JP2666153B2 - Tempering furnace - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a tempering furnace, and in particular, automatically reheats a glass hardened by a temperature decrease before a primary molding or through a primary molding process before a secondary molding. Related to a tempering furnace.

[Prior Art] Conventionally, glass instruments for physics and chemistry experiments, such as beakers and flasks, which require a high degree of precision, have been manufactured by blow rod molding by a skilled worker.

In this manual blow rod shaping, the glass formed by winding or other methods from a glass melting furnace is subjected to a primary shaping operation called a rinsing operation in which the inner surface is adjusted to a required shape by a hemispherical lincer. Before the primary molding, it is necessary to eliminate the windings at the time of collecting the glass and smooth the surface, and to raise the temperature of the glass surface which has been lowered in temperature by the primary molding to the temperature required for the secondary molding. There is a need. Therefore, in order to raise the temperature to the level required before the glass surface is corrected and after secondary molding, the operator visually inserts the rod into the melting furnace and rotates it while keeping the blow rod almost horizontal so that it does not come into contact with the glass substrate. The glass is reheated while checking the degree of straightening and softening of the glass.

This reheating is called tempering, and the tempering corrects the glass surface, and when the temperature reaches a required temperature, the glass is taken out of the furnace and blow-molded to perform secondary molding with a final mold.

[Problems to be Solved by the Invention] Conventionally, since the above-described series of operations are performed manually, the production cost is high, and not only is the worker required to have a high level of skill, but also the skill There was a problem that the person could not be trained.

Particularly, in the tempering process, the state of softening due to reheating must be visually monitored, so that there is a problem that skill is required and a high burden is imposed on an operator.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and is capable of automatically detecting a state in which glass is reheated and softened by using a dedicated tempering furnace to achieve an automatic tempering operation. It is intended to provide a furnace.

Means for Solving the Problems In order to achieve the above object, a tempering furnace according to the present invention includes a heating tank for reheating glass, a detecting means for detecting a softened state of glass in the furnace, and the detecting means And a controller that calculates the rotation speed of the blowing rod and the timing of pulling the blowing rod out of the furnace based on the detection information from the controller, and controls the rotation speed of the blowing rod and draws the blowing rod out of the furnace by a command signal from the controller. And a glass attitude control device for performing the following.

[Action] According to the present invention, the glass having the winding before the primary molding or the glass which has been hardened by the temperature decrease through the primary molding process is inserted into the heating tank and the glass is detected by the detecting means during the reheating. The detected state is input to a controller to calculate the rotation speed of the blow rod and the timing of withdrawal from the furnace, and the rotation speed of the glass attitude control device is controlled by a command signal based on the calculation result. At the same time, the blow rod can be pulled out of the furnace.

Embodiment An embodiment of the tempering furnace according to the present invention will be described below with reference to FIGS. 1 to 5.

As shown in FIG. 1, the tempering furnace 1 includes a heating tank 2 and a heating device 3 including a gas burner disposed at the bottom of the heating tank 2.

The ambient temperature in the heating tank 2 is detected by a thermocouple Ts,
The inside of the tank is controlled to a constant temperature (about 1370 ° C). The furnace wall of the tempering furnace 1 is formed of a refractory, and a heat insulating material is provided on an outer surface thereof. Further, an insertion port 4, an observation window 5, and an exhaust hole 6 are formed in the furnace wall of the tempering furnace 1 as shown in FIG.

The insertion port 4 is configured such that a blow rod 8 with a ponte holding a glass 7 for reheating at a tip thereof can be taken in and out.

At the rear end of the blow rod 8, an articulated robot A constituting a glass attitude control device and a servomotor 9 fixed to the wrist are connected, and the blow motor 8 is held horizontally by the servomotor 9. The robot A is rotated while being moved, and is put in and out by the robot A.

On the other hand, a sensor 10 for observing the softened state of the glass 7 facing the observation window 5 is provided outside the furnace, and this sensor 10 is connected to a controller 12 via a relay 11.

The controller 12 is connected to the servo motor 9 via the repeater 13.

The surface temperature and the degree of deformation of the glass 7 are detected by the sensor 10, and the detected signal is converted by a repeater 11 including an A / D converter or a D / A converter, and the converted signal is converted by a controller 12.
Is being entered.

The controller 12 determines the softening state of the glass 7 based on the input signal, calculates the rotation speed of the blow rod 8 if heating is necessary, and outputs the calculation result as a command signal.
If the heating is not already required, the drawer timing is output.

The command signal from the controller 12 is converted by a repeater 13 including an A / D converter or a D / A converter, and the converted signal controls the servomotor 9 to control the rotation speed of the blow rod 8. At the same time, the blowing rod 8 is pulled out of the furnace by the robot A.

Next, the operation of the tempering furnace configured as described above will be described in the third.
This will be described with reference to the block diagrams of FIGS.

(A) FIG. 3 is a block diagram in the case where the radiation thermometer 14 is used for the sensor.

The surface temperature of the glass 7 is detected by the radiation thermometer 14, and this detection signal is input to the CPU 15 via the A / D converter 11a.

The correlation between the crow's surface temperature and the viscosity of the glass is stored in the CPU 15 in advance, and based on this relationship, the softening state of the glass 7 is determined based on the detection signal. The calculation is performed, and the calculation result is output to the motor driver 16 as a command signal.

On the other hand, if heating is not already required, a draw command is output to the robot A.

Then, the servo motor 9 is driven by the motor driver 16.
And the robot A draws the blow rod 8.

(B) FIG. 4 is a block diagram when the CCD camera 18 is used for the sensor 10.

The CCD camera 18 recognizes the outer shape of the glass 7 and detects a slight displacement of the outer shape in the process of softening.

This detection signal is sent to the CPU 15 via the camera controller 19.
To enter.

The correlation between the displacement of the glass and the viscosity of the glass is stored in the CPU 15 in advance, and based on this relationship, the softening state of the glass 7 is determined by the detection signal,
As in (a), the rotation speed of the servomotor 9 is controlled, and the blow rod 8 is pulled out by the robot A.

(C) FIG. 5 is a block diagram showing a case where the state of the glass 7 is not detected directly by the sensor but is detected indirectly by the torque fluctuation of the servomotor.

When the glass softens and hangs down under its own weight, the axial torque of the servomotor 9 increases by an amount corresponding to gravity.

At this time, a slight change in current is observed in the servo motor 9.

The change in the current is monitored by the CPU 15, the softening state of the glass 7 is determined, the rotation speed of the servo motor 9 is controlled in the same manner as in (a), and the blow rod 8 is drawn out by the robot A.

Thus, according to the present embodiment, the softening state of the glass in the furnace is detected by a sensor or the like, and based on this detection signal,
Calculates the appropriate rotation speed of the blowing rod, judges the timing of drawing the blowing rod, controls the rotation speed of the blowing rod, and pulls the blowing rod out of the furnace. It can be carried out.

[Effects of the Invention] As described above, according to the present invention, the tempering operation performed before the primary molding and between the primary molding and the secondary molding can be automatically performed according to the present invention. As a result, the production cost can be reduced, and a skilled engineer is not required.

Further, the automation of the tempering operation makes it possible to automate a series of molding operations including primary molding and secondary molding, thereby achieving a dramatic reduction in production cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a tempering furnace according to the present invention,
FIG. 2 is a perspective view of the tempering furnace, and FIGS. 3 to 5 are block diagrams for explaining the attitude control method. DESCRIPTION OF SYMBOLS 1 ... Tempering furnace, 2 ... Heating tank, 3 ... Heating device, 8 ... Blowing rod, 9 ... Servo motor (glass attitude control device) 10 ... Sensor, 11, 13 ... Repeater 12 ... Controller, A ... Robot (glass attitude control device)

Claims (4)

(57) [Claims] 1. A heating tank for reheating glass, a detecting means for detecting a softening state of the glass in the furnace, and a rotation speed of the blowing rod and the inside of the furnace of the blowing rod based on detection information from the detecting means. A controller that calculates the withdrawal timing from the
A tempering furnace comprising: a glass attitude control device for controlling the rotation speed of the blowing rod and drawing the blowing rod out of the furnace in response to a command signal from the controller. 2. The apparatus according to claim 1, wherein said detecting means comprises a radiation thermometer for detecting a surface temperature of the glass.
Tempering furnace as described. 3. The tempering furnace according to claim 1, wherein said detecting means comprises a CCD camera for detecting a displacement of the outer shape of the glass. 4. The tempering furnace according to claim 1, wherein said detecting means comprises a detector for detecting a change in the current of the servomotor accompanying a change in the rotational torque of the blow rod.