JPH03110460A - Inspecting method for glass tube - Google Patents

Abstract

PURPOSE:To decide the quality of a tube body at high precision in a simple stage by arranging the electrodes to the inside and outside of the joint part of glass tubes and impressing prescribed voltage between these inner and outer both electrodes and deciding the quality of the joint part of the tube body. CONSTITUTION:Both a glass tube 7a having large diameter and a glass tube 7b having small diameter are joined to form a valve 7. This valve 7 is set to an inspection device. In this case, a metallic ring 11 is arranged to the outer peripheral side of a joint part 7c. Then an earth rod 15 is moved to the upper part and inserted into the tube 7b. When the earth rod 15 is inserted into the whole body of the tube 7b, prescribed voltage necessary to glow discharge is impressed. Therein for example, when a fine hole part 7g is formed in the joint part 7c, glow discharge is caused through the hole part 7g. Thereby it is decided that the joint part 7c is defective in drilling.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) This invention is directed to a method for connecting at least two glass tubes in series, such as glass tubes for single-sealed light bulbs. The present invention relates to a glass tube inspection method for inspecting whether or not a tube body is a good product.

(Prior art) A light bulb, such as a one-arm stop type halogen light bulb, has a large diameter glass tube that serves as the main body, and a glass tube that serves as an exhaust pipe with a diameter sufficiently smaller than that of the glass tube at the end of the main body. A tube body formed by joining in series is used. A filament and an internal lead wire are housed in this bulb, and a cap connected to an external lead wire led out from the sealing portion is connected to a sealing portion formed at the end of the large diameter glass tube. Furthermore, after sealing a halide and an inert gas into the bulb from a small-diameter glass tube, the small-diameter glass tube is sealed to form a single-sealed halogen light bulb.

By the way, in order to assemble such a light bulb, it is necessary to use a good quality bulb having a predetermined size and shape.

That is, the glass tubes are joined together by softening the ends of both glass tubes by heating, then bringing the ends of the glass tubes into abutment and welding the ends together. For this reason, the bonded portion is likely to vary, and minute holes may be formed in the bonded portion, resulting in defects. These defective products must be removed.

Therefore, before assembly, a valve is inspected to determine whether it is a good product or a defective product.

Conventionally, the method for inspecting defective glass tubes was as follows:
The pressure inside the valve is set to above atmospheric pressure or negative pressure, and the pressure change inside the valve is observed to determine whether a hole is formed in the joint and whether the joint state is secured. was.

(Problem to be Solved by the Invention) However, the above-mentioned inspection method using pressure changes requires holding the openings at both ends of the valve and measuring the pressure after a predetermined time has elapsed, and the structure of the device is complicated and the connection is difficult. 1. It is troublesome and requires a long time for inspection. This poses a problem when performing a 100% inspection on a mass production line.

This invention was made with attention to these circumstances,
The purpose is to provide a glass tube inspection method that can easily determine whether a product is defective.

[Structure of the invention]

(Means for Solving the Problems and Their Effects) In order to achieve the above object, the inspection method of the present invention includes inserting an internal electrode into a tube body formed by connecting at least two glass tubes in series. An external electrode is disposed around the outer periphery of the joint of the tube body, and a predetermined voltage is applied between these internal electrodes and the external electrode to determine the quality of the joint of the tube body.

This inspection method involves the process of applying voltage to an external electrode placed around the joint between the inserted internal electrode and the glass tube.
If so, a discharge will occur between the electrodes through the hole. In other words, it is possible to determine whether the joint state of the joint portion is good or bad.

(Example) The present invention will be described below based on an example shown in FIGS. 1 to 3.

FIG. 1 shows a defective product inspection device to which the method of the present invention is applied, and 1 is a frame. A lower grounding rod guide 3 is installed at the tip of the frame 1 via a holder 2 in the vertical direction. A glass tube holder 4 is arranged at the upper part of the lower earth rod guide 3 together with an upper earth rod guide 5 attached to the lower part of the glass tube holder 4. Furthermore, an elongated tube storage chamber 6 is formed inside the glass tube support 4 and the upper earth rod guide 5, extending from the upper end of the glass tube support 4 to the lower side of the upper earth rod guide 5. In this tube storage chamber 6, a large diameter glass tube 7a and a small diameter glass tube 7 are arranged.
A valve 7 (corresponding to the tube body of the present invention) formed by connecting the tubes b and b in series can be held in a freely insertable and removable manner.

Specifically, when the small diameter side of the bulb 7 is inserted into the tube storage chamber 6, the entire bulb is held by the glass tube holder 4. Note that 8 is a holder that holds the glass tube holder 4 and the upper earth rod guide 5.

The holder 8 is connected to the output part of a rotary actuator 10 installed on the base side of the frame 1 via a stand 9, and the holder 8 is connected to the output part of a rotary actuator 10 installed on the base side of the frame 1 via a stand part 9, and the holder 8 is connected to the output part of a rotary actuator 10 installed on the base side of the frame 1 through a stand part 9. It can be rotated to the front and back). By this rotation, the valve 7 that has been inspected can be guided to a chute (not shown) and removed. Although not shown, detachment is also performed by a tube pull-out mechanism.

Further, at the opening edge of the upper opening on the entrance/exit side of the tube storage chamber 6, for example, a metal ring 1 constituting an external electrode is provided.
1 is buried. By embedding the opening edge, the metal ring 11 is inserted into the tube housing chamber 6 with the valve 7.
When inserted, it is arranged so that it is placed on the outer peripheral side of the joint portion 7C.

Further, an electrical device 12 for glow discharge is connected to this metal ring 11 via a current-carrying portion 12a. For example, the electric device 12 for glow discharge consists of a high frequency oscillator that oscillates at about 300 kilohertz.

Further, on the lower side of the holder 2, an earth rod chuck portion 13 is arranged. Further, the earth rod chuck portion 13 is connected, for example, to the tip of a reciprocating rod 14a of a hydraulic piston mechanism 14 provided along the vertical direction. In other words, the earth rod chuck section 13 can move in the vertical direction with the operation of the hydraulic piston mechanism 14 (elevating mechanism).

Further, the earth rod chuck portion 13 holds a lower end portion of a long earth rod 15 that constitutes an internal electrode. The earth rod 15 has an outer diameter that is approximately the same as the inner diameter of the glass tube 7b of the bulb 7. The upper end of the earth rod 15 is movably inserted through a passage provided in each earth rod guide 3.5, and the valve 7 housed in the tube housing chamber 6 is joined by the operation of the hydraulic piston mechanism 14. Part 7c
The earth rod 15 can be inserted all the way to the inside. Note that the earth rod 15 is connected to the glow discharge electric device 12.

Above the glass tube holder 4 is a tube storage chamber 6.
As an extension of this, a sensor 16 composed of, for example, an optical sensor is disposed in an adjacent portion so as to be able to detect the bulb 7 that pops out upward from the tube storage chamber 6.

On the other hand, 17 is a control section composed of, for example, a microcomputer. This control section 17 is connected to the hydraulic piston drive section 14a of the hydraulic piston mechanism 14, the actuator drive section 10a1 of the low reactor 10, and the glow discharge electrical device 12, and is connected to each device according to set information. control the earth rod 15
is inserted into a bulb 7 set in the tube accommodation chamber 6, and a predetermined glow discharge voltage is applied between the metal ring 11 and the earth rod 15. Further, an operation section 18 is connected to the control section 17 . The operation unit 18 includes a perforation defect display unit 19 (for example, a voltmeter) that indicates whether there is a hole or the like in the joint 7C of the bulb 7 based on changes in voltage during discharge, for example. , in response to the output of the sensor 16, the junction 7 of the valve 7
A hole diameter defect indicator 20 (for example, a lamp, a sounding body, etc.) is built in to notify whether or not the hole diameter of C is maintained at a predetermined value, so that defective products can be confirmed.

Next, the method of the present invention will be explained using such an inspection device.

First, a light bulb 7 as an object to be inspected is made by joining a large diameter glass tube 7a and a small diameter glass tube 7b.
Set it on the inspection device. This is glass tube 7b
This is done by inserting the tube from the upper end opening of the tube storage chamber 6 in an upright state. As a result, the entire glass tube 7b of the bulb 7 is housed in the tube housing chamber 6, and the large diameter glass tube 7a is exposed from the glass tube holder 4. In addition, at this time, the metal ring 11 is connected to the joint part 7C.
are placed on the outer periphery of the

Next, the operation unit 18 is operated. As a result, the control unit 1
7, the hydraulic piston mechanism 14 starts operating. Then, the ground rod 15 that was waiting on the lower side
is moved upward, and the upper end of the earth rod 15 is inserted into the glass tube 7b of the bulb 7 housed in the tube housing chamber 6 through the respective earth rod guides 3 and 5.

Here, as shown in FIG.
If the inner diameter of the grounding rod 15 is small and defective, the tip of the grounding rod 15 will come into contact with the portion 7f protruding into the hole 7e.
Push up the entire valve. Then, the bulb 7 protrudes from the glass tube receiver 4. When it protrudes to a certain point, the control unit 17 is sent from the six company sensor 16.
The movement of the valve 7 is then output. Then, the control section 17 determines that the diameter of the hole 7e of the joint portion 7c is not secured to a predetermined value (poor diameter defect), and displays this on the display section 19 for hole diameter defect.

On the other hand, when the grounding rod 15 is inserted all the way into the glass tube 7b of the bulb 7, the controller 17 then commands the
The electric device 12 for glow discharge is activated, and a predetermined voltage necessary for glow discharge is applied.

Here, as shown in FIG.
For example, if a minute hole 7g is formed in the hole 7g, a glow current will be discharged through the hole 7g.

Then, the voltage change at this time is transmitted through the control section 17.
The information is transmitted to the hole defective display section 19, and the same hole defect display section 19 is transmitted.
The needle of the voltmeter that makes up the system starts to waver.

That is, based on the deflection of the voltmeter needle, it is determined that the joint 7C has poor drilling.

If neither of the cases applies, the valve 8 is determined to be a good product.

Next, after completing the judgment, rotary actuator 1
0a is activated to tilt the glass tube holder 4 onto a chute (not shown). Subsequently, the tube pull-out mechanism is activated to pull out the valve 8 in the tube storage chamber 6.
Discharge into the chute above. Then, the products are separated into good products and defective products by discharging from this chute.

In this way, it is possible to continuously determine whether the valve 8 is good or defective with simple equipment and steps such as applying a voltage between the electrodes, and it is possible to incorporate the valve 8 into a mass production line. The discrimination accuracy is also good. Furthermore, unlike discharging in an inert gas atmosphere, the method of discharging in air (into fire) does not use an inert gas, and therefore is easy to handle.

Also, as in the above-mentioned embodiment, the earth rod 15 is connected to the valve 7.
The method used as the jig has the advantage that two types of defective items can be inspected at one time, and the inspection can be carried out efficiently in a short time.

In one embodiment, this invention was applied to an inspection method for inspecting defective tube bodies made by joining glass tubes of different diameters; however, the present invention is not limited to this and is not limited to this. It may also be applied to a method of inspecting non-defective products.

Further, in one embodiment, the present invention is applied to an inspection method using a grounding rod as a jig, but the present invention may be applied to an inspection method that does not use a grounding rod as a jig.

Furthermore, in one embodiment, a metal ring was used for the external electrode, but
The external electrode is not limited to an annular shape, and metal members having other shapes may also be used. In this case, by rotating the glass tube, it is possible to determine whether the connection is good or not, as in the first embodiment.

[Effects of the Invention] As explained above, according to the present invention, it is possible to determine whether a tube body is good or defective by a simple process of applying a voltage between electrodes. The discrimination accuracy is also good. Moreover, inspection can be carried out efficiently.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and Fig. 1 is a schematic configuration diagram showing a failure inspection device to which the inventive method is applied to explain the inventive method, and Fig. 2 shows an embodiment of the inventive method. FIG. 3 is a cross-sectional view showing a state when a defective product that is not secured in a predetermined position is determined, and FIG. 7g, 7b...Glass tube, 7...Bulb (tube body), 11...Metal ring (external electrode), 15
...Earth rod (internal electrode).

Claims (1)

[Claims] An internal electrode is inserted into a tube body formed by joining at least two glass tubes in series, an external electrode is placed around the outer periphery of the joint of the tube body, and a predetermined distance is placed between the internal electrode and the external electrode. A glass tube inspection method characterized by applying a voltage to determine the quality of a joint of a tube body.