JP4624337B2 - Fluorescent lamp - Google Patents

Description

  The present invention relates to a fluorescent lamp, and more particularly to a fluorescent lamp in which a part for preventing overheating of an electrode portion when a filament of the fluorescent lamp reaches the end of its life is provided in the base.

  The fluorescent lamp has an arc tube in which a phosphor film is formed on the inner surface and stems are formed at both ends, and a base that fixes an end of the arc tube and is connected to an external power source with a pair of base pins. ing. At both ends of the fluorescent lamp, one end is connected to the base pin, the other end is connected to the inside of the arc tube via the stem, and a pair of metal lead wires are connected to the other end of each lead wire. The filament is provided.

  In the fluorescent lamp, when the filament is energized, the heated electron-emitting substance emits thermoelectrons, which collide with mercury in the arc tube to generate ultraviolet rays, and the ultraviolet rays cause the phosphors in the arc tube to illuminate. Excites and generates visible light.

  The electron-emitting material filled in the filament is worn away by scattering or evaporation during lighting, and eventually is exhausted, and the fluorescent lamp reaches the end of its life. However, the depletion of the electron-emitting substance does not occur simultaneously with a pair of filaments, but usually occurs first with one filament. In such a case, electrons are not emitted from the filament on the depletion side, and discharge occurs only from the filament on one side.

  As a ballast for lighting a fluorescent lamp, an electronic ballast for lighting a fluorescent lamp by oscillating at a high frequency of several tens of KHz is generalized. Electronic ballasts have the advantage of reducing the power used for illumination because they are less flickering and less lossy than conventional ballasts. However, on the other hand, since the current supply capability is high, the electrode portion that has reached the end of its life and is depleted of the electron-emitting material and has no ability to discharge may be abnormally heated. The process of this abnormal overheating varies depending on the circuit system and the like, but no clear cause has been specified. Therefore, in order to prevent this abnormal overheating, it is common to provide a detection circuit for detecting the depletion of the electron-emitting substance in the electronic ballast, and to provide a circuit for stopping the discharge in the lighting circuit of the electronic ballast.

  The base of the fluorescent lamp is provided with a base pin for connecting the electrode part of the fluorescent lamp and the lighting circuit, and the lead wire connected from the filament of the electrode part and the base pin are connected by pressure contact. . A fluorescent lamp in which a protective element for protecting an abnormal temperature rise of the electrode portion at the end of the life is provided in the base has been put on the market.

For example, in the fluorescent lamp disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 10-188906), a temperature protection element that makes a current cut-off state in response to heat generated in the electrode sealing portion includes an electrode lead wire and a lead terminal in the base portion. It is provided between. In the discharge lamp lighting device disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 10-188906), a negative temperature characteristic resistance element that can prevent heating of the discharge lamp even when the filament is disconnected and a short-circuit current flows through the deposited film is in parallel with the filament. Is provided. In the fluorescent lamp disclosed in Patent Document 3 (Japanese Patent Application Laid-Open No. 11-111231), a thermal fuse is disposed in the connection space between the hot cathode electrode and the contact so as to be exposed in the internal space of the base. . In the low-pressure mercury vapor discharge lamp of Patent Document 4 (Japanese Patent No. 3327224), a temperature protection element is provided in series with one electrode external lead wire in the base, and the connection with the electrode external lead wire is connected to the inside of the base. It is connected by caulking to the installed caulking terminal.
JP-A-10-188906 JP-A-10-188906 JP-A-11-111231 Japanese Patent No. 3327224

  As disclosed in Patent Document 1 to Patent Document 4 described above, the protective element for preventing an abnormal temperature rise in the electrode section at the end of the life is connected in series or in parallel with the filament via the lead wire. The protective element is usually connected to the lead wire by soldering or welding.

  An example of a conventional method for attaching an electrode portion abnormal temperature rise protection element will be described with reference to the drawings. Here, the same components as those in the embodiments described later will be described using the same reference numerals as those in the embodiments.

  FIG. 4 is a schematic cross-sectional side view of the structure inside the base of the fluorescent lamp of the conventional example and the structure inside the fluorescent tube. The fluorescent lamp 1 includes an arc tube 11 having a phosphor film 13 formed on the inner surface and a stem 12 made of a glass member for fixing the filament 31 at both ends, and an end of the arc tube 11 fixed. Each end portion has a base 21 that is connected to an external power source by a pair of base pins 22.

  At both ends of the fluorescent lamp 1, one end is connected to the base pin 22 and the other end is connected to the inside of the arc tube 11 through the stem 12, and the other end of each lead wire 32. And a filament 31 having both ends connected to each other. The surface of the filament 31 is filled with an electron emitting substance. Mercury and rare gas are sealed inside the arc tube.

  Further, a resistor 34, which is a protective element for protecting the abnormal temperature rise of the electrode portion, is connected to the lead wire 32 and the solder so that the filament 31 is parallel to the pair of lead wires 32 in the base 21 of the fluorescent lamp 1. Alternatively, they are connected by welding.

  When the fluorescent lamp is normally lit, a high-frequency current of several tens of KHz is input from the lighting circuit to the filament through the lead wire. In the case of connection by soldering or welding, if there is a portion with high resistance due to contact resistance in the connected portion, not only will heat be generated at that portion, but excess power will be consumed, and the resin that forms the base 21 due to heat generation at this portion Has the potential to promote the degradation of

  In the low-pressure mercury vapor discharge lamp described in Patent Document 4, the connection between the temperature protection element and the electrode external lead wire is caulked to a caulking terminal implanted in the base, and the possibility of heat generation in this portion However, it is necessary to provide a dedicated caulking terminal for connection.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fluorescent lamp having a cap pin that can be connected by caulking a connecting wire of a protective element for preventing an abnormal temperature rise of an electrode simultaneously with a lead wire from a filament.

The fluorescent lamp of the present invention is
A fluorescent lamp having an arc tube having a phosphor film formed on the inner surface and stems formed at both ends, and a base for fixing the end of the arc tube, provided at both ends of the arc tube, and having one end A pair of lead wires connected to the base and having the other end extending into the arc tube via the stem, a filament having both ends connected to the other end of each lead wire, and a pair of lead wires are provided. A varistor for protecting an abnormal temperature rise of the electrode part, and a hollow part provided on the base, into which one end of at least one lead wire and one connecting line of the varistor can be inserted so as to be press-contacted, And a cylindrical cap pin that can be connected to the power source.

It is preferable that one end of the lead wire, the connection line of the varistor , and the inner surface of the base pin are pressed by pressing from the outside of the base pin.

  There may be one place where the base pin is pressed from the outside, and there may be a plurality of places where the base pin is pressed from the outside.

  Since at least the lead wire and the connection line of the protection element are inserted into the inside of the cylindrical base pin so as to be press-contactable with the base pin, heat generation due to the resistance of the contact portion between the lead line and the connection line of the protection element is prevented. .

  In the present invention, since at least the lead wire and the connection line of the protective element are inserted into the cylindrical base pin so as to be press-contactable with the base pin, the resistance is the same as the connection between the base pin of the normal fluorescent lamp and the lead wire. There is an effect that heat generation due to the resistance of the contact portion between the lead wire and the connection line of the protective element is prevented. In addition, even if the temperature rises, the danger is reduced compared to the case where the temperature rises in the base resin because of the metal member. Furthermore, there is an effect that the step of directly connecting the lead wire and the connection line of the protection element can be omitted.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view of a fluorescent lamp according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional side view of the structure inside the base of the fluorescent lamp shown in FIG. Here, a circular fluorescent lamp will be described as an example. However, in a straight tube fluorescent lamp, the same effect can be obtained by making each base part the same configuration. This will be collectively referred to as a lamp.

  In the fluorescent lamp according to the embodiment of the present invention, when the protective element provided to prevent the electrode part from being abnormally heated at the end of the life of the fluorescent lamp is attached to the lead wire, the resistance at the connection part is not increased. Can connect. In the present embodiment, the protection element is described as a resistance element. However, the protection element is not limited to a resistance element, and may be a varistor, a thermal fuse, or the like.

  The fluorescent lamp 1 according to the embodiment of the present invention includes an arc tube 11 having a phosphor coating 13 formed on the inner surface and formed with stems 12 made of glass members for fixing filaments 31 at both ends, and the arc tube 11. The base 21 is fixed and each end is connected to an external power source by a pair of base pins 22. The ring-shaped fluorescent lamp shown in FIGS. 1 and 2 has a single base 21, but a straight tube fluorescent lamp is divided into two bases each having two base pins. Each is attached to both ends.

  At both ends of the fluorescent lamp 1, one end is connected to the base pin 22 and the other end is connected to the inside of the arc tube 11 through the stem 12, and the other end of each lead wire 32. And a filament 31 having both ends connected to each other. The surface of the filament 31 is filled with an electron emitting substance. Mercury and rare gas are sealed inside the arc tube.

  An electronic ballast (not shown) that drives the fluorescent lamp 1 supplies only a low voltage to the filament 31 of the electrode portion 30 of the fluorescent lamp 1 during normal lighting, but the electron emitting material applied to the filament 31 is depleted and has a long life. At that time, a high voltage is supplied from the electronic ballast to continue the discharge in an attempt to discharge electrons, thereby causing a large current to flow through the lead wire 32 and the filament 31, which causes abnormal overheating near the electrode portion 30. It was.

  In order to prevent the abnormal overheating, as explained in the problem to be solved by the invention, the lead wire 32 is connected to the lead wire 32 so as to be in series or in parallel with the electrode 31 for protecting an abnormal temperature rise of the electrode portion such as a resistor or a thermal fuse. The protective element was connected to the lead wire by soldering or welding.

  FIG. 3 is a schematic explanatory view of a cap pin according to an embodiment of the present invention, where (a) is a side view, (b) is a cross-sectional view, and (c) is a lead wire and resistor connection wire inserted therein. FIG. 6D is a cross-sectional view showing a state in which the lead wire inserted into the base pin and the resistor connecting wire are pressed against each other.

  The base pin 22 has a cylindrical shape having electrical conductivity, and has a flange portion to be fixed to the base 21 on the outside in the vicinity of the center portion. Conventionally, the lead wire 32 is inserted into the cylindrical portion of the base pin 22 and the cylindrical portion is crimped to press-contact the base pin 22 and the lead wire.

  In the present embodiment, at least the lead wire 32 and the connecting wire 34a of the protective element can be inserted into the cylindrical cap pin 22. The lead wire 32 and the protective element connection line 34a are inserted into the inside of the cylindrical cap pin 22, and the portion where the lead wire 32 of the cap pin 22 and the protective element connection line 34a are inserted is pressed from the outside. By deforming, the lead wire 32, the connecting wire 34a, and the inner wall surface of the cap pin 22 are pressed against each other. As a result, the connection line 34a of the protection element is in strong contact with the lead wire 32 and the inner wall surface of the cap pin 22 and is electrically connected. As a result, heat generation due to the resistance of the contact portion between the lead wire 32 and the connection line 34a of the protective element is prevented.

  In addition, the connection portion is not provided in the resin of the base 21, and the resin can be prevented from being melted or damaged even when the temperature of the connection portion is increased. Further, since it is not necessary to connect the connecting wire 34a of the protective element to the lead wire 32 by soldering or welding, the process is saved.

  When the protective element is provided in parallel with the filament 31, the connection wires 34a on both sides of the protective element can be directly crimped to the cap pin 22 as shown in FIG. 2, but the protective element is provided in series with the filament. One of the connecting wires 34 a needs to be directly joined to the lead wire 32 of the filament 31. However, since the other connection line 34a is crimped to the cap pin 22, the overall safety is enhanced.

  In FIG. 3, the pressure contact portion 22a is one place, but it may be pressed by a plurality of pressure contact portions 22a in one cap pin, and safety is further improved.

It is a typical perspective view of the fluorescent lamp of an embodiment of the invention. FIG. 2 is a schematic cross-sectional side view of the structure inside the base of the fluorescent lamp of FIG. 1 and the structure inside the fluorescent tube. It is typical explanatory drawing of the cap pin of embodiment of this invention, (a) is a side view, (b) is sectional drawing, (c) is the state by which the lead wire and the resistor connection line were inserted in the inside. FIG. 4D is a cross-sectional view showing a state in which the lead wire inserted into the base pin and the resistor connecting wire are pressed against each other. It is a typical cross-sectional side view of the structure inside the base of the fluorescent lamp of the conventional example and the structure inside the fluorescent tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fluorescent lamp 11 Arc tube 12 Stem 13 Phosphor film 21 Base 22 Base pin 22a Pressure contact part 30 Electrode part 31 Filament 32 Lead wire 34, 134 Resistor 34a Resistor connection line

Claims (4)

A fluorescent lamp having an arc tube having a phosphor film formed on the inner surface and stems formed at both ends, and a base for fixing an end of the arc tube,
A pair of lead wires provided at both ends of the arc tube, one end connected to the base and the other end extending into the arc tube via the stem, and both ends connected to the other end of each lead wire Filaments that have been
A varistor for protecting an abnormal temperature rise of the electrode provided between the pair of lead wires;
A cylindrical cap that is provided in the base and has a hollow portion into which one end of at least one lead wire and one connecting wire of the varistor can be press-contacted and can be connected to an external power source. And a fluorescent lamp. The fluorescent lamp according to claim 1, wherein
One end of the lead wire, the connection line of the varistor , and the inner surface of the base pin are pressed against each other by pressing from the outside of the base pin. The fluorescent lamp according to claim 1 or 2,
The fluorescent lamp has one pressing portion from the outside of the cap pin. The fluorescent lamp according to claim 1 or 2,
The fluorescent lamp has a plurality of pressing points from the outside of the cap pin.

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