JPH09155525A - Method and device for controlling light alloy injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably draw a plug at the tip end of the nozzle and to stabilize the quality of a formed product by confirming temp. at the tip end of the nozzle in a set temp. range and injecting a material into the die. SOLUTION: In injecting a material from the nozzle 7 of a cylinder barrel device 1 into a molding die 20, comparison is made by a controller 18 between a temp. of the nozzle 7 measured by a thermocouple 5a and a temp. set in a device 16 for setting the upper limit of injection temp. and in a device 17 for setting the lower limit of injection temp., after closing the die and before starting injection. If the temp. of the nozzle 7 is within these set temp ranges, a command is given for supplying a hydraulic fluid to the drive shaft 12 side of an injection hydraulic cylinder 9 through a signal line (a) so as to perform injection. On the other hand, if the temp. of the nozzle 7 is outside these set temp. ranges, a heater 4a is adjusted so that the temp. of nozzle 7 may stay within the set range by a temp. adjuster 15, commencing injection with the temp. coming into the set range. Thus, a plug 6 is surely drawn that is formed in the tip end hole of the nozzle 7, eliminating the contraflow of a molten material or the weight variance of a formed product and stabilizing its quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection control method and apparatus for injecting material into a mold in a light alloy injection molding machine.

[0002]

2. Description of the Related Art Conventionally, an in-line screw type injection molding machine can be used for molding a light alloy material. This injection molding machine includes a cylinder barrel that is heated from the outside by a heater, a screw that is driven to rotate and move axially in the cylinder barrel, and a hopper that is provided above the rear portion of the cylinder barrel so that material can be input. And a drive device for driving the screw in the rotational and axial directions. In such a configuration, after the injection, when the screw is driven to rotate by the driving device and the light alloy chip that is the injection material is supplied from the hopper to the cylinder barrel,
It is conveyed to the front of the cylinder barrel while being kneaded and melted by the frictional force, the shearing force due to the rotation of the screw, the heat heated from the outside, and the like. Then, a predetermined amount of molten material is accumulated in front of the cylinder barrel, the screw is retracted by the pressure and the forced retraction of the screw due to the accumulation, and the required injection amount is measured by the backward stroke of the screw.

However, since the light alloy material has a low viscosity in a molten state, when the light alloy material is in a molten state in the hole at the nozzle tip when the screw is rotationally driven as described above, that is, at the time of measurement, the nozzle tip is melted. There is a risk that the molten metal will leak from the hole. Therefore, after injection, the temperature of the tip of the nozzle is lowered and a plug (solid plug) is formed in the hole at the tip of the nozzle. After that, the operation is performed according to the sequence order of sequence control, and at the time of injection, the plug is filled in the mold together with the molten metal.

[0004]

As described above, in forming a light alloy, a plug is formed at the tip of the nozzle in order to prevent the injection material from leaking from the hole at the tip of the nozzle when the screw is rotationally driven. At the time of injection, the plug is filled in the mold together with the molten metal.

However, if the temperature of the tip of the nozzle remains low during injection, the plug may not come off and the molten material may flow backward in the cylinder barrel. Also, if the amount of the plug of the hole at the tip of the nozzle varies, the pressure with which the plug is pulled out will vary even when the plug is pulled out, resulting in variations in the weight of the molded product. The quality of the molded product may become unstable.

In view of the above problems in forming a light alloy, the present invention ensures that the plug can be pulled out,
Eliminates backflow of molten material and variation in weight of molded products,
An object of the present invention is to provide a control method and device for a light alloy injection molding machine, which also stabilizes the quality of molded products.

[0007]

In order to achieve the above object, the present invention has a cylinder barrel device having a nozzle at its tip and a screw capable of rotating and axially driving therein, and a metering device. In a control method of a light alloy injection molding machine in which a plug is formed in the hole at the tip of the nozzle in order to prevent material from leaking through the hole at the tip of the nozzle, the tip temperature of the nozzle is within a set temperature. It is characterized by injecting the material into the mold after confirming that

Further, a control device for realizing this method includes an injection temperature upper limit setter and an injection temperature lower limit setter for setting the temperature upper and lower limit set values at which injection is possible, and at least the tip temperature of the nozzle, A temperature controller that adjusts the temperature to a range determined by the injection temperature upper limit setter and the injection temperature lower limit setter, the tip temperature of the nozzle before mold injection and before the start of injection, and the injection temperature upper limit setter. And the temperature set by the injection temperature lower limit setter, and if the tip temperature of the nozzle is not within the set temperature, the temperature adjuster adjusts the tip temperature of the nozzle to be within the set temperature, And a controller for performing an injection operation when the temperature is within the temperature range.

The set temperature is a temperature at which the metal material becomes a solid-liquid coexisting phase.

(Operation) A plug is formed in the hole at the tip of the nozzle in order to prevent the material from leaking from the hole at the tip of the nozzle during measurement, but the metal material coexists in solid-liquid state before injection. Confirm that the tip temperature of the nozzle is within the set temperature that makes a phase, and inject the material into the mold.
The plug is stably pulled out during the injection process, the backflow of the molten material and the weight variation of the molded product are eliminated, and the quality of the molded product is also stable.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a control device suitable for an injection control method in a light alloy injection molding machine of the present invention.

As shown in FIG. 1, the injection molding machine of the present embodiment comprises a cylinder barrel device 1, a screw drive device 14, and a control device 19.

In the injection cylinder barrel 2 of the cylinder barrel device 1, a screw 3 is provided so as to be freely driven in the axial rotation direction and the axial direction. An opening is formed near the rear end of the cylinder barrel 2 on the right side in the drawing, and a hopper 8 for loading the material is attached to the opening.
Further, a nozzle 7 for injection is provided in front of the cylinder barrel 2 (on the left side in the drawing), and a plurality of temperature-controlled individual fine temperature controls are provided on the cylinder barrel 2 and the outer peripheral portion of the nozzle 7. Heaters 4, 4a and thermocouples 5, 5a are provided.

The screw drive unit 14 is composed of an injection hydraulic cylinder 9, a hydraulic motor 13, and a piston 10. A piston rod 11 in the injection hydraulic cylinder 9 is mechanically connected to the screw 3 in the cylinder barrel 2. ,
The drive shaft 12 of the piston 10 in the injection hydraulic cylinder 9 is likewise mechanically connected to the rotating machine of the hydraulic motor 13. Therefore, when the hydraulic motor 13 is rotated, the screw 3 is rotationally driven, and at the same time, the hydraulic oil is measured by supplying hydraulic oil to the piston rod 11 side of the injection hydraulic cylinder 9, and is measured on the drive shaft 12 side of the injection hydraulic cylinder 9. When hydraulic oil is supplied, the screw 3 advances and the measured injection material is injected together with the plug 6 into the mold 20 from the nozzle 7 at the front end of the cylinder barrel 2.

The control device 19 comprises a temperature controller 15, an injection temperature upper limit setting device 16, an injection temperature lower limit setting device 17, and a controller 18. Injection temperature upper limit setter 1
6. The injection temperature lower limit setter 17 sets the upper and lower limit set values of the temperature at which injection is possible, and these upper and lower limits are appropriately set according to the value at which the light alloy as the injection material becomes the solid-liquid coexisting phase. To be done. The temperature adjuster 15 compares the set temperature of the heater 4 with the measurement value of the thermocouple 5 and adjusts the heater 4 individually and precisely so as to reach the set temperature. In particular, the heater 4a of the nozzle 7 is adjusted so that the temperature is within the range determined by the injection temperature upper limit setting device 16 and the injection temperature lower limit setting device 17.

The controller 18 has a sequence function for operating the injection molding machine according to the process, a comparison calculation function, and the like. Then, the temperature of the nozzle 7 measured by the thermocouple 5a and the set temperatures set in the injection temperature upper limit setter 16 and the injection temperature lower limit setter 17 are compared after the mold is closed and before the injection is started. When the temperature of the nozzle 7 is within the set temperature, a command to supply the hydraulic oil to the drive shaft 12 side of the hydraulic cylinder 9 for injection is given through the signal line a to inject, while the temperature is within the set temperature. If there is no temperature in the nozzle 7,
The heater 4a is adjusted by the temperature adjuster 15 so that the temperature of the nozzle 7 is within the set range, and the heater 4a emits when the temperature is within the set range.

Next, referring to FIG. 1, along with an example of a control flow chart of the light alloy injection molding machine shown in FIG. 2, a light alloy material having a low melt viscosity, for example, magnesium alloy, aluminum, lead alloy, zinc alloy. An example of injecting etc. will be described.

Before the start of molding, the cylinder barrel 2 is heated by the temperature controller 15 to a temperature suitable for the injection material. Injection temperature upper limit setter 16 and injection temperature lower limit setter 17
In addition, the optimum temperature is set for the injection material of the hole at the tip of the nozzle 7 to become the solid-liquid coexisting phase.

After moving to the molding step, the mold 20 is closed (step S1). It is determined whether the temperature of the nozzle 7 measured by the thermocouple 5a is between the set value of the injection temperature upper limit setter 16 and the set value of the injection temperature lower limit setter 17 (step S2). If the temperature of the nozzle 7 is out of the set range,
The temperature adjuster 15 adjusts the heater 4a so that the temperature of the nozzle 7 is within the set range (step S3).

When the temperature measured by the thermocouple 5a of the nozzle 7 is within the set range, injection is possible. At this time, the controller 1
8 gives a command to supply the hydraulic oil to the drive shaft 12 side of the injection hydraulic cylinder 9 via the signal line a, so that the molten metal is injected into the mold 20 (step S4).

During the cooling process after the completion of injection, the nozzle 7 is kept in contact with the mold 20 to allow the mold 20 to absorb the heat of the nozzle 7 and lower the temperature of the nozzle 7, thereby reducing the temperature of the nozzle 5. The plug 6 is formed in the hole at the tip.

Whether or not the plug 6 is formed can be determined by comparing the measured temperature of the nozzle 7 and the set value of the injection temperature lower limit setter 17. Therefore, when the measured temperature of the nozzle 7 becomes lower than the set value of the injection temperature lower limit setter 17, the controller 18 controls the hydraulic motor 1 via the signal line c.
Give a command to drive 3. Further, the controller 18 gives a command to supply the hydraulic oil to the piston rod 11 side of the injection hydraulic cylinder 9 via the signal line b. This allows
The screw 3 rotates and retreats and weighing is performed (step S
5).

Then, the mold 8 is opened (step S6),
The product is taken out (step S7).

After the series of molding steps as described above, for molding again, the process returns to step S1, the mold 20 is closed, the nozzle tip temperature is measured before injection, and the injection temperature setting devices 16, 17 are used.
It is performed after comparing with the upper and lower limit values to determine whether injection is possible.

As described above, in this embodiment, the injection temperature upper limit setting device 16 and the injection temperature lower limit setting device 17 are provided, and the nozzle 7 is provided.
Since the injection is performed after confirming whether the measured temperature is the solid-liquid coexisting phase of the injection material, the hole at the tip of the nozzle 7 can always be stably removed during the injection process.

[0027]

According to the present invention described above, it is confirmed before injection that the tip temperature of the nozzle is within the set temperature that makes the metal material into the solid-liquid coexisting phase, and if it is not within the set temperature, the setting is performed. It is a control method and control device for a light alloy injection molding machine that injects the material into the mold after adjusting it so that the temperature is within the temperature range. Therefore, the weight variation can be eliminated, and the quality of the molded product can be stabilized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a control device suitable for an injection control method in a light alloy injection molding machine of the present invention.

FIG. 2 is a control flowchart according to an embodiment of a control device for a light alloy injection molding machine of the present invention.

[Explanation of symbols]

 1 Cylinder Barrel Device 2 Cylinder Barrel 3 Screw 4, 4a Heater 5, 5a Thermocouple 6 Plug 7 Nozzle 8 Hopper 9 Injection Hydraulic Cylinder 10 Piston 11 Piston Rod 12 Drive Shaft 13 Hydraulic Motor 14 Screw Drive Device 15 Temperature Controller 16 Injection Temperature upper limit setter 17 Injection temperature lower limit setter 18 Controller 19 Controller 20 Mold

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C22C 1/02 501 C22C 1/02 501B // B29C 45/54 9350-4F B29C 45/54 45 / 78 7365-4F 45/78

Claims (3)

[Claims] 1. A cylinder barrel device (1) provided with a nozzle (7) at a tip thereof and a screw (3) being capable of rotating and driving in an axial direction, the nozzle (7), wherein the nozzle is provided during measurement.
In order to prevent the material from leaking from the hole at the tip of (7), a plug (6) is formed in the hole at the tip of the nozzle (7) in the control method of a light alloy injection molding machine, wherein the nozzle (7 The method for controlling a light alloy injection molding machine is characterized in that the material is injected into the mold (20) after confirming that the tip temperature of () is within the set temperature. 2. The method for controlling a light alloy injection molding machine according to claim 1, wherein the set temperature is a temperature at which the metal material becomes a solid-liquid coexisting phase. 3. A cylinder barrel device (1) provided with a nozzle (7) at a tip thereof and a screw (3) being rotatable and axially drivable therein, the nozzle being provided during measurement.
In order to prevent the material from leaking through the hole at the tip of (7), the plug (6) is formed in the hole at the tip of the nozzle (7) in the control unit (19) of the light alloy injection molding machine, The control device (19) is an injection temperature upper limit setter (16) and an injection temperature lower limit setter (17) for setting the temperature upper and lower limit set values at which injection is possible, and at least the tip temperature of the nozzle (7), A temperature controller (1) for adjusting the temperature to a range determined by the injection temperature upper limit setter (16) and the injection temperature lower limit setter (17).
5), the tip temperature of the nozzle (7), the injection temperature upper limit setter (16) and the injection temperature lower limit setter (17) after the mold is closed and before the injection is started.
If the tip temperature of the nozzle (7) is not within the set temperature, the temperature controller (15) adjusts the temperature of the nozzle (7) to be within the set temperature. , A controller (18) that makes the injection operation when it enters the set temperature,
A control device for a light alloy injection molding machine, comprising: