JP3517355B2 - Rough molding equipment for glass bottle molding machines - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rough molding apparatus for a glass bottle molding machine called an IS type machine, and more particularly to a coarse molding apparatus for molding a parison. 2. Description of the Related Art Generally, a servomotor for driving a plunger is provided, and the plunger is raised to a loading position by the servomotor to put a gob into a rough mold, and the plunger is raised from the loading position. There is known a rough molding device of a glass bottle molding machine for molding a parison. In this type of apparatus, the drive control of the servomotor is generally switched from the position / speed control to the torque limiting control so as not to apply extra pressure to the parison in the final step of pressing by the plunger (Japanese Patent Laid-Open Publication No. HEI 9-19764). 9-142
No. 853). In the conventional configuration, since the position / speed control is switched to the torque limiting control at a preset time, when the weight of the gob changes, in a strict sense, the volume change of the gob changes. Therefore, there is a problem that extra pressure is applied to the parison in the final step of pressing without following. With this type, the weight of the gob put into the rough mold will change slightly each time unless the change in the volume of the gob is followed, making it difficult to carry out proper barison molding. There is a problem that causes. SUMMARY OF THE INVENTION It is an object of the present invention to provide a rough molding apparatus for a glass bottle molding machine which enables appropriate barison molding even if the weight of the gob changes every time. [0006] In order to achieve the above object, according to the present invention, a servo motor for driving a plunger is provided, and the servo motor raises the plunger to a loading position. gob was poured into a blank mold in Te, in the rough molding apparatus for a glass bottle molding machine for molding a parison is raised the plunger from the loading position, provided monitoring means for monitoring the torque value of the servo motor, the The weight of the gob put into the rough mold
When the torque value monitored by the monitoring means reaches a predetermined torque value so that the switching position is changed in accordance with the amount, the drive control of the servo motor is switched from position / speed control to torque limiting control. Providing means,
After switching to the torque limit control, the torque limit control is continued until a next operation command is received. In general, when the ascending plunger reaches a predetermined position, control for switching the drive control of the servo motor from position / speed control to torque limiting control is performed. In this control, however, the control is performed according to the temperature of the gob or the outside air temperature. Since the viscosity of the gob changes, accurate switching control cannot be performed unless the position of the gob (lumps of molten glass) put into the rough mold is constantly changed by the weight. According to the present invention, when the torque value monitored by the monitoring means reaches a predetermined torque value, the drive control of the servomotor is switched from the position / speed control to the torque limiting control. Even if the weight changes, the switching position will be changed every time,
Accurate switching control is performed. An embodiment of the present invention will be described below with reference to the drawings. For example, when a glass bottle is formed by a press-and-blow method, a parison is roughly formed by a press, followed by finish molding by a blow. FIG. 1 shows an apparatus structure for roughly molding a parison by a press. Reference numeral 1 denotes a rough mold, and a mouth mold 3 and a guide ring 5 are provided below the rough mold 1. 7 is a baffle and 9 is a plunger. Lower end 9 of this plunger 9
A is connected to a plunger adapter 13 via a split ring 11, and an output shaft 15 driven by a servomotor (not shown) is connected to the plunger adapter 13. The upper end 9b of the plunger 9 is configured to be able to enter the inner part of the rough mold 1 in accordance with the vertical movement of the output shaft 15. When a parison is formed by using the rough mold 1, as shown in FIG. 1, a gob G is put in the rough mold 1, and the upper part of the rough mold 1 is covered with a baffle 7 and is shown in FIG. like,
The plunger 9 is raised by the drive of the servomotor to press the gob G, so that the gob G is
The parison 21 including the mouth 21a is simultaneously formed by closely adhering to the baffle 7, the mouth mold 3, and the guide ring 5. FIG. 3 is a control block diagram of the servomotor for driving the plunger. The activation signal a1 is transmitted to the control device 31
Is input to the motor driver 3
2 outputs a command signal a2. Then, the exciting current a3 flows to the servomotor 33, which is driven and the plunger 9 is raised. The position of the plunger 9 is detected by the position detector 34, and the position detection data a4 detected by the position detector 34 is input to the control device 31, and the motor driver 32 supplies an exciting current for driving the servo motor 33. Is always input to the control device 31. 35 is a set value input device.
FIG. 4 shows the displacement of the plunger 9 with respect to time. The molding sequence of the parison will be described together with the displacement of the plunger 9. First, the servomotor is driven to raise the plunger 9 from the down position P0 to the loading position P1 shown in FIG. Is In this case, loading is performed at a position just before the gob G contacts the baffle 7. Then, the plunger 9 is raised to press the gob G. In this case, in the first stage, the position and speed of the servomotor are controlled. This position / speed control is to move the plunger 9 between predetermined positions at an initially set moving speed.
This is control for displacement. Generally, the plunger 9 at the start of the pressing process
Is moved and controlled at the initially set speed. However, the propulsion speed of the plunger 9 gradually changes (decelerates) in accordance with the propulsion speed of the plunger 9 when the torque value exceeds a certain set value, and becomes zero when the parison molding is completed. However, even if the speed becomes zero, a thrust is generated in the plunger 9 and the plunger 9 maintains this state until receiving the next operation command. If this state continues, extra pressure is applied to the parison, making it difficult to form the parison properly, and causing defective bottles, particularly in the mouth forming. Therefore, the drive control of the servomotor is controlled by the position
Control that switches from speed control to torque limit control is required, but control that switches from position / speed control to torque limit control when the ascending plunger reaches a predetermined position, as in the past, would have been performed. Since the viscosity of the gob changes depending on the temperature of the gob and the temperature of the outside air, the position of the gob (lumps of molten glass) must be constantly changed according to the weight of the gob (lumps of molten glass), and as a result, accurate Control cannot be executed. In this embodiment, when the torque value monitored by the monitoring means (the control device 31 in FIG. 3) reaches a predetermined torque value, the control for switching the drive control of the servo motor from the position / speed control to the torque limiting control. Is executed.
This torque limiting control is a control for limiting the initially set thrust of the plunger 9. More specifically, as shown in FIG. 3, the excitation current value for driving the servo motor input to the control device 31 and the set current value set by the set value input device 35 are:
If the actual excitation current value exceeds the predetermined set current value, the torque value is determined to have reached the predetermined torque value, and the drive control of the servo motor is changed from the position / speed control. Switch to torque limit control. According to this, even when the weight of the gob (the lump of molten glass) changes every time, the timing for switching from the position / speed control to the torque limiting control is changed each time, so that accurate switching is performed. Control is executed. Referring to FIG. 4, when the press is started from the loading position P1, the exciting current value I increases as shown by the dotted line. This exciting current value I is equal to a predetermined set current value Ia.
Is reached, it is determined that the torque value has reached the predetermined torque value, and at the position P2, the drive control of the servo motor
Switch from speed control to torque limit control. This position P
If the position / speed control is continued without switching to the torque limit control in step 2, the position control of the plunger 9 from the position P2 to the position P3 (fixed pseudo completion position) is executed, and an extra Pressure is applied. In this embodiment, the drive control of the servo motor is performed at the position P2.
Since the control is switched from the speed control to the torque limiting control, the position of the plunger 9 is thereafter displaced as shown by a solid line,
The process ends at the position P3 '(press completion position). This position P
3 'changes depending on the weight of the gob or the like, so that setting is unnecessary. As described above, in the present embodiment, when the torque value monitored by the monitoring means reaches the predetermined torque value, the control is switched from the position / speed control to the torque limiting control. Even if the weight changes, the switching position is changed every time, and accurate switching control is performed. FIG. 5 is a diagram showing displacement of the plunger 9 with respect to time when the parison is roughly formed by the blow-and-blow method. In this blow-and-blow method, when the servomotor is driven, the plunger 9 is moved to the down position P0.
From the first loading position P1 to the first loading position P1.
Then, the gob is put into the rough mold, the plunger 9 is further raised from the position P1 to the press position P2, and the settle blow is performed. Then, the plunger 9 is lowered to the second loading position P3 and the counter blow is performed. . In this embodiment, the switching from the above-described position / speed control to the torque limiting control is performed during the ascent from the first loading position P1 to the press position P2. According to this, appropriate barison molding can be performed without applying extra pressure to the parison, and the occurrence of defective bottles is suppressed particularly in the molding of the mouth. As described above, the present invention has been described based on one embodiment, but the present invention is not limited to the above embodiment. For example, the monitoring means for monitoring the torque value is not limited to monitoring based on the excitation current of the servomotor, and it goes without saying that any torque value monitoring means can be used. According to the present invention, when the torque value monitored by the monitoring means reaches a predetermined torque value, the drive control of the servomotor is switched from the position / speed control to the torque limit control, so that the gob (melting) is performed. Even if the weight of the glass lump changes, the switching position is changed each time, and accurate switching control is performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a rough molding device of a glass bottle molding machine. FIG. 2 is a view showing a rough molding device of the glass bottle molding machine. FIG. 3 is a control block diagram. FIG. 4 is a diagram showing displacement of a plunger with respect to time when a parison is roughly formed by a press and blow method. FIG. 5 is a diagram showing displacement of a plunger with respect to time when a parison is roughly molded by a blow-and-blow method. [Description of Signs] 1 Rough type 9 Plunger 21 Parison 31 Control device 32 Motor driver 33 Servo motor 34 Position detector 35 Setting value input device

Claims (1)

(57) [Claim 1] A servo motor for driving a plunger is provided, and the plunger is raised to a loading position by this servo motor, a gob is put into a rough mold, and the plunger is loaded into the rough mold. In a rough molding apparatus for a glass bottle molding machine that forms a parison by rising from a position, a monitoring means for monitoring a torque value of the servomotor is provided, and a switching position is set according to a weight of a gob put into the rough mold.
Switching means for switching drive control of the servo motor from position / speed control to torque limiting control when the torque value monitored by the monitoring means reaches a predetermined torque value so that the position is changed ; A rough molding apparatus for a glass bottle molding machine, wherein the torque limiting control is continued until the next operation command is received after switching to the torque limiting control.