JPH11204039A - Evacuation apparatus of fluorescent character display tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly seal an evacuation hole by precise, stable pressure control by setting pressure to an evacuation hole of a cover member to a protrusive upper member, and vertically moving a weight which is balanced with force to the protrusive upper member. SOLUTION: A cover member 60 is placed on an upper end face of a sealing heater 6 with the member 60 being locked downward by attraction of a magnet 16, a fluorescent display tube 2 is placed at a uniform heat plate 5 on an evacuation head 3 via an O-ring 26, after which a rotary table 12 is moved. The evacuation head 3 and the fluorescent character display tube 2 are evacuated by means of a vacuum pump. When the fluorescent character display tube 2 reaches a position of a push-up part 14, a weight 59 is lowered by lowering a shaft 62 of a directly driven motor 61 supporting the weight 59, and the push-up part 14 rises via sprockets 56a and 56b. The lower part of a sealing heater 6 is pushed up, and the push-up part 14 stops at a position at which the cover member 60 is pushed to an evacuation hole 8 part of the fluorescent character display tube 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display tube exhaust device having a structure in which an exhaust pipe for exhaust is not provided and an exhaust hole is sealed with a cover member, and in particular, a plurality of fluorescent display tubes are continuously evacuated. The present invention relates to an exhaust device for a fluorescent display tube for sealing an exhaust hole.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing an example of a conventional exhaust device for a fluorescent display tube. A fluorescent display tube having a structure in which there is no exhaust pipe for exhaust and an exhaust hole is sealed with a lid member is generally well known. As an exhaust device 1 for evacuating and sealing such a fluorescent display tube, for example, as shown in FIG.
In the exhaust head 3 having the heat equalizing plate 5 at the upper end surface, the fluorescent display tube 2 is mounted on the O-ring 26 fitted in the inner diameter of the heat equalizing plate 5 and the heat equalizing plate 5. The exhaust hole 8 of the fluorescent display tube 2 is placed so as to be the center of the O-ring 26. The plurality of exhaust heads 3 are fixed to a rotary table 12.

[0003] Inside the cylindrical exhaust head 3, a stick-shaped sealing heater 6 having a lid member 60 mounted on the upper end surface thereof is mounted so as to be able to move up and down in the exhaust head 3 in an airtight manner. . In addition, the sealing heater 6 is attracted to the lower bottom plate 19 by a magnet 16 fixed to the lower end of the guide shaft 9 disposed below the sealing heater 6 due to a magnetic force that cannot be sucked up even during vacuum evacuation. Locked to the plate 17. Further, the sealing heater 6 is provided with the exhaust head 3.
The power is supplied from a circuit wired to the turntable 12 to which is fixed.

When the exhaust head 3 is rotated at a set index time and positioned at a predetermined position,
The sealing heater 6 is raised by raising a protruding portion 14 disposed at a predetermined position outside the rotary table 12.

[0005] In the process of evacuating and sealing the fluorescent display tube 2, first, a lid member 60 coated with a low-melting glass on the upper surface is placed on the upper end surface of the sealing heater 6, and the heat equalizing plate 5 on the exhaust head 3 is placed. The fluorescent display tube 2 is placed via an O-ring 26 to evacuate the exhaust head 3. Next, a constant process index time can be obtained by rotating the turntable 12 at the set index time. By proceeding with this step, the fluorescent display tube 2 is sufficiently evacuated and the heating furnace 1
5 heats to a predetermined temperature.

[0006] The sealing heater 6 starts heating at a predetermined position after the start of evacuation, and is controlled to a temperature at which the low-melting glass applied on the lid member 60 is melted. Further, when the fluorescent display tube 2 reaches the position of the protruding portion 14 in accordance with the rotation of the turntable 12, the heating by the sealing heater 6 is stopped, and the shaft 53 of the air cylinder 54 is raised.
The magnet 47 fixed to the upper end of the sealing heater 6 and attracted to the suction plate 17 below the sealing heater 6 is separated from the magnet 16 by abutting the suction plate 17 to push up the entire sealing heater 6. Thereby, the lid member 60 is pressed against the exhaust hole 8 of the fluorescent display tube 2 with a pressing force determined by the inner diameter of the air cylinder 54 and the used compressed air pressure, and sealing is performed for a certain time. After the push-up sealing is completed for a certain time, the push-up portion 14
Is lowered, the sealing heater 6 is lowered, and the magnet 16
Is locked downward by the magnetic force.

[0007]

In the above-described conventional exhaust device for a fluorescent display tube, when the cover member 60 is sealed, the shaft 53 is raised by the air cylinder 54 and comes into contact with the suction plate 17 via the magnet 47. As a result, the bottom portion 19 of the sealing heater 6 is raised, and the position of the lid member 60 is determined such that the lid member 60 above the sealing heater 6 is pressed against the vicinity of the exhaust hole 8 of the fluorescent display tube 2 with a predetermined pressure. ing.

[0008] However, the pressure of the air supplied to the air cylinder 54 fluctuates due to the consumption of the factory, and the fluctuation of the air pressure is further promoted by a throttle valve provided in the middle of the air supply pipe. For this reason, when the pressure of the supplied air decreases, the pressing force in the vicinity of the exhaust hole 8 is insufficient, and the lid member 60 is not adhered to the fluorescent display tube 2, or the air pressure increases and the excessive pressing force is generated in the vicinity of the exhaust hole. And the exhaust hole 8 is partially deformed. In addition, the ability to follow the air supply is poor, making it difficult to finely adjust the pressure when setting the pressure.
There was also a problem that a great deal of time was wasted on adjustment.

On the other hand, Japanese Patent Application Laid-Open No. 04-06172 discloses an exhaust device for a fluorescent display tube in which a cover member can be stably moved in an exhaust head and pressed against an exhaust hole with an appropriate pressing force.
No. 7 discloses this. In this exhaust device, a vertical direction motion is applied to the heater portion via a guide member for guiding a heater portion on which a lid member is placed at a tip end portion of the exhaust head, and a compression spring installed in the exhaust head. And a transmission device.

Then, the heater is raised by the transmission device and guided by the guide member, and the lid member comes into contact with the exhaust hole without falling from the heater. Thereafter, the cover member is pressed against the exhaust hole by a compression spring whose spring pressure has been adjusted in advance to seal the exhaust hole. However, in this exhaust sealing device,
Since it is evacuated through multiple grooves in the guide member,
There is a disadvantage that it takes a long time to exhaust air. Also, providing compression springs in all exhaust heads requires a great deal of adjustment man-hours. Further, this kind of compression spring is liable to be deteriorated due to fatigue, frequently replaced, and reduces the operation rate of the device.

Accordingly, it is an object of the present invention to keep the lid member in a stable position at the time of sealing the exhaust hole of the fluorescent display tube, press the lid member against the exhaust hole with a constant pressing force to exhaust the fluorescent display tube, and exhaust the gas. It is an object of the present invention to provide a fluorescent display tube exhaust device capable of sealing a hole.

[0012]

SUMMARY OF THE INVENTION A feature of the present invention is that a plurality of exhaust heads having an exhaust pipe for evacuating a vacuum from an exhaust hole of a fluorescent display tube in a heating furnace and being mounted around a rotary table; A rod-shaped sealing head which can move up and down in an airtight manner, mounts a lid member used for sealing an exhaust hole of the fluorescent display tube, and has a heater for heating and fusing the lid member. An exhaust device having a mechanism for gripping an end of the sealing heater protruding downward from the exhaust head, and a push-up portion for imparting vertical movement to the sealing heater. A weight that balances a force applied to the push-up portion that sets the pressure of the lid member on the exhaust hole, and a motor that moves the weight up and down while supporting the weight. With a moving mechanism An exhaust system of an optical display tube.

Preferably, the mechanism for gripping the end of the sealing heater includes a magnet. Furthermore, it is necessary to provide a shock absorber which is mounted with the magnet facing upward, as required. On the other hand, it is preferable that the motor is a direct-acting motor whose axis moves up and down. Further, it is desirable to have a guide mechanism for linearly guiding the vertical movement of the weight. It is preferable that the guide mechanism includes a rolling friction linear motion type bearing. further,
It is preferable that a shock absorber that abuts on an end of the sealing heater of the push-up portion is provided.

[0014]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an exhaust device for a fluorescent display tube according to an embodiment of the present invention. As shown in FIG. 1, the exhaust device for a fluorescent display tube has an exhaust tube 13 for evacuating the vacuum from an exhaust hole 8 of the fluorescent display tube 2 in a heating furnace 15 and is attached around a rotary table 12. A plurality of exhaust heads 3, and a heater unit that mounts a lid member 60 that can move vertically upward and downward in the exhaust head 3 and seals the exhaust hole 8 of the fluorescent display tube 2 and heat-bonds the lid member 60. A stick-shaped sealing heater 6 provided, and a push-up portion for holding the end of the sealing heater 6 protruding downward from the exhaust head 3 by magnetic force and giving the sealing heater 6 a vertical movement. 14, a weight 59 having a weight that balances the force applied to the push-up portion 14 that sets the pressure of the lid member 60 to the exhaust hole 8, and a direct-acting type that moves the weight 59 up and down while supporting the weight 59. And a weight moving mechanism having a motor 61. To have.

The push-up portion 14 includes a push-up shaft 64 extending from the linear motion bearing 58a and extending above a member connected to the chain 57, and a magnet 47 attached to the tip of the push-up shaft 64. It is composed of Further, the weight 59 suspended from the chain 57 via the sprockets 56a and 56b is guided linearly by a direct-acting bearing 58b so as not to sway when moving up and down.

In addition, a rotary table 12 for mounting a plurality of exhaust heads, a seal portion 18 at the lower end of the exhaust head 3 for moving the sealing heater 6 airtightly, and a sealing heater 6 At the lower end of the guide plate 9 and guided by the guide shaft 9.
And a magnet 1 attached to the tip of the guide shaft 9 for attracting and holding the suction plate 17.
6 are provided in the same manner as in the prior art.

The exhaust head 3 has an O-ring 26 on its upper end surface for ensuring close contact between the exhaust head 3 and the fluorescent display tube 2, and a heat equalizing plate 5 for supporting and uniformly heating the fluorescent display tube 2. The fluorescent display tube 2 has an exhaust hole 8 on the O-ring 2
6 are arranged. The inside of the exhaust head 3 is built in a sealing heater 6 on which a heater sufficient to fuse the low melting point glass applied to the upper surface of the lid member 60 is attached.

The end of the sealing heater 6 protruding from the seal portion 18 of the exhaust head 3 has a lower end connected to a suction plate 17 made of a magnetized metal attached to a bottom plate 19 and a guide shaft 9. The sealing heater 6 is locked downward by the magnetic force generated between the magnet 16 and the magnet 16 attached thereto. The suction plate 17 of the bottom plate 19 is in a state where it can move along the guide shaft 9. The magnetic force of the magnet 16 locks the sealing heater 6 downward without pulling the sealing heater 6 toward the exhaust hole 8 even when the inside of the exhaust head 3 is vacuum, and raises the push-up portion 14 during sealing. In this case, the magnetic force is applied to such an extent that the magnetic force easily comes off.

Further, the sealing heater 6 includes the rotary table 1
The power is supplied from a circuit (not shown) wired to 2. A plurality of the exhaust heads 3 are fixed on the rotary table 12, and are moved at a set index time by intermittently rotating the rotary table 12.
This movement makes it possible to pass through the fixed heating furnace 15 and to evacuate the exhaust head 3 via the exhaust pipe 13.

On the other hand, the push-up portion 14 arranged at a predetermined position outside the rotary table 12 is attached to the column 55 via the direct-acting bearing 58 as described above, and is further provided at two positions above the column 55. Sprockets 56a, 56
It is connected to a weight 59 on the opposite side of the support 55 by a chain 57 via b. The weight 59 is attached to a direct-acting bearing 58b provided with the direct-acting bearing 58 and the support 55 therebetween, and the bottom surface thereof is supported by the upper end surface of the shaft 62 of the direct-acting motor 61. , Prop 55
The push-up portion 14 on the opposite side is normally lowered.

The push-up portion 14 includes a push-up shaft 64 and a push-up shaft 64.
And a magnet 47 for lowering the sealing heater by being attracted by the attracting plate 17. The magnet 47 is given a magnetic force weaker than its own weight of the push-up portion 14, and the weight of the weight 59 is set by applying a pressing force to the predetermined lid member 60 to the weight of the push-up portion 14. is there. Further, a structure such as a wire and a pulley may be used instead of the chain 57 and the sprockets 56a and 56b. In any case, it is desirable to smoothly move the weight 59 up and down.

Next, the operation of the exhaust device will be described. First, a lid member 60 coated with a low-melting glass on its upper surface is placed on the upper end surface of the sealing heater 6 locked downward by the attraction force of the magnet 16, and the O-ring 26 is attached to the heat equalizing plate 5 on the exhaust head 3. After placing the fluorescent display tube 2 through the
Then, the inside of the exhaust head 3 and the inside of the fluorescent display tube 2 are evacuated by a vacuum pump fixed outside the rotary table 12.

Next, by moving the rotary table 12 at the set index time, the fluorescent display tube 2 obtains a constant process index time. The degree of vacuum in the exhaust head 3 and the fluorescent display tube 2 is gradually increased by moving the rotary table 12 and sequentially switching the vacuum pump fixed outside the rotary table 12 to advance the process.

Further, by passing through the heating furnace 15 for the purpose of releasing high-temperature gas from the fluorescent display tube 2, the fluorescent display tube 2
Is heated to a predetermined temperature. The sealing heater 6 is energized and heated at a predetermined position after the rotation table 12 is moved, and the lid member 6 is heated.
The temperature is controlled to a temperature at which the low-melting glass applied to 0 is melted.

Then, the degree of vacuum in the fluorescent display tube 2 is sufficiently increased to reach a predetermined temperature, and the fluorescent display tube 2
Upon arrival at the position, the shaft 62 of the direct-acting motor 61 supporting the weight 59 is lowered, whereby the weight 59 is lowered, and the push-up portion 14 connected to the chain 57 via the sprockets 56a and 56b is moved. Rise. Then, the lower portion of the sealing heater 6 is pushed up, and the lid member 60 is moved to the fluorescent display tube 2.
The push-up portion 14 stops at a position where the push-up portion 14 is pressed against the exhaust hole 8, but the shaft 62 of the direct-acting motor 61 is moved a few mm further below the lowered position of the weight 59 that has stopped at the same time.
Is lowered and stopped, so that the weight of the weight 59 can be reliably transmitted to the push-up portion 14.

The mechanism for moving the sealing heater 6 does not use a transmission mechanism that easily causes backlash.
The linear motion motor 61 is used for lowering the weight 59, and the linear motion bearing 58 by rolling contact with small friction as a guide for the motion of the weight 59 and the push-up portion 14.
The use of a and 58b enables smooth movement without causing uneven movement due to backlash and stick-slip phenomenon due to friction.

Next, the cover member 60 in which the low-melting glass is sufficiently melted is maintained at a predetermined pressure from the push-up portion 14 via the sealing heater 6 for a predetermined time to seal the exhaust hole 8. The shaft 62 of the direct-acting motor 61 rises, and the weight 5
By lifting and supporting 9, the push-up portion 14 is lowered. When the push-up portion 14 is lowered, the magnet 47 attracts the suction plate 17 and simultaneously lowers the suction plate 17, and the suction plate 17 is stopped by the magnet 16 serving as a stopper, and the sealing heater 6 is locked downward.

The magnet 47 is separated from the suction plate 17 by its own weight due to the weight of the entire push-up portion 14, so that the push-up portion 14 is locked downward at a position where the chain 57 is tight against the weight. With the lowering of the sealing heater 6, the sealing of the lid member 60 to the fluorescent display tube 2 is completed.

FIG. 2 is a sectional view showing a modified example of the exhaust device for the fluorescent display tube of FIG. In this exhaust device, as shown in FIG. 2, the push-up portion 14 has a small dimension (5 to 5) below the magnet 47.
(About 10 mm) is provided. Otherwise, it is the same as the exhaust device described above.

When the push-up portion 14 is pushed up, the shock absorber 63 absorbs the impact when it comes into contact with the lower portion of the sealing heater 6. Further, both the stroke of the shock absorber 63 and the amount of shock absorption are small, so that the stroke end of the shock absorber 63 reaches the stroke end before the sealing heater 6 rises and comes into contact with the exhaust hole 8, so that the pressure is not affected. ing.

The weight 59 is connected to the cover member 6 to the exhaust hole 8.
The structure is such that it can be easily replaced so that the pressing force of 0 can be changed.

[0033]

As described above, according to the present invention, the weight corresponding to the pressing force of the lid member to the exhaust hole, and the weight is moved without causing uneven feeding and the stick-slip phenomenon and transmitted as a load to the lid member. By providing a mechanism, precise and stable pressure control can be performed at the time of sealing the exhaust hole, and there is an effect that the sealing of the exhaust hole can be surely performed and the yield is improved.

Further, unlike the conventional art, when setting the pressing force, there is no need to adjust the unstable air pressure supplied to the air cylinder or adjust the spring pressure in each exhaust head, which wastes a lot of time. It is only necessary to set the weight of the device in advance, and simply mount the device on a mechanism that transmits the weight, so that the pressing force at the time of sealing can be easily adjusted in a very short time, and the stopping time of the device is short, and the operation rate of the device is improved. This has the effect.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an exhaust device for a fluorescent display tube according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a modified example of the exhaust device of the fluorescent display tube of FIG.

FIG. 3 is a cross-sectional view showing one example of a conventional exhaust device for a fluorescent display tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust apparatus 2 Fluorescent display tube 3 Exhaust head 5 Heat equalizing plate 6 Sealing heater 8 Exhaust hole 9 Guide shaft 12 Rotary table 13 Exhaust pipe 14 Push-up part 15 Heating furnace 16, 47 Magnet 17 Adsorption plate 18 Seal Part 19 Bottom plate 53 Shaft 54 Air cylinder 55 Support 56a, 56b Sprocket 57 Chain 58a, 58b Direct-acting bearing 59 Weight 60 Cover member 61 Direct-acting motor 62 Shaft 63 Shock absorber 64 Protruding shaft

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[Procedure amendment]

[Submission date] December 21, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 6

[Correction method] Change

[Correction contents]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

[0012]

SUMMARY OF THE INVENTION A feature of the present invention is that a plurality of exhaust heads having an exhaust pipe for performing vacuum exhaust from an exhaust hole of a fluorescent display tube in a heating furnace and being attached to a periphery of a rotary table are provided. A stick-shaped sealing heater having a heater portion which can move up and down in a head-tight manner, mounts a lid member used for sealing an exhaust hole of the fluorescent display tube, and heat-fuses the lid member; in the exhaust system of a fluorescent display tube, a thrust-up part to give a vertical motion to the sealing heater and having a mechanism for grasping the end portion of the sealing heater protrudes downward from the exhaust head, to the exhaust hole A fluorescent light having a weight that balances the force applied to the push-up portion for setting the pressing force of the lid member, and a moving mechanism including a motor that moves the weight up and down while supporting the weight. An exhaust system of 示管.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

Preferably, the mechanism for grasping the end of the sealing heater includes a magnet. In addition, a shock absorber may be provided below the magnet as required.
On the other hand, it is preferable that the motor is a direct-acting motor whose shaft moves up and down. Further, it is desirable to have a guide mechanism for linearly guiding the vertical movement of the weight. Then, the guide mechanism is not to desirable comprise direct-acting bearings rolling friction.

Claims (6)

[Claims] 1. A plurality of exhaust heads having an exhaust pipe for evacuating a vacuum from an exhaust hole of a fluorescent display tube in a heating furnace and being attached to a periphery of a rotating table, and moving up and down in the exhaust head in an airtight manner. And a rod-shaped sealing heater having a heater for mounting a lid member used for sealing an exhaust hole of the fluorescent display tube and heating and fusing the lid member. A mechanism for gripping an end portion of the sealing heater protruding downward from the exhaust head, a push-up portion for vertically moving the sealing heater, and a lid member for the exhaust hole. And a weight moving mechanism including a motor that moves the weight up and down while supporting the weight while balancing the force given to the push-up portion for setting the pressing force. Exhaust of fluorescent display tube apparatus. 2. The exhaust device for a fluorescent display tube according to claim 1, wherein the mechanism for gripping an end of the sealing heater includes a magnet. 3. The exhaust device for a fluorescent display tube according to claim 1, wherein said motor is a direct-acting motor whose axis moves up and down. 4. The exhaust device for a fluorescent display tube according to claim 1, further comprising a guide mechanism for linearly guiding the vertical movement of the weight. 5. The exhaust device for a fluorescent display tube according to claim 4, wherein the guide mechanism according to claim 4 includes a direct-acting bearing by rolling contact. 6. The exhaust device for a fluorescent display tube according to claim 2, further comprising a shock absorber that abuts on an end of said sealing heater of said push-up portion.