JPS6144365Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a high-pressure sodium lamp in which a starter device is built into an outer bulb housing the arc tube together with the arc tube. In particular, the bimetal switch in the starter is made easier to adjust to stabilize its operation, and the starter's assembly and installation inside the outer bulb are improved.

High-pressure sodium lamps, which have sodium, mercury, and dilute scum sealed inside an arc tube made of translucent ceramic, generally have a high starting voltage of 2 to 3 kV, and cannot be started simply by applying a normal commercial power supply voltage. Therefore, recently, as shown in Fig. 1, a starting device consisting of a bimetal switch 2 and a tungsten filament 3 connected in series was connected in parallel to the arc tube 1 of a high-pressure sodium lamp, and these were housed in an outer bulb 4. In addition, a lamp configured to be connected to an AC power source 6 via a chiyoke coil 5 has been proposed. With this configuration, current flows through the series circuit of the bimetal switch 2 that turns on the AC power supply 6 and the tungsten filament 3, and the heat generated by the tungsten filament 3 causes the bimetal switch 2 to open and close. Then, a high voltage pulse is generated in the choke coil 5, and this is applied to the arc tube 1 along with the power supply voltage, so that the lamp can be easily started. In such a configuration, the tungsten filament 3
is for controlling the high voltage pulse generated by limiting the current flowing to the starting device to a value necessary and sufficient for starting the lamp. Taking a 400W high-pressure sodium lamp as an example, approximately
The resistance value is set so that a current of 1A flows.
However, tungsten filaments with such resistance values generally have a considerably long overall length, so conventionally,
For example, as shown in FIG. 2, a method is adopted in which a tungsten filament 3 is wound around the arc tube 1, or an anchor wire is erected on a separately provided insulating plate and the anchor wire is strung thereupon. However, when the tungsten filament is wrapped around the arc tube, not only does the luminous flux during lamp lighting decrease, but also mechanical and thermal shocks are applied to both, which tends to cause deformation of the tungsten filament and cracking of the arc tube. Furthermore, although the means for stretching a tungsten filament on an insulating plate does not have the above-mentioned drawbacks, there are problems in how compactly it can be constructed and how to select the mutual relationship of the positions of the bimetal switches. In addition, in the above configuration, the bimetal switch 2 conventionally has one end of a bimetal piece provided with an opening/closing contact at the tip thereof fixed to an arc tube supporting conductor or a tungsten filament supporting insulating plate, and the opening/closing contact is fixed to an arc tube supporting conductor or a tungsten filament supporting insulating plate. It was constructed by making contact with a fixed contact that cannot be finely adjusted and is mounted on an insulating plate.

However, in devices using such bimetal switches, the height of the high voltage pulse is not constant due to variations in the operation of the bimetal switch, mainly due to variations in opening and closing speed caused by differences in the contact pressure of the opening and closing contacts. A major drawback was that the characteristics were unstable.

The present invention has been made to solve all the drawbacks of conventional lamps equipped with a starting device as described above, and aims to provide a high-pressure sodium lamp which has the following features: the contact pressure of the opening and closing contacts of the bimetal switch in the starting device can be adjusted, thereby obtaining a high-voltage pulse of a constant height, thereby stabilizing the starting characteristics; the starting device can be easily assembled and installed in the lamp, and the emitted light flux is not obstructed.

Hereinafter, the present invention will be explained based on illustrated embodiments. FIG. 3 is a front view showing an embodiment of the high-pressure sodium lamp according to the present invention, FIG. 4 is a front view of the main part thereof, and FIG. 5 is a side view of the main part. In the figure, reference numeral 1 denotes an arc tube made of translucent ceramic, with electrodes sealed at both ends and sodium, mercury, and dilute scum sealed inside. The arc tube 1 is supported by arc tube supports 8a and 8b by lead wires 7 made of a material such as tantalum, and is housed inside the outer bulb 4. At least one end of the arc tube 1 inside the outer bulb 4 is provided with a starter device in which the tungsten filament 3 and the bimetal switch 4 are mounted on an insulating plate 9 in the configuration and positional relationship described below. be.

Next, such a starting device will be explained in detail based on FIGS. 6 to 12. Figures 6a and 6b are a front view and a plan view of an insulating plate for attaching a tungsten filament and a bimetal switch. An appropriate number of anchor wire attachment holes 11a, 11 are provided along the edge of the shape.
b, 11c... and the mounting groove 12 connected thereto
A structure in which a, 12b, 12c, . . . are provided is used. FIGS. 7a, b, c, and d show a front view, a plan view, and left and right side views of the bimetal switch mounted on the insulating plate 9 as described above. However, the anchor wire attachment hole and attachment groove of the insulating plate 9 are omitted. In such a structure, when attaching a bimetal switch to the insulating plate 9,
First, a pair of struts 13a and 13b having threaded portions are temporarily fixed in the strut holes of the insulating plate 9 using nuts 14a and 14b.

Next, on one of the pillars 13a, there is an opening/closing contact 15 at the tip.
One end of the bimetal piece 16 provided with is fixed by spot welding or the like.

Further, the opening/closing contact 1 is provided on the other support 13b.
A rod-shaped opening/closing contact 17 that contacts the support 13b is fixed by spot welding or the like in a direction perpendicular to the support 13b. The contact pressure of the bimetal switch thus assembled is adjusted as follows.

First, the support 13a to which the bimetal piece 16 is fixed
By rotating in the direction of the arrow mark, the contact pressure is largely adjusted, and then the nut 14a is tightened to completely fix the support column 13a. Furthermore, when performing fine adjustment of the contact pressure, the support 13b to which the rod-shaped opening/closing contact 17 is fixed is rotated in the direction of the arrow. Then, the 8th
As shown in the figure, since the tip of the rod-shaped opening/closing contact 17 moves greatly as shown by the dotted line, the support 13b
Just by rotating the switch slightly, the opening/closing contacts 15, 17
The contact pressure between the two can be finely adjusted. After adjustment, the support column 13b is completely fixed with the nut 14b.

Next, a case will be described in which a tungsten filament is stretched and supported on an insulating plate 9 as shown in FIG. First, as shown in FIG. 9, two types of anchor wires 19a and 19b, long and short, each having a preheat-treated tungsten filament 3 and a winding portion 18 for holding the tungsten filament at the tip as shown in FIG. prepare. Then, these are arranged alternately long and short, and their ends are connected to the anchor wire attachment hole 11a of the insulating plate 9,
Insert and fix into 11b, 11c... FIG. 11 shows a state in which the tungsten filament 3 is suspended and supported on the insulating plate 9 by the above-mentioned components. FIG. 12 shows a front view and left and right side views of a starter unit constructed by mounting both the bimetal switch 2 and the tungsten filament 3 on the insulating plate 9 using the means described above. In the present invention, the starter device constructed as described above is installed close to at least one end of the arc tube 1 within the outer bulb 4, as shown in FIGS. 3 and 4.

Next, examples will be described. In a high-pressure sodium lamp with a rated power of 400 W and constructed as shown in Figure 3, the specifications of the tungsten filament in the starting device are as follows: wire diameter: 44 MG (0.121 mm), pitch: 110 mm.
%, primary coil length (CL) 22 x 10 mm, total turn (TT) 173 x 10 turns, UCL 394 x 10 mm, and when using a 200V-400W mercury lamp ballast, the filament current is 1.1A and the distribution temperature is 1950.
When we conducted a blinking test of 10 such lamps, selected to give a value of ~2050〓, with a 15-minute on/15-minute off cycle as the blinking condition, we obtained the following results. That is, after 6000 flashes, there was no occurrence of abnormal high voltage pulses or starting failures, and extremely stable starting characteristics were obtained, and the lamp survival rate was 100%. Furthermore, very good results were obtained without sputtering of the filament or welding of the bimetallic switch.

As is clear from the above explanation, the present invention can easily and accurately control the contact pressure of the opening/closing contacts of the bimetal switch in the starting device, resulting in a high voltage pulse with a constant height, resulting in extremely stable This results in excellent starting characteristics. In addition, since the tungsten filament and bimetal switch of the starter device are mounted on an insulating plate, assembly is easier than in structures where the tungsten filament is wrapped around the arc tube or the bimetal switch is mounted on the arc tube support. It is also easy to incorporate. Moreover, since the starter unit is installed close to at least one of the arc tubes,
It has advantages such as not interfering with the luminous flux and ensuring reliable operation of the bimetal switch.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a high-pressure sodium lamp with a built-in starter device, Figure 2 is a side view of the arc tube support of a conventional lamp, Figure 3 is a front view of the lamp of the present invention, and Figures 4 and 5 are the same. A front view and a side view of the main parts of the lamp, Figure 6 is a front view and a plan view of the insulating plate of the starter, and Figure 7 is a front view, plan view, and both left and right sides when a bimetal switch is attached to the insulating plate. side view,
Figure 8 is an enlarged view of the opening/closing contact part of the bimetal switch in Figure 7, Figures 9 and 10 are front views of the tungsten filament and anchor wire, and Figure 11 is a front view of the tungsten filament attached to the insulating plate. FIG. 12 is a front view and left and right side views of a starter unit in which a tungsten filament and a bimetallic piece are attached to an insulating plate. In FIGS. 3 to 12, 1... arc tube,
2... Bimetal switch, 3... Tungsten filament, 4... Outer sphere, 9... Insulating plate, 13
a, 13b... Support column, 14a, 14b... Nut, 16... Bimetal piece, 17... Rod-shaped opening/closing contact.

Claims (1)

[Scope of utility model registration request] In parallel with the arc tube 1 made of translucent ceramic,
In a configuration in which a bimetal switch 2 and a tungsten filament 3 are connected in series to a starting device, and these are housed inside an outer bulb 4, the bimetal switch 2 has a threaded portion on an insulating plate 9. A pair of pillars 13a and 13b are rotatably and fixedly attached with nuts 14a and 14b, one end of a bimetal piece 16 equipped with an opening/closing contact is fixed to the tip of one pillar 13a, and the other end of the bimetal piece 16 is fixed to the tip of the other pillar 13b. A rod-shaped switching contact 17 that contacts the switching contact of the bimetal piece 16 is fixed in a direction perpendicular to the support 13b, and the contact pressure between the switching contacts can be adjusted by rotating the support 13a, 13b. A high-pressure sodium lamp characterized in that a tungsten filament is supported in a tension manner opposite to a bimetal piece 16, and these are installed close to at least one end of the arc tube 1.