JP2767775B2 - Pinch sealing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pinch sealing machine used for forming a pressure-sealed portion of a light bulb.

[Prior art and its problems] For example, a tubular halogen incandescent lamp used as a light source for exposure of an electrophotographic copying machine has a filament assembly disposed in a quartz glass tube for an envelope, and both ends of the quartz glass tube are connected to each other. A pinch seal is formed to form a pressure-sealed portion. This pinch sealing operation is performed by a pinch sealing machine provided with a burner for heating the glass tube and a pincher for pressing the heated glass tube.

A conventional pinch sealing machine will be described with reference to FIG. 6. A quartz glass tube G for an envelope in which a filament assembly is disposed is held vertically by a holder 110, and the lower end thereof is pinch sealed. Is done. At this time, in order to prevent oxidation of the filament assembly, the glass tube G
A nitrogen gas is supplied to a branch pipe B extending laterally from the side. A pair of burners 101, 101 attached to the rotating plate 106 are opposed to each other around the glass tube G, and a link mechanism 105
A pair of pinchers 102, 102 driven by the burners 101, 1
It is arranged opposite to the lower side of 01 in the same direction. When the glass tube G is heated to a predetermined temperature by the burners 101, 101, the first
The air cylinder 103 operates. Therefore, the rotating plate 106 is
Rotating around 106a, the burners 101, 101 also rotate and jump up. At the same time, an air cylinder (not shown) is operated to raise the pinchers 102 and 102 to the heating position, and the second air cylinder 104 is operated and the link mechanism 105 is operated.
Is rotated about the shaft 105a, and the pinchers 102 and 102 approach each other, and presses the heated glass tube G to form a flat crimp sealing portion.

As described above, since there is a pair (two) of burners, a portion directly hit by the flame becomes hot, and a temperature difference is generated between a portion perpendicular to the burner and the high temperature portion. Therefore, the part where the glass tube is heated by the burner and the part that is pressed by the pincher are in the same direction,
Burner and pincher cannot be placed crosswise. That is, after heating, the burner moves and the pincher moves to that position. Therefore, it is difficult to precisely adjust the position of the burner operation position and the position of the pincher operation position, and the operation mechanism is complicated and vibration during movement is large. Also, it takes about 0.4 seconds from the time of heating to the time of pressure bonding, and there is a time loss. Moreover,
Since the movement of the burner is driven by the air cylinder, the movement time varies due to fluctuations in air pressure and room temperature. For this reason, the glass tube heated to a high temperature of about 2500 ° C. has a nitrogen gas flowing inside, so the temperature suddenly drops during this time, and there is variation in time loss.
Stable sealing conditions could not be maintained.

Also, since there are two burners, there is a large temperature gradient between the part where the burner directly hits and the part where the burner does not hit, and the heating temperature of the glass tube is uneven. There was a problem with low yield. For this reason, a method of heating uniformly while rotating a burner or a glass tube is also known, but in any case, there is a problem that a rotating mechanism is required and the structure becomes complicated.

[Object of the invention]

Therefore, the present invention can reduce unevenness in the heating temperature without rotating the burner or the glass tube, and can maintain stable sealing conditions without a time loss from heating to pressure bonding, and can improve the yield. It is an object of the present invention to provide a pinch sealing machine having a high performance.

[Configuration of the invention and its operation]

The pinch sealing machine of the present invention comprises four burners arranged radially at an equal angle so that a flame is radiated toward a vertically held glass envelope glass, and is advanced between the burners. And the pinchers are arranged to oppose each other so as to press the heated glass tube for the envelope, and pulsate the two burners opposing each other with the same burning pattern and the pulsation pattern of the adjacent burners. The method is characterized in that the glass tube for the envelope is heated in the opposite phase.

That is, the four burners are radially arranged at an equal angle, and the flame radiates toward the glass tube, so that the interval between the part directly hitting the burner and the part not hitting it becomes narrower,
Furthermore, the two burners opposing the combustion power of the burner were pulsated in the same pattern, and the pulsation pattern of the adjacent burners was set to the opposite phase, so the temperature gradient was reduced as if the burners were rotated, and the glass The tube is heated uniformly, and the unevenness of the heating temperature is reduced. Therefore, it is not necessary to make the direction of heating by the burner and the direction of crimping by the pincher coincide with each other, and the pincher can advance between the burners to crimp the glass tube. Therefore, there is no need to move the burner after the completion of heating, and it is not necessary to adjust the burner operating position and the pincher operating position, and a complicated drive mechanism is not required. Then, it is possible to perform pressure bonding almost at the same time as the completion of heating or while heating, and there is no time loss, so that stable sealing conditions can be maintained, quality is improved, cracks are less likely to occur, and manufacturing yield is improved.

〔Example〕

Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings.

In FIG. 1, a quartz glass tube for sealing G in which a filament assembly is disposed 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 projecting from the lower end opening of the glass tube G is inserted into the chuck 91 so that the metal foil of the filament assembly is located at the lower end of the glass tube G.
Is gripping. The holders 9 are arranged in a line, and each time the pinch seal operation is completed, the holders 9 sequentially move in the direction of the arrow.

The base 1 is arranged near the holder 9.
A pair of rails 11 are provided on the upper surface of the
The moving table 2 is arranged movably along the rail 11. A motor 61 is mounted on the base 1, and a rotation shaft 64 of the cam 6 is connected to the motor 61 via a clutch 63 and a speed reducer 62. The cam 6 has a substantially gourd shape, and its peripheral surface is a cam profile.

A plate 21 having a U-shaped cut 21a is attached to an end of the movable base 2. On the plate 21 around the cut 21a, four burners 3a, 3b, 3c, 3d in which a flame is formed by oxygen gas and hydrogen gas are radially arranged at an equal angle, and four flames are formed. Burners 3a, 3b, 3
It radiates toward the center of c and 3d. Also,
A water-cooled pincher holder 42 is attached to the pair of slides 41, and the pincher 4 is fixed on the pincher holder 42. The slide table 41 is arranged so as to be movable along the rail 22, and the pinchers 4 and 4 perform an approaching and reciprocating motion passing between the burners 3a and 3b and between the burners 3c and 3d. That is, even when the pincher 4 moves, the burners 3a, 3b, 3c, 3d do not move, and the burners 3a, 3b, 3
No moving mechanism and rotating mechanism for c and 3d are required, and no vibration occurs. Further, the burners 3a, 3b, 3c, 3d and the pincher 4 are arranged on a single plate 21 and
Moves on the plate 21, so that it is not necessary to adjust the burner operating position and the pincher operating position. The illustration of the piping for cooling water and gas is omitted.

Next, a pair of substantially rectangular links 5 are attached so as to be rotatable about a shaft 53 erected on the movable base 2. And one end of the link 5 is a slide table of the pincher 4.
Each is supported by a cam follower at the other end.
51 is installed. A spring 52 is arranged between the links 5, 5 so that the cam followers 51, 51 firmly abut against the peripheral surface of the cam 6 by the elastic force of the spring 52. Therefore, when the cam 6 rotates, the link 5 rotates, and when the cam followers 51, 51 abut in the longitudinal direction of the cam 6, the pinchers 4, 4 approach, and when they abut 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.
Burns into the cut 21a of the plate 21 and burners 3a, 3
b, 3c, 3d and cam follower 51,
51 abuts a predetermined position of the cam 6. Then, as shown in FIG. 3, the burners 3a, 3b, 3c, 3d are ignited and the four flames F
Is heated so as to enclose the glass tube G, but the burning heat power pulsates as the burners 3a, 3c and the burners 3b, 3d facing each other form a pair. The pulsation method is, for example, as shown in FIG. 4 (A), in which the gas flow rate is within 80% of the maximum flow rate, and the sine curve of a 1 second cycle, and FIG. 4 (B) and FIG. As shown in the figure, the flow is sent under the strong and weak flow control, but the phases of the burners 3a and 3c and the burners 3b and 3d are shifted by 180 °. Accordingly, the temperature gradient is reduced as if the burners 3a, 3b, 3c, 3d were rotated, and the glass tube G was uniformly heated, so that the unevenness in the heating temperature was reduced.

When the temperature of the glass tube G rises to a predetermined temperature of about 2500 ° C., the burners 3a, 3b, 3c and 3d extinguish, while the clutch 63 is connected at a timing that can be pressed almost simultaneously with the extinguishing, and the cam 6 rotates and the pincher 4 As shown in FIG. 5, 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, and the pinch seal at one end is completed. I do. In addition, burner 3
Although a, 3b, 3c, and 3d may be pressed together with the pincher 4 while ignited, in any case, there is no time loss from heating to pressing, and the pressing can be performed at a constant heating temperature. Cracks are less likely to occur due to the uniform heating of the tube G, and there is no variation in sealing conditions, and the quality is improved.

Even when the pressure bonding is completed, the cam 6 continues to rotate, and when the pinchers 4 and 4 separate and return to the original position, the clutch 63 is separated and the cam 6 stops. Thereafter, the movable table 2 is retracted to return to the state shown in FIG. 1, the holding member 9 is also moved, and the glass tube G to be processed next stops before the cut 21a of the plate 21, and one cycle is completed. .

〔The invention's effect〕

As described above, the pinch sealer according to the present invention includes four burners radially arranged at an equal angle so that a flame is radiated toward the sealing glass tube, and advances between the burners. It consists of pinchers that are opposed to each other so as to crimp the glass tube, and the combustion heat of the burners pulsates the two burners facing each other in the same pattern, and the pulsation pattern of the adjacent burners is in opposite phase, The glass tube is uniformly heated without rotating the burner, and the time loss from heating to pressing is eliminated. Therefore, there are advantages that stable sealing conditions can be maintained, quality is improved, cracks are less likely to occur, and manufacturing yield is improved.

[Brief description of the drawings]

1 and 2 are perspective views of an embodiment of the present invention, FIG. 3 is an explanatory view of a heating state, FIGS. 4 (A), (B) and (C) are explanatory views of a pulsation method, and FIG. FIG. 6 is an explanatory view of a crimped state, and FIG. 6 is an explanatory view of a conventional example. 1 ... base, 2 ... mobile stand, 3a, 3b, 3c, 3d ... burner, 4 ... pincher, 5 ... link, 6 ... cam, 9
...... Holder, G ... Glass tube for sealing

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Yamashita 1194, Sado, Bessho-cho, Himeji-shi, Hyogo Ushio Inc. (72) Inventor Mitsuhiro Inoue 1194, Sado, Bessho-cho, Himeji-shi, Hyogo (56) References JP-A-2-94247 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01K 3 / 12,3 / 14 C03B 23 / 043,23 / 045,23 / 13

Claims (1)

(57) [Claims] 1. Four burners arranged radially at an equal angle so that a flame is radiated toward a glass tube for an enclosure held in a vertical direction, and heated by being advanced between the burners. And pinchers arranged to oppose each other so as to crimp the sealed glass tube. The combustion thermal power of the burner is caused to pulsate two opposing burners in the same pattern, and the pulsation pattern of the adjacent burner is inverted. A pinch sealing machine characterized by heating a glass tube for an enclosure.