Injection molding machine control method

Abstract

It meets safety standards and enables molding using an efficient injection machine. [Solution] A control method for an injection molding machine 10 having a mold clamping device that clamps an upper mold 8 and a lower mold 7, the control method comprising: a rotary table 2 on which a plurality of lower molds are attached; and a movable platen 3 on which an upper mold is attached; a rear intrusion detection sensor 40 that detects intrusion from a molded product removal area K2 into the mold clamping area K1; a front intrusion detection sensor 50 that detects intrusion into the molded product removal area from the outside; and a mold clamping detection sensor 60 that detects that mold clamping has been performed; when the mold clamping detection sensor detects that mold clamping has been performed, the rear intrusion detection sensor detects the intrusion; and when the mold clamping detection sensor detects that mold clamping has not been performed, the control method switches to detecting the intrusion using the front intrusion detection sensor.

Description

[Technical Field]

[0001] The present invention relates to a method for controlling an injection molding machine. [Background technology]

[0002] The injection molding machine described in Patent Document 1 has a rotary table rotatably supported on a fixed plate, multiple fixed molds arranged at equal angles on the rotary table, and a movable mold that is movable up and down relative to the fixed mold. The injection molding machine rotates the rotary table intermittently to sequentially inject and fill molds placed at the injection position. This injection molding machine has an openable safety door on one side of the space in which the movable mold moves up and down. When the safety door is opened, the movement of the movable mold in the mold closing direction is mechanically locked.

[0003] When a safety door is provided, the worker must open and close the safety door each time they remove a molded product from the mold, which makes the work complicated. Therefore, an opening that is always open to the outside is provided on one side of the space in which the movable mold moves up and down, and an intrusion detector (e.g., a light curtain) is sometimes provided to detect objects that enter the interior from the outside through the opening. If the intrusion detector detects an object entering the interior during mold closing, the mold closing is interrupted. This prevents part of the worker's body from becoming pinched between a component that moves during mold closing (e.g., the movable mold) and a component that does not move during mold closing (e.g., the fixed mold).

[0004] Previously, molded products were removed during the injection operation, but with the establishment of JIS B 6711, if the light curtain on the operator side is blocked, not only the mold opening and closing operations and the rotary table rotation operations that were previously performed, but also the injection and supply operations must be prohibited. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7019488 Summary of the Invention [Problem to be solved by the invention]

[0006] If, in accordance with the established JIS standard, the light curtain on the operator's side is blocked and the injection and supply operations are stopped, the greatest advantage of a rotary table type injection machine, namely, removing the product during molding and inserting the workpiece, will no longer be possible. Furthermore, if the light curtain is positioned so as not to interfere with the mold in front where the workpiece is inserted, the safety distance required by the JIS standard will be insufficient.

[0007] The present invention has been made in view of the above circumstances, and aims to achieve an object of enabling molding with an efficient injection machine while satisfying safety standards and without unnecessary extension of takt time. [Means for solving the problem]

[0008] (1) The method for controlling an injection molding machine of the present invention comprises: A control method for an injection molding machine having a mold clamping device that clamps an upper mold and a lower mold, comprising: the mold clamping device includes a rotary table to which the plurality of lower molds are attached, a fixed platen fixed to a machine body and rotatably supporting the rotary table from below, a movable platen provided above the fixed platen and fixed to upper ends of tie bars to which the upper molds are attached, a rotation mechanism that rotates the rotary table, and an elevation mechanism that elevates the movable platen, a mold clamping area in which the upper mold and one of the lower molds are clamped by raising and lowering the movable platen, and a molded product removal area in which a molded product molded in the mold clamping area is removed, a rear intrusion detection sensor provided between the mold clamping area and the molded product removal area to detect intrusion from the molded product removal area into the mold clamping area; a front intrusion detection sensor that detects intrusion into the molded product removal area from the outside; a mold clamping detection sensor that detects a mold clamping state between the upper mold and one of the lower molds; and When the mold clamping detection sensor detects a mold clamped state, the rear intrusion detection sensor detects intrusion, and When the mold clamping detection sensor detects that mold clamping is not being performed, the system switches to detecting intrusion using the front intrusion detection sensor. This solved the above problem. (2) The control method for an injection molding machine of the present invention comprises the steps of: The lifting mechanism includes an end plate fixed to the lower end of the tie bar below the fixed platen and movable up and down together with the movable platen relative to the fixed platen; a screw shaft whose upper end is journaled on the fixed platen and which is provided vertically below the fixed platen to prevent axial movement and which is rotated in a circumferential direction by a drive source; a crosshead screwed to the screw shaft so as to be movable up and down; and a toggle mechanism provided between the fixed platen and the end platen, which expands and contracts with the vertical movement of the crosshead to move the movable platen to open and close the mold, The mold clamping detection sensor can detect mold clamping by detecting the position of the crosshead when the upper mold and one of the lower molds are in a mold clamped state. (3) The method for controlling an injection molding machine of the present invention comprises the steps of: When the mold clamping detection sensor detects that mold clamping has been performed, the front intrusion detection sensor is switched so as not to detect intrusion. It is possible. (4) The method for controlling an injection molding machine of the present invention comprises the steps of: When an injection operation is performed on the upper mold and one of the lower molds, the intrusion is detected by the rear intrusion detection sensor. It is possible. (5) The control method for an injection molding machine of the present invention comprises the steps of: the rear-side intrusion detection sensor detects intrusion at a position in the molded product removal area that is closer to the mold clamping area than the lower mold. It is possible.

[0009] According to the configuration (1) above, by detecting the mold clamping state with the mold clamping detection sensor and switching between intrusion detection with the rear intrusion detection sensor and the front intrusion detection sensor, it is possible to simultaneously carry out the process in which an operator enters the molded product removal area during the injection molding process, and to simultaneously carry out safety management. This makes it possible to simultaneously carry out injection, molded product removal, and workpiece insertion in the injection molding machine while carrying out safety management in accordance with JIS standards.

[0010] According to the above configuration (2), the clamping of the upper and lower dies is confirmed by detecting the position of the crosshead that drives the toggle mechanism that extends and retracts the movable platen, which moves integrally with the upper die, and the end plate, which moves integrally with the upper die via the tie bars, when the upper and lower dies come into contact. In practice, detection can be ensured by detecting the crosshead slightly before the contact position. This makes it possible to reliably maintain a state in which workability and safety are ensured when switching between intrusion detection by the rear-side intrusion detection sensor and the front-side intrusion detection sensor.

[0011] According to the configuration (3) above, the mold clamping detection sensor detects that mold clamping has been performed, and the mold clamping detection sensor detects that mold clamping has been released, so that a state of safety can be maintained reliably when switching between intrusion detection by the rear intrusion detection sensor and the front intrusion detection sensor.

[0012] According to the configuration (4) above, by not using the front intrusion detection sensor during the injection operation but using the rear intrusion detection sensor to detect intrusion, it is possible to simultaneously perform injection, removal of the molded product, and insertion of the workpiece while ensuring safety.

[0013] According to the configuration (5) above, even if an operator works on the lower mold in the molded product removal area, the operator will not cause the rear intrusion detection sensor to detect an intrusion. This makes it possible to simultaneously remove a molded product and insert a workpiece during the injection operation while ensuring safety. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a control method for an injection molding machine that can simultaneously perform injection, removal of a molded product, and insertion of a workpiece while meeting the safety standards of the JIS standard. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a front view showing an embodiment of an injection molding machine according to the present invention. [Figure 2] FIG. 2 is a side view showing a molded product removal area, a mold clamping area, a rear intrusion detection sensor, and a front intrusion detection sensor in an embodiment of the injection molding machine according to the present invention. [Figure 3] FIG. 2 is a top view showing a mold clamping detection sensor and other components in the injection molding machine according to the embodiment of the present invention. [Figure 4] 10A and 10B are front views showing the operation of a mold clamping detection sensor in an embodiment of the injection molding machine according to the present invention. [Figure 5] 1 is a flowchart showing an embodiment of a control method for an injection molding machine according to the present invention. [Figure 6] 1 is a top view showing an operation in an embodiment of a control method for an injection molding machine according to the present invention. [Figure 7] 1 is a front view showing an operation in an embodiment of a control method for an injection molding machine according to the present invention. [Figure 8] 1 is a front view showing an operation in an embodiment of a control method for an injection molding machine according to the present invention. [Figure 9] 1 is a top view showing an operation in an embodiment of a control method for an injection molding machine according to the present invention. [Figure 10]1 is a front view showing an operation in an embodiment of a control method for an injection molding machine according to the present invention. [Figure 11] 1 is a front view showing an operation in an embodiment of a control method for an injection molding machine according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for controlling an injection molding machine according to the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing an injection molding machine of this embodiment. FIG. 2 is a side view showing the molded product removal area, mold clamping area, and other areas of the injection molding machine of this embodiment. FIG. 3 is a top view showing the mold clamping detection sensor and other areas of the injection molding machine of this embodiment. In the figures, reference numeral 10 denotes the injection molding machine. The X, Y, and Z directions are mutually perpendicular. The X and Y directions represent horizontal directions, and the Z direction represents the vertical direction. The Y direction is sometimes referred to as the front-to-rear direction. The X direction is sometimes referred to as the left-to-right direction or lateral direction.

[0017] As shown in Figures 1 to 3, the injection molding machine 10 of this embodiment has a movable platen 3 fixed to the upper ends of tie bars 4 above a fixed platen 1a and a rotary table 2 fixed to a machine body 1, and an end plate 5 fixed to the lower ends of tie bars 4 below the fixed platen 1a so as to be able to move freely up and down together with the movable platen 3 relative to the fixed platen 1a and the rotary table 2.

[0018] The end plate 5 has a roughly triangular outline when viewed from above. The rear side of the end plate 5 in the Y direction is a side that runs along the X direction. The center of the end plate 5 in the X direction forms a corner that protrudes forward in the Y direction. Tie bars 4 are arranged near the three corners of the end plate 5.

[0019] The end plate 5, the fixed plate 1a, the turntable 2, and the movable plate 3 extend substantially horizontally. The end plate 5, the fixed plate 1a, the turntable 2, and the movable plate 3 are substantially parallel to each other. The tie bars 4 extend substantially vertically. Multiple tie bars 4 are arranged. The multiple tie bars 4 are arranged spaced apart in the horizontal direction. For example, three tie bars 4 are arranged.

[0020] A lower die (die) 7 is attached to a turntable 2 that is placed parallel to the fixed platen 1a. The turntable 2 is rotatable around a vertical axis. The turntable 2 is driven to rotate by a rotation mechanism (not shown) so that it can stop at a predetermined angular position. The lower die (die) 7 is composed of a lower die (die) 7A and a lower die (die) 7B. The lower die 7A and the lower die 7B are arranged on the turntable 2 separated from each other in the Y direction. The lower die 7A and the lower die 7B are arranged rotationally symmetrical with respect to the rotation axis of the turntable 2. The lower die 7A may be referred to as die A, and the lower die 7B as die B.

[0021] An upper mold (mold) 8 is attached to the movable platen 3. A nozzle (injection device) 9 is connected to the upper mold 8. Injection molding is performed using the upper mold 8 and the lower mold 7. During injection molding, the lower mold 7A or the lower mold 7B rotates and moves to a position corresponding to the upper mold 8 as the turntable 2 rotates. As the turntable 2 rotates, injection molding can be performed using the upper mold 8 and the lower mold 7A, or the upper mold 8 and the lower mold 7B.

[0022] A cover C is erected above the fixed platen 1a so as to surround the periphery thereof. The cover C has a front opening on its front surface in the Y direction. The front opening of the cover C is sized and shaped to allow an operator to enter the area above the fixed platen 1a and work there. The entire upper area of ​​the cover C is open. A rear intrusion detection sensor 40 and a front intrusion detection sensor 50 are arranged adjacent to each other on the cover C, as will be described later.

[0023] A mold clamping area K1 and a molded product removal area K2 are formed above the fixed platen 1a (FIG. 2). The mold clamping area K1 and the molded product removal area K2 are set side by side in the Y direction. The mold clamping area K1 is located further back in the Y direction than the molded product removal area K2. The molded product removal area K2 is located closer to the operator in the Y direction than the mold clamping area K1. Here, the rear side and the front side refer to a position that is farther away from an operator standing in front of the injection molding machine 10 in the Y direction, and similarly, the front side refers to a position that is closer to the operator.

[0024] Both the mold clamping area K1 and the molded product removal area K2 have an X-direction length (width dimension) equal to the overall length of the injection molding machine 10 in the X direction. The boundary between the mold clamping area K1 and the molded product removal area K2 is a straight line along the X direction. The boundary between the mold clamping area K1 and the molded product removal area K2 is close to the rotation axis of the turntable 2. When the lower mold 7A is located in one area of ​​the mold clamping area K1 and the molded product removal area K2, the lower mold 7B can be located in the other area. When injection molding is performed using the upper mold 8 and the lower mold 7A, the lower mold 7B is located in the molded product removal area K2. When injection molding is performed using the upper mold 8 and the lower mold 7B, the lower mold 7A is located in the molded product removal area K2. The area arrangement of the lower mold 7A and the lower mold 7B is switched by the rotation of the turntable 2.

[0025] The mold clamping area K1 has an area including the movable platen 3 in top view. In top view, the molded product removal area K2 is where the lower mold 7 that is not combined with the upper mold 8 is located. In other words, when the lower mold 7A is in the mold clamping area K1, the lower mold 7B is located in the molded product removal area K2. When the lower mold 7B is in the mold clamping area K1, the lower mold 7A is located in the molded product removal area K2. An ejector 71 for removing a molded product from the mold 7 is provided in the molded product removal area K2 (FIG. 2). The ejector 71 removes a molded product from the mold 7 located in the molded product removal area K2. The ejector 71 is capable of advancing and retreating through the mold 7, and releases the molded product from the mold 7. The ejector 71 is capable of advancing and retreating in the Z direction.

[0026] A rear entry detection sensor 40 is disposed at the boundary between the mold clamping area K1 and the molded product removal area K2. The rear intrusion detection sensor 40 is a so-called light curtain. The rear intrusion detection sensor 40 has a pair of an emitting unit and a light receiving unit. Sensor light such as laser light is emitted from the emitting unit on one side and received by the light receiving unit on the other side. When an object enters the optical path of the laser light, the rear intrusion detection sensor 40 blocks the laser light. The rear intrusion detection sensor 40 detects an intrusion by blocking the laser light.

[0027] The rear intrusion detection sensor 40 emits laser light along the X direction. This laser light is approximately horizontal. The rear intrusion detection sensor 40 has multiple emitting units. The multiple emitting units are arranged at intervals in the Z direction. The multiple laser light beams are emitted approximately parallel to each other. The distance between the irradiation parts in the Z direction of the rear-side intrusion detection sensor 40 is set to a size that can detect the fingers of an operator. The distance between the laser beams in the Z direction of the rear-side intrusion detection sensor 40 is set to a range of 5 mm to 35 mm, or a range of 10 mm to 30 mm, or a range of 15 mm to 25 mm.

[0028] The detection range of the rear-side intrusion detection sensor 40 in the Z direction is set so that its upper limit is higher than the movable range of the upper surface of the movable platen 3 and its lower limit is up to the combined height of the upper mold 8 and lower mold 7. The lower limit of the detection range of the rear-side intrusion detection sensor 40 in the Z direction is not affected by the workpiece or molded product placed on the turntable 2. The detection range of the rear-side intrusion detection sensor 40 in the X direction is set to be equal to the entire length of the fixed platen 1a in the X direction. The rear-side intrusion detection sensor 40 can detect intrusions over the entire length between the covers C on both sides in the X direction. The irradiation unit and the light receiving unit are both disposed near the covers C on both sides in the X direction.

[0029] The front intrusion detection sensor 50 is disposed at the front boundary in the Y direction of the molded product removal area K2. The front intrusion detection sensor 50 is a so-called light curtain. The front intrusion detection sensor 50 has a pair of an emitting section and a light receiving section. Sensor light such as laser light is emitted from the emitting section on one side and received by the light receiving section on the other side. When an object enters the optical path of the laser light, the front intrusion detection sensor 50 blocks the laser light. The front intrusion detection sensor 50 detects an intrusion by blocking the laser light.

[0030] The front intrusion detection sensor 50 emits laser light along the X direction. This laser light is approximately horizontal. The front intrusion detection sensor 50 has multiple emission units. The multiple emission units are arranged at intervals in the Z direction. The multiple laser light beams are emitted approximately parallel to each other. The front intrusion detection sensor 50 has its irradiating parts spaced apart in the Z direction such that they can detect the fingers of an operator. The front intrusion detection sensor 50 has its laser beams spaced apart in the Z direction in a range of 5 mm to 35 mm, or 10 mm to 30 mm, or 15 mm to 25 mm.

[0031] The front intrusion detection sensor 50 is set so that the detection range in the Z direction coincides with the vertical dimension of the front opening of the cover C in the Z direction. The front intrusion detection sensor 50 is set so that its detection range in the X direction is equal to the front opening of the cover C in the X direction. The light emitting unit and light receiving unit of the front intrusion detection sensor 50 are both disposed near both sides of the front opening of the cover C in the X direction. The front intrusion detection sensor 50 may be referred to as sensor A, and the rear intrusion detection sensor 40 may be referred to as sensor B.

[0032] Two sets of left and right toggle mechanisms 11 are connected to the fixed platen 1a and the end plate 5. The two sets of left and right toggle mechanisms 11 are configured to be substantially symmetrical. The toggle mechanism 11 has a toggle pin 12 , a toggle piece 13 , a toggle pin 14 , a toggle pin 15 , a face piece 16 , a connecting pin 17 , a connecting piece 18 , a connecting pin 19 , a crosshead 20 , and a screw shaft 22 .

[0033] The toggle pin 12 extends horizontally. The toggle pin 12 is attached by a support portion at one end of a toggle piece 13. The toggle piece 13 is attached to the lower surface of the fixed platen 1a via the toggle pin 12. The toggle piece 13 is attached by the toggle pin 12 so as to be rotatable up and down. The toggle pin 14 extends horizontally. The toggle pin 14 is parallel to the toggle pin 12. The toggle pin 14 is attached to the end plate 5 by one end of a support portion on the upper surface of the end plate 5. The toggle pin 14 is provided directly below the toggle pin 12 in a plan view.

[0034] The face piece 16 is attached to the upper surface of the end plate 5 by a toggle pin 14. The face piece 16 is attached so that it can rotate freely up and down by the toggle pin 14. The toggle pin 14 is provided in the middle of the face piece 16. One end of the face piece 16 is connected to the toggle piece 13. One end of the face piece 16 is connected to the toggle piece 13 by a toggle pin 15.

[0035] The toggle pin 15 extends horizontally. The toggle pin 15 is parallel to the toggle pins 14 and 12. The toggle pin 15 is attached to a support portion at one end of the toggle piece 13. The toggle pin 15 connects the toggle piece 13 and the face piece 16. The toggle piece 13 and the face piece 16 can be bent up and down by the toggle pin 15 .

[0036] The screw shaft 22 is journaled by a bearing 23 in the fixed platen 1a. The screw shaft 22 is prevented from moving in the axial direction. The screw shaft 22 is provided so as to be rotatable in the circumferential direction. The screw shaft 22 is provided vertically. The screw shaft 22 is preferably a ball screw shaft or a roller screw shaft. The nut of the screw shaft 22 is connected to the other end of the face piece 16 via the crosshead 20 , the connecting pin 17 , the connecting piece 18 and the connecting pin 19 .

[0037] The crosshead 20 is threadedly attached to a nut of the screw shaft 22. The crosshead 20 is guided by a plurality of guide rods (not shown) fixed vertically to the fixed platen 1a or the machine body 1. The crosshead 20 moves up and down as the screw shaft 22 rotates.

[0038] A driven pulley is attached to the end of the screw shaft 22. The driven pulley is connected to a drive pulley by a timing belt. The drive pulley is driven to rotate by a drive motor such as a servo motor. The driven pulley, drive pulley, and belt constitute a transmission mechanism that transmits the rotation of the drive motor to the screw shaft 22. The transmission mechanism may also use other transmission members such as gears.

[0039] The mounting positions of the driven pulley, driving pulley, and driving motor are not particularly limited. For example, the driven pulley may be mounted on either end of the screw shaft 22. In this case, the position of the driving motor can also be changed accordingly.

[0040] A plurality of tie bars 4 are arranged. Two or more tie bars 4 are arranged. Four tie bars 4 may be arranged. The lower ends of the tie bars 4 are threaded into adjustment nuts 4a. By rotating the adjustment nut 4a, the gap between the movable platen 3 and the rotary table 2 is adjusted. By rotating the adjustment nut 4a, it is possible to adjust the gap to match the thickness of the molds 7 and 8.

[0041] A mold clamping detection sensor 60 is attached to the end plate 5. A detection dog is attached to the crosshead 20. The detection dog is attached in a position and shape such that the output signal from the mold clamping detection sensor 60 can be switched between a detection signal and a release signal just before the upper mold 8 and the lower mold 7 come into contact. The mold clamping detection sensor 60 detects the position of the crosshead 20 just before the upper mold 8 and the lower mold 7 come into contact. At this time, the output signal of the mold clamping detection sensor 60 switches from a release signal to a detection signal. The crosshead 20 moves further downward from the above position to extend the toggle mechanism, and by moving the end plate to its lower limit, the upper mold 8 is pressed against the lower mold 7, achieving a mold clamping completion state. During this time, the output signal of the mold clamping detection sensor 60 remains a detection signal. In other words, the mold clamping detection sensor 60 detects whether the upper mold 8 and the lower mold 7 are in a position just before contact to a mold clamping completion position. The clamping state is defined as the state from the position slightly before contact to the state where clamping is completed.

[0042] The mold clamping detection sensor 60 is a contact-type limit switch sensor. The mold clamping detection sensor 60 has a sensor body attached to the end plate 5. The mold clamping detection sensor 60 has a detection dog disposed on the crosshead 20. The mold clamping detection sensor 60 may have the sensor body and detection dog disposed in reverse. The mold clamping detection sensor 60 outputs a detection signal indicating a mold clamped state when the sensor body is driven by the detection dog. When the sensor body is not driven by the detection dog, the mold clamping detection sensor 60 outputs a release signal indicating a mold clamped state.

[0043] The mold clamping detection sensor 60 outputs a detection signal indicating a mold clamped state when the crosshead 20 descends and approaches the end plate 5 and the sensor body is driven by the detection dog. The mold clamping detection sensor 60 outputs a release signal indicating a mold clamped state when the crosshead 20 rises and moves away from the end plate 5 and the sensor body is not driven by the detection dog.

[0044] In the toggle-type mold clamping device of the electric vertical injection molding machine (molding machine) 10, the drive motor is operated to rotate the screw shaft 22 during mold clamping. Then, due to the rotation of the screw shaft 22, the crosshead 20 threadedly attached to the nut moves downward, causing the toggle mechanism 11 to extend linearly. When the toggle mechanism 11 extends linearly, the end plate 5 descends. When the end plate 5 descends, the movable platen 3 also descends at the same time. When the movable platen 3 descends, the upper mold 8 comes into contact with and presses against the lower mold 7 between the rotary table 2. The upper mold 8 and the lower mold 7 reach a mold clamping completion state.

[0045] In the toggle-type mold clamping device of the injection molding machine 10, the toggle mechanism 11 is folded in the mold open state (see the right side of FIG. 4). In the mold open state, the toggle mechanism 11 is reduced in size in the up-down direction. When the toggle-type mold clamping device of the injection molding machine 10 changes from a mold open state to a mold clamped state, the drive motor is operated to rotate the screw shaft 22. The rotation of the screw shaft 22 lowers the crosshead 20. As the crosshead 20 lowers, the connecting piece 18 also lowers. The lowering connecting piece 18 presses down the inner end of the face piece 16.

[0046] As a result, the face piece 16 and the toggle piece 13 rotate around the toggle pin 14 and the toggle pin 12 as fulcrums. The face piece 16 and the toggle piece 13 rotate inward. As the face piece 16 and the toggle piece 13 rotate, the toggle pin 15 approaches the screw shaft 22. The face piece 16 and the toggle piece 13 extend and become closer to a straight line. As the toggle mechanism 11 extends linearly, the end plate 5 descends. As a result, the movable platen 3 descends together with the end plate 5. The movable platen 3 moves downward to clamp the mold. The toggle piece 13 and face piece 16 extend linearly, completing the clamping operation.

[0047] In the toggle-type mold clamping device of the injection molding machine 10, the toggle mechanism 11 is extended in the mold clamping state (see the left side of FIG. 4). In the mold clamping state, the toggle mechanism 11 is at its longest in the vertical direction. When the toggle-type mold clamping device of the injection molding machine 10 is changed from a mold clamped state to a mold open state, the drive motor is operated to rotate the screw shaft 22. At this time, the screw shaft 22 is rotated in the opposite direction to that when the mold open state is changed to the mold clamped state. The crosshead 20 rises due to the rotation of the screw shaft 22. As the crosshead 20 rises, the connecting piece 18 also rises. The rising connecting piece 18 pushes up the inner end of the face piece 16.

[0048] As a result, the face piece 16 and the toggle piece 13 rotate around the toggle pin 14 and the toggle pin 12 as fulcrums. The face piece 16 and the toggle piece 13 rotate outward. As the face piece 16 and the toggle piece 13 rotate, the toggle pin 15 moves away from the screw shaft 22. The face piece 16 and the toggle piece 13 bend from a straight line. As the toggle mechanism 11 bends from a straight line, the end plate 5 rises. As a result, the movable platen 3 rises together with the end plate 5. The movable platen 3 moves upward to open the mold. The toggle piece 13 and face piece 16 bend, completing the mold opening.

[0049] FIG. 4 is a front view showing the operation of the mold clamping detection sensor in the injection molding machine of this embodiment. 4, in the injection molding machine 10 of this embodiment, when the toggle mechanism 11 is operated to open or close the movable platen 3, if the mold clamping detection sensor 60 detects that the upper mold 8 and the lower mold 7 are in a clamped state, it outputs a detection signal detecting mold clamping, and if it detects that the mold clamping is released, it outputs a release signal. The detection signal by the mold clamping detection sensor 60 is issued at a position slightly before the upper mold 8 and the lower mold 7 come into contact with each other, and thereafter the upper mold 8 further presses the lower mold 7 to apply a clamping force. In other words, the timing of the detection signal by the mold clamping detection sensor 60 does not coincide with the timing at which the rotation of the screw shaft 22 is stopped. The detection signal from the mold clamping detection sensor 60 maintains its output while the mold is clamped. The release signal from the mold clamping detection sensor 60 is maintained while the mold is in the open state.

[0050] In the injection molding machine 10 of this embodiment, intrusion is detected by the rear intrusion detection sensor 40 in the mold clamping state, and intrusion is detected by the front intrusion detection sensor 50 in the mold open state. Detection is switched between the rear intrusion detection sensor 40 and the front intrusion detection sensor 50 by a detection signal and a release signal output from the mold clamping detection sensor 60. Details of detection switching between the rear intrusion detection sensor 40 and the front intrusion detection sensor 50 by the detection signal and release signal output from the mold clamping detection sensor 60 will be described later. In the mold clamping state, while the mold clamping detection sensor 60 is outputting a detection signal, the rear side intrusion detection sensor 40 continues to detect intrusion. During the mold open state, while the mold clamping detection sensor 60 is outputting a release signal, the front intrusion detection sensor 50 continues to detect intrusion.

[0051] In the injection molding machine 10 of this embodiment, in the mold open state, the turntable 2 is rotated to interchange the positions of the lower mold 7A and the lower mold 7B. This allows the lower mold 7, on which a molded product injected between the upper mold 8 and the lower mold 7A is placed, to be moved to the front side, and also allows an operator to move the lower mold 7, on which a workpiece is placed, to the back side.

[0052] FIG. 5 is a flowchart showing an embodiment of the control method for the injection molding machine of this embodiment. As shown in FIG. 5, the control method for the injection molding machine of this embodiment includes B mold molding completion S10b, B mold opening start S11a, B mold opening completion S11b, cycle start button operation S30, table rotation S21, A mold clamping start S12a, A mold clamping completion S12b, A mold injection start S13a, B mold ejector forward S31, B molded product removal S32, and B mold ejector backward S33. 33, B-type workpiece insert S34, A-type molding completion S13b, A-type opening start S14a, A-type opening completion S14b, table rotation S22, B-type clamping start S15a, B-type clamping completion S15b, B-type injection start S16a, A-type ejector forward S35, A-type molded product removal S36, A-type ejector backward S37, and A-type workpiece insert S38.

[0053] Fig. 6 is a top view showing the operation of the embodiment of the control method for the injection molding machine of the present embodiment, and Fig. 7 is a front view showing the operation of the embodiment of the control method for the injection molding machine of the present embodiment. The control method for the injection molding machine according to this embodiment will be explained starting from the following state. First, in the B mold molding completion S10b, as shown in Figures 6 and 7, the lower mold 7B is in the mold clamping area K1. The lower mold 7B is in a mold clamping state. The lower mold 7B is in a state where molding has been completed. The lower mold 7A is in the molded product removal area K2. The lower mold 7A has a workpiece inserted therein as part of preparation before molding. Since the lower mold 7B is in the mold clamping state, the mold clamping detection sensor 60 outputs a detection signal. Therefore, the rear intrusion detection sensor 40 is in the intrusion detection state. The front intrusion detection sensor 50 has its detection for the rear side turned off. Therefore, an operator can enter the molded product removal area K2, and the device operation will not be stopped even if an operator enters the molded product removal area K2.

[0054] FIG. 8 is a front view showing the operation of the embodiment of the control method for the injection molding machine of the present embodiment. Next, in the mold B opening start S11a, the mold clamping device is driven to release the mold clamped state of the lower mold 7B as shown in Fig. 8. Then, in the mold clamping detection end S41, the intrusion detection by the rear side intrusion detection sensor 40 and the detection by the front side intrusion detection sensor 50 are switched. In mold clamping detection end S41, the mold clamping detection sensor 60 stops outputting the detection signal and outputs a release signal. Here, the mold clamping detection sensor 60 stops outputting the detection signal and outputs a release signal when the crosshead 20 rises and the upper mold 8 is released from pressing and contacting the lower mold 7, and this state is maintained while the crosshead 20 is moving upward, and further while the crosshead 20 is stopped at the raised position. As the mold clamping detection sensor 60 stops outputting the detection signal and outputs the release signal, the intrusion detection state of the rear intrusion detection sensor 40 is released. At the same time, the intrusion detection state by the front intrusion detection sensor 50 is started.

[0055] Next, at mold B opening completion S11b, the crosshead 20 stops at the raised position. The upper mold 8 and the lower mold 7B separate. The mold clamping detection sensor 60 continues to stop outputting the detection signal and to output the release signal. The rear intrusion detection sensor 40 is released from intrusion detection, and the front intrusion detection sensor 50 is maintained in the intrusion detection state.

[0056] In the cycle start button operation S30, the operator operates the cycle start button. Strictly speaking, this operation starts the cycle of the injection molding machine 10.

[0057] FIG. 9 is a top view showing the operation of the embodiment of the control method for the injection molding machine of the present embodiment. Next, the turntable 2 rotates in table rotation S21. The lower mold 7B moves from the mold clamping area K1 to the molded product removal area K2, as shown in FIG. 9. The molded product completed in B mold completion S10b is placed on the lower mold 7B. The lower mold 7A moves from the molded product removal area K2 to the mold clamping area K1. The lower mold 7A is positioned below the upper mold 8 so that it can be clamped. The output of the detection signal is stopped and the output of the release signal is maintained in the mold clamping detection sensor 60. The release of the intrusion detection by the rear intrusion detection sensor 40 and the intrusion detection state by the front intrusion detection sensor 50 are maintained.

[0058] Next, at the A mold clamping start S12a, the mold clamping device is driven to release the mold open state of the lower mold 7B. The crosshead 20 descends, and the end plate 5 also descends. At the start of A mold clamping S12a, the output of the detection signal is stopped and the output of the release signal is maintained in the mold clamping detection sensor 60. The release of the intrusion detection by the rear intrusion detection sensor 40 and the intrusion detection state by the front intrusion detection sensor 50 are maintained.

[0059] FIG. 10 is a front view showing the operation of the embodiment of the control method for the injection molding machine of the present embodiment. Next, in mold A clamping completion S12b, at a position slightly before the upper mold 8 and the lower mold 7A come into contact, the mold clamping detection sensor 60 outputs a detection signal and stops outputting a release signal as mold clamping detection start S42. When the crosshead 20 further moves to the lower limit position, the mold clamping is completed as shown in FIG. 10. As the mold clamping detection sensor 60 outputs a detection signal and stops outputting a release signal, detection by the rear intrusion detection sensor 40 and detection by the front intrusion detection sensor 50 are switched. The intrusion detection state of the rear intrusion detection sensor 40 is started. At the same time, the intrusion detection state of the rear side by the front intrusion detection sensor 50 is released. Here, the state in which the mold clamping detection sensor 60 outputs the detection signal and stops outputting the release signal starts when the crosshead 20 is at a position slightly before the upper mold 8 and the lower mold 7A come into contact with each other, and is maintained even while the crosshead 20 is stopped at the lowest position. Therefore, this state is maintained even after the mold clamping force is applied to the upper mold 8 and the lower mold 7A.

[0060] Next, in the A-type injection start S13a, the injection process starts. At the start of A-type injection S13a, the output of the detection signal and the stop of the output of the release signal are maintained in the mold clamping detection sensor 60. The intrusion detection by the rear intrusion detection sensor 40 and the release of intrusion detection for the rear side by the front intrusion detection sensor 50 are maintained.

[0061] Next, in the B-type ejector advance S31, the ejector 71 operates in the molded product removal area K2. The ejector 71 rises relative to the lower mold 7B in the molded product removal area K2, and ejects the molded product from the lower mold 7B. In the B-type ejector advance S31, the mold clamping detection sensor 60 maintains the output of a detection signal and the stop of output of a release signal. The rear-side intrusion detection sensor 40 maintains intrusion detection, and the front-side intrusion detection sensor 50 maintains the release of intrusion detection for the rear side.

[0062] Next, in the B-type molded product removal step S32, the molded product is removed from the lower mold 7B in the molded product removal area K2 to the outside of the apparatus. At this time, an operator enters the molded product removal area K2, but the front intrusion detection sensor 50 continues to release intrusion detection on the rear side. At the same time, the mold clamping detection sensor 60 continues to output a detection signal and stop outputting a release signal. The rear intrusion detection sensor 40 continues to detect intrusion, and there is no safety problem.

[0063] Next, in the B-type ejector retraction S33, the ejector 71 retracts in the molded product removal area K2. The ejector 71 descends toward the lower mold 7B in the molded product removal area K2 and retreats from the lower mold 7B from which the molded product has been removed. In the B-type ejector retraction S33, the mold clamping detection sensor 60 continues to output a detection signal and stop outputting a release signal. Intrusion detection by the rear-side intrusion detection sensor 40 and release of intrusion detection for the rear side by the front-side intrusion detection sensor 50 are maintained.

[0064] Next, in the B-type workpiece insert S34, a workpiece is supplied from outside the apparatus to the lower mold 7B in the molded product removal area K2. At this time, an operator enters the molded product removal area K2 and places the workpiece in a predetermined position on the lower mold 7B, but the front intrusion detection sensor 50 remains in the released state of intrusion detection on the rear side. At the same time, the mold clamping detection sensor 60 continues to output a detection signal and stop outputting a release signal. The rear intrusion detection sensor 40 continues to detect intrusion, and there is no safety problem. The B-type molded product removal S32 and B-type workpiece insert S34 can be carried out simultaneously with the injection step.

[0065] Next, in the A-molding completion S13b, the injection molding process ends. In the A-molding completion S13b, the output of the detection signal and the stop of the output of the release signal from the mold clamping detection sensor 60 are maintained. The intrusion detection by the rear intrusion detection sensor 40 and the release of the intrusion detection for the rear side by the front intrusion detection sensor 50 are maintained.

[0066] FIG. 11 is a front view showing the operation of the embodiment of the control method for the injection molding machine of the present embodiment. Next, in the A mold opening start S14a, the mold clamping device is driven to release the mold clamped state of the lower mold 7A as shown in Fig. 11. Then, in the mold clamping detection end S43, the intrusion detection by the rear side intrusion detection sensor 40 and the detection by the front side intrusion detection sensor 50 are switched. In mold clamping detection end S43, the mold clamping detection sensor 60 stops outputting the detection signal and outputs a release signal. Here, the mold clamping detection sensor 60 stops outputting the detection signal and outputs a release signal when the crosshead 20 rises and the upper mold 8 is released from pressing and contacting the lower mold 7A, and this state is maintained while the crosshead 20 is moving upward, and further while the crosshead 20 is stopped at the upper limit position. As the mold clamping detection sensor 60 stops outputting the detection signal and outputs the release signal, the intrusion detection state of the rear intrusion detection sensor 40 is released. At the same time, the intrusion detection state by the front intrusion detection sensor 50 is started.

[0067] Next, at the completion of mold A opening S14b, the crosshead 20 stops at the completed ascent position. The upper mold 8 and the lower mold 7B separate. The mold clamping detection sensor 60 continues to stop outputting the detection signal and to output the release signal. The rear intrusion detection sensor 40 is released from intrusion detection, and the front intrusion detection sensor 50 is maintained in the intrusion detection state.

[0068] Next, the turntable 2 rotates in table rotation S22. The lower mold 7A moves from the mold clamping area K1 to the molded product removal area K2, as shown in FIG. 6. The molded product completed in A-molding completion S13b is placed on the lower mold 7A. The lower mold 7B moves from the molded product removal area K2 to the mold clamping area K1. The lower mold 7B is positioned below the upper mold 8 so that it can be clamped. In the table rotation S22, the output of the detection signal is stopped and the output of the release signal is maintained in the mold clamping detection sensor 60. The release of the intrusion detection by the rear intrusion detection sensor 40 and the intrusion detection state by the front intrusion detection sensor 50 are maintained.

[0069] Next, in the B mold clamping start S15a, the mold clamping device is driven to release the mold open state of the lower mold 7B. The crosshead 20 descends, and the end plate 5 also descends. At the start of mold B clamping S15a, the output of the detection signal is stopped and the output of the release signal is maintained in the mold clamping detection sensor 60. The release of the intrusion detection by the rear intrusion detection sensor 40 and the intrusion detection state by the front intrusion detection sensor 50 are maintained.

[0070] Next, in mold B clamping completion S15b, at a position slightly before the upper mold 8 and the lower mold 7B come into contact, the mold clamping detection sensor 60 outputs a detection signal and stops outputting a release signal as mold clamping detection start S42. When the crosshead 20 further moves to the lower limit position, the mold clamping is completed as shown in FIG. 7. As the mold clamping detection sensor 60 outputs a detection signal and stops outputting a release signal, detection by the rear intrusion detection sensor 40 and detection by the front intrusion detection sensor 50 are switched. The intrusion detection state of the rear intrusion detection sensor 40 is started. At the same time, the intrusion detection state of the rear side by the front intrusion detection sensor 50 is released. Here, the state in which the mold clamping detection sensor 60 outputs the detection signal and stops outputting the release signal starts when the crosshead 20 is at a position slightly before the upper mold 8 and the lower mold 7B come into contact with each other, and is maintained even while the crosshead 20 is stopped at the lowest position. Therefore, this state is maintained even after the mold clamping force is applied to the upper mold 8 and the lower mold 7B.

[0071] Next, in the B-type injection start S16a, the injection process starts. At the start of B-type injection S16a, the output of the detection signal and the stop of the output of the release signal are maintained in the mold clamping detection sensor 60. The intrusion detection by the rear intrusion detection sensor 40 and the release of intrusion detection for the rear side by the front intrusion detection sensor 50 are maintained.

[0072] Next, in the A-type ejector advance S35, the ejector 71 operates in the molded product removal area K2. The ejector 71 rises relative to the lower mold 7A in the molded product removal area K2, and ejects the molded product from the lower mold 7A. In the A-type ejector advance S35, the mold clamping detection sensor 60 continues to output a detection signal and stop outputting a release signal. Intrusion detection by the rear-side intrusion detection sensor 40 and release of intrusion detection for the rear side by the front-side intrusion detection sensor 50 are maintained.

[0073] Next, in the A-type molded product removal step S36, the molded product is removed from the lower mold 7A in the molded product removal area K2 to the outside of the apparatus. At this time, an operator enters the molded product removal area K2, but the front intrusion detection sensor 50 continues to release intrusion detection on the rear side. At the same time, the mold clamping detection sensor 60 continues to output a detection signal and stop outputting a release signal. The rear intrusion detection sensor 40 continues to detect intrusion, and there is no safety problem.

[0074] Next, in the A-type ejector retraction S37, the ejector 71 retracts in the molded product removal area K2. The ejector 71 descends toward the lower mold 7A in the molded product removal area K2 and retreats from the lower mold 7A from which the molded product has been removed. In the A-type ejector retraction S37, the mold clamping detection sensor 60 continues to output a detection signal and stop outputting a release signal. Intrusion detection by the rear-side intrusion detection sensor 40 and release of intrusion detection for the rear side by the front-side intrusion detection sensor 50 are maintained.

[0075] Next, in the A-type workpiece insert S38, a workpiece is supplied from outside the apparatus to the lower mold 7A in the molded product removal area K2. At this time, an operator enters the molded product removal area K2 and places the workpiece in a predetermined position on the lower mold 7A, but the front intrusion detection sensor 50 continues to release intrusion detection on the rear side. At the same time, the mold clamping detection sensor 60 continues to output a detection signal and stop outputting a release signal. The rear intrusion detection sensor 40 continues to detect intrusion, and there is no safety problem. The A-type molded product removal S36 and A-type workpiece insert S38 can be carried out simultaneously with the injection step.

[0076] Next, the process returns to the B-molding completion step S10b, where the cycle in the control method for the injection molding machine of this embodiment is ended. Note that in the control method for the injection molding machine of this embodiment, the above cycle is repeated.

[0077] In the control method for the injection molding machine of this embodiment, the mold clamping detection sensor 60 detects the mold clamped state and the mold open state and outputs a detection signal and a release signal, and in response to these signals, it is possible to switch between intrusion detection by the rear intrusion detection sensor 40 and intrusion detection by the front intrusion detection sensor 50. As a result, intrusion detection by the front intrusion detection sensor 50 is performed during the mold clamping process, table rotation process, and ejector retraction process to ensure safety in the molded product removal area K2, and in the injection process, which requires work by an operator in the molded product removal area K2, switching to intrusion detection by the rear intrusion detection sensor 40 ensures safety in accordance with JIS standards. At the same time, it is possible to perform injection molding without reducing the manufacturing efficiency of the injection molding machine 10. [Explanation of symbols]

[0078] 10...Injection molding machine 1...Machine body 1a…Fixed board 2. Rotary table 3…Movable plate 4...Tie bar 5...End plate 7, 7A, 7B...Lower mold (mold) 8...Upper mold (mold) 11...Toggle mechanism 12, 14, 15...Toggle pins 13...Toggle piece 16...Facepiece 17...Connecting pin 18...Connecting piece 20...Crosshead 22...Screw shaft 40...Rear intrusion detection sensor 50...Front intrusion detection sensor 60...Mold clamping detection sensor K1: Clamping area K2: Molded product removal area

Claims

1. A control method for an injection molding machine having a mold clamping device that clamps an upper mold and a lower mold, comprising: the mold clamping device includes a rotary table to which the plurality of lower molds are attached, a fixed platen fixed to a machine body and rotatably supporting the rotary table from below, a movable platen provided above the fixed platen and fixed to upper ends of tie bars to which the upper molds are attached, a rotation mechanism that rotates the rotary table, and an elevation mechanism that elevates the movable platen, a mold clamping area in which the upper mold and one of the lower molds are clamped by raising and lowering the movable platen, and a molded product removal area in which a molded product molded in the mold clamping area is removed, a rear intrusion detection sensor provided between the mold clamping area and the molded product removal area to detect intrusion from the molded product removal area into the mold clamping area; a front intrusion detection sensor that detects intrusion into the molded product removal area from the outside; a mold clamping detection sensor that detects a mold clamping state between the upper mold and one of the lower molds; and When the mold clamping detection sensor detects a mold clamped state, the rear intrusion detection sensor detects intrusion, and When the mold clamping detection sensor detects that mold clamping is not being performed, the system switches to detecting intrusion using the front intrusion detection sensor. A method for controlling an injection molding machine, comprising:

2. The lifting mechanism includes an end plate fixed to the lower end of the tie bar below the fixed platen and movable up and down together with the movable platen relative to the fixed platen; a screw shaft whose upper end is journaled on the fixed platen and which is provided vertically below the fixed platen to prevent axial movement and which is rotated in a circumferential direction by a drive source; a crosshead screwed to the screw shaft so as to be movable up and down; and a toggle mechanism provided between the fixed platen and the end platen, which expands and contracts with the vertical movement of the crosshead to move the movable platen to open and close the mold, The mold clamping detection sensor detects mold clamping by detecting the position of the crosshead when the upper mold and one of the lower molds are in a mold clamped state.

2. The method for controlling an injection molding machine according to claim 1.

3. When the mold clamping detection sensor detects that mold clamping has been performed, the front intrusion detection sensor is switched so as not to detect intrusion.

2. The method for controlling an injection molding machine according to claim 1.

4. When an injection operation is performed on the upper mold and one of the lower molds, the intrusion is detected by the rear intrusion detection sensor.

4. The method for controlling an injection molding machine according to claim 3.

5. the rear-side intrusion detection sensor detects intrusion at a position in the molded product removal area that is closer to the mold clamping area than the lower mold.

4. The method for controlling an injection molding machine according to claim 1.

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