JPH0732435A - Method and apparatus for correcting mold thickness of toggle injection molding machine - Google Patents

Abstract

(57) [Abstract] [Purpose] When the amount of position change from the mold touch position of the mold clamping housing 18 to the mold clamping completion position changes by more than a predetermined amount during the molding operation of the toggle injection molding machine, the mold thickness is corrected. Make the work automatic. A pair of racks 20 and 22 formed in a mold clamping housing of an injection molding machine are engaged with a pinion 24 and a gear portion of a position sensor 26. The position sensor is
The position of the mold clamping housing can be detected. The pinion shaft is connected to the motor 28. Mold thickness correction command device 3
0 is the housing position change amount basic table 42, the housing position change amount storage unit 44, the first comparison unit 46, the correction data table 48, the measurement die thickness storage unit 50, and the second comparison unit 5.
The second and third comparison units 54 are included. The mold thickness correction command device calculates based on each position of the mold clamping housing at the time of mold clamping force adjustment and completion of mold clamping at the time of actual molding and the measured mold thickness, and outputs the correction command signal 36 to the motor. Output. As a result, the molding operation can always be performed with a predetermined mold clamping force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for correcting a mold thickness of a toggle type injection molding machine.

[0002]

2. Description of the Related Art A conventional mold clamping force adjusting device for a toggle type injection molding machine is shown in FIG. The mold clamping force adjusting device shown in the drawing includes racks 20 and 22 provided in a mold clamping housing 18 of a toggle type injection molding machine,
It has a pinion 24 engaged with the rack 20, a position sensor 26, and a motor 28. Position sensor 2
A gear portion is formed at 6, and the gear portion is engaged with the rack 22. Pinion 24 is motor 28
Is connected with. A mold clamping cylinder 38 is attached to the mold clamping housing 18. The movable plate 12 is attached to the piston rod of the mold clamping cylinder 38 via the toggle mechanism 16.
Are connected. The fixed plate 10 is fixed at a position facing the movable plate 12. A fixed side mold 14a and a movable side mold 14b are attached to both boards 10 and 12, respectively. The fixed platen 10, the movable platen 12, the mold 14, the toggle mechanism 16, the mold clamping housing 18, the mold clamping cylinder 38, and the like constitute a toggle-type injection molding machine. In order to adjust the mold clamping force when exchanging the mold, the toggle mechanism 16 is fully expanded by driving the mold clamping cylinder 38 in the piston extending direction in advance. Next, the motor 28 is driven to drive the pinion 24 and the rack 20.
By moving the mold clamping housing 18 in the mold closing direction via the, the molds 14a and 14b are brought into close contact (mold touch). As a result, the mold clamping housing 1 when the mold is touched
The position 8 is detected by the position sensor 26 as the measurement die thickness. Next, the motor 28 is driven to drive the mold clamping housing 1
8 is moved in the mold clamping direction by a predetermined amount, and in synchronization with this, the mold clamping cylinder 38 is driven in the piston contracting direction, so that the toggle mechanism 1 is maintained while maintaining the mold touch state.
6 is placed in a predetermined bending position as shown. This makes it possible to generate a predetermined mold clamping force when the toggle mechanism 16 is fully expanded from the mold touch state. The position of the mold clamping housing 18 at the completion of the mold clamping is also detected by the position sensor 26 as a housing position change amount. The toggle mechanism 16 can increase the mold clamping force generated at the completion of mold clamping as the bending angle when the mold is touched is larger. In this way, the mold clamping housing 18
Is positioned with respect to the fixed platen 10 via the toggle mechanism 16. Simultaneously with the positioning, the driving of the motor 28 and the mold clamping cylinder 38 is stopped. This completes the adjustment of the mold clamping force. At the time of molding operation, by driving the mold clamping cylinder 38 in the piston extending direction from the mold open state,
After the die is touched at the predetermined position shown in the figure, the toggle mechanism 16 is in a fully extended state, and the die clamping force as set can be applied to the die 14 via the toggle mechanism 16 to perform the injection process.

[0003]

However, in the conventional mold clamping force adjusting device for an injection molding machine as described above, the ambient atmospheric temperature is changed during the automatic molding operation after the mold clamping force is adjusted. When the size of the device in the mold opening / closing direction changes due to the reason, there is a problem that the mold clamping force as set cannot be applied. For example, when the apparent mold thickness dimension becomes smaller than the reference dimension due to the temperature decrease, the actual mold clamping force becomes smaller than the set value, and the molten material injected into the mold 14 becomes There is a possibility that leakage may occur from the mating surface between the molds 14a and 14b to cause burrs and defective molding. Further, when the apparent mold thickness dimension becomes larger than the reference dimension due to the temperature rise, the actual mold clamping force becomes larger than the set value, which may damage the device. Therefore, when the mold touch position and the mold clamping completion position deviate by a predetermined amount or more, it is necessary to interrupt the automatic molding operation and perform the manual mold clamping force adjustment work again. The present invention aims to solve such problems.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above problems by enabling mold thickness correction between automatic molding cycles. That is, in the method of correcting the mold thickness of the toggle type injection molding machine of the present invention, the amount of movement of the mold clamping housing from the mold touch position to the mold clamping completion position when adjusting the mold clamping force is taken as the reference position change amount and the actual position. The deviation from the position change amount at the time of molding is obtained, and the mold clamping housing is moved according to the sign of the deviation and the magnitude of the absolute value before starting the next injection cycle. The correction may be performed only when the absolute value of the deviation is larger than a predetermined amount determined in advance. Further, the apparatus for carrying out the above method includes a motor (28) capable of moving the mold clamping housing (18) in the mold opening and closing direction, and a position sensor (26) capable of detecting the position of the mold clamping housing (18) in the mold opening and closing direction. ), And a mold thickness correction command device (30) is provided, and the mold thickness correction command device (30) adjusts the mold clamping force detected by the position sensor (26). The difference between the movement amount of the mold clamping housing (18) from the die touch position to the mold clamping completion position and the movement amount at the time of actual molding is obtained to determine the mold clamping housing (18) required for mold thickness correction. The moving direction and the moving amount are calculated, and the correction command signal (36) is output to the motor (28) before the next injection cycle is started. The mold thickness correction command device (30) includes a housing position change amount basic table (42) and a housing position change amount storage unit (44).
And three comparison units (46, 52 and 54), a correction data table (48), a measurement die thickness storage unit (50),
The measurement die thickness storage section (50) has a measurement die based on the position signal (26a) from the position sensor (26) of the die touch position at the time of adjusting the die clamping force of the injection molding machine. The thickness is stored, and the measurement type thickness signal (50a) is sent to the second comparing section (52) and the third comparing section (5).
4), and the housing position change amount basic table (42) is provided with the position sensor (26) from the mold touch position to the mold clamping completion position when adjusting the mold clamping force of the injection molding machine. The detected amount of movement of the mold clamping housing (18) is read as a reference position change amount, and this can be output to the first comparing section (46) as a first output signal (42a), thereby changing the housing position. The amount storage section (44) stores therein the moving amount of the mold clamping housing (18) detected by the position sensor (26) from the mold touch position to the mold clamping completion position at each actual molding of the injection molding machine. Is updated and stored as the amount of position change in each case, and is also stored in the second output signal (44
a) can be output to the first comparison unit (46),
The comparison unit (46) can compare the first output signal (42a) and the second output signal (44a) and output the deviation signal (46a) to the correction data table (48). (48) selects the data corresponding to the deviation signal (46a) from the data table section, and uses this as the third output signal (48a) for the second comparing section (52) and the third comparing section (54). And the second comparison section (52) outputs the third output signal (48a).
A first correction command signal (36a) for mold thickness correction can be output to the motor (28) on the basis of the measurement mold thickness signal (50a) and the third comparison unit (54) outputs the third output. A second correction command signal (36b) for mold thickness correction can be output to the motor (28) based on the signal (48a) and the measured mold thickness signal (50a), and the mold thickness correction command device (30).
Is preferably configured to output only the first correction command signal (36a) and the second correction command signal (36b) corresponding to the sign of the deviation signal (46a). In addition,
Reference numerals in parentheses indicate corresponding members of the embodiment.

[0005]

[Function] During the automatic operation of the injection molding machine, the position sensor detects the positional change amount of the mold clamping housing from the mold touch position to the mold clamping completion position (to generate a predetermined mold clamping force). The first comparison unit compares the reference position change amount and the actual position change amount at the time of adjusting the mold clamping force, and the deviation between them is output to the correction data table as a deviation signal. The correction data table selects data corresponding to the sign of the deviation signal and the magnitude of the absolute value from the data table, and outputs this as a third output signal to the second comparison unit and the third comparison unit, respectively. Further, the measurement die thickness is output from the measurement die thickness storage unit to the second comparison unit and the third comparison unit as a measurement die thickness signal. As a result, the correction command signal is output from the second comparison unit or the third comparison unit according to the sign of the correction command signal, and the correction command signal is output in the mold thickness decreasing direction or the mold thickness increasing direction corresponding to the code of the correction command signal. The motor is driven by the amount of rotation corresponding to the size of. That is, if the position of the mold clamping housing changes due to temperature fluctuations during automatic operation of the injection molding machine, position correction of the mold clamping housing, that is, mold thickness correction work is automatically performed between injection cycles. Will be done in a regular manner. The automatic molding operation can be restarted immediately after the completion of the mold thickness correction work.

[0006]

1 and 2 show an embodiment of the present invention. 1 shows a block diagram of mold thickness correction, and FIG. 2 shows a mold thickness correction device of the present invention together with a mold clamping device of an injection molding machine. First, a toggle type injection molding machine to which the present invention is applied will be described. In FIG. 2, the fixed platen 10 is fixed to the fixed portion. The movable platen 1 is provided at a position facing the fixed platen 10.
2 are arranged. The fixed plate 10 has a fixed mold 14a.
Is attached to the movable platen 12, and the movable side mold 14b is attached to the movable platen 12. The right end side of the link of the toggle mechanism 16 in the drawing is connected to the movable platen 12, and the left end side of the link in the drawing is connected to the mold clamping housing 18. The crosshead 16a of the toggle mechanism 16 is
It is connected to the piston rod 38a of the mold clamping cylinder 38. Movable plate 12 and movable side mold 14b integral therewith
Is driven by the mold clamping cylinder 38 via the toggle mechanism 16 so that it can move in a direction approaching the fixed platen 10 and a direction away from the fixed platen 10. Next, the mold thickness correction device of the present invention will be described. The mold clamping housing 18 of the mold clamping device is provided with a pair of racks 20 and 22 at opposed positions. Rack 20 in the upper part of the figure
The pinion 24 is meshed with the rack, and the gear portion of the position sensor 26 is meshed with the rack 22 on the lower side in the drawing. The position sensor 26 is the mold clamping housing 18.
It is possible to output the measurement position signal 26a indicating the position of 1 to the mold thickness correction command device 30 described later. Mold thickness correction command device 30
Can output the correction command signal 36 to the motor 28 as described later. The motor 28 is connected to the shaft of the pinion 24. Correction command signal 3 from the mold thickness correction command device 30
By driving the motor 28 based on 6, the mold clamping housing 18 can be moved in the mold opening / closing direction by the required amount via the pinion 24, that is, the mold thickness can be corrected. The mold thickness correction command device 30 has a configuration as shown in FIG. That is, the mold thickness correction command device 30 includes the housing position change amount basic table 42, the housing position change amount storage unit 44, the first comparison unit 46, the correction data table 48, the measured mold thickness storage unit 50, and the second comparison unit 52. , And the third
It has a comparison unit 54. The mold thickness correction command device 30 includes
A mold clamping completion signal 32 and a 1-cycle completion signal 34 from a control device (not shown) of the injection molding machine can be respectively input. The output from the above-mentioned position sensor 26 is adapted to be taken into the corresponding device section of the mold thickness correction command device 30 at a predetermined timing. That is, the measurement position signal 26a at the mold touch position at the time of adjusting the mold clamping force is stored in the measurement mold thickness storage unit 50 as the measured mold thickness, and similarly, the mold clamping completion position at the time of adjusting the mold clamping force. The measurement position signal 26a in FIG. 2 is input to the housing position basic table 42 as a reference position change amount (movement amount from the mold touch position), and the measurement position signal at the actual mold clamping completion position at the time of molding. 26a is stored in the housing position change amount storage unit 44 as an actual position change amount. The data in the housing position change amount storage unit 44 is updated and stored each time actual molding is performed. The first comparison unit 46 uses the mold clamping completion signal 32 as a trigger,
First output signal 4 from housing position change amount storage unit 44
2a and the second output signal 44a from the housing position change amount storage unit 44, respectively. First comparison unit 46
Compares the two output signals 42a and 44a and outputs the deviation signal 4
6a is output to the correction data table 48. As will be described later, the correction data table 48 is configured to selectively output either one of the two data tables on the plus side and the minus side according to the sign of the deviation signal 46a input thereto. The measurement type thickness storage unit 50 uses the one cycle end signal 34 as a trigger to output the measurement type thickness signal 50a as a second value.
It outputs to each of the comparison unit 52 and the third comparison unit 54. The second comparing unit 52 uses the third data from the correction data table 48.
The output signal 48a and the measurement die thickness signal 50a from the measurement die thickness storage unit 50 are compared, and the first correction command signal (signal for die thickness reduction instruction) 36a can be output to the contact AX1 of the first relay AX. Similarly, the third comparison unit 54 compares the third output signal 48a from the correction data table 48 and the measurement die thickness signal 50a from the measurement die thickness storage unit 50 to generate a second correction command signal (die thickness increase). The command signal) 36b can be output to the contact AX2 of the first relay AX. The contacts AX1 and AX2 of the first relay AX are connected to the second relay BX and the third relay FX, respectively. As shown in FIG. 1B, the second relay BX and the third relay FX are connected to the motor 28, respectively. Mold thickness correction command device 30
Is triggered by the mold clamping completion signal 32, and the correction command signal 36 (one of the first correction command signal 36a and the second correction command signal 36b) described above is used as one of the second relay BX and the third relay FX. It is possible to output to the motor 28 via.

Next, the operation of this embodiment will be described. The position touched by the mold when adjusting the mold clamping force of the injection molding machine is detected by the position sensor 26, and this position signal 26a is input to the measurement mold thickness storage unit 50 and stored as the measurement mold thickness. Further, in the mold clamping force adjustment, the position of the mold clamping housing 18 at the time of completion of mold clamping is detected by the position sensor 26, and this position signal 26a indicates a housing position change amount (movement amount from the mold touch position, that is, The reference position change amount) is stored in the housing position change amount basic table 42. Next, the molding operation is started. During automatic operation, the position of the mold clamping housing 18 at the completion of mold clamping is detected by the position sensor 26 by using the mold clamping completion signal 32 as a trigger, and the position signal 26a at this time is the actual housing position change amount (from the mold touch position). Is moved and stored in the housing position change amount storage unit 44 and is output to the first comparison unit 46 as a second output signal 44a. At the same time, the reference position change amount is output from the housing position change amount basic table 42 as the first output signal 42a to the first comparison unit 46.
Is output to. In the first comparison section 46, the first output signal 42a and the second output signal 44a are compared, and the deviation thereof is output to the correction data table 48 as the deviation signal 46a. The correction data table 48 outputs the corresponding data in the data table as the third output signal 48a to the second comparing section 52 and the third comparing section 54, respectively.
In the second comparison unit 52 and the third comparison unit 54, the output signal 48a from the correction data table 48 and the measurement die thickness signal 50a from the measurement die thickness storage unit 50 are compared, and the correction command signal 36 (second When output from the comparison unit 52, the first correction command signal 36a is output, and when output from the third comparison unit 54, the second correction command signal 36b) is output. The correction command signal 36 can be set so as not to output when the value is too small, and to output when the value becomes larger than a preset value. As a result, it is possible to prevent a minute amount of mold thickness correction. If the output signal 48a has a positive sign, the second comparing section 52 outputs the first correction command signal 36a (correction command signal in the direction of decreasing the mold thickness) (the signal from the third comparing section 54). Will be canceled). Therefore, the first relay AX is excited by the 1-cycle end signal 34 as a trigger, and the second relay BX is excited in response to the trigger, so that the motor 28 corresponds to the magnitude of the first correction command signal 36a in the die thickness reducing direction. It is driven by the rotation amount (rotation angle or rotation number). If the sign of the output signal 48a is negative, the third correction unit 54b outputs the second correction command signal 36b.
(Correction command signal for increasing die thickness) is output (the signal from the second comparing section 52 is canceled). Therefore 1
The first relay AX is excited by the cycle end signal 34 as a trigger, and the third relay FX is excited in response to this, so that the motor 28 rotates in the mold thickness increasing direction in accordance with the magnitude of the second correction command signal 36b. Will be driven only. That is, when the position of the mold clamping housing 18 in the mold opening / closing direction changes by a predetermined amount or more based on temperature fluctuations during automatic operation of the injection molding machine, position correction of the mold clamping housing 18 between injection cycles, That is, the work of correcting the mold thickness is automatically performed, and the automatic molding operation is restarted immediately after the work of correcting the mold thickness is completed. As a result, it is possible to always generate a predetermined mold clamping force.

[0008]

As described above, according to the present invention, when the position of the mold clamping housing is changed by a predetermined amount or more during the automatic operation of the injection molding machine, the correction work of the mold thickness can be performed between the injection cycles. Since it is automatically performed and the automatic operation of the injection molding machine can be restarted following the mold thickness correction operation, the productivity can be improved. In addition, it is possible to avoid problems such as leakage of molten material from the mating surface of the mold, resulting in defective molding, or damage to the device due to the actual mold clamping force becoming larger than the set value. The mold clamping force can be applied.

[Brief description of drawings]

FIG. 1 is a block diagram showing a mold thickness correction command device for an injection molding machine according to the present invention.

FIG. 2 is a view showing the mold thickness correcting device of the present invention together with the mold clamping device of the injection molding machine.

FIG. 3 is a view showing a conventional mold clamping force adjusting device together with a mold clamping device of an injection molding machine.

[Explanation of symbols]

 10 Fixed plate 12 Movable plate 14 Mold 16 Toggle mechanism 18 Mold clamping housing 20, 22 Rack 24 Pinion 26 Position sensor 28 Motor 30 Mold thickness correction command device 36 Correction command signal 36a First correction command signal 36b Second correction command signal 38 Mold clamping cylinder 42 Housing position change amount basic table 44 Housing position change amount storage unit 46 First comparison unit 48 Correction data table 50 Measurement die thickness storage unit 52 Second comparison unit 54 Third comparison unit

Claims (4)

[Claims] 1. A deviation between the moving amount of a mold clamping housing from a mold touch position to a mold clamping completion position when adjusting a mold clamping force is used as a reference position change amount and a position change amount in actual molding. , Before starting the next injection cycle,
A method for correcting a mold thickness of a toggle type injection molding machine, which comprises moving a mold clamping housing according to a sign of a deviation and a magnitude of an absolute value. 2. The correction is performed only when the absolute value of the deviation is larger than a predetermined amount determined in advance.
A method for correcting a mold thickness of the toggle-type injection molding machine described. 3. A motor (28) capable of moving the mold clamping housing (18) in the mold opening and closing direction, and a mold clamping housing (18).
Position sensor (26) that can detect the position of the mold opening and closing direction
A mold thickness correction command device (30) is provided in a toggle-type injection molding machine having: and a mold thickness correction command device (30).
The difference between the amount of movement of the mold clamping housing (18) from the mold touch position during mold clamping force adjustment to the mold clamping completion position, which was detected by Injection molding configured to calculate the necessary moving direction and moving amount of the mold clamping housing (18) and output a correction command signal (36) to the motor (28) before starting the next injection cycle. Machine thickness correction device. 4. The mold thickness correction command device (30) includes a housing position change amount basic table (42), a housing position change amount storage unit (44), and three comparison units (46, 52 and 54). It has a correction data table (48) and a measurement die thickness storage section (50), and the measurement die thickness storage section (50) has a die touch for adjusting the die clamping force of the injection molding machine. Position sensor (2
The measurement die thickness based on the position signal (26a) from 6) is stored, and this measurement die thickness signal (50a) can be output to the second comparing section (52) and the third comparing section (54), respectively. The housing position change amount basic table (42) is provided with a mold clamping housing (26) detected by the position sensor (26) from the mold touch position to the mold clamping completion position when adjusting the mold clamping force of the injection molding machine. The movement amount of 18) is read as the reference position change amount and can be output to the first comparison unit (46) as the first output signal (42a), and the housing position change amount storage unit (44) In addition, the movement amount of the mold clamping housing (18) detected by the position sensor (26) from the mold touch position to the mold clamping completion position at each actual molding of the injection molding machine is the value. The displacement amount is updated and stored, and can be output to the first comparing unit (46) as the second output signal (44a). The first comparing unit (46) outputs the first output signal (42a). And the second
The deviation signal (46a) can be output to the correction data table (48) by comparing with the output signal (44a). The correction data table (48) converts the deviation signal (46a) into the deviation signal (46a). The corresponding data is selected and the second data is used as the third output signal (48a).
It is possible to output to the comparison unit (52) and the third comparison unit (54) respectively, and the second comparison unit (52) outputs the mold thickness based on the third output signal (48a) and the measured mold thickness signal (50a). First for correction
The correction command signal (36a) can be output to the motor (28), and the third comparison unit (54) performs mold thickness correction based on the third output signal (48a) and the measured mold thickness signal (50a). Second for
The correction command signal (36b) can be output to the motor (28), and the mold thickness correction command device (30) outputs the first correction command signal (36).
The toggle type injection molding machine according to claim 3, wherein only the signal corresponding to the sign of the deviation signal (46a) is output from among the a) and the second correction command signal (36b). Mold thickness compensator.