JP3977792B2 - Molding machine control method - Google Patents

Description

  The present invention relates to a process when it becomes difficult to release a molded product molded by a molding machine from a mold.

  Patent Document 1 discloses a technique for accurately measuring only the mold release force of a molded product by an ejector. Other methods for detecting the release force include a method of detecting a load applied to the ejector pin with a strain gauge or the like, or detecting the release force indirectly based on the length of the ejector protruding time.

  However, any of the above methods does not reflect the detection result of the mold release force in other controls, and cannot effectively avoid interruption of the automatic molding operation.

JP 2002-144383 A

  The present invention has been made in view of the above circumstances, and is a molding machine that controls to continue the automatic molding operation even when an appropriate response to the increase in the release force is made and even the occurrence of defects is concerned. An object is to provide a control method.

  In the present invention, when the ejector driving device of the molding machine is driven to release the molded product, the control device detects the driving force of the ejector, and when the driving force exceeds the first monitoring value, the spray device is turned on. The main feature is that when the driving force exceeds the second monitoring value, the molded product is transported to a location different from the location where the non-defective product is transported.

  The present invention provides a first monitoring value and a second monitoring value, operates the spray device when the ejector driving force exceeds the first monitoring value, and further the ejector driving force is the second monitoring value. Since the molded product is transported to a location different from the location where the non-defective product is transported, the appropriate response to the increase in the release force is taken, and the driving force is further increased to cause defects in the molded product. Even if there is a concern, automatic molding will continue and the production efficiency of the molded product will be significantly improved.

Embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a front view showing a main part of a molding machine for carrying out the present invention. FIG. 2 is a flowchart showing the control method of the present invention.

  As shown in FIG. 1, the molding machine 10 includes a mold clamping device 11 and an injection device (not shown) that supplies molten resin or the like to a mold cavity including a movable mold 3 and a fixed mold 6. . The molding machine 10 includes an injection molding machine, a compression molding machine, a transfer molding machine and the like having a mold clamping device 11, and the molding material is rubber, metal or ceramic in addition to thermoplastic and thermosetting plastics. May be. The mold clamping device 11 moves the movable plate 1 close to and away from the fixed plate 5 by opening / closing / pressing means (not shown), and the movable die 3 attached to the movable plate 1 is fixed to the fixed plate 5. After contacting the mold 6, the movable mold 3 and the fixed mold 6 are pressed.

  After the molten resin or the like is solidified after the mold cavity formed by the movable mold 3 and the fixed mold 6 is filled, the molded product 4 is formed, and the movable plate 1 is separated from the fixed plate 5. Open the mold. In the situation shown in FIG. 1, the ejector driving device 2 attached to the anti-movable mold 3 side of the movable platen is operated, and the drive member of the ejector driving device 2 penetrating the movable platen 1 is the ejector of the movable die 3. The pin is pressed, and the ejector pin protrudes the molded product 4 to release the molded product 4 from the movable mold 3.

  The ejector drive device 2 includes a hydraulic cylinder or a combined mechanism such as a servo motor, a ball screw, and a ball nut. The drive force of the ejector of the ejector drive device 2 is obtained from a hydraulic sensor provided in the hydraulic cylinder, a strain gauge provided in the ejector pin, a current sensor of a current flowing through the servo motor, or the like, and is input to the control device 9 as a drive force signal 12. Is done. If the ejector driving device 2 is composed of a servo motor, the control device 9 outputs a current for driving the servo motor, so that a current signal can be obtained in the process. May be unnecessary.

  The molded product 4 released from the movable mold 3 by the ejector is automatically dropped or taken out by a separately prepared take-out device and conveyed outward from between the movable platen 1 and the fixed platen 5.

  The spraying device 7 is often attached to the above-described take-out device, and is attached to the upper surface of the fixed platen 5, and after the molded product 4 is taken out, the mold cavity surface of the movable mold 3 and / or the fixed mold 6. Furthermore, in order to improve the mold release of the molded product 4, it is an apparatus for spraying a mold release agent. An arm 15 is provided between the movable mold 3 and the fixed mold 6 so as to move up and down, and a plurality of nozzles 8 on which a release agent is sprayed are provided at the tip of the arm 15 as necessary. . A signal for instructing the spraying time and the amount of spraying is transmitted from the control device 9 to the spraying device 7.

  The control device 9 is a programmable device configured based on a microprocessor, and stores a CPU as a central processing unit, an operation unit for setting and inputting molding conditions and the like, a set value, a constant, and a program. A storage unit such as a RAM / ROM, an input unit that inputs a driving force signal 12 from the ejector driving device 2 and is connected to a thermocouple of the heating cylinder and various manual switches, an ejector driving device 2 and a spray device 7 (an extraction device) ) And output signals connected to the operation unit. The control device 9 controls the temperature of the heating cylinder in addition to controlling the speed and force of the mold clamping device 11, the ejector driving device 2, the injection device, and the like of the molding machine 10 by sequence control.

  Next, the operation will be described with reference to FIG. First, a drive signal 13 is transmitted from the control device 9 to the ejector drive device 2, and the ejector is projected and driven (S1). The driving force of the ejector is detected by various methods as described above (S2). The drive force of the ejector varies depending on the shape of the molded product. That is, as the molded product 4 has a box shape and the depth of the box is deeper, a larger driving force is required. Also, a large driving force is required when the shrinkage rate of the raw material is large and the molded product 4 is firmly attached to the core of the mold when solidified. Furthermore, the mold release property may be deteriorated depending on the surface shape of the mold cavity. In any of the above cases, the releasability strongly depends on the temperature of the mold cavity and the temperature of the molten resin.

  At the start of molding, the optimum driving force based on the above situation is determined. That is, when the driving force is set to be relatively low, it becomes difficult to release when the release property deteriorates due to a temperature change or the like, and the automatic molding operation stops. On the other hand, when the driving force is set relatively high, the molded product 4 is forcibly pushed by the ejector pin when the releasability deteriorates due to a temperature change or the like, and the ejector pin pressing portion of the molded product 4 is whitened or deformed. As a result, the molded product 4 becomes defective. Therefore, at the start of molding, the driving force is set low enough to prevent the molded product 4 from being defective, and the measured driving force at the time of molding is stored in the storage unit of the control device 9. Then, the first monitoring value is set by adding a predetermined value as a margin to the stored driving force, and the second monitoring value is set by adding another predetermined value to the first monitoring value. To do. Thus, the first monitoring value is set to a value smaller than the second monitoring value.

  When the detected driving force of the ejector does not reach the second monitoring value and the first monitoring value, the flowchart of FIG. 2 is led to S3 and S5, respectively, so that no special processing is performed after the ejector is driven. The molded product 4 is taken out by the take-out device and conveyed to a predetermined good product location. When the detected driving force does not reach the second monitoring value (S3) and exceeds the first monitoring value (S5), the control device 9 transmits a driving signal 14 to the spraying device 7 to cause the spraying device 7 to move. Operate (S6). This operation includes an operation of changing the spray amount by increasing / decreasing the amount of spray according to the amount of deviation from the first monitoring value of the driving force, in addition to an operation of changing the spray of the release agent on and off to change it intermittently. Including. As described above, when the releasability deteriorates during the continuous molding, the release agent is first sprayed to improve the releasability. At this time, the molded product 4 is taken out by the take-out device in the same manner as described above, and is conveyed to a predetermined good product place.

  Further, when the detected driving force exceeds the second monitoring value while the molding is continued (S3), the control device 9 transmits a driving signal to the take-out device and the place where the molded product 4 is conveyed by the non-defective product It is conveyed to a different place (S4). In addition, the said conveyance may be performed with a conveyor etc. irrespective of a taking-out apparatus. In this way, the pseudo-goods that are conveyed separately from the non-defective products are inspected when they are appropriately accumulated, and defective products such as whitening and deformation mixed together are removed.

  In addition, this invention includes what can be implemented in the aspect which added various change, correction, improvement, etc. based on the knowledge of those skilled in the art. Further, it goes without saying that any of the embodiments to which the above-described changes are added is included in the scope of the present invention without departing from the gist of the present invention.

It is a front view which shows the principal part of the molding machine which implements this invention. It is a flowchart which shows the control method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Movable board 2 Ejector drive device 3 Movable metal mold 4 Molded product 5 Fixed board 6 Fixed metal mold 7 Spraying device (extraction device)
8 Nozzle 9 Control device 10 Molding machine 11 Clamping device 12 Driving force signal 13, 14 Driving signal 15 Arm

Claims (1)

When the ejector driving device of the molding machine is driven to release the molded product by the ejector, the control device detects the driving force of the ejector and operates the spray device when the driving force exceeds the first monitoring value. Then, when the driving force exceeds a second monitoring value that is larger than the first monitoring value , the molded product is transported to a location different from the location where the non-defective product is transported to avoid interruption of the automatic molding operation. A control method for a molding machine.

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