JPH0447418B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a discharge lamp in which a plurality of discharge tubes are connected through a connecting portion.

BACKGROUND ART Conventionally, a compact fluorescent lamp in which four linear discharge tubes are connected through a connecting portion is known. That is, it has four linear discharge tubes arranged in parallel with a square cross section, the first discharge tube and the second discharge tube are connected at the first connection part, and the second discharge tube and the third discharge tube are connected at the first connection part. The discharge tube is connected to the second connecting part, and the third discharge tube and the fourth discharge tube are connected to each other by the third connecting part, and one end of each discharge tube is closed and the other end is sealed. death,
Electrodes are provided at the first discharge tube and the fourth discharge tube among the other ends thereof. In this fluorescent lamp, the first to fourth discharge tubes are communicated via the first to third connecting portions, and discharge occurs between one electrode and the other electrode.

Problems to be Solved by the Invention However, if a cap is fixed to one end of such four discharge tubes with a cap adhesive used in general fluorescent lamps, the discharge tubes will thermally expand during lighting, causing discharge to occur. The problem is that as the tubes move outward, a force is generated that tends to widen the distance between the discharge tubes, and this force is applied to the connection part located on the opposite side of the cap, causing cracks to occur near this connection part. It was hot.

The present invention provides a discharge lamp that can sufficiently maintain the fixation strength of the cap during lighting and can prevent cracks from occurring near the joints of the discharge tube.

Means for Solving the Problems In order to solve these problems, the discharge lamp of the present invention has a plurality of discharge tubes connected through a connecting part, and two of the discharge tubes are having an electrode at one end of the discharge tube, providing a cap at one end of the plurality of discharge tubes, and fixing the cap to the electrode side end of the discharge tube with a cap adhesive made of a thermosetting resin;
The cap is fixed to the non-electrode side end of the discharge tube with thermoplastic resin.

Function Since the electrode side ends of the discharge tube are fixed to the cap with a cap adhesive made of thermosetting resin, it is possible to prevent the cap adhesive from deteriorating due to temperature rise at these ends during lighting. . In addition, although multiple discharge tubes thermally expand during lighting and try to move outward, the cap fixation strength can be maintained sufficiently, while the non-electrode side end of the discharge tube is made of thermoplastic material. Since the resin is attached to the cap, the thermoplastic resin softens, allowing the end of the discharge tube to move outward.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the fluorescent lamp according to the embodiment of the present invention includes four linear discharge tubes 1, 2, 3, and 4 arranged close to each other and in parallel with a square cross section.
The discharge tube 1 and the second discharge tube 2 are connected at the connection part 5, the second discharge tube 2 and the third discharge tube 3 are connected at the connection part 6,
The third discharge tube 3 and the fourth discharge tube 4 are connected by a connecting portion 7 (see FIG. 3). As a result, the discharge tubes 1, 2, 3, 4 connect to the connecting portions 5, 6, 7.
communicated through. One end of the discharge tubes 1, 2, 3, and 4 is closed, and a stem is sealed at the other end, and a pair of internal lead wires are implanted in each of the stems of the discharge tubes 1 and 4. Electrodes 8 and 9 are held between the respective internal lead wires. Note that the other end of the discharge tubes 2 and 3 may not be sealed with a stem, but may have a structure in which the other end is closed in the same way as the one end. Also, as shown in Figure 4,
The discharge tubes 1, 2, 3, and 4 have a phosphor coating 10 formed on the inner surface of a glass tube made of lead glass, and mercury and a rare gas are sealed inside. discharge tube 1,
A synthetic resin base 11 made of polycarbonate resin is fixed to one end of each of 2, 3, and 4.

The cap 11 has a two-part structure, and as shown in FIG. Holes 14, 15, 16, 17 are provided. As shown in FIG. 6, the back surface of the cap body 12 is provided with a cross-shaped projection 18, and the inner surface is formed with four engaging projections 19 and a large number of ribs 20 extending around the entire circumference. In the figure, only a portion of the ribs are shown and the rest are omitted). Figure 7 is the 5th
A sectional view taken along the - line in the figure is shown. On the other hand, as shown in FIG. 8, four engagement grooves 21 are provided on the outer surface of the other cap body 13, and a cylindrical protrusion 22 is provided on the bottom surface. Four pins 23 are provided on the bottom surface. By fitting and fixing the engagement protrusions 19 into the engagement grooves 21, the cap bodies 12, 1
It integrates 3.

FIG. 9 shows a bottom view of the other base body 13. In FIG. 9, reference numeral 24 denotes a notch for preventing misuse, and its position is slightly different depending on the wattage of the fluorescent lamp. Therefore, the combination of this fluorescent lamp with a compatible ballast can be ensured.

The structure for fixing the cap 11 to the other end of the discharge tubes 1, 2, 3, and 4 is as follows.

That is, as shown in FIG.
Discharge tubes 1, 2,
The other parts 3 and 4 are inserted through with a slight gap. A cap adhesive 25, which is used in general fluorescent lamps, is applied between approximately half the inner surface of the cap body 12 and the electrode-side ends of the discharge tubes 1 and 4, and between the electrode-side ends thereof. A resin such as a phenolic resin is provided between a portion of the remaining approximately half circumference of the inner surface of the cap body 12 and the non-electrode side ends of the discharge tubes 2 and 3, and between the non-electrode side ends thereof. , and between the electrode side ends of the discharge tubes 1 and 4 and the non-electrode side ends of the discharge tubes 2 and 3, a thermoplastic resin 26 made of polyamide resin or the like is provided. That is, at the non-electrode side ends of the discharge tubes 2 and 3, the base body 1
There is a portion where the thermoplastic resin 26 is not provided between the inner surface of the thermoplastic resin 26 and the inner surface of the thermoplastic resin 26. With the above configuration, the cap body 12 is attached to the end of the discharge tubes 1, 2, 3, and 4.
As a result, the cap 11 is fixed.

Now, when power supply voltage is applied between electrodes 8 and 9 via pin 23, electrode 8 → discharge tube 1 → connecting part 5 →
One discharge path is formed by the path of discharge tube 2 → connection part 6 → discharge tube 3 → connection part 7 → discharge tube 4 → electrode 9 or the opposite direction, and a discharge is started between electrodes 8 and 9. , the fluorescent lights turn on. Then, the discharge tubes 1, 2, 3, and 4 expand thermally, and the discharge tubes 2 and 3, and the discharge tubes 1 and 4, each try to move outward.

In this case, if the cap body 12 is fixed to all the ends of the discharge tubes 1, 2, 3, and 4 using only the cap adhesive 25 made of thermosetting resin, the discharge tubes 1,
Since the ends of 2, 3 and 4 cannot move outwards, the connections 5 and 7 are strained, thereby causing cracks in the vicinity of these connections.

However, in the fluorescent lamp according to the embodiment of the present invention,
Since the cap body 12 is fixed to the electrode side ends of the discharge tubes 1 and 4 with a cap adhesive 25 made of thermosetting resin, the cap fixing strength is prevented from decreasing due to temperature rise at these ends during lighting. As a result, the fixing strength of the cap 11 to the ends of the discharge tubes 1, 2, 3, and 4 can be maintained sufficiently, and the cap body 12 can be attached to the non-electrode side ends of the discharge tubes 2, 3. Since the thermoplastic resin 26 is fixed, the thermoplastic resin 26 becomes soft during lighting, and gaps are formed between the ends of the discharge tubes 3 and 4 and the holes 15 and 16, so that the discharge The ends of the tubes 3, 4 are allowed to move outwards. Therefore, according to the fluorescent lamp having such a structure, it is possible to reliably prevent the occurrence of cracks in the vicinity of the connecting portions 5 and 7 due to distortion of the connecting portions 5 and 7.

Note that it is not preferable to fix the cap body 12 to all the ends of the discharge tubes 1, 2, 3, and 4 with the thermoplastic resin 26 because the fixation strength of the cap during lighting will be insufficient.

Further, in the above embodiment, a case was explained in which four discharge tubes, that is, two pairs of discharge tubes were used, but it is clear that the present invention can be implemented with a discharge lamp using at least two pairs of discharge tubes.

Effects of the Invention As explained above, the present invention includes a plurality of discharge tubes connected to each other via a connecting portion, two of the discharge tubes have an electrode at one end, and the plurality of discharge tubes have an electrode at one end. A cap is provided at one end of the discharge tube, and the cap is fixed to the electrode side end of the discharge tube with a cap adhesive made of thermosetting resin, while the cap is fixed to the non-electrode end of the discharge tube using thermoplastic resin. By fixing with resin, it is possible to maintain sufficient adhesion strength of the cap to the ends of multiple discharge tubes during lighting, and also to ensure that cracks do not occur near these coupling parts due to distortion of the coupling parts during lighting. It is possible to provide a discharge lamp that can prevent this.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of a fluorescent lamp according to an embodiment of the present invention, Fig. 2 is a perspective view of the same fluorescent lamp, Fig. 3 is a diagram showing the communication state of the discharge tubes in the fluorescent lamp, and Fig. 4
The figure is a partially cutaway front view of the same fluorescent lamp, Figure 5 is a plan view of one base body, Figure 6 is a bottom view of the base body, and Figure 7 is a cut along the - line in Figure 5. A sectional view, FIG. 8 is a perspective view showing a part of the other mouthpiece body with a cutaway, and FIG. 9 is a bottom view of the other mouthpiece body. 1, 2, 3, 4...discharge tube, 5,6,7...connection section, 8,9...electrode, 10...phosphor coating, 1
1...cap, 12,13...cap body, 14,1
5, 16, 17...hole, 25...cap adhesive, 2
6...Thermoplastic resin.

Claims (1)

[Claims] 1 Consisting of a plurality of discharge tubes connected through a connecting part, two of the discharge tubes have an electrode at one end, a cap is provided at one end of the plurality of discharge tubes, and the discharge tube A discharge lamp characterized in that the cap is fixed to the electrode side end of the tube with a cap adhesive made of a thermosetting resin, and the cap is fixed to the non-electrode side end of the discharge tube with a thermoplastic resin. .