JP3506567B2 - Control method of injection molding machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for an injection molding machine, and more particularly to a control method for a mold clamping device having a mold opening / closing cylinder and a mold clamping cylinder. 2. Description of the Related Art In general, a composite mold clamping apparatus of an injection molding machine as shown in FIG. 1 is provided with a movable die plate 38 which is opposed to a fixed die plate 40 and inserted and supported via a tie bar 14.
A mold opening / closing cylinder 10 comprising a boost cylinder 16 disposed in parallel with the tie bar 14 for moving the mold forward and backward to perform a mold opening / closing operation, and a movable die plate closed with the fixed die plate 40 and the mold. And a mold clamping cylinder 20 provided with a ram mechanism 22 for pressing the mold 38 to perform a mold clamping operation. In this case, the mold opening / closing cylinder 10 is controlled via a mold opening / closing valve 36, and moves the movable die plate 38 with respect to the fixed die plate 40 to thereby move the movable mold 38a and the fixed mold 38, respectively. The mold opening / closing operation is performed with the mold closing cylinder 20.
2 and a predetermined mold clamping is performed on the two dies 38a and 40a. In addition, at the time of this mold clamping operation,
The tie bar 14 inserted into the movable die plate 38 opens and closes the half nut 12 controlled via the operation valve 32 and the operation cylinder 34 with respect to the threaded portion 14a, thereby connecting the movable die plate 38 to the tie bar 14. On the other hand, the movable die plate 38 is configured to be detachable so that the mold closed state by the movable die plate 38 is stably maintained. Reference numeral 30 in the drawing indicates a hydraulic pressure source. Therefore, according to the control method in such a combined type mold clamping apparatus, as shown in FIG. 4, for example, in the first step (the mold closing step), the mold opening / closing valve 36 is switched to b to move the movable die plate. 38 is advanced and both dies 38a, 40
a, the operation valve 32 is switched to b, and the half nut 12 is closed. Then, in the second step (clamping step), the mold clamping valve 42 is switched to a to switch the two molds 38a, 40a.
In a third step (mold cooling step), a molten resin is injected to form a molded article, and the molded article is cooled and solidified. Then, in a fourth step (mold opening step), a mold clamping valve is provided. 42 is switched to b to release the pressure, the operating valve 32 is switched to a, the half nut 12 is opened, and the mold opening / closing valve 36 is switched to a so that the movable die plate 38 is retracted to form the two dies 38a, 40a. By opening and removing the molded article in the fifth step (molded article removing step), the molded article by the injection molding machine can be produced automatically and continuously. [0005] However, the control method of the conventional injection molding machine has room for improvement as described below. That is, as described above, the conventional control method includes five steps of a mold closing step, a mold clamping step, a molding cooling step, a mold opening step, and a molded article removing step, and these five steps are sequentially performed in sequence. The control, that is, continuous control individually and independently, is configured so that a molded article can be continuously produced. However, the mold opening step, which is the fourth of the five steps, forms a preparatory mold opening step of releasing the pressure and opening the half nut, and retreats the moving die plate that is continuous with the step. And a substantial mold opening process. In the former preparatory mold opening process, at least all of the process time does not directly affect the molding or quality of the molded product. Therefore, in the conventional control method,
In the preparatory mold opening process, as in the other processes, the entire process time is sequence-controlled, that is, the cooling completion signal TRA of the preceding third process (mold cooling process) (see FIG. 4).
Is controlled to follow. For this reason, the molding cycle time T is actually unnecessarily extended, and as a result, the production efficiency is significantly reduced. Therefore, an object of the present invention is to set at least a part of the process time of the preparatory mold opening process (predetermined start process time) so as to be performed in parallel with the remaining process time of the preceding process. An object of the present invention is to provide a control method of an injection molding machine capable of shortening a molding cycle time and improving production efficiency. [0010] In order to achieve the above object, a control method of an injection molding machine according to the present invention comprises a mold clamping device having a mold opening / closing cylinder and a mold clamping cylinder. A mold closing step for closing the mold, a mold closing step for closing the closed mold, and a process of injecting a molten resin into the closed mold to mold the molded article and cool and solidify the molded article. A molding cooling process, a mold opening process of opening a mold to release a cooled and solidified molded product, and a molded product removal process of taking out a molded product are sequentially controlled to sequentially execute a molded product. In the control method, the mold opening step includes a preparatory mold opening step of depressurizing and opening a half nut, and a substantial mold opening step of retracting a moving die plate that is continuous with the fixed die plate. , The preparatory mold opening process Is controlled via a timer control system, which is set separately from the sequence control and starts operation a predetermined time before the completion of the preceding molding and cooling step , and the substantial mold
The opening step waits for the end of the molding cooling step to
It is characterized by control by the sense control . In the present invention, the preparatory mold opening step is controlled via a timer control system which starts its operation a predetermined time before the completion of the preceding molding and cooling step. In other words, the predetermined process time of the preparatory mold opening process is set in parallel with the remaining process time of the preceding molding cooling process within a range that does not affect the molding or quality of the molded product. You. Therefore, according to the present invention, the molding cycle time can be reduced as compared with the conventional control method of this kind,
It is clear that production efficiency can be improved. Next, an embodiment of a method for controlling an injection molding machine according to the present invention will be described in detail with reference to the accompanying drawings. First, in the present invention, an apparatus for implementing the control method is substantially the same as the conventional mold clamping apparatus (see FIG. 1), and the control process is the same as the conventional control step (see FIG. 1). 4). Therefore, the following description of the control method of the present invention will be made with reference to FIG. 1 based on FIG. 2 showing the control process of the present invention. That is, in FIGS. 2 and 1, the basic control process of the present invention is the same as that of the conventional case. In order to facilitate understanding, the description will be given again. In the first step (the mold closing step), the mold opening / closing valve 36 is switched to b, and the movable die plate 38 is advanced to move both the molds 38a,
While closing the mold 40a, the operating valve 32 is switched to b to close the half nut 12, and then the second step (clamping step)
In the above, the mold closing valve 42 is switched to "a" and the two molds 38a, 4
0a is clamped, and the third step (mold cooling step)
In the step (3), the molten resin is injected to mold the molded article, and the molded article is cooled and solidified. Then, in the fourth step (mold opening step), the mold closing valve 42 is switched to b to release the pressure, and the operation valve 32
Is switched to a, the half nut 12 is opened, the mold on-off valve 36 is switched to a, the movable die plate 38 is retracted to open the molds 38a, 40a, and the fifth step (molded article removal step) By taking out the molded product in the above, the molded product by the injection molding machine can be produced automatically and continuously. However, in the present invention, in the control step, the fourth preparatory mold opening step (depressurization and opening of the half nut) is the same as the conventional sequence control (see FIG. 4). It is set separately and is controlled by a timer control system by a preparation operation start setting timer TRB that starts its operation a predetermined time before the completion of the preceding third step (molding cooling step). That is, in this case, the preparation operation start setting timer TRB is set to operate a predetermined time ΔT before the cooling completion signal (TRA). The predetermined time (parallel operation time) ΔT is, of course, set within a range that does not affect the molding or quality of the molded product. Therefore, in the present invention,
Since the preparatory mold opening process is performed in parallel within the remaining process time ΔT of the preceding molding cooling process, the molding cycle time T ′ is also compared with the conventional molding cycle time T (see FIG. 4). Similarly, it can be shortened ΔT ′ (see FIG. 2). That is, in this case, as shown in FIG. 3, the respective molding cycle times T, T when the parallel operation time ΔT is not set (conventional) and when the parallel operation time ΔT is set for 2 seconds (the present invention). ', The difference (shortened) time Δ2 between the two was 2.05 seconds (about 10%).
It was confirmed that T 'occurred. Therefore, according to the present invention, since the molding cycle time T 'can be shortened, it is apparent that the production efficiency can be improved as compared with the conventional control method of this kind. Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and many design changes can be made without departing from the spirit of the present invention. That is, for example, removing and attaching the half nut,
If a tie bar is used instead of the tie bar, or if a preparatory process similar to the mold opening process described above is set in a process separate from the mold opening process, Even
It is possible to set the same parallel operation time as described above. As described above, the method for controlling an injection molding machine according to the present invention comprises a mold clamping apparatus having a mold opening / closing cylinder and a mold clamping cylinder, and the mold for closing the mold. A closing step, a mold clamping step of clamping the closed mold, a molding cooling step of injecting a molten resin into the clamped mold to mold the molded article, and cool and solidify the molded article, A mold opening step of opening the mold to release the cooled and solidified molded product,
In a control method of an injection molding machine, which is sequence-controlled so as to sequentially execute a molded product removing step of removing a molded product, the mold opening step includes a preparatory mold opening step of depressurizing and opening a half nut. consists of a substantial mold opening step of retracting away the movable die plate relative to a fixed die plate continuous to this, the preliminary mold opening process, the said sequence control was set separately, the shaped cooling said previous Controlled through a timer control system that starts operating a predetermined time before the completion of the step , wherein the substantial mold opening step includes the forming and cooling operation.
Waiting for the end of the rejection process
By that, a predetermined process time of preliminary mold opening process,
As long as it does not affect the molding or quality of the molded product, it can be set in parallel with the remaining molding time of the preceding molding cooling step, thereby effectively shortening the molding cycle time. . Therefore, according to the present invention, since the molding cycle time is shortened as described above, there is an advantage that the production efficiency can be greatly improved as compared with the conventional control method of this kind.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of a general device for implementing a control method of an injection molding machine. FIG. 2 is an explanatory diagram showing a control process according to an embodiment of a control method according to the present invention in the apparatus shown in FIG. FIG. 3 is a data diagram showing measured values of molding cycle times according to the control method of the present invention shown in FIGS. 2 and 4 and a conventional control method. FIG. 4 is an explanatory diagram showing a control step in the apparatus shown in FIG. 1 according to a conventional control method. DESCRIPTION OF SYMBOLS 10 Mold opening / closing cylinder 12 Half nut 14 Tie bar 14a Tie bar screw portion 16 Boost cylinder 20 Mold clamping cylinder 22 Ram mechanism 30 Hydraulic source 32 Operating valve 34 Operating cylinder 36 Mold opening / closing valve 38 Moving die plate 38a Moving mold 40 Fixed die plate 40a Fixed mold 42 Mold closing valve

──────────────────────────────────────────────────の Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 45/76 B29C 45/66

Claims (1)

(57) [Claims 1] A mold closing step for closing a mold, comprising a mold clamping device having a mold opening / closing cylinder and a mold clamping cylinder;
A mold clamping step of clamping the closed mold, a molding cooling step of injecting a molten resin into the clamped mold to mold the molded article, and cool and solidify the molded article; A mold opening step of opening the mold to release the article, and a control method of an injection molding machine that performs sequence control so as to sequentially execute a molded article removing step of removing a molded article, wherein the mold opening step is performed. A preparatory mold-opening step of opening the half nut by depressurizing, and a substantial mold-opening step of retracting and moving the moving die plate following the fixed die plate. The control is performed via a timer control system, which is set separately from the sequence control and starts operation a predetermined time before the completion of the preceding molding cooling step , and the substantial mold opening step is performed by the molding cooling step.
The method of controlling an injection molding machine, wherein the this <br/> be controlled by the sequence control waiting for enough for completion.