JP6746686B2 - Injection molding machine - Google Patents

Description

The present invention relates to an injection molding machine.

The injection molding machine described in Patent Document 1 drives a mold thickness adjusting motor to move a toggle support together with a movable platen in a mold closing direction, and monitors a detection value from a mold clamping force sensor. When the detected value reaches the threshold value, it is determined that the mold touch has been performed, the driving of the mold thickness adjusting motor is stopped, and the advance of the toggle support is stopped.

Japanese Patent Laid-Open No. 2006-334944

However, the mold thickness adjusting motor does not stop suddenly due to inertia. Therefore, the toggle support was displaced from the target position, and the accuracy of die thickness adjustment was poor.

The present invention has been made in view of the above problems, and a main object of the present invention is to provide an injection molding machine with improved accuracy of mold thickness adjustment.

In order to solve the above problems, according to one embodiment of the present invention,
A mold mounting plate on which one of a fixed mold and a movable mold is mounted, a connecting plate that is connected to the mold mounting plate with a gap in the mold opening/closing direction, and a mold thickness can be adjusted by adjusting the gap. A mold thickness adjusting mechanism for performing, and a control device for controlling the mold thickness adjusting mechanism,
The mold thickness adjusting mechanism includes a screw shaft formed on a rod connecting the mold mounting plate and the connecting plate, a screw nut held by one of the mold mounting plate and the connecting plate, and a screw nut that is screwed together. A mold thickness adjusting motor for rotating one of the screw shaft and the screw nut to be combined,
The control device detects a die touch that the movable die and the fixed die touch while driving the die thickness adjusting motor, and detects the die touch to stop driving the die thickness adjusting motor. An injection molding machine is provided that detects gap deviations.

According to one aspect of the present invention, there is provided an injection molding machine with improved precision of mold thickness adjustment.

It is a figure which shows the state at the time of completion of mold opening of the injection molding machine by one Embodiment. It is a figure which shows the state at the time of mold clamping of the injection molding machine by one Embodiment. 5 is a flowchart of a mold thickness adjustment process of the control device according to one embodiment. FIG. 6 is a diagram showing a time change of a rotation speed of a mold thickness adjusting motor and a time change of an interval L when the mold thickness is adjusted by advancing the toggle support from the mold open state according to the embodiment. FIG. 6 is a diagram showing a time change of a rotation speed of a mold thickness adjustment motor and a time change of an interval L when the toggle support is retracted from the mold clamping state according to one embodiment to perform the mold thickness adjustment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In each of the drawings, the same or corresponding components will be denoted by the same or corresponding reference numerals and description thereof will be omitted.

FIG. 1 is a diagram showing a state at the time of completion of mold opening of an injection molding machine according to an embodiment. FIG. 2 is a diagram showing a state when the injection molding machine according to the embodiment is clamped. As shown in FIGS. 1 and 2, the injection molding machine includes a frame Fr, a mold clamping device 10, an injection device 40, an ejector device 50, and a control device 90. In the following description, the moving direction of the movable platen 13 when the mold is closed (rightward in FIGS. 1 and 2) is the front, and the moving direction of the movable platen 13 when the mold is opened (left in FIGS. 1 and 2) is the direction. This will be described as the rear.

The mold clamping device 10 performs mold closing, mold clamping, and mold opening of the mold device 30. The mold clamping device 10 is a horizontal mold in which the mold opening/closing direction is horizontal. The mold clamping device 10 includes a fixed platen 12, a movable platen 13, a toggle support 15, a tie bar 16, a toggle mechanism 20, a mold clamping motor 25, and a motion conversion mechanism 26.

The fixed platen 12 is fixed to the frame Fr. A fixed mold 32 is attached to a surface of the fixed platen 12 facing the movable platen 13.

The movable platen 13 is movable along a guide (for example, a guide rail) 17 laid on the frame Fr, and is movable back and forth with respect to the fixed platen 12. The movable mold 33 is attached to the surface of the movable platen 13 facing the fixed platen 12.

By moving the movable platen 13 back and forth with respect to the fixed platen 12, mold closing, mold clamping, and mold opening are performed. The fixed mold 32 and the movable mold 33 constitute a mold device 30.

The toggle support 15 is connected to the fixed platen 12 with a space L and is movably mounted on the frame Fr in the mold opening/closing direction. The toggle support 15 may be movable along a guide laid on the frame Fr. The guide of the toggle support 15 may be the same as the guide 17 of the movable platen 13.

In the present embodiment, the fixed platen 12 is fixed to the frame Fr, and the toggle support 15 is movable in the mold opening/closing direction with respect to the frame Fr. However, the toggle support 15 is fixed to the frame Fr and the fixed platen is fixed. 12 may be movable in the mold opening/closing direction with respect to the frame Fr.

The tie bar 16 connects the fixed platen 12 and the toggle support 15 with a space L therebetween. A plurality of tie bars 16 (for example, four) may be used. Each tie bar 16 is parallel to the mold opening/closing direction and extends according to the mold clamping force. At least one tie bar 16 is provided with a mold clamping force detector 18. The mold clamping force detector 18 detects the mold clamping force by detecting the distortion of the tie bar 16, and sends a signal indicating the detection result to the control device 90.

The mold clamping force detector 18 is not limited to the strain gauge type, and may be a piezoelectric type, a capacitive type, a hydraulic type, an electromagnetic type, or the like, and its mounting position is not limited to the tie bar 16.

The toggle mechanism 20 moves the movable platen 13 with respect to the fixed platen 12. The toggle mechanism 20 is arranged between the movable platen 13 and the toggle support 15. The toggle mechanism 20 includes a crosshead 21, a pair of link groups, and the like. Each link group has a first link 22 and a second link 23 that are flexibly connected by a pin or the like. The first link 22 is swingably attached to the movable platen 13 with a pin or the like, and the second link 23 is swingably attached to the toggle support 15 with a pin or the like. The second link 23 is coupled to the crosshead 21 via the third link 24. When the crosshead 21 is moved back and forth, the first link 22 and the second link 23 are bent and stretched, and the movable platen 13 is moved back and forth with respect to the toggle support 15.

The configuration of the toggle mechanism 20 is not limited to the configurations shown in FIGS. 1 and 2. For example, although the number of nodes is five in FIGS. 1 and 2, it may be four, and one end of the third link 24 may be coupled to the nodes of the first link 22 and the second link 23. ..

The mold clamping motor 25 is attached to the toggle support 15 and operates the toggle mechanism 20. The mold clamping motor 25 moves the crosshead 21 forward and backward, thereby bending and stretching the first link 22 and the second link 23, and moving the movable platen 13 forward and backward.

The motion conversion mechanism 26 converts the rotational motion of the mold clamping motor 25 into the linear motion of the crosshead 21. The motion conversion mechanism 26 includes a screw shaft and a screw nut screwed onto the screw shaft. A ball or roller may be interposed between the screw shaft and the screw nut.

The operation of the mold clamping device 10 is controlled by the control device 90. The control device 90 has a CPU (Central Processing Unit) 91, a storage medium 92 such as a memory, an input interface 93, and an output interface 94, as shown in FIGS. 1 and 2. The control device 90 executes various programs by causing the CPU 91 to execute the programs stored in the storage medium 92. Further, in the control device 90, the input interface 93 receives a signal from the outside, and the output interface 94 transmits the signal to the outside. The controller 90 controls a mold closing process, a mold clamping process, a mold opening process, and the like.

In the mold closing process, the mold clamping motor 25 is driven to move the crosshead 21 forward to the mold closing completed position at a set speed, thereby moving the movable platen 13 forward and touching the movable mold 33 to the fixed mold 32. The position and speed of the crosshead 21 are detected using, for example, the encoder 25a of the mold clamping motor 25. The encoder 25a detects the rotation of the mold clamping motor 25 and sends a signal indicating the detection result to the control device 90.

In the mold clamping process, the mold clamping motor 25 is further driven to further advance the crosshead 21 from the mold closing completed position to the mold clamping position, thereby generating a mold clamping force. A cavity space 34 is formed between the movable die 33 and the fixed die 32 during mold clamping, and the injection device 40 fills the cavity space 34 with a liquid molding material. A molded product is obtained by solidifying the filled molding material. There may be a plurality of cavity spaces 34, in which case a plurality of molded products can be obtained at the same time.

In the mold opening process, the mold clamping motor 25 is driven to retract the crosshead 21 to the mold opening completion position at a set speed, thereby retracting the movable platen 13 and separating the movable mold 33 from the fixed mold 32. Then, the ejector device 50 projects the molded product from the movable mold 33.

By the way, the toggle mechanism 20 amplifies the driving force of the mold clamping motor 25 and transmits it to the movable platen 13. The amplification factor is also called the toggle factor. The toggle magnification changes according to the angle θ formed by the first link 22 and the second link 23 (hereinafter, also referred to as “link angle θ”). The link angle θ is obtained from the position of the crosshead 21. When the link angle θ is 180°, the toggle magnification becomes maximum.

When the thickness of the mold device 30 changes due to the replacement of the mold device 30 or the temperature change of the mold device 30, the mold thickness is adjusted so that a predetermined mold clamping force can be obtained during mold clamping. In the mold thickness adjustment, for example, the distance L between the fixed platen 12 and the toggle support 15 is adjusted so that the link angle θ of the toggle mechanism 20 becomes a predetermined angle at the time of a mold touch in which the movable mold 33 touches the fixed mold 32. Adjust.

The mold clamping device 10 has a mold thickness adjusting mechanism 60 that adjusts the mold thickness by adjusting the distance L between the fixed platen 12 and the toggle support 15. The mold thickness adjusting mechanism 60 rotates a screw shaft 61 formed at the rear end of the tie bar 16, a screw nut 62 rotatably held by the toggle support 15, and a screw nut 62 screwed to the screw shaft 61. And a mold thickness adjusting motor 63.

The screw shaft 61 and the screw nut 62 are provided for each tie bar 16. The rotation of the mold thickness adjusting motor 63 may be transmitted to the plurality of screw nuts 62 via the rotation transmitting portion 64 including a belt, a pulley, and the like. The plurality of screw nuts 62 can be rotated in synchronization. It is also possible to individually rotate the plurality of screw nuts 62 by changing the transmission path of the rotation transmission unit 64.

The rotation transmission unit 64 may be configured by gears or the like instead of the belt or the pulley. In this case, a passive gear is formed on the outer periphery of each screw nut 62, a drive gear is attached to the output shaft of the mold thickness adjusting motor 63, and a plurality of passive gears and an intermediate gear meshing with the drive gear are provided at the center of the toggle support 15. It is rotatably held in.

The operation of the mold thickness adjusting mechanism 60 is controlled by the controller 90. The controller 90 drives the mold thickness adjusting motor 63 to rotate the screw nut 62, thereby adjusting the position of the toggle support 15 that holds the screw nut 62 rotatably with respect to the fixed platen 12, and the fixed platen 12 and The distance L from the toggle support 15 is adjusted.

In the present embodiment, the screw nut 62 is rotatably held by the toggle support 15 and the tie bar 16 on which the screw shaft 61 is formed is fixed to the fixed platen 12, but the present invention is not limited to this.

For example, the screw nut 62 may be rotatably held with respect to the fixed platen 12, and the tie bar 16 may be fixed with respect to the toggle support 15. In this case, the interval L can be adjusted by rotating the screw nut 62.

Further, the screw nut 62 may be fixed to the toggle support 15, and the tie bar 16 may be rotatably held on the fixed platen 12. In this case, the interval L can be adjusted by rotating the tie bar 16.

Furthermore, the screw nut 62 may be fixed to the fixed platen 12, and the tie bar 16 may be rotatably held to the toggle support 15. In this case, the interval L can be adjusted by rotating the tie bar 16.

The mold thickness adjusting mechanism 60 adjusts the interval L by rotating one of the screw shaft 61 and the screw nut 62 that are screwed together. A plurality of mold thickness adjusting mechanisms 60 may be used, and a plurality of mold thickness adjusting motors 63 may be used.

Here, the fixed platen 12 corresponds to the mold mounting plate described in the claims, the toggle support 15 corresponds to the connecting plate described in the claims, and the tie bar 16 corresponds to the rod described in the claims. Corresponding to.

FIG. 3 shows a flowchart of a mold thickness adjustment process of the control device according to the embodiment. The mold thickness adjusting process by the control device 90 is started when the thickness of the mold device 30 changes due to the replacement of the mold device 30 or the temperature change of the mold device 30.

The control device 90 drives the mold thickness adjusting motor 63 in a state where the link angle θ of the toggle mechanism 20 is set to a predetermined angle and the mold clamping motor 25 is stopped, and the movable mold 33 moves the fixed mold 32 during the driving. A die touch touching is detected (step S11). The distance L between the fixed platen 12 and the toggle support 15 at the time when the die touch is detected is the target distance L0 (see FIGS. 4 and 5).

For detecting the die touch, for example, the movable die 33 is moved from the fixed die 32 to drive the die thickness adjusting motor 63 to move the toggle support 15 forward, and the movable platen 13 connected to the toggle support 15 is moved forward. It is done while letting. That is, the die touch is detected by closing the die of the die apparatus 30.

When the movable mold 33 touches the fixed mold 32, the mold clamping force starts to increase. Therefore, the control device 90 monitors the mold clamping force during driving of the mold thickness adjusting motor 63, and detects the mold touch based on the mold clamping force. The control device 90 may determine that the mold touch is performed, for example, when the detection value of the mold clamping force detector 18 reaches the threshold value. For the determination, time differentiation of the detection value of the mold clamping force detector 18 or the like may be used.

When the movable mold 33 touches the fixed mold 32, the torque of the mold thickness adjusting motor 63 starts to increase. Therefore, the controller 90 may monitor the torque of the mold thickness adjusting motor 63 during driving of the mold thickness adjusting motor 63 and detect the mold touch based on the torque. The control device 90 may determine that the mold touch has been performed when the detection value of the torque detector 65 reaches the threshold value. The time differentiation of the detection value of the torque detector 65 or the like may be used for the determination. As the torque detector 65, for example, a current detector that detects the current of the mold thickness adjusting motor 63 is used.

The control device 90 detects a mold touch by closing the mold device 30 by the mold thickness adjusting motor 63, but detects a mold touch by depressurizing the mold device 30 by the mold thickness adjusting motor 63. You may. Depressurization of the mold device 30 is performed from the mold clamping state. When the detection value of the mold clamping force detector 18 reaches the threshold value, it may be determined that the state of the mold device 30 has returned to the state of mold touch. Alternatively, when the detection value of the torque detector 65 reaches the threshold value, it may be determined that the mold apparatus 30 has returned to the mold touch state.

Only one of the mold clamping force detector 18 and the torque detector 65 may be used to detect the mold touch, or both may be used.

When detecting the die touch, the controller 90 stops driving the die thickness adjusting motor 63 (step S12). Since the mold thickness adjusting motor 63 cannot be stopped suddenly due to inertia, the distance L between the fixed platen 12 and the toggle support 15 deviates from the target distance L0. For example, when the driving of the mold thickness adjusting motor 63 is stopped while the toggle support 15 is moving forward, the distance L between the fixed platen 12 and the toggle support 15 becomes smaller than the target distance L0. Further, when the driving of the mold thickness adjusting motor 63 is stopped while the toggle support 15 is retracted, the distance L between the fixed platen 12 and the toggle support 15 becomes wider than the target distance L0.

Therefore, the control device 90 detects the deviation of the interval L from the detection of the die touch to the driving stop of the die thickness adjusting motor 63 (step S13). The deviation of the interval L is detected using, for example, the encoder 63a of the mold thickness adjusting motor 63. The encoder 63a detects the rotation angle, the number of rotations, the rotation direction, etc. of the mold thickness adjustment motor 63, and sends a signal indicating the detection result to the control device 90.

The controller 90 corrects the interval L based on the detected deviation of the interval L (step S14). For example, the control device 90 rotates the mold thickness adjusting motor 63 in the direction opposite to that at the time of detecting the mold touch, thereby returning the interval L to the target interval L0. Therefore, the accuracy of mold thickness adjustment can be improved, and a predetermined mold clamping force can be obtained during mold clamping. Further, the depressurizing position for moving the crosshead 21 in an emergency can be appropriately set. In an emergency, the pressure acting on the mold apparatus 30 can be sufficiently reduced, and the mold opening of the mold apparatus 30 can be suppressed. This is particularly effective when the mold device 30 includes a movable core.

The correction of the interval L may be performed only when the amount of deviation of the interval L from the target interval L0 (magnitude of deviation) is equal to or larger than a predetermined amount. The amount of deviation can be represented by the rotation angle of the mold thickness adjusting motor 63.

The controller 90 of the present embodiment returns the distance L between the fixed platen 12 and the toggle support 15 to the target distance L0 by the reverse rotation of the mold thickness adjusting motor 63, but before the distance L returns to the target distance L0. The reverse rotation may be stopped at, or the reverse rotation may be stopped after the interval L exceeds the target interval L0. It is sufficient that the amount of deviation of the distance L from the target distance L0 becomes smaller than that before the reverse rotation.

As will be described later in detail, when the mold thickness adjusting motor 63 is rotated in the direction opposite to the direction when the mold touch is detected, and further, when the mold thickness adjusting motor 63 is rotated in the same direction as when the mold touch is detected, the above interval is set. The reverse rotation may be stopped after a while after L has passed the target interval L0. This is because it is possible to perform an operation thereafter to bring the distance L closer to the target distance L0.

The controller 90 may determine whether or not the interval L changes during mold clamping due to the backlash of the mold thickness adjusting mechanism 60 based on the immediately preceding rotating direction of the mold thickness adjusting motor 63 (step S15). The backlash of the mold thickness adjusting mechanism 60 is, for example, the play between the screw shaft 61 and the screw nut 62, the play between the gears forming the rotation transmitting portion 64, and the like. At the time of mold clamping, the reaction force of the mold clamping force acts on the screw nut 62. The reaction force acts in the direction of separating the movable mold 33 and the fixed mold 32 from each other.

When the rotation direction of the mold thickness adjusting motor 63 immediately before is a direction in which the movable mold 33 and the fixed mold 32 are separated from each other, it is determined that the interval L does not change during mold clamping due to backlash of the mold thickness adjusting mechanism 60. .. On the other hand, when the mold thickness adjusting motor 63 immediately before is rotated in the direction in which the movable mold 33 and the fixed mold 32 are brought close to each other, it is determined that the interval L changes during mold clamping due to the backlash of the mold thickness adjusting mechanism 60.

When the controller 90 determines that the interval L changes during mold clamping due to the backlash of the mold thickness adjusting mechanism 60 based on the immediately preceding rotating direction of the mold thickness adjusting motor 63, the mold thickness is adjusted in the direction opposite to the immediately preceding rotating direction. The motor 63 is rotated (step S16). The rotation amount may be an amount corresponding to backlash. It is possible to prevent impact due to backlash of the mold thickness adjusting mechanism 60 during mold clamping.

For example, the control device 90 determines, based on the rotation direction of the mold thickness adjusting motor 63 when correcting the interval L, whether the interval L changes during mold clamping due to backlash of the mold thickness adjusting mechanism 60. When the controller 90 determines that the interval L changes during mold clamping, then the controller 90 may rotate the mold thickness adjusting motor 63 in the same direction as when the mold touch is detected. The rotation amount may be an amount corresponding to backlash.

In FIG. 3, the interval L described in step S14 is corrected before the determination in step S15, but the present invention is not limited to this. For example, when the mold thickness adjusting motor 63 can be suddenly stopped in step S12, the control device 90 may skip steps S13 and S14 and proceed to step S15. In this case, in step S15, the control device 90 determines whether or not the interval L changes during mold clamping due to the backlash of the mold thickness adjusting mechanism 60 based on the rotation direction of the mold thickness adjusting motor 63 when the mold touch is detected. To judge.

FIG. 4 is a diagram showing a time change of the rotation speed of the mold thickness adjusting motor and a time change of the interval L when the mold thickness is adjusted by advancing the toggle support from the mold open state according to the embodiment. In FIG. 4, the positive rotation speed of the mold thickness adjusting motor means that the rotation direction is the direction in which the toggle support is advanced. Further, the negative rotation speed of the mold thickness adjusting motor means that the rotation direction is the direction in which the toggle support is retracted.

When the toggle support is moved forward from the mold open state to adjust the mold thickness, the controller 90 sets the link angle θ of the toggle mechanism 20 to a predetermined angle and stops the mold clamping motor 25 to operate the mold thickness adjusting motor 63. To drive. By moving the toggle support 15 forward from the mold open state by the mold thickness adjusting motor 63, the movable platen 13 can be moved forward, and the mold can be closed.

The controller 90 detects a die touch in which the movable die 33 touches the fixed die 32 at time t1 (step S11 in FIG. 3 ). As described above, the mold clamping force detector 18, the torque detector 65 of the mold thickness adjusting motor 63, and the like are used to detect the mold touch.

The controller 90 stores the distance L between the fixed platen 12 and the toggle support 15 at the time when the die touch is detected as the target distance L0. That is, the control device 90 stores the position of the toggle support 15 at the time when the die touch is detected as the target position.

As the toggle support position detector that detects the position of the toggle support 15, for example, an encoder 63a of the mold thickness adjusting motor 63, a linear encoder, a laser displacement meter, or the like is used.

When the controller 90 detects a mold touch at time t1, the controller 90 stops driving the mold thickness adjusting motor 63 (step S12 in FIG. 3). Since the mold thickness adjusting motor 63 does not stop suddenly due to inertia, the interval L between the toggle support 15 and the fixed platen 12 is increased by the time t2 when the mold thickness adjusting motor 63 stops and the toggle support 15 stops. Becomes smaller than the target interval L0.

Conventionally, the mold thickness adjusting process is ended in a state where the interval L is smaller than the target interval L0, so the accuracy of the mold thickness adjustment is poor, and the accuracy of the mold clamping force obtained during mold clamping is poor. Further, the accuracy of the depressurizing position for moving the crosshead 21 in an emergency is poor, and it is difficult to sufficiently reduce the pressure acting on the mold device 30 and to suppress the mold opening of the mold device 30.

On the other hand, the control device 90 of the present embodiment detects the deviation of the interval L from the detection of the die touch (time t1) to the stop of the toggle support 15 (time t2) (step S13 in FIG. 3). The gap of the interval L is proportional to the time integration value A1 of the rotation speed of the mold thickness adjusting motor 63 from time t1 to time t2. Therefore, the deviation of the interval L may be represented by the time integration value A1.

The control device 90 corrects the distance L based on the detected deviation of the distance L (step S14 in FIG. 3). For example, the control device 90 rotates the mold thickness adjusting motor 63 in a direction opposite to that at the time of detecting the mold touch from the time t3 to the time t4 to move the toggle support 15 backward. Thereby, the position of the toggle support 15 can be corrected and the interval L can be corrected.

The time integral value A2 of the rotation speed of the mold thickness adjusting motor 63 from the time t3 to the time t4 is opposite to the time integral value A1 of the rotation speed of the mold thickness adjusting motor 63 from the time t1 to the time t2. And the size may be the same. As a result, the toggle support 15 can be retracted to increase the interval L, and the interval L can be returned to the target interval L0.

By returning the interval L to the target interval L0, the accuracy of mold thickness adjustment can be improved, and a predetermined mold clamping force can be obtained during mold clamping by the mold clamping motor 25. Further, the depressurizing position for moving the crosshead 21 in an emergency can be appropriately set. In an emergency, the pressure acting on the mold apparatus 30 can be sufficiently reduced, and the mold opening of the mold apparatus 30 can be suppressed. This is particularly effective when the mold device 30 includes a movable core.

The correction of the distance L (that is, the position correction of the toggle support 15) may be performed only when the amount of deviation of the distance L from the target distance L0 is a predetermined amount or more. Further, it is sufficient that the amount of deviation of the interval L from the target interval L0 becomes smaller after the interval L is corrected than before the interval L is corrected, and the interval L does not have to be accurately returned to the target interval L0.

When the toggle support 15 is retracted by the mold thickness adjusting motor 63 to correct the distance L, a force in the same direction as when the mold clamping motor 25 clamps the mold acts on the screw nut 62. Therefore, the control device 90 ends the mold thickness adjustment process. After the mold thickness adjustment process, the gap L does not change during mold clamping by the mold clamping motor 25 due to backlash between the screw nut 62 and the screw shaft 61. Therefore, the reverse rotation of the mold thickness adjusting motor 63 again is unnecessary.

The magnitude of the deviation between the interval L and the target interval L0 at the end of the mold thickness adjustment process (time t4) is zero in FIG. 4, but when the toggle support 15 is stopped immediately after the mold touch is detected (time t2). It is sufficient that the distance L is smaller than the target distance L0. Compared with the case where the mold thickness adjustment process is finished at time t2, the accuracy of mold thickness adjustment can be improved, and a predetermined mold clamping force can be obtained during mold clamping by the mold clamping motor 25. Further, the depressurizing position for moving the crosshead 21 in an emergency can be appropriately set. In an emergency, the pressure acting on the mold apparatus 30 can be sufficiently reduced, and the mold opening of the mold apparatus 30 can be suppressed. This is particularly effective when the mold device 30 includes a movable core.

FIG. 5 is a diagram showing a time change of the rotation speed of the mold thickness adjusting motor and a time change of the interval L when the mold support is retracted from the mold clamping state according to the embodiment to adjust the mold thickness. In FIG. 5, the positive rotation speed of the mold thickness adjusting motor means that the rotation direction is the direction in which the toggle support is advanced. Further, the negative rotation speed of the mold thickness adjusting motor means that the rotation direction is the direction in which the toggle support is retracted.

When the toggle support is retracted from the mold clamping state to adjust the mold thickness, the control device 90 sets the link angle θ of the toggle mechanism 20 to a predetermined angle and stops the mold clamping motor 25 to operate the mold thickness adjusting motor 63. To drive. By moving the toggle support 15 backward from the mold clamping state by the mold thickness adjusting motor 63, the movable platen 13 can be moved backward, and the mold device 30 can be depressurized.

At time t1, the control device 90 detects completion of depressurization in which the movable mold 33 separates from the fixed mold 32 from the mold clamping state as a mold touch in which the movable mold 33 touches the fixed mold 32 from the mold open state. (Step S11 in FIG. 3). As described above, the mold clamping force detector 18, the torque detector 65 of the mold thickness adjusting motor 63, and the like are used to detect the completion of depressurization of the mold device 30.

The controller 90 stores the distance L between the fixed platen 12 and the toggle support 15 at the time of detecting the completion of depressurization as the target distance L0. That is, the control device 90 stores the position of the toggle support 15 at the time of detecting the completion of depressurization as the target position.

As the toggle support position detector that detects the position of the toggle support 15, for example, an encoder 63a of the mold thickness adjusting motor 63, a linear encoder, a laser displacement meter, or the like is used.

When the controller 90 detects completion of depressurization at time t1, it stops driving the mold thickness adjusting motor 63 (step S12 in FIG. 3). Since the mold thickness adjusting motor 63 does not stop suddenly due to inertia, the interval L between the toggle support 15 and the fixed platen 12 is increased by the time t2 when the mold thickness adjusting motor 63 stops and the toggle support 15 stops. Becomes larger than the target interval L0.

Conventionally, the mold thickness adjusting process is ended in a state where the interval L is larger than the target interval L0, so the accuracy of the mold thickness adjustment is poor, and the accuracy of the mold clamping force obtained during mold clamping is poor. In addition, the accuracy of the depressurizing position for moving the crosshead 21 in an emergency was poor.

On the other hand, the control device 90 of the present embodiment detects the deviation of the interval L from the detection of the die touch (time t1) to the stop of the toggle support 15 (time t2) (step S13 in FIG. 3). The gap of the interval L is proportional to the time integration value A1 of the rotation speed of the mold thickness adjusting motor 63 from time t1 to time t2. Therefore, the deviation of the interval L may be represented by the time integration value A1.

The control device 90 corrects the distance L based on the detected deviation of the distance L (step S14 in FIG. 3). For example, the control device 90 rotates the mold thickness adjusting motor 63 in a direction opposite to that at the time of detecting a mold touch from time t3 to time t4 to move the toggle support 15 forward. Thereby, the position of the toggle support 15 can be corrected and the interval L can be corrected.

The time integral value A2 of the rotation speed of the mold thickness adjusting motor 63 from the time t3 to the time t4 is opposite to the time integral value A1 of the rotation speed of the mold thickness adjusting motor 63 from the time t1 to the time t2. And the size may be the same. As a result, the toggle support 15 can be moved forward to reduce the distance L, and the distance L can be returned to the target distance L0.

By returning the interval L to the target interval L0, the accuracy of mold thickness adjustment can be improved, and a predetermined mold clamping force can be obtained during mold clamping by the mold clamping motor 25. Further, the depressurizing position for moving the crosshead 21 in an emergency can be appropriately set. This is particularly effective when the mold device 30 includes a movable core.

The correction of the distance L (that is, the position correction of the toggle support 15) may be performed only when the amount of deviation of the distance L from the target distance L0 is a predetermined amount or more. Further, it is sufficient that the amount of deviation of the interval L from the target interval L0 becomes smaller after the interval L is corrected than before the interval L is corrected, and the interval L does not have to be accurately returned to the target interval L0.

When the toggle support 15 is moved forward by the mold thickness adjusting motor 63 in order to correct the distance L, a force in the direction opposite to that at the time of mold clamping by the mold clamping motor 25 acts on the screw nut 62. Therefore, if the mold thickness adjusting process is terminated as it is, the interval L changes during mold clamping by the mold clamping motor 25 due to backlash between the screw nut 62 and the screw shaft 61 after the mold thickness adjusting process.

Therefore, the control device 90 rotates the mold thickness adjusting motor 63 in a direction opposite to the immediately preceding rotation direction from time t5 to time t6 (step S16 in FIG. 3). The rotation amount may be equivalent to backlash, and the position of the toggle support 15 may remain stopped from time t5 to time t6 as shown in FIG. It is possible to prevent impact due to backlash of the mold thickness adjusting mechanism 60 during mold clamping.

As the rotation amount corresponding to the backlash, a rotation amount previously stored in the storage medium 92 is read and used. When the rotation amount corresponding to the backlash is performed, the torque of the mold thickness adjusting motor 63 increases. Therefore, the torque of the mold thickness adjusting motor 63 may be monitored by the torque detector 65 to rotate the amount of rotation corresponding to the backlash.

Although the position of the toggle support 15 is not displaced in FIG. 5 while rotating the mold thickness adjusting motor 63 in the direction opposite to the immediately preceding rotation direction from the time t5 to the time t6, the position of the toggle support 15 may be displaced. .. At the end of the mold thickness adjustment process (time t6), the amount of deviation between the interval L and the target interval L0 is determined by the interval L and the target interval L0 when the toggle support 15 is stopped (time t2) immediately after the die touch is detected. It should be smaller than the size of the deviation from. Compared with the case where the mold thickness adjustment process is finished at time t2, the accuracy of mold thickness adjustment can be improved, and a predetermined mold clamping force can be obtained during mold clamping by the mold clamping motor 25. Further, the depressurizing position for moving the crosshead 21 in an emergency can be appropriately set. This is particularly effective when the mold device 30 includes a movable core.

Further, in FIG. 5, from time t3 to time t4, the toggle support 15 is advanced to reduce the interval L, and at time t4 when the advance of the toggle support 15 is stopped, the interval L is returned to the target interval L0. L may be smaller than the target interval L0. After that, the interval support L may be increased from the time t5 to the time t6 to increase the interval L to return the interval L to the target interval L0 at the time t6.

According to one aspect of the above disclosure, there are provided the following molding condition setting methods (1) to (5) and the following injection molding machines (6) to (10).

(1) When the toggle support is moved in a predetermined direction and the die touch of the fixed mold and the movable mold is detected, the movement of the toggle support is stopped and the toggle support is moved in the opposite direction to the predetermined direction. , Molding condition setting method.
Due to inertia, the toggle support detects the mold touch and does not stop immediately. Therefore, by moving the toggle support in the opposite direction, the toggle support can be brought closer to the position at the time of die touch detection, and the accuracy of the die clamping force can be improved.

(2) A molding condition setting method of moving a toggle support to a predetermined position, wherein the toggle support is moved to the predetermined position by moving the toggle support in a direction in which a fixed mold and a movable mold are separated from each other, A molding condition setting method for completing a process of moving the toggle support to the predetermined position.
At the time of mold clamping, a force acts on the toggle support in a direction in which the fixed mold and the movable mold are separated from each other. Therefore, if the toggle support is moved to a predetermined position by moving the toggle support in a direction in which the fixed mold and the movable mold are separated from each other, and the moving process of the toggle support to the predetermined position is completed, the toggle support causes toggle due to backlash. The displacement of the support can be suppressed.

(3) A molding condition setting method for rotating a die thickness adjusting motor to move a toggle support to a predetermined position, wherein the toggle support is moved in a direction in which a fixed die and a movable die approach each other. After moving the mold to the predetermined position, the mold thickness adjusting motor is rotated in a direction in which the fixed mold and the movable mold are separated from each other.
At the time of mold clamping, a force acts on the toggle support in a direction in which the fixed mold and the movable mold are separated from each other. Therefore, when moving the toggle support to a predetermined position by moving the toggle support in the direction in which the fixed mold and the movable mold approach each other, then move the mold thickness adjustment motor in the direction in which the fixed mold and the movable mold are separated from each other. When it is rotated, displacement of the toggle support due to backlash can be suppressed during mold clamping.

(4) The molding condition setting method according to (1), wherein the toggle support is moved in a direction opposite to the predetermined direction by an amount corresponding to the movement from the detection of the die touch until the toggle support stops.
The toggle support can be returned to the position when the die touch is detected, and the precision of the die clamping force can be improved.

(5) The molding condition setting method according to (3), in which the mold thickness adjusting motor is rotated by a backlash of a motion converting mechanism that converts the rotational motion of the mold thickness adjusting motor into the linear motion of the toggle support.
The position shift of the toggle support due to backlash can be suppressed during mold clamping.

(6) Toggle support that can be moved in a predetermined direction, a die touch detector that detects die touch between a fixed die and a movable die, and the toggle support when a die touch is detected by the die touch detector And a control device for stopping the movement of the toggle support and moving the toggle support in a direction opposite to the predetermined direction.
Due to inertia, the toggle support detects the mold touch and does not stop immediately. Therefore, by moving the toggle support in the opposite direction, the toggle support can be brought closer to the position at the time of die touch detection, and the accuracy of the die clamping force can be improved. As the mold touch detector, for example, a mold clamping force detector or a torque detector of a mold thickness adjusting motor is used.

(7) A toggle support that is moved to a predetermined position, and the toggle support is moved to the predetermined position by moving the toggle support in a direction in which the fixed mold and the movable mold are separated from each other, and the predetermined position of the toggle support. An injection molding machine having a control device that completes a process of moving to a position.
At the time of mold clamping, a force acts on the toggle support in a direction in which the fixed mold and the movable mold are separated from each other. Therefore, if the toggle support is moved to a predetermined position by moving the toggle support in a direction in which the fixed mold and the movable mold are separated from each other, and the moving process of the toggle support to the predetermined position is completed, the toggle support causes toggle due to backlash. The displacement of the support can be suppressed.

(8) Mold thickness adjusting motor, toggle support that is moved by rotation of the mold thickness adjusting motor, and the toggle support is moved to a predetermined position by moving the toggle support in a direction in which a fixed mold and a movable mold approach each other. And a control device for rotating the mold thickness adjusting motor in a direction in which the fixed mold and the movable mold are separated from each other.
At the time of mold clamping, a force acts on the toggle support in a direction in which the fixed mold and the movable mold are separated from each other. Therefore, when moving the toggle support to a predetermined position by moving the toggle support in the direction in which the fixed mold and the movable mold approach each other, then move the mold thickness adjustment motor in the direction in which the fixed mold and the movable mold are separated from each other. When it is rotated, displacement of the toggle support due to backlash can be suppressed during mold clamping.

(9) The injection molding according to the above (6), wherein the control device moves the toggle support in a direction opposite to the predetermined direction by an amount corresponding to the movement from the detection of the mold touch to the stop of the toggle support. Machine.
The toggle support can be returned to the position when the die touch is detected, and the precision of the die clamping force can be improved.

(10) Having a motion conversion mechanism that converts the rotational motion of the mold thickness adjusting motor into the linear motion of the toggle support, and the control device rotates the mold thickness adjusting motor by the backlash of the motion converting mechanism. The injection molding machine according to (8) above.
The position shift of the toggle support due to backlash can be suppressed during mold clamping.

The process of moving the toggle support is not limited to the process of moving when the mold touch is detected in the mold thickness adjustment, and for example, the process of moving the position of the toggle support based on the difference between the detected value of the mold clamping force and the set value (mold clamping). Force correction processing). The process of moving the toggle support includes all processes of moving the toggle support other than the above.

Although the embodiments of the injection molding machine and the like have been described above, the present invention is not limited to the above embodiments and the like, and various modifications within the scope of the gist of the present invention described in the claims. It can be improved.

The control device 90 of the above-described embodiment detects the deviation of the interval L between the toggle support 15 and the fixed platen 12 from the detection of the mold touch to the stop of the driving of the mold thickness adjustment motor 63 (step S13), and the detected deviation. The distance L is corrected based on (step S14), but the present invention is not limited to this. For example, the control device may output an alarm when the deviation is equal to or more than a threshold value. Machine failure etc. can be detected.

The mold clamping device 10 of the above embodiment is a horizontal mold in which the mold opening/closing direction is horizontal, but may be a vertical mold in which the mold opening/closing direction is vertical.

The vertical mold clamping device includes a lower platen, an upper platen, a toggle support, a tie bar, a toggle mechanism, a mold clamping motor, and a mold thickness adjusting mechanism. One of the lower platen and the upper platen is used as a fixed platen, and the other one is used as a movable platen. A lower die is attached to the lower platen, and an upper die is attached to the upper platen. The lower mold and the upper mold constitute a mold device. The lower mold may be attached to the lower platen via a rotary table. The toggle support is arranged below the lower platen. The toggle mechanism is arranged between the toggle support and the lower platen. The tie bar is parallel to the vertical direction, penetrates the lower platen, and connects the upper platen and the toggle support.

The vertical mold thickness adjusting mechanism adjusts the mold thickness by adjusting the distance between the upper platen and the toggle support according to the change in the thickness of the mold device. In this mold thickness adjustment, the interval between the upper platen and the toggle support is adjusted so that the link angle of the toggle mechanism becomes a predetermined angle at the time of the die touch where the lower die and the upper die touch. The link angle can be adjusted to a predetermined angle when the mold is closed, and a predetermined mold clamping force can be obtained when the mold is clamped. The mold thickness adjusting mechanism includes a screw shaft formed on the tie bar, a screw nut held on one of the upper platen and the toggle support, and a mold thickness adjusting motor for rotating one of the screw shaft and the screw nut screwed together. Have. The mold thickness adjusting mechanism may further include a screw nut held on the other of the upper platen and the toggle support. The upper platen corresponds to the mold mounting plate described in the claims, the toggle support corresponds to the connecting plate described in the claims, and the tie bar corresponds to the rod described in the claims.

Although the mold clamping device 10 of the above-described embodiment has the toggle mechanism 20 and the mold clamping motor 25 that operates the toggle mechanism 20, it may have a linear motor for mold opening/closing and an electromagnet for mold clamping.

The electromagnet type mold clamping device has, for example, a fixed platen, a movable platen, a rear platen, a tie bar, a suction plate, a rod, and a mold thickness adjusting mechanism. The rear platen is arranged on the side opposite to the fixed platen (that is, behind the movable platen) with the movable platen as a reference. The tie bar connects the fixed platen and the rear platen at intervals in the mold opening/closing direction. The suction plate is movable back and forth together with the movable platen behind the rear platen. The rod is inserted into the through hole of the rear platen and connects the movable platen and the suction plate. An electromagnet is formed on at least one of the rear platen and the suction plate, and the suction force of the electromagnet acts between the rear platen and the suction plate to generate a mold clamping force.

The electromagnet type mold thickness adjusting mechanism adjusts the mold thickness by adjusting the distance between the movable platen and the suction plate. In this mold thickness adjustment, the gap between the movable platen and the suction plate is adjusted so that a predetermined gap is formed between the suction plate and the rear platen at the time of the mold touch in which the movable mold and the fixed mold touch. To do. A predetermined gap can be formed between the suction plate and the rear platen when the mold is closed, and a predetermined mold clamping force can be obtained when the mold is clamped. The mold thickness adjusting mechanism includes a screw shaft formed on the rod, a screw nut held by one of the movable platen and the suction plate, and a mold thickness adjusting motor that rotates one of the screw shaft and the screw nut screwed together. Have. The mold thickness adjusting mechanism may further include a screw nut held on the other of the movable platen and the suction plate. The movable platen corresponds to the mold mounting plate described in the claims, and the suction plate corresponds to the connecting plate described in the claims.

This application claims priority based on Japanese Patent Application No. 2016-062417 filed with the Japan Patent Office on March 25, 2016, and the entire contents of Japanese Patent Application No. 2016-062417 are incorporated into the present application. ..

10 Mold Clamping Device 12 Fixed Platen 13 Movable Platen 15 Toggle Support 16 Tie Bar 18 Mold Clamping Force Detector 20 Toggle Mechanism 21 Crosshead 25 Mold Clamping Motor 26 Motion Conversion Mechanism 30 Mold Device 40 Injection Device 50 Ejector Device 60 Mold Thickness Adjusting Mechanism 61 screw shaft 62 screw nut 63 type thickness adjusting motor 64 rotation transmitting section 65 torque detector

Claims (17)

A mold mounting plate to which one of a fixed mold and a movable mold is mounted, a connecting plate that is connected to the mold mounting plate with a gap in the mold opening/closing direction, and a mold thickness adjustment by adjusting the gap. A mold thickness adjusting mechanism for performing, and a control device for controlling the mold thickness adjusting mechanism,
The mold thickness adjusting mechanism includes a screw shaft formed on a rod connecting the mold mounting plate and the connecting plate, a screw nut held by one of the mold mounting plate and the connecting plate, and a screw nut that is screwed together. A mold thickness adjusting motor for rotating one of the screw shaft and the screw nut to be combined,
The control device detects a mold touch that the movable mold and the fixed mold touch while the mold thickness adjusting motor is being driven, and detects the mold touch and stops driving the mold thickness adjusting motor. An injection molding machine that detects gap deviations. The injection molding machine according to claim 1, wherein the control device corrects the interval based on the detected deviation. 3. The control device according to claim 1, wherein the controller determines whether or not the interval changes during mold clamping due to backlash of the mold thickness adjusting mechanism, based on the immediately preceding rotational direction of the mold thickness adjusting motor. Injection molding machine. When the control device determines that the interval changes during mold clamping due to backlash of the mold thickness adjusting mechanism based on the rotating direction of the mold thickness adjusting motor immediately before, the immediately preceding rotating direction of the mold thickness adjusting motor is The injection molding machine according to claim 1, wherein the mold thickness adjusting motor is rotated in a reverse direction. 5. The control device detects the mold touch by performing mold closing of a mold device configured by the movable mold and the fixed mold by the mold thickness adjusting motor. The injection molding machine according to item 1. The control device detects the mold touch by performing depressurization of a mold device including the movable mold and the fixed mold by the mold thickness adjusting motor. The injection molding machine according to item 1. The injection molding machine according to claim 1, wherein the control device monitors a mold clamping force during driving of the mold thickness adjusting motor, and detects the mold touch based on the mold clamping force. .. 8. The controller according to claim 1, wherein the control device monitors the torque of the mold thickness adjusting motor during driving of the mold thickness adjusting motor, and detects the mold touch based on the torque. Injection molding machine. A mold mounting plate to which one of a fixed mold and a movable mold is mounted, a connecting plate that is connected to the mold mounting plate with a gap in the mold opening/closing direction, and a mold thickness adjustment by adjusting the gap. A mold thickness adjusting mechanism for performing, and a control device for controlling the mold thickness adjusting mechanism,
The mold thickness adjusting mechanism includes a screw shaft formed on a rod connecting the mold mounting plate and the connecting plate, a screw nut held by one of the mold mounting plate and the connecting plate, and a screw nut that is screwed together. A mold thickness adjusting motor for rotating one of the screw shaft and the screw nut to be combined,
The controller is an injection molding machine that determines whether or not the interval changes during mold clamping due to backlash of the mold thickness adjusting mechanism, based on the immediately preceding rotational direction of the mold thickness adjusting motor. Drive the mold thickness adjustment motor to move the toggle support in the specified direction,
Detecting a mold touch that the movable mold and the fixed mold touch while driving the mold thickness adjusting motor,
When detecting the touch of the movable mold and the fixed mold, the movement of the toggle support is stopped, the stationary mold and the movable mold from the detection of the touch to the drive stop of the type thickness adjusting motor the rewritable detecting a shift interval while the mold mounting plate mounted type and the toggle support is moved in the opposite direction to the toggle support the predetermined direction, the molding condition setting method. A mold mounting plate to which one of a fixed mold and a movable mold is mounted, a toggle support connected to the mold mounting plate with a gap in the mold opening/closing direction, and a mold thickness adjustment by adjusting the gap. A molding condition setting method of an injection molding machine having a mold thickness adjusting mechanism and a control device,
The mold thickness adjusting mechanism,
Mold thickness adjustment motor,
A motion conversion mechanism that converts the rotational motion of the mold thickness adjustment motor into a linear motion of the toggle support,
The control device is
Drive the mold thickness adjusting motor to move the toggle support in a predetermined direction,
Upon detecting the type touch of the movable mold and the fixed mold, to stop the movement of the toggle support is moved in the direction opposite to the predetermined direction of said toggle support,
A molding condition setting method for determining whether or not the interval changes during mold clamping due to backlash of the mold thickness adjusting mechanism, based on the immediately preceding rotational direction of the mold thickness adjusting motor . A molding condition setting method of rotating a mold thickness adjusting motor to move a toggle support to a predetermined position,
After moving the toggle support to the predetermined position by moving the toggle support in the direction in which the fixed die and the movable die approach each other, the rotational movement of the die thickness adjusting motor is converted into the linear movement of the toggle support. A molding condition setting method in which the mold thickness adjusting motor is rotated in a direction in which the fixed mold and the movable mold are separated from each other by the amount of backlash of the motion converting mechanism . The molding condition setting method according to claim 10 or 11 , wherein the toggle support is moved in a direction opposite to the predetermined direction by an amount corresponding to the movement from the detection of the mold touch until the toggle support stops. Toggle support moved by the mold thickness adjustment motor ,
A mold touch detector that detects a mold touch between a fixed mold and a movable mold,
And a control device,
The control device is
Drive the mold thickness adjusting motor to move the toggle support in a predetermined direction,
Detecting the mold touch with the mold touch detector while driving the mold thickness adjusting motor,
When the touch is detected by the touch detector, the movement of the toggle support is stopped, the stationary mold and the movable mold from the detection of the touch to the drive stop of the type thickness adjusting motor the rewritable detecting a shift of one is attached mold mounting platen and a distance between the toggle support is moved in the opposite direction to the toggle support the predetermined direction, an injection molding machine. A mold mounting board to which one of a fixed mold and a movable mold is mounted,
A toggle support that is connected to the mold mounting board at intervals in the mold opening and closing direction ,
A mold thickness adjusting mechanism for adjusting the mold thickness by adjusting the spacing,
-Type touch detector for detecting the type touch with the movable mold and the fixed mold,
And a control device,
The mold thickness adjusting mechanism,
Mold thickness adjustment motor,
A motion conversion mechanism that converts the rotational motion of the mold thickness adjustment motor into a linear motion of the toggle support,
The control device is
Drive the mold thickness adjusting motor to move the toggle support in a predetermined direction,
When the touch is detected by the touch detector, to stop the movement of the toggle support is moved in the direction opposite to the predetermined direction of said toggle support,
An injection molding machine that determines whether or not the interval changes during mold clamping due to backlash of the mold thickness adjusting mechanism, based on the immediately preceding rotational direction of the mold thickness adjusting motor . Mold thickness adjustment motor,
A toggle support that is moved by rotation of the mold thickness adjustment motor,
A motion conversion mechanism that converts the rotational motion of the mold thickness adjusting motor into the linear motion of the toggle support,
After moving the toggle support to a predetermined position by moving the toggle support in a direction in which the fixed mold and the movable mold approach each other, the backlash of the motion conversion mechanism, the mold thickness adjusting motor, the fixed mold And a control device for rotating the movable mold in a direction in which the movable mold is separated from each other. The injection molding machine according to claim 14 or 15, wherein the control device moves the toggle support in a direction opposite to the predetermined direction by an amount corresponding to the movement from the detection of the die touch to the stop of the toggle support.

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