JPH06256033A - Production of glass bulb and its device - Google Patents

Abstract

PURPOSE:To provide a method and a device to produce a bent glass bulb capable of controlling temperature of a mold in high accuracy and preventing deformation and variation of residual strain. CONSTITUTION:In a method where a straight pipe glass bulb is softened and bent to a given shape, the bent part 3 is received in a reshaping mold 10 and hold in a forming space of the reshaping mold until its hardening, and the reshaping mold is cooled by letting cooling water run in cooling water passes 15a and 15b made in the reshaping mold, temperature is detected and amount of cooling water is regulated corresponding to the temperature to control the reshaping mold temperature. As the amount of the cooling water which runs in the cooling water pass is automatically regulated by this device, it is able to control the temperature of the reshaping mold in high accuracy, thus eliminating a time lag required to cool and solidify the bulb and preventing deformation of the bulb and variation of residual strain.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when manufacturing a glass bulb having a bent portion like a bulb of a compact fluorescent lamp, cools a shaping die for adjusting the bent shape to a predetermined shape and gradually cooling. The present invention relates to a method and an apparatus for manufacturing a bent glass bulb according to the method and the apparatus.

[0002]

2. Description of the Related Art Generally, in a compact fluorescent lamp having a bent shape such as a U-shape or a W-shape, a straight tube glass bulb is formed by bending to obtain the bent bulb. It is supposed to do. That is, for example, in the case of a compact fluorescent lamp having a U shape, the central portion of the straight tube type glass bulb is heated and softened, and the central portion is bent into a U shape.

In this case, since the glass bulb immediately after bending is still soft, if it is left as it is, it will be deformed by its own weight, and the U-shape will be deformed and the cross-sectional shape will be distorted. In order to prevent this, the bent portion is housed in a shaping mold, the U-shaped bent portion is held in a molding space formed in the mold, and the valve is held in this mold until it cools and solidifies, followed by gradual cooling. While adopting a means to arrange the shape.

When the shape is adjusted by gradually cooling with such a shaping mold, the temperature of the shaping mold is low at the initial stage of the work in the process of continuously molding a large number of valves, but the work is continued successively. The temperature of the mold rises while receiving heat from the valve while reaching a saturated state. That is,
When the work is continued throughout the day, the temperature of the mold is low in the early stage of the work, so that the bent valve is cooled quickly. Then, when the temperature of the mold gradually rises due to the heat from the valve, the time required for cooling and solidifying the valve becomes longer, and when the mold temperature finally reaches the saturation temperature,
It takes the longest time to cool and solidify the valve.

Therefore, there is a problem that variations occur in the cooling and solidification time of each molded valve, deformation occurs due to the difference in the cooling progress rate, and variations in the residual strain amount due to the difference in shrinkage temperature.

[0006]

SUMMARY OF THE INVENTION In order to prevent this,
A means of water cooling the shaping mold is adopted. That is,
This cooling means forms a passage through which cooling water is passed in the wall of the shaping die, and the cooling water is caused to flow through the passage, thereby forcibly cooling the shaping die.

However, in the conventional case, the amount of water flowing through the cooling water passage is constant. Therefore, although the mold can be regulated so as not to rise to the maximum temperature in the related art, the temperature of the mold becomes unstable. , The shape of the curved part may be changed or thermal distortion may occur.

The present invention has been made in view of the above circumstances. An object of the present invention is to control the temperature of a shaping die with high precision, eliminate the difference in valve solidification time, and deform the valve. An object of the present invention is to provide a method and an apparatus for manufacturing a bent glass bulb capable of preventing the dispersion of residual strain and the residual strain.

[0009]

According to the manufacturing method of the present invention, a straight tube type glass bulb is softened, bent into a predetermined bent shape, and then this bent portion is housed in a shaping die, and this shaping metal is used. By holding the bending portion of the valve until it hardens in a molding space corresponding to the shape of the bending portion formed in the mold, and at this time, passing cooling water through the cooling water passage formed in the shaping mold, this shaping metal In the method of manufacturing a bent glass bulb that cools the mold, the temperature of the shaping mold is detected, and the flow rate of the cooling water supplied to the cooling water passage is adjusted according to this temperature to adjust the temperature of the shaping mold. Is controlled.

Further, in the manufacturing apparatus of the present invention, the straight tube type glass bulb is softened, bent into a predetermined bending shape, and then the bent portion is housed in the shaping mold to form the shaping mold. The bending portion of the valve is held until it hardens in a molding space corresponding to the shape of the bending portion, and in this case, the shaping die is cooled by passing cooling water through a cooling water passage formed in the shaping die. In the bending glass bulb manufacturing apparatus configured as above, a temperature sensor for detecting the temperature of the shaping die, and a flow rate adjustment for adjusting the flow rate of the cooling water supplied to the cooling water passage in accordance with the temperature detected by the temperature sensor. Means for controlling the temperature of the shaping mold by the temperature sensor and the flow rate adjusting means.

[0011]

According to the manufacturing method and the manufacturing apparatus of the present invention, the temperature of the shaping die is detected by the temperature sensor, and the amount of the cooling water flowing through the cooling water passage is controlled by the flow rate adjusting means according to the detected temperature. The temperature of the shaping die can be controlled with high accuracy. Therefore, it is possible to eliminate the difference in time required for cooling and solidifying the valve, and prevent deformation of the valve and variation in residual strain.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings.

In the figure, reference numeral 1 denotes a glass bulb of a U-shaped fluorescent lamp, which is provided with a U-shaped bent portion 3 between linear portions 2 and 2 at both ends. An electrode (not shown) is sealed at the end of the bulb 1. The U-shaped bulb 1 is formed by heating and softening the central portion of a straight tube type glass bulb and bending the softened portion.

The U-shaped valve 1 is housed in the shaping mold 10 immediately after bending, when the valve 1 is still softened.
The shaping die 10 is configured by abutting and separating a pair of dividing members 11a and 11b, and forming U-shaped molding grooves 12a and 12b on the abutting surfaces thereof, and the pair of dividing members 11a. , 11b, the U-shaped molding grooves 12a, 12b form a U-shaped molding space 13. The U-shaped space 13 corresponds to the shape of the U-shaped bent portion 3 of the bent valve 1. To put it the other way around, the bent portion 3 of the U-shaped valve 1 in the U-shaped space 13 of the shaping mold 10 in a state where it is still softened.
, And then close the shaping mold 10 and wait for a predetermined time,
The bent portion 3 of the valve 1 conforms to the shape of the U-shaped space 13 of the shaping mold 10 and is shaped so as to follow the shape of the U-shaped space 13.

Cooling water passages 15a and 15b are formed in the dividing members 11a and 11b so as to cross the dividing members 11a and 11b, respectively. The cooling water passages 15a and 15b are provided with cooling water supply pipes 16a and 16b and a discharge pipe. 17a, 1
7b is connected. These cooling water supply pipes 16
When cooling water such as tap water is passed through a and 16b, this cooling water is cooled by the cooling water passage 15 formed inside the shaping mold 10.
It flows through a and 15b, and is discharged through discharge pipes 17a and 17b. For this reason, the heat of the shaping die 10 is taken by the cooling water, so that the shaping die 10 is cooled.

Dividing members 11a, 11 of the shaping die 10 described above.
Temperature sensors 20a and 20b for detecting the temperatures of the split members 11a and 11b, respectively, are installed in b. The temperature sensors 20a and 20b are adapted to convert the detected temperature information into an electric signal and transmit it to the controller 21.

The cooling water supply pipes 16a, 16 are also provided.
For example, electromagnetic flow control valves 22a and 22b as a flow control means are attached to b. The flow rate control valves 22a and 22b operate by receiving a signal from the controller 21.

That is, the controller 21 uses the setting device 2
11 and a comparator 212, the comparator 212 compares the temperature set in the setter 211 and the detected temperature sent from the temperature sensors 20a and 20b. As a result, when the temperature of the dividing members 11a and 11b is lower than the set temperature, an instruction is issued to close the flow rate control valves 22a and 22b. Conversely, when the temperature of the dividing members 11a and 11b is higher than the set temperature, the above is performed. A command is issued to open the flow control valves 22a and 22b. As a result, the flow rate of the cooling water, that is, the cooling capacity is controlled. A method of adjusting the shape of the U-shaped valve 1 using the shaping die 10 having such a configuration will be described.

A central portion of a straight tube type glass bulb (not shown) is softened by heating and the softened portion is bent to form a U-shaped bulb 1.
To form. The U-shaped valve 1 is housed in the shaping mold 10 when the bent portion 3 is still softened. That is, the pair of split members 11a of the shaping die 10,
11b are separated from each other to form U-shaped forming grooves 12a and 12b
A U-shaped bent portion 3 is sandwiched between these divided members 11a, 1
Abut 1b. In this state, the cooling water supply pipe 16
Cooling water is caused to flow through a and 16b, and the temperature of the mold is set in the setter 211 of the controller 21.

Since the shaping die 10 receives heat from the valve 1 in a high temperature state, the temperature rises. In this case, by passing the cooling water through the cooling water supply pipes 16a and 16b, the cooling water passages 15a and 15b formed inside the shaping mold 10 are formed.
Cooling water flows to prevent the excessive temperature rise of the shaping mold 10. The temperature of the shaping die 10 is as shown in FIG.
Inversely proportional to the flow rate of cooling water.

In this case, the pair of dividing members 11a, 11b
The temperature of 20 is detected by the temperature sensors 20a and 20b, and the detected temperature is compared with the set temperature by the comparator 212. As a result, when the temperature of the split members 11a, 11b is lower than the set temperature, the controller 21 causes the flow control valve 22a,
22b is instructed to close the flow path, thereby reducing the flow rate of the cooling water. Therefore, the cooling capacity of the dividing members 11a and 11b is reduced, the heat of the dividing members 11a and 11b is not taken, and the temperature is controlled by receiving the heat from the valve 1.

On the contrary, when the temperature of the split members 11a and 11b is higher than the set temperature, the controller 21 commands the flow rate control valves 22a and 22b to open the flow path, thereby increasing the flow rate of the cooling water. . Therefore, the dividing member 11
The cooling capacity of a and 11b is improved, and the dividing members 11a and 11b
The heat of b is taken away, and the temperature is controlled so as not to rise due to the heat from the valve 1.

Therefore, the temperature of the shaping die 10 can be controlled with high accuracy, the amount of heat escaping from the valve after bending to the cooling water through the shaping die 10 becomes uniform, and the cooling and solidifying time of each valve is increased. Since it becomes constant and the progress rates of slow cooling become equal, it is possible to eliminate deformation and variations in residual strain due to difference in shrinkage. Therefore, the U of the bent portion 3
The character shape can be shaped with high accuracy, the quality is improved, and the quality variation is eliminated. In addition, if the shaping die temperature control device as described above is used, since it is automatically controlled, no special manpower is required.

In the above embodiment, the flow control valve 22a,
22b is installed in the cooling water supply pipes 16a and 16b, but these flow control valves 22a and 22b are connected to the discharge pipe 17
The same effect can be obtained even when attached to a and 17b.

[0025]

As described above, according to the present invention, the temperature of the shaping die is detected by the temperature sensor, and the amount of the cooling water supplied to the cooling water passage is controlled by the flow rate adjusting means according to the detected temperature. Therefore, the temperature of the shaping mold can be controlled automatically and with high accuracy. Therefore, it is possible to eliminate the time difference required for cooling and solidifying the valves, and it is possible to prevent variations in deformation and residual strain from occurring in each valve,
Quality is stable.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention in which a bulb and a shaping mold of a U-shaped fluorescent lamp are disassembled.

FIG. 2 is a perspective view showing a state where the valve of the embodiment is housed in a shaping mold and cooled.

FIG. 3 is a diagram schematically showing the temperature control device for the shaping mold of the embodiment.

FIG. 4 is a characteristic diagram showing the relationship between the flow rate of cooling water and the temperature of the shaping mold.

[Explanation of symbols]

1 ... U-shaped glass bulb 2 ... Straight part
3 ... Bending part 10 ... Orthogonal mold 11a, 11b ... Dividing member 12a, 12b ... U-shaped groove 13 ... Molding space 15a, 15b ... Cooling water passage 16a, 16b ... Cooling water supply pipe 17a, 17b ... Discharge pipe 20a, 20b ... Temperature sensor 21 ... Controller 22a, 22b ... Electromagnetic flow control valve

Claims (3)

[Claims] 1. A straight tube type glass bulb is softened, bent into a predetermined bending shape, and then the bending portion is housed in a shaping mold, and the bending portion is formed in a shape corresponding to the shaping portion. A bent glass bulb that holds the bent portion of the bulb until it hardens in the molding space and cools the shaping die by passing cooling water through a cooling water passage formed in the shaping die. In the manufacturing method, the temperature of the shaping mold is detected, and the temperature of the shaping mold is controlled by adjusting the flow rate of the cooling water supplied to the cooling water passage according to the temperature. Method for manufacturing bent glass bulb. 2. A straight tube type glass bulb is softened, bent into a predetermined bending shape, and then this bending portion is housed in a shaping mold, and the bending portion is formed in a shape corresponding to the shaping portion. A bent glass bulb in which the bent portion of the bulb is held in the molding space until it hardens, and in this case, the shaping die is cooled by passing cooling water through a cooling water passage formed in the shaping die. In the manufacturing apparatus, the temperature sensor for detecting the temperature of the shaping mold and the flow rate adjusting means for adjusting the flow rate of the cooling water supplied to the cooling water passage according to the temperature detected by the temperature sensor are provided. An apparatus for manufacturing a bent glass bulb, characterized in that the temperature of the shaping mold is controlled by a temperature sensor and a flow rate adjusting means. 3. The shaping mold is formed by abutting two split members, a cooling water passage is formed in each of the split members, and cooling water supplied to the temperature sensor and the cooling water passage, respectively. 3. A bendable glass bulb according to claim 2, wherein a flow rate adjusting means for adjusting the flow rate is provided, and the temperature of each of the two split members is controlled by each temperature sensor and the flow rate adjusting means. apparatus.