JPS60193232A - Apparatus for enclosing inactive gas into bulb - Google Patents

Abstract

PURPOSE:To increase the speed of enclosing an inactive gas, by providing a pressure detector for delivering a control signal for opening or closing a valve so as to keep the pressure within a tank constant. CONSTITUTION:A pressure within a tank 3 is determined by a pressure detector 4 which delivers a control signal 5. According to this control signal 5, an electromagnetic valve 1 serves to keep a constant pressure in an enclosing circuit containing the tank 3. The tank 3 is further provided with an evacuating circuit constituted by a vacuum pump and an electromagnetic valve 6 so that the tank is cleaned if it is contaminated for example by a fluorescent lamp broken during the enclosing process. Ar gas is supplied to a fluorescent lamp via a center valve 7. According to the aforementioned construction, the gas pressure within the enclosing circuit is not decreased substantially when the Ar gas is started to be injected into a fluorescent lamp, and moreover this decrease in gas pressure can be compensated quickly through the electromagnetic valve operated by the pressure detector. Thus the gas can be enclosed at a tripped speed with respect to a conventional method.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention is applicable to a manufacturing apparatus for bulbs such as fluorescent lamps and incandescent lamps. The present invention relates to an improvement in an exhaust device for exhausting impure gas in a glass tube, in which an inert gas such as Ar gas is filled immediately before the exhaust is completed and the exhaust tube is burned out.

[Background of the invention]

Generally, for example, a fluorescent lamp has an A of several rrtnHg.
It is filled with r gas. As a method of enclosing it, for example, JP-A-51-111777 or JP-A-53-
As described in Publication No. 14984, there is a constant volume filling method in which two solenoid valves are operated alternately to fill in Ar gas between the two solenoid valves, or a pressure detector using a strain gauge in the Ar filling circuit. For this purpose, a constant pressure encapsulation method is used in which measured pressure is fed back to operate a solenoid valve.

Among these filling methods, the constant pressure filling method cannot keep up with the speeding up of fluorescent lamp manufacturing equipment due to problems such as the response speed of various devices and the gas diffusion rate, and even if the filling speed was increased, There are problems such as large variations in sealing pressure. Therefore, the production rate is approximately 1000 pieces/
H is the limit, and some kind of improvement is desired.

[Object of the Invention] Accordingly, an object of the present invention is to provide an inert gas filling device for a tube that has an extremely fast filling speed.

[Summary of the invention]

In order to achieve the above object, the present invention includes a constant pressure capacity tank provided between an inert gas pressure vessel and a tube, and a constant pressure capacity tank provided between the pressure vessel and this tank, The inert gas in the tube is supplied from a valve that opens and closes and a pressure sensor that is installed in the tank and that measures the pressure inside the tank and sends a control signal to open and close the valve so that this pressure is always constant. It is characterized by comprising an enclosure device.

Due to the characteristic configuration of the present invention, even when the inert gas starts to be filled into the tube, the gas pressure in the sealing circuit decreases only slightly because it is a constant pressure capacity tank, and this decrease in gas pressure is equal to the pressure. The activation of the valve by the detector enables recovery in a very short time. As a result, it has become possible to provide an inert gas filling device that has a gas filling speed approximately three times faster than the conventional gas filling speed.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 1 shows the basic structure of an inert gas filling device for a tube according to the present invention.

This embodiment relates to an apparatus for filling a fluorescent lamp with Ar gas. Solenoid valve 1 from Ar cylinder. A constant pressure capacity tank 3 is filled with Ar gas at a constant pressure through an orifice 2. This constant pressure capacity tank 3 is 500cc~1
This is a 0Q tank, and the pressure inside this tank 3 is measured by a pressure detector 4 and a control signal 5 is sent out. This control signal 5 causes the solenoid valve 1 to maintain a constant pressure in the enclosed circuit including the tank 3. Further, the tank 3 is provided with an exhaust circuit using a vacuum pump and a solenoid valve 6, so that the inside of the tank 3 can be cleaned if the interior of the tank 3 becomes contaminated due to breakage of the fluorescent lamp during sealing. Note that the Ar gas is sent to the fluorescent lamp via the center bulb 7.

By the way, in such an Ar-filled circuit, if the fluorescent lamp breaks, outside air will flow into the tank 3 and become contaminated. If contaminated, the inside of the tank 3 is evacuated using the vacuum pump mentioned above to clean it, but it takes at least several tens of seconds to create a vacuum, and during this time the completed fluorescent lamp is not filled with Ar gas and becomes defective. . Therefore, in order to solve this problem, a check valve (backflow prevention valve) 8 was provided in the enclosed circuit closer to the fluorescent lamp than the tank 3. This makes it possible to instantly prevent outside air from entering and significantly reduce its loss.

By configuring the inert gas filling device as described above, even when the filling of Ar gas into the fluorescent lamp is started, the gas pressure in the filling circuit is only slightly reduced. Therefore, this drop in gas pressure can be recovered in a short time by operating the solenoid valve using the pressure detector. As a result, it was possible to achieve encapsulation at about three times the encapsulation speed of the conventional technique.

〔Effect of the invention〕

As described above, the present invention has made it possible to provide an extremely high-performance inert gas filling device and to greatly improve the productivity of fluorescent lamps.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of an inert gas filling device for a tube according to the present invention. 1.6... Solenoid valve, 2... Orifice, 3...
- Constant pressure capacity tank, 4...pressure detector, 5...control signal, 7...center valve, 8...check valve.

Claims (1)

[Claims] 1. A constant pressure capacity tank provided between the inert gas pressure container and the bulb, a valve provided between the pressure container and the tank and opened and closed in response to a control signal, and a valve provided in the tank. and a pressure detector that measures the pressure inside the tank and sends out the control signal for opening and closing the valve so that the pressure is always constant. Active gas filling device.