JPH03297049A - Pinch seal machine - Google Patents

Abstract

PURPOSE:To maintain stable sealing conditions, enhance the quality, prevent easy initiation of cracks, and enhance the yield from production by pulsating the combusting powers of two oppositely situated burners with the same pattern, and making pulsation patters for adjoining burners in opposite phases. CONSTITUTION:Four burners 3a-3d are arranged radially at equal angle intervals, and flame is cast to a glass tube G, so that the gap between the part where the burners 3a-3d touch directly and the part out of touching is narrowed. The combusting powers of two oppositely situated burners are pulsated with the same pattern, while the pulsation patterns for adjoining burners are made in opposite phases. Therefore the temp. gradient is made gradual as if the burners were rotated. Thus, the glass tube G is heated uniformly to accomplish lesser unevenness in the heating temp. Pressure contacting can be made directly after completion of the heating, or during heating, which eliminates time loss. This allows maintaining stable sealing conditions, enhances the quality, prevent easy initiation of cracks, and enhances the yield.

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.

The conventional pinch seal machine will be explained based on Fig. 6.
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, a pair of burners 101, 101 are attached to a rotating plate 106 that flows nitrogen gas from the glass tube G to a branch pipe B extending laterally.
A pair of pinchers 1 oz, 1 are arranged facing each other with the glass tube G at the center and are driven by a link mechanism 105.
02 is also disposed below the burners 101 and 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 10
3 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 in the illustrated path is activated to raise the pinchers 102, 102 to the heating position, the second air cylinder 104 is activated, and the link mechanism 105 is rotated around the shaft 105a, causing the pincher 1 to rise to the heating position.
02 and 102 approach and press the heated glass tube G to form a flat pressure sealing part.

In this way, since there is a pair of burners (two burners), the part that is directly hit by the flame 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 pincher are in the same direction, making it impossible to arrange the burner and pincher in a crossed manner. In other words, after heating, the burner moves and the pincher moves to that position. Therefore, it is difficult to accurately adjust the burner operating position and the vincher 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 loss of one hour. 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°C, nitrogen gas flows inside it, so the temperature drops rapidly during this time, and the time loss varies, so a stable seal can be achieved. conditions could not be maintained.

In addition, since there are two burners, there is a large temperature gradient between the areas directly in contact with the burners and the areas that are not in direct contact with the glass tube, resulting in uneven heating temperature of the glass tube, which may cause cracks when crimped. There was a problem with low yield. For this reason.

Methods of uniformly heating the burner or glass tube by rotating them are also known, but either method requires a rotating mechanism and has the problem of complicating the structure.

[Purpose of the invention]

Therefore, the present invention makes it possible to reduce uneven heating temperature without rotating the burner or glass tube, maintain stable sealing conditions without any time loss from heating to crimping, and improve yield. The purpose of this invention is to provide a pinch sealing machine with high performance.

[Structure of the invention and its operation]

The pinch sealing machine of the present invention has four burners arranged radially at equal angles so that the flame is radiated toward a glass envelope tube held vertically, and the pinch sealing machine moves forward between the burners. The pinchers are arranged facing each other to press the heated glass tube for the seal, and the combustion power of the burners is pulsated in the same pattern between the two opposing burners, and the pulsation pattern of the adjacent burners is It is characterized by heating the glass tube for the sealing body with the phase opposite to that of the glass tube.

In other words, the four burners are arranged radially at equal angles, and the flame radiates toward the glass tube, which narrows the distance between the parts directly hit by the burners and the parts that don't, which further reduces the combustion power of the burners. The two opposing burners are pulsated in the same pattern, and the pulsation patterns of adjacent burners are set in opposite phases, so the temperature gradient is reduced and the glass tube is heated evenly, as if the burners were rotating. This reduces unevenness in heating temperature. 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. Then, pressure bonding can be carried out almost simultaneously with the completion of heating or while heating, eliminating time loss, and thus stable sealing conditions can be maintained, quality is improved, and cracks are less likely to occur, which improves 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 base 1 is placed near the holder 9, and a pair of rails 11 are provided on the top surface of the base 1 facing the holder 9.
A moving table 2 is arranged movably along a rail 11. 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 curved surface is the cam profile.

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

Then, on the plate 21 around the notch 218, there are four burners 30 in which a flame is formed with oxygen gas and hydrogen gas.
．． 3b, 3c, 3d are arranged radially at equal angles, and the flames are four burners 3a, 3b, 3c, 3.
It is designed to radiate toward the center of d. Further, a water-cooled pincher holder 42 is attached to a pair of sliding tables 41, and the pincher 4 is fixed on top of this pincher holder 42. The slide table 41 is arranged movably along the rail 22, and the slide table 41 is movably arranged along the rail 22.
4, 4 is between burners 3a and 3b and burner 3c
, 3d to perform approach and departure movements. In other words, even when the pincher 4 moves, the burners 3a, 3b,
3c and 3d do not move, and burners 3a, 3b, 3
c. No moving mechanism or rotation mechanism for 3D is required, and no vibration is generated. In addition, burners 3a, 3b, 3c,
3d and the pincher 4 are arranged on one plate 21 surface, and the pincher 4 moves on the plate 21 surface, so there is no need to adjust the burner operating position and the pincher operating position. Cooling water and gas piping are not shown.

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 by 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 the cam follower 51.51 moves the cam 6.
When they collide in the longitudinal direction of the cam 6, the pinchers 4, 4 approach each other, and 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.
a, 3b, 3c, and 3d, and the cam followers 51 and 51 abut against the cams 6 at predetermined positions. Then, as shown in FIG. 3, burner 3a,
3b, 3c, and 3d are ignited, and the four flames F surround and heat the glass tube G.

Opposing burners 3a, 3c and burners 3b, 3d
are combined and their combustion firepower pulsates. The pulsation method is, for example, as shown in Fig. 4 (A), where the gas flow rate is within 80% of the maximum flow rate, and a sine curve with a 1 second cycle, or a sine curve as shown in Fig. 4 (B) and (C). As shown in the figure, the flow rate is controlled to be strong or weak, but the phase is shifted by 180° between burners 3a and 3c and burners 3b and 3d. Therefore, the temperature gradient becomes smaller as if the burners 3a, 3b, 3c, and 3d were rotated, and the glass tube G is heated uniformly, reducing uneven heating temperature.

When the glass tube G rises to a predetermined temperature of about 2500°C, the burners 3a, 3b, 3c, and 3d are extinguished, and at the same time, the clutch 63 is connected almost at the same time as the extinguishing, and the cam 6 rotates to open the pincher. 4 and 4 approach each other, and as shown in Fig. 5, the heated glass tube G is crimped to form a flat crimped seal in which the metal foil of the filament assembly is embedded, and a pinch seal on one end is formed. Complete. Note that the burners 3a, 3b, 3c, and 3d may be crimped with the pinchers 4 while they are lit, but in any case, there is no time loss from heating to crimping, and the heating temperature is constant. Since the glass tube G is heated uniformly, cracks are less likely to occur.
There is no variation in sealing conditions, improving quality.

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 four burners arranged radially at equal angles so that the flame is radiated toward the glass tube for the enclosure, and the pinch sealing machine advances between the burners. The pinchers are placed opposite each other so as to press the glass tube together.

The combustion power of the two burners facing each other is pulsated in the same pattern, and the pulsation patterns of adjacent burners are set in opposite phases, so that the glass tube is heated evenly without rotating the burners. Eliminates time loss from heating to crimping. Therefore, there are advantages in that stable sealing conditions can be maintained, quality is improved, cracks are less likely to occur, and manufacturing yield is improved.

[Brief explanation of drawings]

Figures 1 and 2 are perspective views of the embodiment of the present invention, Figure 3 is an illustration of the heating state, Figures 4 (A), (B), and (C) are illustrations of the pulsation method, and Figure 5 6 is an explanatory diagram of a crimped state, and FIG. 6 is an explanatory diagram of a conventional example.

Claims (1)

[Claims] Four burners radially arranged at equal angles so that flames are radiated toward a glass envelope tube held vertically, and a glass envelope heated by moving forward between the burners. It consists of pinchers arranged facing each other so as to press the tubes together, and the combustion power of the burners is made to pulsate in the same pattern in the two opposing burners, and the pulsation patterns of the adjacent burners are set in opposite phases to create a sealing glass. A pinch sealing machine that heats the tube.