JP2719108B2 - Gate cut and protrusion control device and control method in electric injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for controlling a gate cut and a protrusion of a molded product in a motorized injection molding machine when a molten material is injected into an injection molding die to produce a molded product. About.

[0002]

2. Description of the Related Art In general, an electric injection molding machine or the like for injection-molding a molten material such as a synthetic resin is provided with a structure and a process for performing gate cutting and projecting a molded product. In some cases, gate cutting and ejection of a molded product are performed by operating the same ejector pin by an ejector device. In this case, the gate is cut by the stroke operation at the preceding stage of the ejector device, and then, after the resin in the cavity is cooled, the ejector is operated again to eject the molded product. Also, in other injection molding machines, a gate cut pin and an ejector pin are provided, and immediately after the completion of filling of the resin or during the pressure holding, the gate is cut by operating the gate cut pin by the ejector device.
Return the gate cut pin to the initial position. Next, after the resin in the cavity is cooled, the gate cut pin and the eject pin are operated by the ejector device to eject the molded product.

An example of such an electric injection molding machine will be described with reference to FIGS. In the vertical sectional view of the mold part shown in FIG. 10, a cavity 3 is formed in the two molds 1 and 2 in a clamped state.
Is connected to a sprue 5 of one of the molds 1 via a gate 4, and the sprue 5 is connected to a tip nozzle 7 of a heating cylinder 6 from which a molten resin is injected. On the other hand, the ejector device 9 is provided with an ejector rod 11 connected to an electric motor 10 as a driving source via a connecting means (not shown), and the ejector rod 11 is used as a force for the torque of the electric motor 10 to advance and retreat in a linear direction. 11 is transmitted. The ejector rod 11 is connected to the first eject plate 13 in the other mold 2, and the gate cut pins 14 implanted in the first eject plate 13 pass through the insertion holes 15 a of the second eject plate 15. The tip can move back and forth in the gate 4. The second eject plate 15 is connected to a first eject pin 17 for projecting the molded product 16 and a second eject pin 19 for projecting the sprue runner 18.

FIG. 11 shows a control device 21 for operating the ejector rod 11 by the electric motor 10.
Is shown in FIG. In the control device 21, the ejector rod 11 (that is, the gate cut pin 1)
4. Target position (stroke distance) and speed values for gate cutting by the first and second ejector pins 17 and 19) and for projecting a molded product are set. When the gate is cut or the molded product is ejected, the electric motor 1
When 0 is driven, the rotation amount (movement amount) of the electric motor 10 is detected from the pulse encoder 22 provided in the electric motor 10.
Is fed back, and the position signal at that position is input to the arithmetic unit 23, and the actual position (stroke)
Is compared with the value of the target position at that position, and a deviation (difference between the target position and the actual position) is calculated. From this deviation, the position control means 24 controls the actual position (motor rotation amount) to reach the target position.

A rotational speed signal fed back from the pulse encoder 22 is converted into an actual operating speed by a speed converter 25, and the actual speed and a set target speed are compared and calculated by a calculator 26. The difference is controlled by the speed control means 27 so that the actual speed reaches the target speed. Then, the current value (torque) input to the electric motor 10 is fed back to the calculator 28, and is compared with the current value (torque) set by the position control means 24 and the speed control means 27. Is converted into a desired target current value (torque) by the current control means 29 based on the Further, the current value is regulated by the regulation circuit 32 so as not to exceed the torque regulation set value preset by the control device 21, and this is inputted to the electric motor 10 as a drive current value of the electric motor 10. I have.

The deviation setting means 34 calculates an allowable deviation (fixed) for the deviation between the target position and the actual position with respect to the position (rotation amount) calculated by the calculator 23.
The allowable deviation value and the actual deviation are compared and calculated by the comparator 35. If the actual deviation exceeds the allowable deviation value, the ejector rod 11, the gate cut pin 14, the first and second ejector pins 1
When it is determined that some abnormality has occurred in the operation of the switches 7 and 19, the switch 36 connecting the regulating means 32 and the electric motor 10 is shut off by the output from the comparator 35,
Since the operation of the electric motor 10 is stopped, safety such as prevention of an accident is ensured.

Next, a description will be given of the gate cutting operation and the molded product ejecting operation with reference to FIG. 10. At the time of the gate cutting operation, the ejector rod 11 is operated by the electric motor 10 to move the first eject plate 13 from the initial position to the second eject plate 15. By moving the gate 4 until it comes into contact, the tip of the gate cut pin 14 moves from the outer wall surface of the gate 4 to the surface of the cavity 3, thereby cutting the gate 4. Thereafter, the gate cut pin 14 is returned to the initial position. When the molded product is ejected, the first eject plate 13 operated by the electric motor 10 pushes the second eject plate 15 and the gate cut pin 14
And the first eject pin 17 and the second eject pin 19
Are operated until the molded product 16 and the sprue runner 18 respectively protrude and are separated from the mold 2.

[0008]

In such an injection molding machine, when the gate cut and the ejection of the molded product are performed by the ejector device 9, the same speed and pressure (torque) are applied to each pin in each case. Gate cut and protrusion are performed. For this reason, when the gate cut is performed according to the set speed and pressure for ejecting the molded product, which is usually set in the injection molding machine, the speed and pressure are too small to perform the gate cut. Gate marks are left on the surface,
There is a drawback that the finished condition is not good and the cycle is long. On the other hand, the ejector rod 1
(1) If the set values of the speed and the pressure for the operation are set to the speed and the pressure value that can improve the finished condition of the gate cut surface, the operation speed is too fast to perform the ejection of the molded product. Cracks and the like sometimes occur in the molded product, and there is a problem that a good molded product cannot be obtained.

At the time of gate cutting, it is better to press the molten resin in the gate portion into the cavity by the pressure of the gate cut pin, so that the finished state of the molded product is better. However, the ejector device of the conventional electric injection molding machine has a positioning control. (That is, control for surely stopping at a preset target position)
Usually, this target position is also the position where the first eject plate 13 abuts on the second eject plate 15. However, the target position may be different due to expansion due to mold temperature, wear due to long-term use of the gate cut portion, and the like. For this reason, a stroke required for gate cutting may not be obtained, or operation to a target position may not be performed. In such a case, when the stroke required for the gate cut cannot be obtained, the gate cut becomes incomplete and the resin cannot be pushed in by the gate cut pin 14, so that the molded product and the gate cannot be separated. In addition, there is a serious problem that the finished condition of the molded product is poor. If the gate cut pin 14 does not reach the target position, the deviation exceeds the allowable deviation, a deviation abnormality occurs, and the machine is stopped.

In an injection molding machine, the target position (stroke distance) at which the gate cut pin should be set varies depending on the type and shape of the mold. It is difficult to measure and set the stroke distance of each mold with precise accuracy. Therefore, when the set target position is long, depending on the mold, the first eject plate 13 abuts on the second eject plate 15 during the stroke operation (gate cutting is completed at this position), and the It may be stopped temporarily. In such a case, in the usual electric injection molding machine, as described in the control system shown in FIG. 11, the target position and the actual position of the ejector rod 11 are shifted with the passage of the gate cut time. To
If the deviation between them increases and exceeds the allowable deviation value set by the deviation setting means 34 of the injection molding machine, it is determined that an abnormal situation has occurred, and the power supply to the electric motor 10 is cut off.

[0011] The present inventors have proposed that in each case as described above,
It has been found that by continuing to operate the gate cut pin, pressure can be continuously applied to the molten resin in the gate portion 4, thereby improving the finished condition of the molded product. However, in the current configuration, the electric motor 1
There is a drawback that the injection molding operation is interrupted because 0 is forcibly stopped. Also, when performing a gate cut by positioning control, the optimal stop position differs depending on the type and shape of the mold and the load pressure of the molten material in the cavity. In some cases, there is an optimal stop position at a position where the tip of the gate cut pin 14 is slightly inserted, and it has been extremely difficult to precisely set the target position.

In view of the above problems, the present invention provides a gate cut and protrusion control device and a control device for an electric injection molding machine, which can be operated at a suitable speed during gate cut and when a molded product is protruded. The aim is to provide a method. Further, another object of the present invention is to provide a motor-driven injection molding in which a good finished product can be obtained even when the ejector member is stopped in a state where the ejector member does not reach a target position at the time of gate cutting and the deviation increases. Machine control device and method.

[0013]

According to the present invention, there is provided a gate cut and protrusion control device for an electric injection molding machine according to the present invention.
One or more ejector pins are actuated by an ejector member of the ejector device of the electric mechanism to close the mold.
While the gate cut in the mold in a state, the mold is opened
Speed setting means for setting the operating speed of the ejector member at the time of gate cutting, and setting the operating speed of the ejector member at the time of ejecting the molded product in the electric injection molding machine in which the molded product is ejected from the mold in a state where the molded product is ejected. The speed setting means is provided separately.

Also, the ejector device comprises a motor, an ejector,
Ejector member that interlocks with the pin and the drive of the motor
Transmission means for transmitting force to the ejector member
It is characterized by. In addition, the ejector
Set the operating speedSpeed setting meansThe gate cutTime
Ejector forward position setting meansEjector at gate cut
Selected with pressure setting means to advance ejector device
Set forward speed during gate cut to set operating speed
MeansIt is characterized by having. Also, when projecting a molded product
The operating speed of the ejector memberSpeed setting means
Protrudes the molded productTimeEjector forward position setting meansSuccess
Selected together with the ejector pressure setting
To set the speed at which the ejector device moves forward.
Ejector advance speed setting meansHave
And features.

According to the gate cut and protrusion control method of the electric injection molding machine according to the present invention, one or more ejector pins are operated by an ejector member of the electric mechanism, and the gate is closed in the mold with the mold closed. While cutting, in an electric injection molding machine in which the molded product is protruded from the mold with the mold opened, at the time of gate cutting, the ejector member is operated at a relatively high speed to perform gate cutting, When the molded product is ejected, the ejector member is operated at a relatively low speed so that the molded product is ejected from the mold.

A control device for an electric injection molding machine according to the present invention operates one or a plurality of ejector pins by an ejector member of an electric mechanism to cut a gate in a mold and to project a molded product from the mold. In the electric injection molding machine described above, the abnormality detection means for stopping the drive source when the deviation between the set target position and the actual position of the ejector member for operating the ejector pin is larger than the allowable deviation, and this abnormality detection means Abnormality control means that is turned off when the gate is cut and turned on when the molded product is ejected.

The abnormality detecting means includes a comparator for outputting a signal when a deviation between the target position and the actual position of the ejector member exceeds an allowable deviation set by the deviation setting means. And a switch for interrupting the drive current applied to the motor. Also, the abnormality control means includes a switch for controlling on / off of energization between the comparator and the switch of the abnormality detection means.
Also, the target of the ejector member at the time of gate cutting
The position is characterized in that the ejector pin is set at a position forward of the gate cut position. The gate cut position is a position where the first eject plate having the gate cut ejector pins is in contact with the second eject plate having the molded product ejecting ejector pins.

The control method of the electric injection molding machine according to the present invention is such that one or a plurality of ejector pins are operated by an ejector member of an electric mechanism to cut a gate in a mold and to project a molded product from the mold. In the electric injection molding machine described above, when the gate is cut, the abnormality detection means for stopping the drive source when the deviation between the target position and the actual position of the ejector member for operating the ejector pin is larger than the allowable deviation is turned off, and the gate is turned off. The cutting is performed, and when the molded product is ejected, the abnormality detecting means is turned on to eject the molded product. or,
The target position of the ejector member at the time of gate cutting is
The ejector pin is set at a position forward of the gate cut position.

[0019]

When the gate is cut, the ejector member is operated at a relatively high speed by the speed setting means for setting the operation speed of the ejector member at the time of the gate cut, and the gate is cut. Absent.
At the time of the subsequent ejection of the molded article, by setting the ejector member operating speed at the time of ejecting the molded article, by operating the ejector member at a relatively low speed different from that at the time of gate cutting, Cracks do not occur in molded products. Also, in the ejector device, the rotation of the motor is transmitted to the ejector member via the transmission means,
The rotary motion is converted to a linear motion, and the ejector pins are activated.

At the time of gate cutting, the abnormality detecting means is automatically maintained in the off state by the abnormality control means, so that the ejector pin reaches the gate cutting position and still reaches the target position by the operation of the ejector member. Even if it is not, the driving source is operated without stopping when the deviation between the target position and the actual position becomes larger than the allowable deviation. Therefore, after the gate is cut, the resin in the cavity is kept pressed by the ejector pins, and a good molded product is completed. Also, when projecting a molded product,
If the abnormality detecting means is automatically maintained in the ON state, and the deviation between the target position and the actual position becomes larger than the allowable deviation during the operation of the ejector member, it is determined that an abnormality has occurred, and the drive source is stopped.

In the abnormality detecting means, when the deviation between the target position and the actual position of the ejector member exceeds the allowable deviation set by the deviation setting means, a signal is output from the comparator and applied to the drive source. The drive current is cut off. Further, the abnormality control means automatically turns off the current between the comparator and the switch of the abnormality detection means when the gate is cut, and turns on when the molded product is ejected. Also, since the target position of the ejector member at the time of gate cutting is set at a position where the ejector pin is located forward of the gate cutting position, even if the ejector pin reaches the gate cutting position,
The drive source is subsequently driven to continuously apply pressure to the resin in the cavity, thereby improving the finished product.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. FIGS. 1 to 6 relate to the first embodiment of the present invention, and the same or similar parts as those in the above-described prior art are denoted by the same reference numerals and description thereof will be omitted. FIG. 1 is a longitudinal sectional view of a mold portion of an electric injection molding machine according to the present embodiment, and FIG.
Block diagram of the main part of the control device of the electric injection molding machine according to
3 to 6 are longitudinal sectional views of a mold portion along the procedures of gate cutting and projecting a molded product. In a vertical sectional view of a mold portion of the electric injection molding machine shown in FIG. 1, an electric ejector device 48 is connected to the first eject plate 13 in one mold 2.

That is, an ejector rod (ball screw) extending in the operating direction of the first ejector plate 13 is provided on the surface of the first ejector plate 13 opposite to the gate cut pin 14.
49 (ejector member) is connected, and the rod 49 is formed with a screw portion 49a. Also, rod 4
A first pulley (ball bearing) 50 is screwed into a screw hole of a central hole (not shown) and mounted on the screw portion 49a of No. 9. A servo motor 51 is used as a drive source of the ejector rod 49, and a second pulley 52 is attached to an output shaft of the servo motor 51 so as to rotate concentrically and integrally. The second pulley 52 and the first pulley 50 are connected by a timing belt 53, whereby the driving force of the servo motor 51 is transmitted to the ejector rod 49, and the ejector rod 49 is rotated by the forward / reverse rotation of the servo motor 51. It is designed to move linearly in the longitudinal direction.

The servo motor 51 is controlled by a control device 55
The control device 55 allows the ejector rod 49 to operate at a high speed so that no gate mark remains on the cut surface when the gate is cut, and to operate at a low speed so that cracks or the like do not occur when the molded product is ejected. The rotation speed is controlled to at least two stages. Servo motor 51
By controlling the speed, torque, rotation amount (movement amount) of
The operation of the ejector rod 49 can be controlled.

Next, the control device 55 of the electric injection molding machine in this embodiment will be described with reference to FIG. In the control device 55, an ejector advance speed setting means 56a at the time of ejecting a molded article, an ejector retreat speed setting means 56b at the time of ejecting a molded article, an ejector advance speed setting means 57a at the time of gate cutting, and an ejector retreat speed at the time of gate cutting The setting means 57b, the ejector pressure setting means 58 at the time of projecting the molded product, and the ejector pressure setting means 59 at the time of gate cutting are connected to the setting switching section 60, respectively. The setting switching section 60 is a CPU of the injection molding machine.
61. Thus, the operating speed of the ejector rod 49 for gate cutting is set to be higher than the operating speed of the ejector rod 49 for ejecting a molded product.
Is set to such a high speed that no gate marks remain, and to a low speed that does not cause cracks when the molded product is protruded.

Further, an ejector advance position setting means 63 for ejecting a molded article for setting a target advance position of the ejector rod 49 for ejecting the molded article, and an advance of the ejector rod 49 (gate cut pin 14) for cutting the gate. Ejector advance position setting means 64 at the time of gate cut for setting a target position is also provided by setting switching section 60.
It is connected to the. The setting switching section 60 is connected to the servomotor 51 via the servo amplifier 65.

As shown in the control block diagram of FIG. 11, the servo amplifier 65 has a target forward position and speed of the ejector rod 49 and a torque regulation according to the time of gate cutting and the time of projecting a molded product. The setting value is selectively input by the setting switching unit 60, and the rotation speed, the rotation amount, and the torque of the servo motor 51 are controlled. Also, a gate cut start timing timer 67 and a gate cut time timer 69 are provided by the CPU 61, respectively.
It is connected to. Usually, there are three types of triggers for the gate cut start timing: detection of the screw position, measurement of the injection time, and a combination of both, and one of them is selected by the timing timer 67. Then, when any of the selected triggers matches the set position as the gate cut start timing, the instruction of the gate cut operation and the measurement of the gate cut time are started.

This embodiment is configured as described above.
Next, the control method will be described with reference to FIGS. First, as shown in FIG. 1, in a state where the two molds 1 and 2 of the electric injection molding machine have been clamped, the molten resin is supplied from the heating cylinder via the nozzle 6 by the operation of an injection cylinder (not shown). Are injected into the sprue 5, the gate 4 and the cavity 3 of the molds 1 and 2, and are filled. On the other hand, in the gate cut start timing timer 67, if, for example, the detection of the screw position is selected in advance as a trigger of the gate cut start timing, the detection signal is input to the CPU 61. Thereby, the CPU 61
Then, a gate cut instruction signal is output to the setting switching unit 60. When the measurement of the injection time or the combination of the two is selected as the trigger of the gate cut start timing by the gate cut start timing timer 67, the measurement of the injection time is performed instead of or together with the above operation. Done.

When a gate cut instruction signal is input from the CPU 61 to the setting switching section 60, the ejector advance position setting means 63 for gate cut, the ejector advance speed setting means 57a for gate cut, and the pressure setting means 5 for gate cut are provided.
9 is selected and input to the servo amplifier 65, and the servo motor 51 is driven based on this signal. The drive control of the servo motor 51 is performed based on the control block diagram shown in FIG.
That is, the output of the servo motor 51 is
Is fed back as a pulse signal, and each time, each target value and actual value of the set position and speed are compared and calculated, and the servo motor drive current value (torque) is adjusted so that each actual value matches each target value. ) Is set and controlled. Thus, the rotation amount (movement amount), speed, and torque of the servomotor 51 are controlled, and the servomotor 51 is driven and controlled.

The rotation of the servo motor 51 driven and controlled by the controller 55 is transmitted from the second pulley 52, which rotates integrally, to the first pulley 50 via the timing belt 53, and the rotation of the first pulley 50 is controlled. The motion is converted into a linear motion by a ball screw mechanism between the ejector rod 49 and the first eject plate 13 to be pushed. The advance speed of the ejector rod 49 during the gate cut is set to a high speed according to the gate cut. In this way, immediately after the filling of the resin is completed or during the dwelling, the gate cut pin 14 moves forward at a relatively high speed integrally with the first eject plate 13 and the gate 4 is crushed,
The tip is held on the surface of the cavity 3 (see FIG. 3). At this position, the first eject plate 13 stops in contact with the second eject plate 15, and the gate cut is completed. After the time measured by the gate cut time timer 69 elapses, the setting switching unit 60 uses the signals from the ejector retreat speed setting means 57b at the time of gate cut and the ejector pressure setting means 59 at the time of gate cut to output the ejector rod. 49 is moved backward, and the first eject plate 13 and the gate cut pin 14 are returned to the initial positions shown in FIG.

Thereafter, when a predetermined cooling time has elapsed, mold opening is started (see FIG. 5). When the mold opening operation is completed, at that time, the setting switching unit 60 controls the servo motor 51 based on signals from the ejector advance position setting means 63, the ejector advance speed setting means 56a, and the ejector pressure setting means 58 when the molded product is ejected. The target position (movement amount) and speed are set, and the drive of the servomotor 51 is controlled. As a result, the ejector rod 49 is actuated, the first eject plate 13 is pushed relatively long at a relatively lower speed than when the gate is cut, and the second eject plate 15 is pushed integrally from the middle. Then, at the same time when the gate cut pin 14 and the first eject pin 17 protrude the molded product 16, the sprue runner 18 is protruded by the second eject pin 19 (see FIG. 6), and can be separated from the mold 2.

Then, in the setting switching section 60, the ejector rod 49 is operated to retreat by a signal from the ejector retreat speed setting means 56b and the ejector pressure setting means 58 when the molded product is ejected. Then, the first eject plate 13 and the second eject plate 15 are respectively returned to the initial positions shown in FIG. 1 (see FIG. 1).

As described above, in the present embodiment, the operating speed of the ejector rod 49 at the time of gate cutting, that is, the speed and torque of the servo motor 51, is appropriately adjusted to a higher speed than that at the time of protruding the molded product 16 and the sprue runner 18. The speed and torque can be set, and at the time of gate cutting, the gate cut pin 14 can be operated at a high speed corresponding to the gate cut, leaving no trace of the gate on the cut surface of the gate cut, thereby shortening the cycle of the gate cutting process. At the same time,
When the molded product 16 or the like is protruded, the pins 14, 17, and 19 can be operated at a corresponding low speed, so that cracks and the like do not occur in the molded product. Moreover, according to the present embodiment, the conventional electric injection molding machine is used to control the drive speed, torque and rotation amount of the servomotor 51 in a plurality of stages, and without adding a new configuration, Gate cutting and molded product ejection can be performed at a suitable speed.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described below. FIG. 7 is a graph showing a command (target) value and an actual value of the ejector rod stroke with respect to the time when the molded product is ejected, and FIG. 8 is a command (target) of the ejector rod stroke with respect to the time when the gate is cut.
FIG. 9 is a control block diagram of the servo motor of the control device according to the present embodiment. In the first embodiment described above, when the molded product is ejected, the ejector advance position setting means 63, the ejector advance speed setting means 56a, and the ejector pressure setting means 58 at the time of ejecting the molded product are set to a predetermined moving amount (rotation). The stroke of the command value (with respect to time) from the initial position to the target position based on the amount and the speed is set as shown by a dashed line in FIG. On the other hand, the drive control method of the servo motor 51 by the control device 55 shown in FIG.
The actual value of the actual stroke of the ejector rod 49 as a function of time is shown by a solid line. This actual value is controlled to move so as to approximate the command value, and finally reach and match the target value G1 at time t1.

When the gate is cut,Target position
(Command value) The actual value of the stroke is adjusted so as to reach G2.
Control, but the first eject plate 13
The actual value at the position (G2 ') in contact with the eject plate 15 is
Stop. FIG. 8 shows that these command values and actual values are indicated by alternate long and short dash lines.
This is indicated by a solid line. Moreover, in each case,
As described in the related art section,
The deviation (deviation) between the command (target) value and the actual value
If the tolerance exceeds the set tolerance, the injection molding machine
Stops servo motor 51 assuming that an error has occurred
It is like that.

In the second embodiment, the target forward position of the ejector rod 49 at the time of gate cutting is set to a stroke having a length exceeding the distance between the first eject plate 13 and the second eject plate 15 at the initial position. I have. This target position
Setting location is performed by the gate cutting when the ejector forward position setting means 64. Further, in the second embodiment, as shown in the control block diagram of this embodiment in FIG. 9, a comparator 35 for comparing the deviation with an allowable deviation set in advance by the deviation setting means 34, and a switch 36 A switch 73 for interrupting power supply is set in the line connecting. When the gate is cut, the switch 36 is automatically turned on.
The CPU 61 is provided with a deviation non-detection signal output means 72 for outputting a deviation non-detection signal for turning off the signal.
Thereby, when the gate is cut, the ejector rod 49
Is operated, and the gate cut is completed in a state where the first eject plate 13 is in contact with the second eject plate 15, but the servomotor 51 is controlled to be driven, and the gate cut pin 14 removes the resin in the cavity 3. Pressurization will continue.

This embodiment is configured as described above.
Next, a control method of the injection molding machine according to the present embodiment will be described. At the time of gate cutting, the controller 55 sets the ejector advance position setting means 64 at the time of gate cutting.
The target position and speed of the ejector rod 49 are set by the outputs of the ejector advance speed setting means 57a and the ejector pressure setting means 59, and the servo motor 51 is driven. At the same time, a deviation non-detection signal output means 72 automatically outputs a deviation non-detection signal, and a switch 73 provided between the comparator 35 and the motor power-off switch 36 is turned off. for that reason,
When the servo motor 51 is driven, the difference between the actual position and the target position of the ejector rod 49 due to the rotation amount signal pulse of the servo motor 51, which is fed back from the pulse encoder 22 provided to the motor 51, is calculated by the calculator 23 as a deviation. Although the calculation is performed, even if the deviation becomes larger than the value of the allowable deviation, the power supply to the servomotor 51 is not cut off.

Here, the target position of the ejector rod 49 by the ejector advance position setting means is set to a size of a stroke exceeding a distance where the first eject plate 13 comes into contact with the second eject plate 15 from the initial position. In the state where the first eject plate 13 is in contact with the second eject plate 15, it has not reached the target position. Then, by driving the servo motor 51 thereafter, as shown in FIG. 8, the deviation between the target value and the actual value becomes larger than the allowable deviation, but the servo motor 51 uses the gate cut time timer 69 for a predetermined time. It will continue to operate until it has passed. Therefore, the gate cut pin 14 can continue to apply pressure to the resin in the cavity 3 at the gate 4 in the stopped state. Therefore, according to the present embodiment, after the gate cut ends, the gate cut pins 14
Can press the resin, and the finished condition of the molded product 16 is improved. In this case, the resin pressure can be increased even if the magnitude of the resin pressure in the cavity 3 is slightly lower. Further, even if there is an error in the gate cut position depending on the type and shape of the mold, no problem occurs. Also, in this case, the position of the tip of the gate cut pin 14 at the time of gate cutting slightly fluctuates with respect to the surface of the cavity 3, but does not adversely affect the molded product.

When the molded product is ejected, the deviation non-detection signal output means 72 does not operate. Therefore, the deviation between the actual position and the target position based on the feedback signal of the rotation amount of the servomotor 51 is allowed as in the conventional case. If the difference is larger than the deviation, it is determined that there is an abnormality, and the switch 36 is shut off by the output signal from the comparator 35 to the switch 36 in the control block diagram shown in FIG. 9, and the servomotor 51 is stopped.

As described above, according to the second embodiment, the target position is set to be larger than the stroke in which the ejector rod 49 can operate at the time of gate cutting, and the drive of the servo motor 51 is stopped due to abnormality detection. As a result, the pressure can be continuously applied to the cavity 3, so that the finished product 16 can be finished regardless of the type and shape of the mold and the set target position. Is advantageous. In addition, the output of the deviation non-detection signal by the deviation non-detection signal output means 72 and the stop control thereof are automatically performed inside the CPU 61 of the control device 55, so that a better configuration can be achieved without adding a new configuration. A gate cut operation for obtaining a molded product can be performed.

The above-described second embodiment can be applied to an injection molding machine in which the gate cutting speed at the time of gate cutting in the first embodiment is different from the ejection speed at the time of ejecting a molded product. Without limitation, it can be applied even when the speed is the same. In addition, gate cut pin 1
4. The first and second ejector pins 17, 19 constitute ejector pins.

[0042]

[Effect of the Invention] As described above, according to the gate cutting and protruding control apparatus and method for an electric injection molding machine according to the present invention, it can set the gate cut molded article ejection and the speed corresponding to each gate When cutting, no gate marks or the like remain on the cut surface of the gate cut, the cycle of the gate cutting step can be shortened, and cracks or the like can be prevented from occurring when the molded product is ejected.
Further, according to the control apparatus and method for an electric injection molding machine according to the present invention, the target position of the ejector member at gate cut
There actually even longer than the stroke distance can be activated when the gate cut, without causing stoppage of the operation by the abnormality detection, the gate that can continue to apply pressure to the molten material in the cavity, in the target position set Regardless, there is an advantage that the finished product is good. Moreover, without adding a new configuration to the conventional drive mechanism,
Since the control of the operation and the stop of the abnormality detecting means can be automatically performed, it is possible to appropriately perform the gate cut and the protrusion of the molded product without complicating the configuration. or,
ADVANTAGE OF THE INVENTION According to the control apparatus and method of the electric injection molding machine which concerns on this invention, the target position of an ejector member at the time of a gate cut.
Since the ejector pin is set at a position where the ejector pin is located forward of the gate cut position, the gate can continue to apply pressure to the molten substance in the cavity, and the finished product is excellent.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a mold portion in a resin-filled state in an electric injection molding machine according to a first embodiment of the present invention.

FIG. 2 is a main block diagram of a control device of the electric injection molding machine shown in FIG.

FIG. 3 is a longitudinal sectional view of a mold portion at the time of gate cutting.

FIG. 4 is a longitudinal sectional view of a mold portion in a state where a gate cut pin is returned to an initial position after gate cut.

FIG. 5 is a longitudinal sectional view of a mold portion in a mold opened state.

FIG. 6 is a longitudinal sectional view of a mold part in a protruding state.

FIG. 7 is a graph showing a command value and an actual value of a stroke of an ejector rod with respect to a time when a molded product is ejected.

FIG. 8 is a graph showing a command value and an actual value of the stroke of the ejector rod with respect to the time when the gate is cut or when there is an abnormality.

FIG. 9 is a control block diagram of a servomotor of the control device according to the second embodiment.

FIG. 10 shows a prior art electric injection molding machine.
FIG. 3 is a longitudinal sectional view of a mold portion in a resin filled state.

FIG. 11 is a control block diagram of a servomotor of a conventional control device.

[Explanation of symbols]

1, 2, die, 4 gate, 14 gate cut pin,
16: molded product, 17: first eject pin, 19: second eject pin, 49: ejector rod, 51: servomotor, 55: control device, 72: deviation non-detection signal output means

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masakazu Ohno 2-11-14 Kugahara, Ota-ku, Tokyo 3 Inside Kyoko Kasei Co., Ltd. (56) References Japanese Utility Model Showa Sho 61-109711 (JP, U)

Claims (12)

(57) [Claims] An ejector pin is operated by an ejector member of an ejector device of an electric mechanism to cut a gate in a mold with the mold closed and to form a mold with the mold open. in the electric injection molding machine to protrude goods from the mold, the speed setting means for setting the operating speed of the ejector member at the gate cut, the speed setting for setting the operating speed of the ejector member in molding article ejection A gate cut and protrusion control device characterized in that means are provided separately. Wherein said ejector device, according to the motor, an ejector member for interlocking said ejector pin, characterized in that it has a transmission means for transmitting the driving force of the motor <br/> motor to the ejector member Item 2. The gate cut and protrusion control device according to Item 1. Wherein the speed setting means for setting the operating speed of the ejector member at the gate cut, the gate cut Tokie di <br/> Ekuta advanced position setting means and the gate cutting when the ejector pressure
Selected with the force setting means to move the ejector device forward
Forward speed setting at gate cut to set forward operation speed
Gate cutting and protruding control device according to claim 1 or 2, characterized in that it has a constant section. 4. A speed setting means for setting an operation speed of an ejector member at the time of projecting a molded product, the speed setting means comprising :
D ejector forward position setting means and the molded product ejection during the Eje
The ejector device is selected together with the
Ejection when molding products are ejected to set the speed at which to advance
4. The gate cut and protrusion control device according to claim 1, further comprising a fin advance speed setting means . 5. A closed mold by operating one or a plurality of ejector pins by an ejector member of an electric mechanism.
State in which the mold is opened along with the gate cut in the mold in Thailand
In the electric injection molding machine in which the molded product is ejected from the mold at the time of gate cut, the ejector member is operated at a relatively high speed to perform the gate cut, and when the molded product is ejected, the speed is relatively low. A method for controlling gate cut and protrusion, wherein the ejector member is operated so that a molded product is protruded from a mold. 6. An electric injection molding machine in which one or more ejector pins are operated by an ejector member of an electric mechanism to cut a gate in a mold and to project a molded product from the mold. Abnormality detecting means for stopping the drive source when the deviation between the set target position and the actual position of the ejector member for operating the pin is larger than the allowable deviation; and turning off the abnormality detecting means when the gate is cut, A control device, comprising: abnormality control means for turning on when a molded product is ejected. 7. A comparator for outputting a signal when a deviation between a target position and an actual position of an ejector member exceeds an allowable deviation set by a deviation setting means, and receiving the signal. The control device according to claim 6, further comprising a switch configured to cut off a drive current applied to the motor. 8. The control device according to claim 7, wherein said abnormality control means includes a switch for controlling on / off of energization between a comparator and a switch of said abnormality detection means. 9. The apparatus according to claim 6, wherein a target position of said ejector member at the time of gate cutting is set to a position where an ejector pin is located forward of a gate cutting position. Control device. 10. The gate cut position is a position where a first eject plate having an ejector pin for gate cutting comes into contact with a second eject plate having an ejector pin for ejecting a molded product. The control device according to claim 1. 11. An electric injection molding machine in which one or more ejector pins are operated by an ejector member of an electric mechanism to cut a gate in a mold and to project a molded product from the mold. Sometimes, when the deviation between the target position and the actual position of the ejector member for actuating the ejector pin is larger than the allowable deviation, the abnormality detection means for stopping the drive source is turned off to perform a gate cut. A control method characterized in that the molded article is ejected by turning on the abnormality detecting means. 12. The control method according to claim 11, wherein a target position of said ejector member at the time of gate cutting is set to a position where an ejector pin is located forward of a gate cutting position.