JPH0355753A - Sealing method of tube bulb - Google Patents

Abstract

PURPOSE:To prevent the crack of a sealing part by heating a part to be press sealed to make the bore diameter to a determined size followed by sealing. CONSTITUTION:A mount 4 is sealed in a bulb 1, and its metal foil conductors 7, 7 and lead wires 8, 8 are press sealed to the bottom part of the bulb 1. A part to be press sealed 2 is preliminarily heated on contact its diameter. When the diameter after contraction is d, the bore diameter of the bulb 1 before contraction, and the lateral maximum size of the metal foil conductors 7, 7 is W, the diameter is contracted to satisfy the relation of D>d>W. Hence, the section of the part to be press sealed 2 is deformed into an ellipse or a flat ellipse. The part of this deformed section is squeezed by a pincher 21. As a short stroke of the pincher suffices for this, the sealed part is difficult to crack.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is a method for crushing and sealing (pinch sealing) the end of a bulb, such as an arc tube of a high-pressure discharge lamp or a halogen lamp. The present invention relates to a method for crushing and sealing a tube.

(Conventional technology) High-pressure discharge lamps such as light tubes and halogen lamps use quartz glass or hard glass as the material for the bulb.
A pressure dip seal is employed to close the end of the valve. A metal foil conductor connected to an internal lead wire and an external lead wire is sealed to this pressure-impregnated IL portion.

Conventionally, in order to form such a crushed sealing part, the end of the valve to be sealed is heated with a gas burner, and once the heated part is softened, the heated softened part is inserted into this end. The method employed was to crush the metal foil conductor in the thickness direction using a pressing jig (pincher).

(Problem to be Solved by the Invention) However, in the above sealing method, once the heated part is softened, the heated softened part is crushed in one direction at once with pinchers, so the valve wall in the direction of being crushed is The deformation stroke is large, resulting in large distortions, which causes cracks to occur in the sealing portion, reducing yield, and cracks to grow during use, leading to leaks and shortening the service life.

The present invention was made under these circumstances, and provides a tube sealing method that reduces the size of crushed melons by bincha, prevents cracks from occurring in the sealing part, and improves yield. This is what I am trying to do.

[Structure of the Invention (Means for Solving the Problems)] The present invention provides a method for heating the end portion of a tube bulb to be crushed and sealed uniformly in the circumferential direction to shrink the heated end portion, and to shrink the heated end portion. If the inner diameter of the part is d, the inner diameter of the valve before sealing is D, and the maximum dimension in the width direction of the metal foil conductor is W, then D>d>W, and then this sintered part is attached to both sides along the crushing direction. The compressed material is then heated and sintered so that the crushing direction becomes the small diameter, deforming it into an elliptical or oblong flat shape, and then sealing by crushing this flat shaped part with pinchers from the small diameter direction. The feature is that a metal foil conductor is sealed to the part.

(Function) According to the present invention, at the stage of crushing with the pinchers, the portion to be crushed has already been deformed into an elliptical or oval flattened shape, and therefore, when crushing with the pinchers, the pressing stroke is small; Less strain is applied to the bulb, preventing cracks from forming and improving yield.

(Example) The present invention will be described below based on an example shown in the drawings.

The drawing shows an example applied to a halogen light bulb.
is a bulb made of quartz glass.

This valve 1 is shown in a state before completion, with a lower end 2 extending straight and open, and an exhaust pipe 3 connected to the upper end.

A mount 4 is mounted inside the bulb 1 from the lower end opening. The mount 4 connects, for example, both ends of the vertical filament 5 to internal lead wires (wells) 6, 6, connects these internal lead wires 6, 6 to metal foil conductors 7, 7 made of molybdenum, and connects these metal foil conductors 7, 7, respectively. The foil conductors 7 and 7 are connected to external leads t! It is configured by connecting to jl8 and jl8. The metal foil conductors 7, 7 are juxtaposed so as to be lined up substantially on the same plane.

Such a mount 4 is held vertically by having its external lead wires 8, 8 chucked by a mount chuck carrier 10. In this case, mount 4
is supported so that it does not rotate.

An exhaust pipe 3 extending from the upper end of the valve 1 is chucked by a valve chuck 12. This valve chuck 12 is supported by a rotating shaft 13, and this rotating shaft 13
is rotatably supported by a bearing (not shown) housed in a bearing box 14. The upper end of the rotating shaft 13 is a gear 15,
16 to the motor 17, and the motor 17
rotates, the rotating shaft 13 rotates, and the bulp chuck 1
The valve 1 supported by the valve 2 is rotated about the tube axis.

A burner 18 is disposed on the side of the portion to be sealed, that is, the lower end portion 2 of the valve 1 supported by the valve chuck 12, and this burner 18 is supported by support legs 19. It is non-rotatably supported.

In this state, as shown in FIG. 2, the motor 17 is rotated to rotate the valve 1 supported by the valve chuck 12 through the rotating shaft 13, and at the same time, the burner 18 is ignited and the burner 18 operates the valve. The lower end 2 of 1 is heated.

At this time, since the bulb 1 is rotated at a predetermined speed, the lower end portion 2 of the bulb 1 is heated evenly in the circumferential direction.

As this heating progresses, the lower end portion 2 of the bulb 1 gradually becomes softer. A glass tube has a property of contracting in diameter when it is heated and softened, and the lower end portion 2 of the bulb 1 is reduced in diameter by being heated and softened, and is evenly contracted in the circumferential direction to maintain a circular state.

In this case, if the inner diameter of the reduced diameter part is d, the inner diameter of the part before diameter reduction is D1, and the maximum dimension in the width direction of the metal foil conductors 7, 7 arranged in parallel with each other is W, then p<d< The diameter of the lower end portion 2 of the valve 1 is reduced so as to satisfy the relationship W.

When such diameter reduction processing is completed, the motor 17 stops rotating and the valve 1 is stopped. Then, with the bulb 1 suspended, the reduced diameter portion is heated from both opposing sides by a pair of burners 20, 20 shown in FIG. The heating direction is perpendicular to the width direction of the metal foil conductors 7, 7 arranged in parallel with each other, that is, the thickness direction of the metal foil conductors 7, 7.

As a result of heating from both sides, only the heated portion of the end portion 2 of the bulb 1, which has been reduced in diameter, is contracted, that is, the walls facing each other in the thickness direction of the metal foil conductors 7 are reduced in diameter. do. As a result, the cross section of the open end 2 is deformed into an ellipse or an ellipse as shown in FIG. The small diameter direction of this oval or elliptical shape is opposite to the thickness direction of the metal foil conductors 7, 7, so that the wall facing the thickness direction of the metal foil conductors 7, 7 is the gold scrap conductor 7, 7. is approaching.

After such deformation, especially when the deformed portion 2 is still in a softened state, as shown in FIG. 6, it is crushed by pinchers 21, 21 as pressing jigs from the direction of the small diameter of the oval or ellipse. Due to this suppressed deformation, parts of the metal foil conductors 7, 7 and the lead wires 6.6, 8.8 connected thereto are sealed to the crushing wall, and the end of the valve 1 is crushed and sealed. It is.

According to such a sealing method, first the end 2 of the valve 1 is
Since the diameter of the sealed part is reduced by heating and softening, the wall thickness of this reduced diameter part becomes large, so that if it is crushed later, the wall thickness of the sealed part will not become thinner, and the width of the sealed part will become excessively large. It won't happen.

In this case, since the burners 1 and 8 are fixed and the valve 1 is rotated, the bulb 1 can be heated evenly around the entire circumference, and the burners 18 do not have to be arranged around the entire circumference.

In addition, contrary to the above, the valve 1 may be fixed and the burner 18 may be rotated, but in this case, the diameter of the rotation locus of the burner 18 becomes large, so there is a risk that the device will become larger.

The thus reduced diameter end is then connected to a pair of burners 20, 2.
0, the metal foil conductors 7, 7 are heated from the thickness direction, the diameter is reduced in this direction, and the metal foil conductors 7, 7 are deformed into a Nagata or elliptical solid shape. Due to this deformation, the Nagata or elliptical wall in the direction of the small diameter approaches the metal foil conductors 7, 7 in the thickness direction.

As a result, since the next direction in which the pincers 21, 21 are used to crush the material is the small diameter direction, the amount of deformation required for crushing, that is, the suppression stroke, can be reduced.

Therefore, the amount by which the glass wall is forcibly deformed is small, and the glass bulb 1 is not subjected to excessive distortion, and no large residual distortion is left behind.

For this reason, the rate of cracks occurring during the crushing sealing process is reduced, improving yield, and problems such as residual strain growing during life and generating minute cracks, leading to leaks, are also reduced.

In addition, although the above embodiment describes a halogen light bulb, the present invention is not limited thereto; for example, in a light tube of a metal vapor discharge lamp, crushing sealing parts are formed at both ends. The sealing method of the present invention can also be applied to these items.

Furthermore, it is not limited to the case where two gold maple foil conductors are sealed in one sealing part, but it is also possible to seal one metal foil conductor, and in this case, W is one metal foil conductor. Corresponds to the width of the foil conductor.

[Effects of the Invention] As explained above, according to the present invention, at the stage of crushing with the pinchers, the portion to be crushed has already been deformed into an elliptical or oval flat shape, and therefore, when crushing with the pinchers, the suppression stroke is The amount of strain applied to the bulb is small, preventing cracks from occurring and improving yield. In addition, there is less residual strain, and problems such as cracks and leaks during the life of the product are eliminated.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a diagram illustrating the outline of a device for uniformly reducing the diameter of the end of a valve, FIG. 2 is a diagram explaining the diameter reduction process, and FIG. FIG. 4 is a diagram illustrating the deformation step of reducing the diameter of the end of the valve in one direction; FIG. 5 is a bottom view showing the deformed end; FIG. The figure is a diagram illustrating the process of crushing and sealing the end of the valve, and FIG. 5 is a bottom view showing the end that has been pressure-sealed. DESCRIPTION OF SYMBOLS 1... Valve, 2... Valve end, 3... Exhaust pipe, 4... Mount, 5... Filament, 6, 6...
...Internal lead wire, 7, 7...Metal foil conductor, 8, 8...
- External lead wire, 10...Mount chuck carrier, 12...Mount chuck, 17
...Motor, 18...Burner, 20...Burner,
21... Pincha.

Claims (1)

[Claims] A method for forming a crush-sealed portion in which a metal foil conductor connected to a lead wire is sealed at an end of a tube bulb, comprising: a portion to be crushed and sealed at the end of the tube bulb; is heated uniformly in the circumferential direction to shrink the heated end, the inner diameter of the heated end is d, the inner diameter of the bulb before sealing is D, and the maximum dimension in the width direction of the metal foil conductor is W. D>d>W, and then this baked-shrinked part is heated from both sides along the crushing direction to shrink it so that the crushing direction becomes a small diameter, deforming it into an elliptical or oval flattened shape, and further this flattened shape. 1. A method of sealing a tube, comprising: sealing the tube by crushing the tube from a small diameter direction, and sealing a metal foil conductor to the crushed sealing section.