JP6774804B2 - Injection molding machine and weighing method - Google Patents

Description

The present invention relates to an injection molding machine and a weighing method.

For example, Patent Document 1 discloses an injection molding machine that injects a molten resin obtained by kneading fibers. In such an injection molding machine, a molten resin in which a fiber material is kneaded by supplying resin pellets and a fiber material into the plasticizing cylinder and rotating a plasticizing screw inside the plasticizing cylinder in a weighing operation. Is generated and sent to the injection nozzle side of the plasticizing cylinder. Then, the injection molding machine measures the pressure applied to the plasticizing screw as the pressure of the molten resin, and retracts the plasticizing screw while performing feedback control so that the measured value of this pressure becomes a predetermined target value. As a result, a predetermined amount of molten resin is weighed on the injection nozzle side of the plasticizing cylinder while suppressing variations in resin density.

JP-A-2015-208879

However, as schematically shown in FIG. 6, the fiber material S supplied from the hopper 111b of the injection molding machine 101 to the plasticizing cylinder 111 is sandwiched between the plasticizing cylinder 111 and the plasticizing screw 112, and the plasticizing screw 112 When the rotational force of the above is applied, a force in the backward direction (a force toward the right in FIG. 6) acts on the plasticizing screw 112, and the measured value of the pressure may rise sharply. Therefore, even though the pressure of the molten resin does not actually increase, the feedback control is performed so as to decrease the pressure, which causes the pressure of the molten resin to temporarily decrease and the resin density to vary. Occasionally occurred. Therefore, there is a risk of affecting the quality of the injection-molded molded product.

Therefore, an object of the present invention is to provide an injection molding machine and a weighing method capable of effectively suppressing inappropriate feedback control.

(1) In order to achieve the above object, the injection molding machine of one aspect of the present invention rotates and moves the injection cylinder, the screw housed in the injection cylinder, and the screw in the injection cylinder. An injection molding machine having a drive unit, a measuring unit that measures a retreating force applied to the screw, and a measured value of the retreating force by the measuring unit as a target value of the retreating force. It has a measurement control unit that rotates and retracts the screw by the drive unit while performing feedback control so that the measurement value exceeds the target value and the ascending speed of the measured value. when but exceeding the speed limit, using positive measurement Osamu over the variation limiting period instead of the measurement value, have rows feedback control such that the modified measurement value becomes the target value, the metering control The unit is characterized in that the measured value when the measured value exceeds the target value and the ascending speed of the measured value exceeds the speed limit value is set as the modified measured value .
(2) In order to achieve the above object, the injection molding machine of one aspect of the present invention rotates and moves the injection cylinder, the screw housed in the injection cylinder, and the screw in the injection cylinder. An injection molding machine having a drive unit, a measuring unit that measures a retreating force applied to the screw, and a measured value of the retreating force by the measuring unit as a target value of the retreating force. It has a measurement control unit that rotates and retracts the screw by the drive unit while performing feedback control so that the measurement value exceeds the target value and the ascending speed of the measured value. When the speed limit value is exceeded, the modified measurement value is used in place of the measurement value over the fluctuation restriction period, feedback control is performed so that the modified measurement value becomes the target value, and the measurement control unit performs the said measurement control unit. The difference value obtained by subtracting the reference measurement value from the measurement value is smaller than 1 with the measurement value when the measurement value exceeds the target value and the ascending speed of the measurement value exceeds the speed limit value as the reference measurement value. It is characterized in that the value obtained by multiplying the coefficient and the value obtained by adding the value to the reference measured value is used as the modified measured value.
(3) In order to achieve the above object, the injection molding machine of one aspect of the present invention rotates and moves the injection cylinder, the screw housed in the injection cylinder, and the screw in the injection cylinder. An injection molding machine having a drive unit, a measuring unit for measuring a retreating force applied to the screw, and a measured value of the retreating force by the measuring unit as a target value of the retreating force. The measurement control unit has a measurement control unit that rotates and retracts the screw by the drive unit while performing feedback control so that the measurement value exceeds the target value and the ascending speed of the measurement value. When the speed limit value is exceeded, the modified measurement value is used in place of the measurement value over the fluctuation restriction period, feedback control is performed so that the modified measurement value becomes the target value, and the measurement control unit performs the said measurement control unit. It is characterized in that the target value is the modified measured value.

In the present invention, even if the measurement control unit sets the measured value when the measured value exceeds the target value and the ascending speed of the measured value exceeds the speed limit value as the modified measured value. Good. Alternatively, the measurement control unit uses the measured value when the measured value exceeds the target value and the ascending speed of the measured value exceeds the speed limit value as a reference measurement value, and from the measurement value to the reference measurement value. The value obtained by multiplying the difference value obtained by subtracting the above value by a coefficient smaller than 1 may be added to the reference measurement value, and the modified measurement value may be used. Alternatively, the measurement control unit may set the target value as the modified measurement value. By doing so, the modified measured value becomes a constant value without fluctuation or a value having less fluctuation than the measured value.

(4) In order to achieve the above object, another measurement method of the present invention is to rotate and move the injection cylinder, the screw housed in the injection cylinder, and the screw in the injection cylinder. It is a weighing method used in an injection molding machine having a drive unit for making the screw, and while performing feedback control so that a measured value obtained by measuring a force in the backward direction applied to the screw becomes a target value of the force in the backward direction. rotate and retracting said screw by said drive unit, when the measured value is rising rate of greater than and the measured value of the target value exceeds the speed limit, the measured positive measurement Osamu over the variation limiting period used in place of value, have rows feedback control such that the modified measurement value becomes the target value, when the measured value is rising rate of greater than and the measured value of the target value exceeds the speed limit It is characterized in that the measured value is used as the modified measured value .
(5) In order to achieve the above object, another measurement method of the present invention is to rotate and move the injection cylinder, the screw housed in the injection cylinder, and the screw in the injection cylinder. It is a weighing method used in an injection molding machine having a drive unit for making the screw, and while performing feedback control so that a measured value obtained by measuring a force in the backward direction applied to the screw becomes a target value of the force in the backward direction. When the screw is rotated and retracted by the drive unit and the measured value exceeds the target value and the ascending speed of the measured value exceeds the speed limit value, the modified measured value is replaced with the measured value over the fluctuation limiting period. The measured value is measured when the modified measured value exceeds the target value and the ascending speed of the measured value exceeds the speed limit value by performing feedback control so that the modified measured value becomes the target value. As the reference measurement value, the modified measurement value is obtained by multiplying the difference value obtained by subtracting the reference measurement value from the measurement value by a coefficient smaller than 1 and adding the value to the reference measurement value. Weighing method.

According to the present invention, when the measured value of the backward force applied to the screw exceeds the target value and the rising speed of the measured value exceeds the speed limit value, the measured value fluctuates from the measured value over the fluctuation limit period. Feedback control is performed using the corrected measurement value corrected to a small value. As a result, even if the measured value of the backward force applied to the screw suddenly rises due to, for example, sandwiching the fibers mixed with the resin, the fluctuation of the measured value is slowed down and feedback control is performed. It can be performed. Therefore, inappropriate feedback control can be effectively suppressed.

It is a figure which shows the schematic structure of the injection molding machine which concerns on one Embodiment of this invention. It is a figure explaining the calculation method of the correction resin pressure in the control part of the injection molding machine of FIG. It is a figure explaining another calculation method of the correction resin pressure in the control part of the injection molding machine of FIG. It is a graph which shows the change of the nozzle internal pressure of an injection cylinder at the time of performing a weighing operation in Example 1. It is a graph which shows the change of the nozzle internal pressure of the injection cylinder when the weighing operation is performed in the comparative example 1. FIG. It is a figure which shows typically the state which the fiber material is sandwiched between a cylinder and a screw.

Hereinafter, the injection molding machine according to the embodiment of the present invention will be described with reference to FIGS. 1 to 5.

The injection molding machine of the present embodiment performs various operations such as injection operation, pressure holding operation, cooling operation, mold opening / closing operation, and weighing operation in the injection molding cycle.

As shown in FIG. 1, the injection molding machine 1 has an injection unit 10 and a control unit 30.

The injection unit 10 includes an injection cylinder 11, a screw 12, a rotation control servomotor 13, a rotation control timing belt 14, a screw pulley 15, a position control servomotor 16, and a position control timing belt 17. It has a ball screw mechanism 18, a rotation detection encoder 19, a position detection encoder 20, and a load cell 21.

The injection cylinder 11 is formed in a tubular shape, and is provided with a heater (not shown) on the outer peripheral surface thereof. The injection cylinder 11 is provided with a nozzle 11a at one end and a hopper 11b at a position near the other end into which a molding material in which a fiber material such as glass fiber or carbon fiber is mixed with a resin material is charged. ing. The fiber material and the resin material may be supplied to the injection cylinder 11 from different locations. The screw 12 is housed in the injection cylinder 11 so as to be rotatable and movable in the front-rear direction (that is, to be able to move forward and backward). In the present specification, the nozzle 11a side of the injection cylinder 11 of FIG. 1 is the front side, and the opposite side is the rear side.

The rotation control servomotor 13 is a drive unit that rotates the screw 12. The rotation of the output pulley 13a of the rotation control servomotor 13 is transmitted to the screw pulley 15 coaxially fixed to the screw 12 via the rotation control timing belt 14. As a result, the screw 12 is rotated about the shaft.

The position control servomotor 16 is a drive unit that moves the screw 12 back and forth. The rotation of the output pulley 16a of the position control servomotor 16 is transmitted to the screw shaft pulley 18b coaxially fixed to the screw shaft 18a of the ball screw mechanism 18 via the position control timing belt 17. As a result, the screw shaft 18a is rotated about the shaft. Then, the rotation of the screw shaft 18a causes the nut portion 18c screwed via the ball (not shown) to move in the axial direction (that is, the front-rear direction). Along with the movement of the nut portion 18c, the screw 12 fixed to the nut portion 18c is also moved in the front-rear direction. When the screw 12 is moved in the front-rear direction by the position control servomotor 16, the pressure applied to the position of the screw 12 and the resin stored in the front space E of the screw 12 in the injection cylinder 11 (hereinafter, simply referred to as simply). "Resin pressure P") is adjusted.

The rotation detection encoder 19 measures the rotation position of the rotation control servomotor 13 and outputs it as a rotation position output A1, and based on this rotation position output A1, the control unit 33 of the control unit 30 described later rotates the screw 12. The speed R is detected. The position detection encoder 20 measures the rotational position of the position control servomotor 16 and outputs it as a rotational position output A2, and the control unit 33 moves or moves the position L in the front-rear direction of the screw 12 based on the rotational position output A2. Detect speed V. The load cell 21 measures the force applied to the screw 12 in the backward direction and outputs the pressure output A3, and the control unit 33 detects the pressure output A3 as the resin pressure P. That is, the load cell 21 corresponds to the measuring unit, and the resin pressure P corresponds to the measured value of the backward force applied to the screw 12.

The control unit 30 includes a setting storage unit 31, a display operation unit 32, a control unit 33, a rotation control servo amplifier 34, and a position control servo amplifier 35.

The setting storage unit 31 is configured to include, for example, a rewritable storage medium such as a hard disk device or a non-volatile memory. The setting storage unit 31 contains conditions for various operations such as the rotation speed R, the position L and the moving speed V of the screw 12 used in various operations included in the injection molding operation, and the resin pressure P in the injection cylinder 11. The value is stored.

The setting storage unit 31 stores, for example, set values of the measurement retreat position Xm [mm], the measurement rotation speed Rm [rpm], and the measurement pressure value Pm [MPa], which are the condition values for the measurement operation. The weighing retreat position Xm is the retreating position of the screw 12 when the weighing is completed. The measuring rotation speed Rm is the measuring rotation speed of the screw 12 from the most advanced position 0 of the screw 12 to the measuring backward position Xm. The measurement pressure value Pm is a pressure value applied to the resin stored in the front space E from the position 0 to the measurement retreat position Xm. The measuring pressure value Pm corresponds to the target value of the backward force applied to the screw 12.

Further, in the setting storage unit, a speed limit value Vpr, which is a limit value of the rising speed Vpu of the resin pressure P, and a fluctuation limit period Tpr, which is a period during which the modified resin pressure Pa described later is used instead of the resin pressure P, are set. The value is also stored.

The display operation unit 32 includes, for example, a display unit 32a composed of a flat panel display such as a liquid crystal display or an organic EL display, and an operation unit 32b provided with a touch panel arranged so as to overlap the display surface of the display unit 32a. Have.

The control unit 33 is composed of a microcomputer or the like. The control unit 33 generates control signals in various operations, outputs the control signals to the rotation control servo amplifier 34 and the position control servo amplifier 35, and causes the rotation control servo motor 13 and the position control servo motor 16 to operate. Control. The control unit 33 also generates a control signal to control a cooling mechanism and a mold opening / closing mechanism (not shown).

In the various operations described above, the control unit 33 determines the rotation speed R of the screw described above based on the rotation position output A1 of the rotation detection encoder 19, the rotation position output A2 of the position detection encoder 20, and the pressure output A3 of the load cell 21. , Movement speed V and position L, and resin pressure P are feedback-controlled.

Next, an example of the operation performed by the injection molding machine 1 described above in the injection molding cycle will be described.

As a preliminary operation before entering the injection molding cycle, the control unit 33 of the injection molding machine 1 feeds the resin into the injection cylinder 11 until the molten resin is discharged from the nozzle 11a of the injection cylinder 11, and also performs a weighing operation described later. Similarly, a preliminary operation for storing the molten resin in the front space E in the injection cylinder 11 is performed. Then, after performing the preliminary operation, the control unit 33 starts various operations such as an injection operation, a pressure holding operation, a cooling operation, a mold opening / closing operation, and a weighing operation included in the injection molding cycle.

In the injection molding cycle, the control unit 33 ejects the resin stored in the front space E in the injection cylinder 11 into the mold by advancing the screw 12 (injection operation). Following the injection operation, the control unit 33 holds the resin stored in the front space E by adjusting the position of the screw 12 in the front-rear direction (holding pressure operation). Following the pressure holding operation, the control unit 33 cools the mold by flowing a refrigerant through a flow path formed in the mold by a cooling mechanism (not shown) to solidify the resin in the mold (cooling operation). ). Following the cooling operation, the control unit 33 opens the mold by a mold opening / closing mechanism (not shown), takes out the molded product, and then closes the mold (mold opening / closing operation).

Further, the control unit 33 performs a weighing operation of weighing and storing the resin in the front space E in parallel with the cooling operation. In this weighing operation, the control unit 33 reads out the measuring rotation speed Rm, the measuring pressure value Pm, and the measuring backward position Xm from the setting storage unit 31. Then, the control unit 33 rotates the screw 12 at the measuring rotation speed Rm to feed the resin into the front space E. As a result, the resin pressure P in the front space E detected from the measured value of the load cell 21 rises, but the control unit 33 sets the resin pressure P (measured value) to be the measured pressure value Pm (target value). The screw 12 is retracted while performing feedback control (for example, PID control), and finally the screw 12 is moved to the measurement retract position Xm. As a result, one injection amount of resin is weighed and stored in the front space E of the screw 12 in the injection cylinder 11. The control unit 33 corresponds to the measurement control unit.

In this measuring operation, when the resin pressure P exceeds the measuring pressure value Pm (for example, 10 MPa) and the rising speed Vpu of the resin pressure P exceeds the speed limit value Vpr (for example, 5 MPa / sec), the control unit 33 determines. Feedback control is performed using the modified resin pressure Pa (corrected measured value) obtained by modifying the resin pressure P to a value smaller than that over the fluctuation limiting period Tpr (for example, 0.3 seconds).

In the present embodiment, the control unit 33 calculates the modified resin pressure Pa by the following method.

The control unit 33 periodically acquires the pressure output A3 from the load cell 21 (for example, every ΔT = 200 μsec) to detect the resin pressure P. Then, as shown in FIG. 2, when the resin pressure P exceeds the measurement pressure value Pm (time T0) and the rising speed Vpu of the resin pressure P exceeds the speed limit value Vpr (time T1), the control unit 33 receives. The resin pressure P (that is, P1) at the time point T1 is defined as the modified resin pressure Pa. Then, the modified resin pressure Pa is used instead of the resin pressure P over the fluctuation limiting period Tpr (time T1 to time T2). The formula (1) for calculating the modified resin pressure Pa is shown below.
Pa = P1 ... (1)

Alternatively, as shown in FIG. 3, in the control unit 33, the resin pressure P exceeds the measurement pressure value Pm stored in the setting storage unit 31 (time T0), and the rising speed Vpu of the resin pressure P sets the speed limit value Vpr. When it is exceeded (time T1), the resin pressure P = P1 at the time T1 is set as the reference pressure value Ps (reference measurement value), and the difference value obtained by subtracting the reference pressure value Ps from the resin pressure P is a coefficient α smaller than 1. For example, the value obtained by multiplying 0.2) may be added to the reference pressure value Ps, and the value obtained may be the modified resin pressure Pa. Then, the modified resin pressure Pa is used instead of the resin pressure P over the fluctuation limiting period Tpr. The formula (2) for calculating the modified resin pressure Pa is shown below.
Pa = P1 + (P [T] -Pm) x α ... (2)
However, P [T] is the resin pressure P at time T.

Alternatively, the control unit 33 controls when the resin pressure P exceeds the metering pressure value Pm stored in the setting storage unit 31 (time T0) and the rising speed Vpu of the resin pressure P exceeds the speed limit value Vpr (time T1). , The measuring pressure value Pm may be set as the modified resin pressure Pa. Then, the modified resin pressure Pa is used instead of the resin pressure P over the fluctuation limiting period Tpr. The calculation formula (3) of the modified resin pressure Pa is shown below.
Pa = Pm ・ ・ ・ (3)

For convenience of explanation, in FIGS. 2 and 3, the ascending speed Vpu was defined as the ascending speed (ΔP / ΔT) in one cycle (ΔT) for detecting the resin pressure P, but the present invention is limited to this. It's not a thing. For example, the control unit 33 may set the ascending speed Vpu as the moving average value of the plurality of ascending speeds in each of the plurality of consecutive cycles as the ascending speed Vpu, and obtains the ascending speed Vpu unless contrary to the object of the present invention. The one is arbitrary.

As described above, according to the injection molding machine 1 of the present embodiment, when the resin pressure P exceeds the measurement pressure value Pm and the rising speed Vpu of the resin pressure P exceeds the speed limit value Vpr, the resin pressure over the fluctuation limit period Tpr. Feedback control is performed using the modified resin pressure Pa obtained by modifying P to a value having a smaller fluctuation. As a result, even when the resin pressure P suddenly rises due to, for example, sandwiching the fiber material mixed with the resin, the fluctuation of the resin pressure P can be blunted and the feedback control can be performed. .. Therefore, inappropriate feedback control can be effectively suppressed.

Although embodiments of the present invention have been described above, the present invention is not limited to these examples. As long as the gist of the present invention is provided, a person skilled in the art appropriately adding, deleting, or changing the design of the above-described embodiment, or combining the features of the embodiment as appropriate is also present. Included in the scope of the invention.

Next, Example 1 and Comparative Example 1 of the present invention will be described with reference to FIGS. 4 and 5.

(Example 1)
In the injection molding machine 1 of the above-described embodiment, long fiber composite pellets obtained by uniformly impregnating a bundle of glass fibers with polypropylene resin and cutting them to a length of 10 mm are put into a hopper 11b, and the measuring rotation speed Rm is 100 rpm and the measuring pressure is measured. The weighing operation was performed with the value Pm set to 10 MPa and the measuring backward position Xm set to 50 mm, and the internal pressure of the nozzle 11a of the injection cylinder 11 during the weighing operation was measured. The graph of the measurement result is shown in FIG. In this measurement operation, as illustrated in FIG. 3, when the resin pressure P exceeds the measurement pressure value Pm and the rising speed Vpu of the resin pressure P exceeds the speed limit value Vpr (5 MPa), the fluctuation limit period Tpr ( Feedback control is performed using the modified resin pressure Pa calculated by the above calculation formula (2) over 0.3 seconds).

(Comparative Example 1)
The measurement operation is performed in the same configuration as in the first embodiment except that the feedback control using only the resin pressure P (that is, the modified resin pressure Pa is not used) is performed, and the nozzle 11a of the injection cylinder 11 during the measurement operation is performed. The internal pressure was measured. The graph of the measurement result is shown in FIG.

(Evaluation)
Since the pressure is measured at the nozzle 11a in Example 1 and Comparative Example 1, the graphs shown in FIGS. 4 and 5 are slightly lower than the value set as the measurement pressure value Pm (about 8 to 8.5 MPa). Is operating so that it becomes the target value.

In the graph of FIG. 5 according to Comparative Example 1, it can be seen that the operation in which the internal pressure of the nozzle 11a suddenly drops from about 8.5 MPa is repeated. This is because the long fiber composite pellets supplied from the hopper 11b into the injection cylinder 11 are sandwiched between the injection cylinder 11 and the screw 12, and a backward force acts on the screw 12 to cause the resin pressure P to rise sharply. This is considered to be due to the fact that the control unit 33 detects the pressure P, and the feedback control is performed so as to lower the resin pressure P even though the resin pressure P does not actually rise. Therefore, the internal pressure of the nozzle 11a, that is, the actual resin pressure in the injection cylinder 11 constantly fluctuates within a width of about 2 to 3 MPa, resulting in variations in the resin density.

On the other hand, in the graph of FIG. 4 according to the first embodiment, the fluctuation is relatively gentle with a width of about 1 to 1.5 MPa centered on about 8 MPa. This is because, as in Comparative Example 1, the resin pressure P suddenly rises due to the sandwiching of the long fiber composite pellets, but the resin pressure P does not rise sharply by using the modified resin pressure Pa. It is considered that this is because the control unit 33 performs feedback control. Therefore, it is clear from the actual operation that in the first embodiment, inappropriate feedback control can be effectively suppressed as compared with the first comparative example, and thus the variation in the resin density can be suppressed.

1 ... Injection molding machine, 10 ... Injection unit, 11 ... Injection cylinder, 11a ... Nozzle, 11b ... Hopper, 12 ... Screw, 13 ... Rotation control servo motor (drive unit), 13a ... Output pulley, 14 ... Rotation control Timing belt, 15 ... Screw pulley, 16 ... Position control servo motor (drive unit), 16a ... Output pulley, 17 ... Position control timing belt, 18 ... Ball screw mechanism, 18a ... Screw shaft, 18b ... Shaft pulley, 18c ... Nut unit, 19 ... Rotation detection encoder, 20 ... Position detection encoder, 21 ... Load cell (measurement unit), 30 ... Control unit, 31 ... Setting storage unit, 32 ... Display operation unit, 32a ... Display unit, 32b ... Operation Unit, 33 ... Control unit (measurement control unit), 34 ... Rotation control servo amplifier, 35 ... Position control servo amplifier, A1 ... Rotation position output, A2 ... Rotation position output, A3 ... Pressure output, E ... Front space, R ... Screw rotation speed, L ... Screw position, V ... Screw moving speed, P ... Resin pressure (measured value), Pa ... Corrected resin pressure (corrected measured value), Ps ... Reference pressure value (reference measured value) , Xm ... Weighing retreat position, Rm ... Weighing rotation speed, Pm ... Weighing pressure value (target value), S ... Fiber material, Tpr ... Fluctuation limit period, Vpu ... Rise speed, Vpr ... Speed limit value.

Claims (5)

An injection molding machine having an injection cylinder, a screw housed in the injection cylinder, and a drive unit for rotating and moving the screw forward and backward in the injection cylinder.
A measuring unit that measures the backward force applied to the screw,
It has a measurement control unit that rotates and retracts the screw by the drive unit while performing feedback control so that the measured value of the force in the backward direction by the measuring unit becomes the target value of the force in the backward direction.
The metering control unit, when the measured value is rising rate of greater than and the measured value of the target value exceeds the speed limit value, a positive measurement Osamu over the variation limiting period using in place of the measurement value , have rows feedback control such that the modified measurement value becomes the target value,
An injection molding machine , wherein the measurement control unit sets the measured value as the modified measured value when the measured value exceeds the target value and the ascending speed of the measured value exceeds the speed limit value . An injection molding machine having an injection cylinder, a screw housed in the injection cylinder, and a drive unit for rotating and moving the screw forward and backward in the injection cylinder.
A measuring unit that measures the backward force applied to the screw,
It has a measurement control unit that rotates and retracts the screw by the drive unit while performing feedback control so that the measured value of the force in the backward direction by the measuring unit becomes the target value of the force in the backward direction.
When the measured value exceeds the target value and the ascending speed of the measured value exceeds the speed limit value, the measurement control unit uses the corrected measured value in place of the measured value over the fluctuation limiting period to perform the correction. Feedback control is performed so that the measured value becomes the target value.
The measurement control unit subtracts the reference measurement value from the measurement value by using the measurement value when the measurement value exceeds the target value and the ascending speed of the measurement value exceeds the speed limit value as a reference measurement value. molding machine out morphism you characterized in that said modified measurement value a value obtained by adding the reference measurement value obtained by multiplying a coefficient smaller than 1 on the difference value. An injection molding machine having an injection cylinder, a screw housed in the injection cylinder, and a drive unit for rotating and moving the screw forward and backward in the injection cylinder.
A measuring unit that measures the backward force applied to the screw,
It has a measurement control unit that rotates and retracts the screw by the drive unit while performing feedback control so that the measured value of the force in the backward direction by the measuring unit becomes the target value of the force in the backward direction.
When the measured value exceeds the target value and the ascending speed of the measured value exceeds the speed limit value, the measurement control unit uses the corrected measured value in place of the measured value over the fluctuation limiting period to perform the correction. Feedback control is performed so that the measured value becomes the target value.
The metering control unit, the molding machine out morphism you characterized in that said modified measurement values the target value. A weighing method used in an injection molding machine having an injection cylinder, a screw housed in the injection cylinder, and a drive unit for rotating and moving the screw forward and backward in the injection cylinder.
The drive unit rotates and retracts the screw while performing feedback control so that the measured value obtained by measuring the backward force applied to the screw becomes the target value of the backward force, and the measured value is the target value. when it exceeds beyond and rate of increase the speed limit value of the measurement values, using a positive measurement Osamu over the variation limiting period instead of the measurement value, as the corrected measurement value becomes the target value There line feedback control,
A measuring method characterized in that the measured value when the measured value exceeds the target value and the ascending speed of the measured value exceeds the speed limit value is set as the modified measured value . A weighing method used in an injection molding machine having an injection cylinder, a screw housed in the injection cylinder, and a drive unit for rotating and moving the screw forward and backward in the injection cylinder.
The drive unit rotates and retracts the screw while performing feedback control so that the measured value obtained by measuring the backward force applied to the screw becomes the target value of the backward force, and the measured value is the target value. When the rate of increase of the measured value exceeds the speed limit value, the modified measured value is used in place of the measured value over the fluctuation limiting period, and feedback control is performed so that the modified measured value becomes the target value. Do,
The difference value obtained by subtracting the reference measurement value from the measurement value is subtracted from 1 with the measurement value when the measurement value exceeds the target value and the ascending speed of the measurement value exceeds the speed limit value as the reference measurement value. A weighing method characterized in that a value obtained by multiplying a small coefficient is added to the reference measured value to obtain the modified measured value.

Images