JPH03297048A - Pinch seal machine - Google Patents

Abstract

PURPOSE:To lessen unevenness in the heating temp., suppress time loss from heating till pressure contact, maintain stable sealing conditions, and enhance the yield by furnishing three or more burners which are arranged radially at equal angle intervals so that flame is cast to a glass tube for sealing. CONSTITUTION:A pinch seal machine according to the present invention is composed of three or more burners 3, which are arranged radially at equal angle intervals so that flame is cast to a glass tube G for sealing, and pinchers 4 which are arranged being opposed so as to advance between these burners 3 to generate pressure contact of the glass tube G. This accomplishes uniform heating of the glass tube G, wherein moving the burners is not required to eliminate time loss from the heating to pressure contact. This allows maintaining stable sealing conditions, enhances the quality, causes crackes not easily to initiate, and enhances the yield from production.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a pinch sealing machine used for forming a crimp seal of a light bulb.

[Prior art and its problems]

For example, in a tubular halogen incandescent light bulb used as an exposure light source in an electrophotographic copying machine, a filament assembly is placed inside a quartz glass tube for the enclosure, and both ends of the quartz glass tube are pinch-sealed to form a crimp seal. is forming. This pinch sealing operation is performed using a pinch sealing machine equipped with a burner that heats the glass tube and a pincher that presses the heated glass tube.

A conventional pinch seal machine will be explained based on Fig. 5.
A quartz glass tube G for an enclosure, in which a filament assembly is disposed, is held vertically by a holder 110, and its lower end is pinch-sealed. At this time, in order to prevent oxidation of the filament assembly, nitrogen gas is flowed into a branch pipe B extending laterally from the glass tube G. A pair of burners 101, 101 attached to the rotating plate 106
A pair of pinchers 102 and 10 are arranged facing each other with the glass tube G at the center, and are driven by a link mechanism 105.
2 is also placed below Novenaer tot and 1ot, facing each other in the same direction. When the glass tube G is heated to a predetermined temperature by the burners 101, 101, the first air cylinder 1
03 is activated. Therefore, the first rotating plate 106 rotates around the shaft 106a, and the burners 101, 101 also rotate and jump up. At the same time, the air cylinder shown in the illustrated path operates to raise the pinchers 102, 102 to the heating position, and at the same time, the second air cylinder 104 operates, and the link mechanism 105 rotates around the shaft 105a, causing the pinchers to rise to the heating position.
102 and 102 approach each other and press the heated glass tube G to form a flat press-sealed portion.

In this way, since there is a pair of burners (two burners), the part where the flame directly shines becomes high temperature, and there is a temperature difference with the part perpendicular to the burner, but it is necessary to press the high temperature part with pinchers. For this reason, the portion of the glass tube heated by the burner and the portion pressed by the pinchers are in the same direction, making it impossible to arrange the burner and pinchers in a crossed manner. In other words, after heating, the burner moves and the pinchers move to that position. Therefore, it is difficult to accurately adjust the burner operating position and the pincher operating position, and the operating mechanism is complicated, causing large vibrations during movement. Also, from heating to crimping, 0.4
It takes a certain amount of time and there is a time loss. Moreover, the movement of the burner is driven by an air cylinder, so
Travel time varies due to changes in air pressure and room temperature. For this reason, when a glass tube is heated to a high temperature of about 2,500℃, nitrogen gas flows inside it, causing a rapid temperature drop during this period, and there is also a slight variation in temperature loss over time. Therefore, stable sealing conditions could not be maintained.

Furthermore, since there are two burners, the heating temperature of the glass tube is uneven, and cracks may appear when the tube is crimped, resulting in a low yield in the pinch sealing process.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a pinch sealing machine that can maintain stable sealing conditions with less uneven heating temperature, no time loss from heating to compression, and has a high yield.

[Structure of the invention and its operation]

The pinch sealing machine of the present invention has three or more burners arranged radially at equal angles so that the flame is radiated toward a glass envelope tube held in a vertical direction, and the burner. The device is characterized by comprising pinchers arranged opposite each other so as to move forward and press the heated glass tube for sealing.

That is, since three or more burners are arranged radially at equal angles and the flame is radiated toward the glass tube, the glass tube is heated uniformly and unevenness in heating temperature is reduced. Therefore, it is not necessary to match the direction of heating with the burner and the direction of pressure bonding with the pinchers, and the pinchers can move forward between the burners and press the glass tube. Therefore, there is no need for the burner to move after heating is completed, no need to adjust the burner operating position and the pincher operating position, and no complicated drive mechanism is required. and,
Pressure bonding can be performed almost simultaneously with the completion of heating or while heating, eliminating time loss, allowing stable sealing conditions to be maintained, improving quality, and reducing cracks and improving manufacturing yield.

〔Example〕

The present invention will be specifically described below based on embodiments shown in the drawings.

In FIG. 1, a quartz glass tube G for an enclosure, in which a filament assembly is arranged, is held vertically by a holder 9, and the lower end of the glass tube G is pinch-sealed. Then, the lead of the filament assembly protruding from the lower end opening of the glass tube G is held in a chuck 91 so that the metal foil of the filament assembly is located at the lower end of the glass tube G.
is holding it. The holders 9 are arranged in a line and are sequentially moved in the direction of the arrow each time the pinch sealing operation is completed.

A pair of rails 11 are provided on the top surface of the base 1 facing the holder 9, and the movable table 2 is movable along the rails 11. It is located in A motor 61 is attached to the base 1, and a rotating shaft 64 of the cam 6 is connected to the motor 61 via a clutch 63 and a reduction gear 62. The cam 6 is approximately gourd-shaped, and its peripheral surface is a cam profile.

A plate 21 in which a U-shaped notch 21a is formed is attached to the end of the moving table 2.

On the plate 21 around the notch 21a, four burners 3, in which flames are formed with oxygen gas and hydrogen gas, are arranged radially at equal angles, and the flames are directed toward the center of the four burners 3. It is designed to radiate light. The number of burners 3 may be three or more, and in any case, the glass tube G at the center of the burners 3 can be uniformly heated. In addition, a pair of sliding tables 41 are equipped with water-cooled pinchers.
A holder 42 is attached, and the pincher 4 is fixed on the pincher holder 42. The sliding table 41 is disposed movably along the rail 22, and the pinchers 4, 4 move toward and away from the burner 3 by passing between them. That is, even when the pincher 4 moves, the burner 3 does not move, so a moving mechanism for the burner 3 is not required, and no vibration occurs. Also, burner 3 and pincher
4 is arranged on the surface of one plate 21, and the pincher 4 moves on the surface of the plate 21, so there is no need to adjust the burner operating position and the pincher operating position.

Note that piping for cooling water and gas is not illustrated.

Next, a pair of substantially dogleg-shaped links 5 are rotatably attached to the movable table 2 about a shaft 53 erected thereon. One end of the link 5 is pivotally supported on the sliding base 41 of the pincher 4, and a cam follower 51 is attached to the other end. Further, a spring 52 is arranged between the links 5.5, and the elastic force of the spring 52 causes the cam follower 51.51 to firmly abut against the circumferential surface of the cam 6. Therefore, when the cam 6 rotates, the link 5 rotates, and when the cam followers 51, 51 collide with each other in the longitudinal direction of the cam 6, the pinchers 4, 4 approach each other.
When they collide in the short direction of the cam 6, they separate.

Then, the movable table 2 is moved in the direction of the holder 9 by a drive mechanism (not shown), and as shown in FIG.
Located in the center of the cam follower 51.51
collides with the cam 6 at a predetermined position. Then, as shown in Fig. 3, the burner 3 is ignited and four flames F are emitted from the glass tube G.
Wrap it around to heat it evenly.

When the glass tube G rises to a predetermined temperature of about 2500°C, the burner 3 is extinguished, and at the same time as the extinguishment, the clutch 63 is connected, the cam 6 rotates, and the pinchers 4, 4 approach. As shown in FIG. 4, the heated glass tube G is crimped to form a flat crimped sealing portion in which the metal foil of the filament assembly is embedded, completing the pinch sealing on one end side. Note that burner 3 remains lit.

Although crimping may be performed using pinchers 4, in any case there is no time loss from heating to crimping, and crimping can be performed at a constant heating temperature, so the glass tube G can be heated uniformly. In combination, cracks are less likely to occur and there is no variation in sealing conditions, improving quality. Furthermore, since there is no temperature drop between heating and compression bonding, there is an advantage that the maximum heating temperature is low.

Even when crimping is completed, the cam 6 continues to rotate, and the pincher 4
, 4 are separated and returned to their original positions, the clutch 63 is separated and the cam 6 is stopped. Thereafter, the moving table 2 moves back and returns to the state shown in FIG. 1, the holder 9 also moves, and the glass tube G to be processed next stops in front of the cut 21a of the plate 21, completing one cycle. .

〔Effect of the invention〕

As explained above, the pinch sealing machine of the present invention has three or more burners arranged radially at equal angles so that the flame is radiated toward the glass tube for the enclosure, and the pinch sealing machine moves forward between the burners. Since the pinchers are arranged opposite to each other so as to press the glass tube, the glass tube is heated uniformly, and there is no need to move the burner, so there is no time loss between heating and press-fitting. Therefore, stable sealing conditions can be maintained, quality is improved, cracks are less likely to occur, and manufacturing yields are also improved.

[Brief explanation of drawings]

1 and 2 are perspective views of the embodiment of the present invention, FIG. 3 is an explanatory view of a heated state, FIG. 4 is an explanatory view of a crimped state, and FIG. 5 is an explanatory view of a conventional example.

Claims (1)

[Claims] Three or more burners arranged radially at equal angles so that the flame is radiated toward a vertically held glass envelope tube, and an envelope heated by moving forward between the burners. A pinch sealing machine characterized by comprising pinchers arranged facing each other so as to crimp a glass tube.