JPH0142812B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to an injection control method for an electric injection machine.

(b) Conventional technology Electric injection machines use an electric motor as a drive source to perform injection, plasticization, and
It performs injection molding operations such as opening and closing the mold. A combination of such an electric injection machine and a flywheel is disclosed in Japanese Patent Application Laid-open No. 132722/1983. According to this, the energy of the injection motor is stored in the flywheel before the filling process, and the screw is moved forward using the energy stored in the flywheel during the filling process. This allows injection at high speed and high pressure.

(C) Problems to be Solved by the Invention However, the above publication only discloses that the rotational force of the flywheel is used in the filling process of filling the mold with molten resin; There is no mention of the subsequent pressure holding process. When performing precision molding, it is extremely important to perform an appropriate pressure holding process. Therefore, precision molding cannot be performed with the invention disclosed in the above publication. The present invention aims to solve these problems.

(d) Means for Solving the Problems The present invention allows drive torque to be input from the injection motor to the screw after the filling process using the rotational force of the flywheel, so that the drive torque of the motor or the The above-mentioned problem is solved by realizing the desired pressure holding process by controlling the transmitted torque of the interposed electromagnetic clutch. In other words, the first invention of the present application stores energy in the flywheel by switching the power system path switching mechanism so that the driving force of the injection motor is input to the flywheel before the filling process. Sometimes, the power system path switching mechanism is switched so that the rotational force of the flywheel is input to the forward/reverse movement mechanism to move the screw forward at high speed, and the signal from the screw position detector detects when the screw has moved to the pressure holding position. The power system path switching mechanism is switched so that the rotational force of the injection motor is input to the forward/backward movement mechanism when It is characterized by performing a pressure process.

In addition, the second invention of the present application stores energy in the flywheel by switching the power system path switching mechanism so that the driving force of the injection motor is input to the flywheel before the filling process, and Sometimes, the power system path switching mechanism is switched so that the rotational force of the flywheel is input to the forward/reverse movement mechanism to move the screw forward at high speed, and the signal from the screw position detector detects when the screw has moved to the pressure holding position. The power system path switching mechanism is switched so that the rotational force of the injection motor is input to the forward/backward movement mechanism when the rotational force is input to the forward/backward movement mechanism, and then the variable transmission torque electromagnetic clutch interposed between the injection electric motor and the forward/backward movement mechanism is transmitted. It is characterized in that the pressure holding process is performed by controlling the torque based on a command from a holding pressure setting device.

(e) Operation By connecting the flywheel in which energy is stored to the forward and backward movement mechanism, the screw moves forward at high speed and the filling process is performed. When the screw advances to a predetermined pressure holding position, the power system path switching mechanism is switched based on the detected value from the screw position detector, and the driving force of the injection motor is transmitted to the screw. In this state, the pressure holding step is carried out by controlling the drive torque of the injection motor in a predetermined manner based on the signal from the holding pressure setting device. This allows the predetermined pressure holding process to be performed, allowing precision molding to be performed. In addition, in the second invention, the same effect as described above can be obtained by controlling the transmission torque of the electromagnetic clutch provided between the injection motor and the forward/backward movement mechanism during the pressure holding process.

(f) Example (Example of the first invention) FIG. 1 shows an example of the first invention. The screw 10 in the injection cylinder 11 is connected to the block 14 by a connecting member 12. Block 14
A ball nut 18, which is combined with the ball screw 16 to form a ball screw mechanism, is integrally attached to the. A ball screw mechanism consisting of this ball screw 16 and ball nut 18 constitutes a forward and backward movement mechanism 19. The ball screw 16 can be connected to an intermediate shaft 22 by means of an electromagnetic clutch 20. Further, the intermediate shaft 22 can be connected to an injection motor 26 via an electromagnetic clutch 24. An integrally rotating gear 28 is provided on the intermediate shaft 22, and this gear 28 meshes with a gear 32 provided on the shaft 30. The shaft 30 can be connected to a flywheel 36 via an electromagnetic clutch 34. The electromagnetic clutch 20, the intermediate shaft 22, the electromagnetic clutch 24, the gear 28, the shaft 30, the gear 32, and the electromagnetic clutch 34 constitute a power system path switching mechanism 37. A gear 38 is integrally provided on the block 14, and this gear 38 meshes with a collared gear 40. The gear 40 is connected to a shaft 44 via a ball spline 42. Therefore, the gear 40 is connected to the shaft 4
4, but is movable in the axial direction. The shaft 44 is connected to a plasticizing electric motor 46.

A screw position detector 48 is provided on the connecting member 12, and a signal from the screw position detector 48 is inputted to a comparator 50. The comparator 50 includes a measuring position setting device 52.
The set value from the holding pressure switching position setter 54 is also input. The output signal from comparator 50 is input to controller 56. The controller 56 also receives set values from holding pressure setters 58a, 58b, and 58c. The controller 56 controls the plasticizing motor 46 and the injection motor 26 via driver amplifiers 60 and 62, respectively, and also controls the electromagnetic clutch 2.
0. The operating states of the electromagnetic clutch 24 and the electromagnetic clutch 34 can be controlled independently.

Next, the effect will be explained. First, when the electromagnetic clutch 20 is released and the plasticizing motor 46 is driven, the shaft 44, ball spline 42, gear 40,
The screw 10 rotates via the gear 38, the block 14, and the connecting member 12, and the resin material in the injection cylinder 11 is kneaded and melted. As kneading and melting progress, the screw 10 moves into the injection cylinder 11.
is pushed back by the pressure of the molten resin at the tip. Therefore, gear 38 and gear 40 move backward in the right direction in FIG. 1 while rotating together. The position of the screw 10 is detected by the screw position detector 48, and when this detected value becomes the same as the setting value preset in the weighing position setting device 52,
A signal is output from the comparator 50, and the controller 56 issues a command to the driver amplifier 60 to stop driving the plasticizing motor 46. While the screw 10 is rotationally driven to knead and melt the resin raw materials as described above, the electromagnetic clutches 24 and 34 are fastened, and the injection motor 26 is driven, so the injection motor 26 is rotated. The force is generated by the electromagnetic clutch 24, the intermediate shaft 22, the gear 28, the gear 32, and the shaft 3.
0 and the electromagnetic clutch 34 to the flywheel 36, where the energy is stored.

Next, the tightening of the mold (not shown) is completed,
A filling process is performed. That is, when the electromagnetic clutch 24 is released and the electromagnetic clutch 20 is engaged, the rotational force of the flywheel 36 is applied to the electromagnetic clutch 34, the shaft 30, the gear 32, the gear 28, and the intermediate shaft 22.
and is input to the ball screw 16 of the forward and backward movement mechanism 19 via the electromagnetic clutch 20. As a result, the ball nut 18 moves forward at high speed, and the screw 10 moves forward via the block 14 and the connecting member 12.
As a result, the filling operation with molten resin is performed at high speed and high pressure. When the screw 10 advances to a predetermined position, that is, the comparator 5 detects that the signal detected by the screw position detector 48 matches the set value set by the holding pressure switching position setter 54.
0, the comparator 50 outputs a signal to the controller 56, and the controller 56 releases the electromagnetic clutch 34 based on this signal and also engages the electromagnetic clutch 24, thereby causing the ball screw 16 to be driven. Power is switched from the flywheel 36 to the injection motor 26. In this state, the controller 56 adjusts the driving torque of the injection motor 26 to the holding pressure setting device 58a,
Control is performed based on the set values from 58b and 58c. As a result, the injection motor 26 outputs a preset driving torque to the holding force setters 58a, 58b, and 58c for a predetermined period of time, and a predetermined pressure holding process is performed. When the pressure holding process is completed, the above-mentioned plasticizing process is started again.

As described above, according to this embodiment, after filling is performed at high speed and high pressure using the energy stored in the flywheel 36, the holding pressure setting devices 58a and 5
An appropriate pressure holding process can be performed as set in 8b and 58c. Therefore, precision molding becomes possible and high quality molded products can be obtained.

(Embodiment of the second invention) FIG. 2 shows an embodiment of the second invention. In this embodiment, the electromagnetic clutch 20 of the embodiment shown in FIG. The current is supplied through the The rest of the structure is the same as that shown in FIG. In this embodiment, when it is detected by the signal from the screw position detector 48 that the screw 10 has advanced to a predetermined position after the filling process is performed, the controller 5
Similarly to the previous embodiment, when the electromagnetic clutch 34 is released, the electromagnetic clutch 24 is also engaged, and at the same time, the value of the current applied to the electromagnetic clutch 20' via the amplifier 70 is changed. This electromagnetic clutch 2
The input current value to 0' is determined by the holding pressure setting device 58a, 58
b and 58c, thereby controlling the axial thrust of the screw 10,
A pressure holding process is performed. Therefore, the same effect as in the previous embodiment can be obtained.

(G) Effects of the Invention As explained above, according to the present invention, after the filling process using the energy stored in the flywheel, by controlling the drive torque of the injection motor, or by controlling the injection motor The pressure holding process is carried out by controlling the transmission torque of the electromagnetic clutch between the engine and the forward/reverse movement mechanism, so that the appropriate pressure holding process can be performed after filling at high speed and high pressure by the flywheel. This makes precision molding possible.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the first invention, and FIG. 2 is a diagram showing an embodiment of the second invention. 10...Screw, 16...Ball screw, 1
8... Ball nut, 19... Forward and backward movement mechanism, 20
...Electromagnetic clutch, 24...Electromagnetic clutch, 26
... Injection motor, 28 ... Gear, 32 ... Gear, 34 ... Electromagnetic clutch, 36 ... Flywheel, 37 ... Power system path switching mechanism, 46 ... Plasticizing motor, 48 ... Screw position Detector, 5
0...Comparator, 52...Measuring position setter, 54...
... Holding pressure switching position setter, 56 ... Controller, 58
a, 58b, 58c... Holding pressure setting device.

Claims (1)

[Claims] 1. A forward and backward movement mechanism that converts rotational motion into linear motion to move the screw of the injection device back and forth, an injection electric motor, a flywheel, and a plurality of clutches. In an injection control method for an electric injection machine having a power system path switching mechanism that can select power transmission between any two of the injection motor and the flywheel, the injection motor is driven before the filling process. The power system path switching mechanism is switched so that power is input to the flywheel to store energy in the flywheel, and during the filling process, the power system path switching mechanism is changed so that the rotational force of the flywheel is input to the forward and backward movement mechanism. The power system is set so that the rotational force of the injection motor is input to the forward and backward movement mechanism when it is detected by the signal from the screw position detector that the screw has moved to the holding pressure position. An injection control method for an electric injection machine, characterized in that a pressure holding process is performed by switching a switching mechanism and then controlling the output torque of an injection motor based on a command from a holding pressure setting device. 2. The forward and backward movement mechanism, the injection motor, the flywheel, and the forward and backward movement mechanism that converts rotational motion into linear motion to move the screw of the injection device back and forth, the injection motor, the flywheel, and a plurality of clutches. In an injection control method for an electric injection machine that has a power system path switching mechanism that can select power transmission between any two of them, the driving force of the injection motor is input to the flywheel before the filling process. The power system path switching mechanism is switched so that energy is stored in the flywheel, and during the filling process, the power system path switching mechanism is switched so that the rotational force of the flywheel is input to the forward and backward movement mechanism to move the screw at high speed. When it is detected by the signal from the screw position detector that the screw has moved to the holding pressure position, the power system path switching mechanism is switched so that the rotational force of the injection motor is input to the forward and backward movement mechanism, and then An electric type that performs a pressure holding process by controlling the transmission torque of a variable transmission torque electromagnetic clutch interposed between an injection motor and a forward/backward movement mechanism based on a command from a holding pressure setting device. Injection control method for injection machine.