4 (only one side is shown) provided with filament electrodes 5 and 5 around which a tungsten wire is wound at the base on the other end side. It is formed. The two glass tubes 2 are connected to each other via a connecting tube 21 to form a substantially U-shaped discharge path 6. Both ends of the discharge path 6 are closed by stems 4, 4. You will be doing.
[0038]
A predetermined phosphor film 25 coated with a three-wavelength rare-earth phosphor or a continuous-wave emission halophosphate phosphor is formed on the inner surfaces of the glass tubes 2 and 2 and a discharge medium is formed inside. A predetermined amount (pressure) of mercury and a rare gas such as argon, krypton, xenon, etc., alone or as a mixture.
[0039]
In the figure, reference numeral 7 denotes a GX10-type base, which is bonded to the ends of the glass tubes 2 and 2 via an adhesive (not shown) so as to cover the sealing portion 22 at the other end of the glass tubes 2 and 2. The conductors from the electrodes 5 and 5 are electrically connected to the pin terminals 71 and 71.
[0040]
The closing of the end face of the glass tube forming the bulb 1, which is an object of the present invention, is performed, for example, through the steps shown in FIGS.
[0041]
Usually, a straight glass tube cut to about twice the required length is used, and a predetermined phosphor is applied to the inner surface of the glass tube and fired to prepare a phosphor film, The central part of the glass tube is heated and melted to be cut off, and one end is similarly closed to obtain a pair of glass tubes because of good workability. After the process, only one of the glass tubes to be worked on the left side will be described in an enlarged cross section.
[0042]
First, in the first step, the portion 2B to be divided of the straight glass tube 2 is heated by a preheating gas burner 81 provided outside. (FIG. 2 (a))
In the subsequent steps, the part 2B to be cut of the glass tube 2 is heated by a plurality of ignition gas burners 82,... Disposed outside, and the glass of the part 2B to be cut is softened and melted so that the glass is placed inside. Approach. (FIG. 2 (b))
In the subsequent process, the heated gas burners 83,... Of the portion 2B to be cut off of the glass tube 2 are weakened while the straight portion 2A of the glass tube 2 is gripped and moved in the opposite direction. The thinned and thinned portions 2C are formed as they are divided and become thinner toward the tip. (Fig. 2 (c))
In the subsequent steps, a heated gas burner 83 is applied to the tip side of the stretched portion 2C of the glass tube 2 to heat it, and the molten glass is formed into a block by surface tension and moved toward the straight portion 2A (see FIG. Substantially within the dashed line A.) to form a glass reservoir 2D at the center of the tip. (Fig. 2 (d))
In the subsequent process, the heating gas burner 83 is heated while moving from the glass reservoir 2D at the central portion at the front end where it has blown toward the straight portion 2A (substantially within the dashed line A in the figure). The closing part 3 is shrink-formed. (FIG. 2 (e))
In the subsequent steps, the heating gas burner 83 is heated while moving from the straight portion 2A to the tip to form the closed portion 3 having the thickly projecting convex portion 31 at the central portion. . (FIG. 2 (f))
In the subsequent steps, a gas is introduced into the glass tube 2 and blown in the state shown in FIG. 2 (f) in the state shown in FIG. 2 (f), and the closed portion 3 is bulged as shown in FIG. 2 (g). By doing so, it is possible to make the angle of the transition portion smaller and further increase the strength.
[0043]
In the last step, the closed portion 3 of the glass tube 2 is gradually cooled by a slow cooling gas burner or a slow cooling furnace to remove distortion.
[0044]
The work process may be such that the work process is sequentially performed at the same position of a single head even if the work process position is different, such as a rotary type or a conveyor type that rotates continuously or intermittently. In the above step, it is preferable to perform the operation while rotating the glass tube or the burner, so that the glass tube or the burner can be uniformly heated and has little variation. In the above-mentioned process, it is permissible to appropriately perform blowing for blowing gas into the glass tube.
[0045]
The glass tubes 2, whose one end is closed, seal the stem 4 having the electrode 5 in the opening at the other end. Next, the straight portion 2A near the closed portion 3 on the opposite side of the two glass tubes 2 and 2 where the stem 4 is sealed is heated, and when melted, gas is blown into the glass tube through the exhaust pipe of the stem 4. As a result, the molten portion is blown off to form a hole. Then, while the perforated portion is in a softened state, the perforated portion and the perforated portion of another similarly perforated glass tube 2 face each other, and both glass portions protruded outward by perforation. Are fused to form a connecting tube 21, and a bulb 1 in which both glass tubes 2 and 2 are joined in a substantially H-shape in a state of being closely parallel to each other is completed.
[0046]
Next, while the bulb 1 is heated in a heating furnace or the like, an impurity gas generated from the glass, the phosphor film 25, the electrode material, and the like is introduced into the bulb 1 through an exhaust pipe provided in the stem 4 of the glass tubes 2 and 2. When the inside of the bulb 1 reaches a predetermined cleanliness level, a discharge medium such as mercury and a rare gas is introduced into the bulb 1, and the exhaust pipe is hermetically sealed.
[0047]
The bulb 1 is subjected to a predetermined aging, and the base 7 is joined to the sealing portions 22 and 22 via an adhesive or the like to complete the compact fluorescent lamp L.
[0048]
In the above-mentioned working process, after connecting the glass tubes 2 and 2 with the connecting tube 21 to form the bulb 1, the stem 4 is sealed to the end of each of the glass tubes 2 and 2, or the glass tubes are connected to each other. Some operations, such as forming a phosphor film after the above, may be mixed up, but this may be done. Further, the connecting tube 21 connecting the two glass tubes 2 may be connected using another glass tube.
[0049]
The cleaning operation in the valve 1 may be performed using the exhaust pipes of both the stems 4 and 4, or may be performed using only one of the exhaust pipes. In the case where a mercury structure is provided in advance on the stem 4 or the like, it is unnecessary to introduce mercury after the cleaning operation.
[0050]
When the base 7 is connected to a lighting device (not shown) and energized, the compact fluorescent lamp L having the above-described configuration emits a discharge between the electrodes 5 and 5 in the same manner as a normal lamp, and is lit. .
[0051]
In the present invention, the configuration of the closing portion 3 is made such that the transition from the straight portion 2A of the glass tube 2 to the closing portion 3 is gradual as shown in (f) or (g) of FIG. By making the thickness thicker, preferably equal to or more than the thickness of the straight portion 2A, and making the central portion a thick convex portion 31 protruding outward, the glass thickness of each portion is made thicker than the material. ing.
[0052]
In addition, after the glass tube 2 is cut, the molten tube is heated and melted from the distal end side of the stretched portion 2C so as to reduce the change on the inner surface side of the glass tube 2 to form a molten mass. Since the remaining convex portion 31 is solidified to form the thick convex portion 31, the influence on the inner surface side is small, and the phosphor in the molten portion can be prevented from gathering in a narrow range or being diffused into the molten glass. In 3, the occurrence of cracks due to the entry of foreign matter can be suppressed.
[0053]
In the process after the division, heating of the divided portion is performed while moving from the center of the tip toward the straight portion 2A, and then moving at a temperature lower than the heating from the transition portion to the center. While moving the glass from the central part to the transition part, the surface could be made smooth.
[0054]
The feature of the lamp L is that the entire structure of the glass closing portion 3 that seals the end face of the bulb 1 that is most likely to collide with other objects during the working process or after the lamp is completed and that is apt to be damaged is generally described. The valve is formed to be thicker and the central portion is formed so as to be a convex portion 31 protruding outwardly at the thicker portion. Therefore, the yield and the ease of handling that can reduce the damage of the valve 1 are improved, and the closing portion 3 is improved. It is possible to provide a fluorescent lamp L that has less damage to the phosphor film 25 on the inner surface and has a good appearance when turned on.
[0055]
The present inventors compared the intensity of the fluorescent lamp according to the present invention with that of the conventional lamp having a closed portion of a glass tube shown in FIGS. 5A and 5B. The result shown in FIG.
[0056]
This strength test was carried out based on the Japan Light Bulb Industry Standard JEL601 (“General rules for safety confirmation test of light source products”, published on December 6, 1996).
[0057]
This test is also called a steel ball test, and the test method is such that the glass tube 2 forming the bulb 1 is vertically supported by the closed portion 3 in an upward vertical direction, and the weight of the closed portion 3 is 1. A 5 g steel ball was dropped at different heights, and its breaking strength (steel ball weight g × fall height cm) was examined.
[0058]
In FIG. 3, the horizontal axis represents the glass thickness (mm) at the center of the closed part, the vertical axis represents the breaking strength (g · cm), and the I-line represents the fluorescent lamp having the closed part according to the present invention. Line b) is a lamp of the same shape with the conventional blockage shown in FIGS. 5A and 5B for comparison.
[0059]
FIG. 4 is a graph in which the thickness of the central portion of the closed portion and the thinnest portion of the lamp of the material subjected to the steel ball test of FIG. 3 are measured. The horizontal axis represents the glass thickness of the central portion of the closed portion. (Mm), the vertical axis is the glass thickness (mm) of the thinnest part.
[0060]
As is clear from the results of FIGS. 3 and 4, the strength of each lamp increases as the wall thickness at the center increases, and the lamp of the present invention has an improved strength due to the thicker glass than the conventional lamp. Was done.
[0061]
The present invention is not limited to the above embodiment, but can be applied to other compact fluorescent lamps having a bulb shape of WH or a bulb-type fluorescent lamp similarly forming a bulb by connecting a straight glass tube.
[0062]
In addition, it is necessary to form closed portions at both ends of a glass tube connected in the middle of a WH type or the like. Instead, even if cutting is performed for each predetermined length, closed portions can be formed at both ends.
[0063]
According to the first aspect of the present invention, since the strength and appearance of the closed portion at the end of the glass tube forming the bulb are improved, it is possible to reduce the occurrence of breakage such as cracks in the closed portion during lamp handling. It is possible to provide a fluorescent lamp of a compact type, a light bulb type, or the like that is resistant to peeling and impact resistance.
[0064]
According to the second aspect of the present invention, it is possible to provide a fluorescent lamp having the same effect as the first aspect by regulating the glass thickness ratio of the glass tube and the closed portion of the end portion.
[0065]
According to the third aspect of the present invention, the transition from the straight portion of the glass tube to the closing portion is gradual, and the thickness is thick, preferably equal to or more than the thickness of the straight portion, and the center of the closing portion is Since the thick convex part that protrudes the part outward is created, the influence on the inner surface is small and the phosphor in the glass melting part gathers in a narrow range and diffuses into the molten glass. It is possible to provide a method of manufacturing a fluorescent lamp which can prevent the occurrence of cracks and the like due to contamination by foreign matter in the closed portion.
[Brief description of the drawings]
FIG. 1 is a partially cutaway front view showing an embodiment of a fluorescent lamp of the present invention.
FIGS. 2 (a) to 2 (g) are explanatory diagrams sequentially showing steps of forming a closed portion at one end of a glass tube constituting a bulb of the lamp of the present invention.
FIG. 3 is a graph showing the strength of a closed portion of a glass tube of the present invention and a conventional fluorescent lamp.
FIG. 4 is a graph in which the wall thickness of the central portion and the thinnest portion of the closed portion of the glass tube of the present invention and the conventional fluorescent lamp is measured.
FIG. 5 is an enlarged sectional front view showing a closed portion at one end of a glass tube constituting a bulb of a conventional fluorescent lamp.
[Explanation of symbols]
L: fluorescent lamp (compact fluorescent lamp), 1: bulb, 2: glass tube, 21: connecting tube, 22: sealing portion, 25: phosphor film, 3: closing portion, 31: convex portion, 4: stem , 5: electrode, 6: discharge path,

Claims (3)

A glass tube having a phosphor film on the inner surface and a closed portion formed on at least one end surface of the end surface having a thick convex portion whose central portion protrudes outward;
A bent bulb in which a plurality of the glass tubes are connected in series to form a discharge path;
A stem sealed to the end of the glass tube at the end of the discharge path of the bent bulb;
An electrode provided on the stem;
A discharge medium enclosed in the bent bulb;
A fluorescent lamp comprising: The thickness of the protruding portion at the center of the closed portion on the end face is 1.5 times or more and the thickness around the closed portion is 0.8 times or more with respect to the thickness of the glass tube. The fluorescent lamp as described. A method of manufacturing a fluorescent lamp in which a plurality of glass tubes each having a phosphor film formed on an inner surface thereof are connected in series to form a discharge path to form a discharge bulb, in which a stem having electrodes is sealed and a discharge medium is sealed inside. ,
The glass tube constituting the bent bulb is
A step of externally heating and melting a portion to be cut of the straight glass tube;
Moving at least one side of the glass tube in a reciprocal direction along the tube axis and fusing from a portion to be cut to form a closed portion;
Heating the blown tip side of the glass tube blockage to form a glass block;
A step of shrinking the closing portion while moving the heating position from the distal end side to the base end side of the glass tube which has been blown, to form a closing portion having a thick-walled outwardly projecting central portion;
Gradually cooling the closed part of the glass tube;
A method for manufacturing a fluorescent lamp, comprising:

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