JP2593372B2 - Control method of injection molding system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an injection molding system suitable for use in an automated factory or an unmanned factory.

[0002]

2. Description of the Related Art Generally, in the production of molded articles by an injection molding machine, production control and quality control are performed for each container (each production lot). The container stores the molded product and is usually set near the injection molding machine. When the number of articles stored in the container reaches the specified quantity, the container (container) containing the articles is moved, and an empty container is set instead. For this reason, switching control for switching from a container to an empty container is required.

Conventionally, in such a container switching control, the number of molding shots corresponding to the number of molded articles to be produced is set in advance in a controller of a molding machine as a switching set value, and is incorporated in the controller during production. The number of molding shots (the number of non-defective products) is counted by a counter that performs the switching, and when the number of molding shots reaches the switching set value, switching is performed by outputting a switching signal. In this case, when the switching of the container is performed artificially by the operator, the switching signal activates an alarm or other notification means, and
When switching containers automatically, the automatic switching conveyor is operated by a switching signal.

On the other hand, unmanned or automated injection molding plants are increasing. In a factory of this type, if the above-mentioned switching signal is output from an arbitrary molding machine, an automatic switching conveyor is operated to switch containers, and at the same time, a request command is sent to a robot car (automated guided vehicle) traveling in the factory. Is issued. Upon receiving the request command, the robot car transports the empty container to the molding machine that issued the request, sets the empty container at a predetermined position, collects the container, and transports the container to the next process or a warehouse.

[0005]

However, the conventional control method associated with such a switching process has the following problems.

That is, when the operator switches the container, the operator starts the switching operation after recognizing the alarm or the like by the switching signal, so that a certain time delay occurs. Therefore, at the time of switching, the number of shots of the molding machine has already progressed by several shots, and the number of molded articles stored in the container exceeds the specified number (switching set value). Can not. Particularly, in an injection molding factory, one operator often manages several to several tens of units, so that it is difficult to cope with a case where switching signals are simultaneously generated in a plurality of molding machines. In order to solve this problem, the molding shot of the molding machine may be stopped when the switching set value is reached, but on the other hand, the idle time of the molding machine increases and the operation rate decreases, Unstable factors associated with the stoppage of operation cause defective products. The same applies to the case where containers are switched by an automatic switching conveyor, and an operator prepares an empty container or unloads a storage container.

[0007] On the other hand, similar problems arise in the case of an unmanned or automated injection molding factory. Normally, one robot car is in charge of about twenty molding machines, but even if a request command is issued to the robot car based on the output of the switching signal described above, the robot car issues a request from the standby state. It takes some time to move to the molding machine. This time tends to increase as the number of molding machines increases, and it often takes about 3 to 5 minutes. In this case, the container holding the produced molded product is in a standby state in the molding machine, so if the molded product is used as it is in the next process, the standby time is lost time, and the production process is delayed and the next process is performed. It will have an adverse effect.

The present invention has been made to solve the problems existing in the prior art, and enhances the production efficiency by appropriately switching processing in the production process and eliminating time loss in the production process, and at the same time, the production cycle is improved. An object of the present invention is to provide a control method of an injection molding system that can contribute to improving productivity and reducing costs by increasing the speed and shortening the molding tact.

[0009]

The present invention comprises a plurality of injection molding machines M1, M2, M3... Mn.
When a predetermined switching process is performed in the production process of..., A switching set value Dc corresponding to the number of molded articles to be produced before the switching process is performed in each injection molding machine M1.
(Including the total production quantity set value Dy)..., And when the quantity of produced molded articles reaches the switch set value Dc. In the control method of S, in advance for each of the injection molding machines M1..., A notice set value Ds (Dx) smaller than a set change value Dc. ) Is set, and when the quantity of produced molded articles reaches the notice set value Ds (Dx)... Corresponding to the container switching processing, an advance notice signal is output, and the quantity of produced molded articles is changed to the container switching processing. Until the switching set value Dc... Corresponding to the above is reached, a predetermined preparation process is performed to prevent a delay in transport of the container due to the switching process from the storage container Cf storing the produced molded product to the empty container Co. ,other When the quantity of the produced articles reaches the notice set value Ds (Dx)... Corresponding to the switching processing accompanying the production completion, an advance notice signal is output, and the quantity of the produced articles is switched to the setting for the production completion. Until the value Dc is reached, preparation processing for the next production including die preparation is performed, and each preparation processing is performed based on advance notice signals output from the plurality of injection molding machines M1. .. Are performed according to the optimum processing pattern.

[0010]

According to the control method of the injection molding system according to the present invention, first, the quantity of the produced molded product is set to the notice set value Ds.
, A notice signal is output at this point.

In this case, the notice set value Ds (Dx) is set as a value smaller than the switch set value Dc, so that when the number of molded articles reaches the notice set value Ds (Dx), the switch set value Dc is changed to the switch set value Dc. Until the predetermined time is reached, a predetermined preparation time is secured, and during this preparation time, the preparation processing relating to the predetermined switching processing is executed. If the switching process is a container switching process, the preparation process is executed as an operation of a notification unit such as an alarm for waiting an operator, preparation of an empty container Co, standby of the robot car E, and the like. If the switching process is a switching process associated with the completion of the production, the switching process is performed as preparation of a die to be used for the next molding.

On the other hand, if the number of produced molded articles reaches the switching set value Dc, a switching signal is output at this time. As a result, a switching process such as a container switching process or a die exchange is performed. In this case, the setting of the empty container Co and the storage container Cf are performed by the preparation processing already executed.
The transfer to the next process, the mold change, and the like are performed promptly without causing a time delay.

When the notice signal is output from the plurality of injection molding machines M1 at substantially the same time, the plurality of injection molding machines M1 are output.
1 ... the most suitable processing pattern, for example, the rank of the most efficient molding machine M1 ..., the traveling route of the robot car E,
Preparation system etc. are set comprehensively.

[0014]

Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, an outline of an injection molding system S in an automated injection molding factory capable of implementing the control method according to the present invention will be described with reference to FIGS.

In FIG. 2, S denotes an injection molding system, which includes a plurality of injection molding machines M installed in an injection molding factory.
1, M2, M3... Mn. Each molding machine M1 is provided with an interface having an optical communication function, and is connected to the group management computer system H via optical fiber cables V1, V2, V3... Vn, and an optical interface (RS-232C or the like) communication line Z. . The group management computer system H always performs bidirectional communication with six personal computers, that is, each molding machine M1..., And thereby collects data relating to the operating state, production state, quality state, etc. of the molding process in each molding machine M1. To collect, production plans,
An on-line processing computer 11 for transmitting setting data such as molding conditions to each molding machine M1, a server computer 12 for filing data or setting data collected from each molding machine M1, and a data collected by the server computer 12. A production control computer 13 for performing production control based on the data, a quality control computer 14 for performing quality control based on the data collected by the server computer 12, and a die maintenance based on the data collected by the server computer 12. The system includes a computer 15 for performing die maintenance and a system control computer 16 for controlling a robot car E, a material supply device (not shown), and the like, which will be described later, according to the production status of each molding machine M1. They are connected by LAN.

The production management computer 13 is connected to a printer 17 for printing out collected data and setting data, and a bar code reader 18 for reading bar codes such as management labels. A printer 19 for printing out data collected from each of the molding machines M1 through the communication line Z is connected. In this case, since the recording sheet 20 of the printer 19 can be used in common for each molding machine M1, an event time display area and a plurality of event content display areas corresponding to each injection molding machine M1 are provided on the recording sheet 20. When an event such as an abnormal occurrence of each molding machine M1, a change in the operation state of the molding process, or a change in the production state occurs, the occurrence time is displayed in a time display area, and the event content (including a product container number and the like). Are recorded in real time in the event content display areas corresponding to the respective molding machines M1.

Each of the computers 11 to 16 is distributed and installed in a manufacturing section, a production control section, a quality control section, and a mold section, and data necessary for each section is transmitted in real time.

On the other hand, in each of the injection molding machines M1, for example, as shown in FIG. 3, the molding machine M1 has an injection device 21 having a heating cylinder 21h, a mold device 22 covered with a safety door 22s, and a mold. A mold clamping device 23 for opening and closing the mold device 22 is provided, and a molded product falling path 24 is provided below the mold device 22.
In addition, when a defective product occurs in the molded product falling path 24,
A reversing shooter 25 for transferring the defective product to a defective product storage box (not shown) is provided. Also, an automatic switching conveyor 26 is installed below the molded article falling path 24, and the conveyor 2
6, two containers C are set. One container C is disposed directly below the molded article falling path 24, and the other container C stands by behind the container C. In addition, a shutter is attached to the molded article falling path 24, and when the container C is switched by the operation of the automatic switching conveyor 26, scattering of the molded article is prevented by the shutter.

Thus, the molded product formed by the molding machine M1 falls through the molded product falling path 24 after the mold is opened, is stored in the container C, and the number of the molded products stored in the container C is reduced. When the set predetermined number is reached, the automatic switching conveyor 26 is operated, and the front container C (storage container Cf) in which the molded articles are stored is sent forward, and instead, the rear container C (empty container Cf). The container Co) is set immediately below the molded article falling path 24. Reference numeral 27 denotes a label printer for issuing a management label, which is installed near the molded article falling path 24 so that the issued management label automatically falls into the storage container Cf.

A robot car E with a lifter, which is controlled by a command from the group management computer system H, travels along the traveling path R around each molding machine M1. Empty container Co into each molding machine M
And transport the storage container Cf in each molding machine M1 to the next process, a product warehouse, a stock yard, and the like.

Next, a control method according to the present invention will be described with reference to the flowchart of FIG.

First, the controller of the molding machine M1 (the same applies to the other molding machines M2,...) Stores the total production quantity of the molded product (product or molded product formed by one shot) with the total production quantity set value. A production quantity setting unit to be set as Dy, a total production quantity notification setting unit to set a total production quantity notification setting value Dx smaller than the total production quantity setting value Dy, and a prescribed quantity of molded articles that can be accommodated in the container C. A switching quantity setting section for setting the switching set value Dc, and various setting sections such as a notice quantity setting section for setting a notice setting value Ds smaller than the switching setting value Dc are provided separately for each molding machine M1. Is set. In this case, when a request command is issued from each molding machine M1 to the robot car E, the advance set value Ds is set to a position where the empty container Co is transported to the molding machine M1 that has issued the request and the storage container Cf is received. Can be set in consideration of the time until waiting. That is, specifically, the number of molded articles molded in this time can be set by the quantity obtained by subtracting the quantity from the switching set value Dc. The control device has a built-in counter for counting the number of molded articles (the number of molded shots).

Then, any molding machine, for example, molding machine M1
When the molding (production) is performed in, the number of molding shots is counted by a counter built in the control device of the molding machine M1 (steps 31 and 32). When the counter value reaches the notice setting value Ds, a notice signal is output (steps 33 and 34), and this notice signal is transmitted to the group management computer system H via the communication line Z, and predetermined preparation processing is performed. (Step 35). That is, the computer system H receives the advance notice signal to perform the transport scheduling for the molding machine M1, and the system control computer 16 gives a command to the robot car E based on the scheduling. This allows
The robot car E transports the empty container Co to the molding machine M1 and stands by. Thus, the preparation processing ends.

On the other hand, the notice setting value Ds is set so that the time when the preparation processing is completed and the time until the quantity of the molded products reaches the switching setting value Dc are almost the same. At approximately the same time as when the process is completed, the number of molded articles reaches the switching set value Dc (step 36). As a result, a switching signal is output from the control device (step 37), and a switching process for the container C is performed (step 38). That is, the automatic switching conveyor 26 operates, and the front container C (storage container Cf) in which the molded product is stored is sent forward, and instead, the rear container C is stored.
(Empty container Co) is set immediately below the molded article falling path 24, and the counter of the control device is reset to zero (step 39).

When the switching process of the container C is completed, the robot car E sets the empty container Co at a predetermined position (standby position) on the automatic switching conveyor 26 and sets the waiting container Cf in the next step. Transport to In this way, by the switching process for the container C, the transport of the related empty container Co and the storage container Cf is performed normally without a time delay.

By the way, when a plurality of advance notice signals are issued from a plurality of molding machines M1 at substantially the same time and a plurality of advance notice signals are transmitted to the group management computer system H, the system H can execute the most efficiently. The processing order for the molding machines M1,..., The traveling route of the robot car E, the preparation system, and the like are comprehensively determined, and a processing pattern for that is set. Then, the robot car E moves according to the processing pattern.

On the other hand, the same processing is performed when the production proceeds and the production is approached, and the number of molded articles to be produced reaches the total production quantity notice set value Dx. That is, the advance notice signal is output, and the robot car E transports the mold to the molding machine where the request is issued and stands by. Thus, the preparation processing ends. And the quantity of the molded product is the total production quantity set value D
When y has been reached, the molding machines M1... can be stopped to perform a mold replacement process (switching process).

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment.
For example, in a case where an operator performs an artificial change of a mold due to a changeover of a container or a completion of the production, the preparation process is an operation of a notification unit such as an alarm by a notice signal. Further, the set values such as the switching set value and the notice set value can be set based on the number of products, time, etc., in addition to the number of molding shots. Furthermore, the switching process and the preparation process include, of course, processes other than those illustrated. In addition, it is possible to arbitrarily change the configuration, technique, and the like of the details without departing from the gist of the present invention.

[0030]

As described above, according to the control method of the injection molding system according to the present invention, the advance setting smaller than the switching set value corresponding to the switching process associated with the completion of the production such as the container switching process and the die exchange is performed. When the value is set and the quantity of molded articles reaches the notice setting value corresponding to the container switching process, an advance notice signal is output, and the quantity of molded articles to be produced corresponds to the switching setting value corresponding to the container switching processing. In the meantime, a predetermined preparation process is performed to prevent a delay in transporting the container due to the switching process from the storage container storing the produced molded product to the empty container, while the quantity of the produced molded product is reduced. When the notice set value corresponding to the switching process accompanying the production completion is reached, a notice signal is output, and the next time including the die preparation, until the quantity of the molded articles to be produced reaches the switch set value accompanying the production completion. Raw It performs a preparation process for the,
Each preparation process is performed based on advance notice signals output from a plurality of injection molding machines in accordance with an optimal processing pattern for a plurality of injection molding machines. It is possible to improve production efficiency ideally by optimizing the switching process and eliminating time loss in the production process, and to contribute to improvement of productivity and cost reduction by speeding up production cycle and shortening molding tact. Has a remarkable effect.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a control method according to the present invention;

FIG. 2 is a schematic configuration diagram of an injection molding system in an injection molding factory;

FIG. 3 is a partial external view of an injection molding machine showing a container,

[Explanation of symbols]

 M1 ... Injection molding machine Cf Storage container Co Empty container Dc Switching setting value Ds Notice setting value Dx Notice setting value S Injection molding system

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-128820 (JP, A) JP-A-2-145314 (JP, A) JP-A-2-147226 (JP, A) JP-A-2- 165928 (JP, A) JP-A-62-249722 (JP, A) "Plastics" Vol. 40, No. 8 (August 1989) pp. 45-51

Claims (1)

(57) [Claims] When a predetermined switching process is performed in a production process of each injection molding machine, a plurality of injection molding machines are provided. In each of the injection molding machines, a molded product to be produced before the switching process is performed is determined. A switching setting value corresponding to the quantity is set, and when the number of produced molded articles reaches the switching setting value, in the control method of the injection molding system in which a switching signal is output and a predetermined switching process is performed, For each injection molding machine, a notice setting value smaller than the switching setting value corresponding to the container switching process and the switching process accompanying the completion of production such as mold replacement is set in advance, and the number of produced molded products is switched. When the notice set value corresponding to the processing is reached, a notice signal is output, and the produced articles are stored until the quantity of the produced articles reaches the switch set value corresponding to the container switching process. container If a predetermined preparation process is performed to prevent a delay in the transport of the container due to the switching process from the empty container to the empty container, on the other hand, if the number of produced molded articles reaches the notice set value corresponding to the switching process following the production completion , Output a notice signal, and perform the preparation processing for the next production including the die preparation until the quantity of the molded products to be produced reaches the switching set value accompanying the production completion. A control method for an injection molding system, characterized in that an optimum processing pattern is applied to a plurality of injection molding machines based on advance notice signals output from the plurality of injection molding machines.