JP-7856505-B2 - Clamping device and injection molding machine

JP7856505B2JP 7856505 B2JP7856505 B2JP 7856505B2JP-7856505-B2

Inventors

三谷聡麻

Assignees

株式会社日本製鋼所

Dates

Publication Date: 20260511
Application Date: 20220624

Claims (2)

Two molds, Multiple ball screw mechanisms connecting the aforementioned panel boards, Multiple servo motors are provided on each of the multiple ball screw mechanisms to drive the ball screw mechanisms, A control device is provided, The control device is configured to independently control the servo motor based on multiple axial force setting values set for each of the multiple ball screw mechanisms. Multiple axial force setting values are set in the control device based on constraints that define the allowable ranges within which they can be set mutually. A clamping device in which, when the maximum value among the multiple axial force setting values set for each of the multiple ball screw mechanisms is set as the maximum axial force setting value, the constraint condition is that the difference between the other axial force setting values and the maximum axial force setting value is less than or equal to an allowable difference amount, and the allowable difference amount decreases as the maximum axial force setting value increases .
A mold clamping device for clamping the mold, It consists of an injection device for injecting injection material, The clamping device comprises two mold plates, Multiple ball screw mechanisms connecting the aforementioned panel boards, Multiple servo motors are provided on each of the multiple ball screw mechanisms to drive the ball screw mechanisms, A control device is provided, The control device is configured to independently control the servo motor based on multiple axial force setting values set for each of the multiple ball screw mechanisms. Multiple axial force setting values are set in the control device based on constraints that define the allowable ranges within which they can be set mutually. An injection molding machine in which, when the maximum value among the multiple axial force setting values set for each of the multiple ball screw mechanisms is set as the maximum axial force setting value, the constraint condition is that the difference between the other axial force setting values and the maximum axial force setting value is less than or equal to an allowable difference amount, and the allowable difference amount decreases as the maximum axial force setting value increases .

Description

This invention relates to a mold clamping device and an injection molding machine, comprising two mold plates and a plurality of ball screw mechanisms connecting these mold plates. Injection molding machines or presses are equipped with a mold clamping device for securing the mold. While there are various types of mold clamping devices, Patent Document 1 describes a mold clamping device consisting of two mold plates. Specifically, the mold plate consists of a fixed plate and a movable plate. The fixed and movable plates are connected by four sets of ball screw mechanisms, each of which is equipped with a servo motor. Therefore, driving the four servo motors drives the four sets of ball screw mechanisms, causing the movable plate to slide relative to the fixed plate. In other words, the mold opens and closes. Japanese Patent Application Publication No. 5-269748 This is a front view showing the injection molding machine according to this embodiment.This is a perspective view showing the clamping device according to this embodiment.This is a plan view of the movable platen according to this embodiment.This is a front view of the clamping device according to this embodiment.This is a flowchart showing the method for inspecting the axial force setting value according to this embodiment.This graph shows the constraints applied in the inspection method for axial force setting values according to this embodiment.This is a graph showing the constraints related to Modification Example 1.This graph shows the constraints related to Modification Example 2. The following describes specific embodiments in detail with reference to the drawings. However, the invention is not limited to the embodiments described below. For clarity, the following descriptions and drawings have been simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanations have been omitted where necessary. Furthermore, hatching has been omitted in some areas to avoid cluttering the drawings. <Injection molding machine according to this embodiment> As shown in Figure 1, the injection molding machine 1 according to this embodiment consists of a clamping device 2 provided on the bed B, an injection device 4, and a control device 5 that controls these. <Injection device> The injection device 4 consists of a heating cylinder 6, a screw 7 placed inside the heating cylinder 6, and a screw drive device 8 that drives the screw 7. The heating cylinder 6 is provided with a hopper 10, and an injection nozzle 11 is provided at its tip. Injection material is fed from the hopper 10, and when the screw 7 is rotated and the injection material is melted, it is metered at the tip of the screw 7. When the screw 7 is driven in the axial direction, the injection material is injected. <Mold clamping device> The mold clamping device 2 according to this embodiment consists of a so-called two-platen mold clamping device. That is, as shown in Figure 2, the mold clamping device 2 comprises two platens 13 and 14, i.e., a fixed platen 13 and a movable platen 14. The fixed platen 13 is fixed on the bed B, and the movable platen 14 is placed on linear guides 15, 15 provided on the bed B. That is, the movable platen 14 is slidable in the direction of approaching and moving away from the fixed platen 13. As shown in Figure 1, a fixed-side mold 16 is attached to the fixed platen 13, and a movable-side mold 17 is attached to the movable platen 14. It is preferable that the fixed-side mold 16 and the movable-side mold 17 be placed at the center of the platen on the fixed platen 13 and the movable platen 14, respectively, but there are cases where they must be placed at a position offset from the center. Figure 1 shows how these molds 16 and 17 are placed at a position offset above the center of the platen. The clamping device 2 according to the first embodiment has two mold plates 13 and 14, that is, a fixed plate 13 and a movable plate 14, connected by four rod-shaped members, that is, four ball screw mechanisms 18, 18, ... Each ball screw mechanism 18, 18, ... comprises a ball screw 19, 19, ... and ball nuts 20, 20, ... attached to the ball screws 19, 19, ... Although not shown in Figure 2, the movable platen 14 has through holes, and ball nuts 20, 20, ... are fixed to these through holes. That is, one end of each ball screw 19, 19, ... is connected to the movable platen 14 via the ball nuts 20, 20, .... The other end of each ball screw 19, 19, ... passes through the fixed platen 13 and is rotatably supported relative to the fixed platen 13. The fixed platen 13 is equipped with servo motors 22, 22, ..., which are connected to the ball screws 19, 19, .... Therefore, when the servo motors 22, 22, ... are driven, the ball screws 19, 19, ... rotate, causing the movable platen 14 to slide. In other words, the molds 16, 17 (see Figure 1) are opened and closed. <When the axial force setting value is constant> In this embodimen