JPH01229609A - Method for automatically changing molding condition in injection molder - Google Patents

Abstract

PURPOSE:To smoothly perform the molding at start and consequently prevent defective product from developing by a method wherein injection molding is done by collating the molding conditions and monitoring conditions with data stored in the memory of an electronic controlling device and actual result data are gathered in said memory so as to be transferred to an injection molding on the basis of the next molding conditions on reference to said data. CONSTITUTION:Injection molding is done on molding conditions A, which are obtained by reading data stored in a memory part of molding conditions at start 10-5 and actual result data are stored in a memory part of actual result data 10-2. By collating stored data with instructed data, the proceeding to next stage is judged to be possible or not. When the proceeding to next stage is intended, injection molding is done on the basis of molding conditions B, which are in line with basic molding conditions and, after the elapse of time T1 with a timer 10-6, changed. The actual result data at that time are stored in the memory part of actual result data 10-2. By comparing stored data with instructed data, the proceeding to next stage is judged again to be possible or not. The actual results of molding are stored without a break. If abnormality is judged, alarm is issued by an alarming device 18 and, at the same time, controlling is done by automatically changing the molding conditions to those as was before change and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for automatically changing molding conditions in an injection molding machine.

(Prior Art) Conventionally, in an injection molding machine, an operator changes the molding conditions of the molded product, such as injection speed, injection speed switching position, metering position, holding pressure, and time, as appropriate during injection molding. I try to do it.

(Problems to be Solved by the Invention) However, in injection molding, the molding conditions for producing good products, such as injection speed, injection speed switching position,
The metering position, holding pressure, time, etc. differ somewhat from when molding is started and after a certain number of shots have been repeated. In other words, when the molding operation starts for the first time, the temperature conditions of the mold, cylinder, oil temperature, etc., and the cross-wire condition of the resin are not stable, so defective products occur before a continuous upward (downward) trend is shown. There was a problem with doing so.

Therefore, in the past, when starting up molding, all of a certain number of shores were treated as defective products, and the molding conditions were changed by an experienced operator looking at the molded product. .

In this way, conventional methods have poor product yields,
It is difficult to stabilize the production of non-defective products, and changing the molding conditions requires an operator, which requires skill and is also problematic in terms of quick response and economy. An object of the present invention is to provide a method for automatically changing molding conditions in an injection molding machine, which can quickly and automatically switch molding conditions sequentially and gradually shift to stable conditions based on the above.

(Means for Solving the Problems) The present invention provides a method for automatically changing molding conditions in an injection molding machine. Molding is performed, performance data is collected in the memory of the electronic control device, and while referring to the data, injection molding is performed under the next molding condition, leading to the normal injection molding stage.

(Function) According to the present invention, certain basic molding conditions and molding and monitoring conditions for the start-up molding stage are set in advance, and after the start of molding, performance data is collected in the memory of the electronic control device. It is possible to automatically change molding conditions to ensure smooth molding at start-up and avoid producing defective products. Further, after transitioning to normal injection molding, if seven consecutive shots show an upward or downward trend, conditions related to performance data showing that trend are automatically changed.

The amount of manipulation of the molding condition parameters (for example, how much to change the holding pressure) can be set by the operator in advance, for example, in percent units.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an injection control device of an injection molding machine to which the present invention is applied.

In the figure, 1 is an injection cylinder, 2 is a screw, 3 is a hydraulic motor for screw rotation, 4 is a mold, 5 is a digital displacement detector, 6 is a speed detector, 7 is a screw tachometer, and 8.9 is a pressure detection The electronic control device 10 includes a CPU (Central Processing Unit) 10-1, a performance data storage unit 10-2 consisting of a RAM, and a ROM consisting of a molding condition and a monitoring condition (upper limit value). , lower limit value), etc., in the storage unit 10-
3. Interface section 10-4, storage section 10-5 for molding conditions at startup consisting of ROM, timer (counter)
10-6, a conversion unit (table) 10-7 for converting monitoring conditions and manipulated variables of molding parameters, and a manipulated variable storage unit 10-8 for molding parameters consisting of a ROM. 11 is an input/output device for data such as basic molding conditions operated by the operator, molding conditions at start-up, and monitoring conditions; 12 is a screw rotation speed regulator; 13 is a servo valve; 14 is a screw back pressure regulator; 15 is a holding pressure regulator, 16 is an injection speed regulator,
17 is a servo valve.

In addition, as shown by the dotted line, a resin temperature sensor 20 and a mold temperature sensor 21 are provided to detect temperature-related data, input it to the control device 10, and output data related to resin temperature control from the control device 10. Needless to say, the resin temperature can be controlled as shown by the dotted line.

FIG. 3 is a diagram showing monitoring conditions (judgment conditions) and molding conditions used for automatically changing molding conditions in the injection molding machine of the present invention.

First, the monitoring conditions are (1) injection time, (2) pre-injection position, (3) V-P switching position, (4) holding pressure completion position,
(5) Cushion position, and (6) Measuring time. Each item has an upper limit and a lower limit. Note that these monitoring conditions are stored in the monitoring condition storage unit 10- of the control B device 10 described above.
3 is stored.

Each of these monitoring conditions is associated with a molding condition parameter as shown in FIG. In this condition parameter example, ■, is the filling speed of the first stage, ■2 is the filling speed of the second stage, ■3 is the filling speed of the third stage, ■ is the filling speed of the fourth stage, P, is the back pressure during measurement, N9 is the screw rotation speed during measurement, and S.

is the measurement position, Pl is the first stage holding pressure, P! is the second stage holding pressure, P is the third stage holding pressure, T.

T2 indicates the pressure holding time of the first stage, T2 indicates the pressure holding time of the second stage, and T indicates the pressure holding time of the third stage.

As shown in FIG. 4, these molding condition parameters are each set with a manipulated variable and stored in the molding condition parameter manipulated variable storage section 10-8 of the control device 10 described above.

Next, a method for automatically changing standard molding conditions in the injection molding machine of the present invention will be explained using FIG. 2.

Note that this flow shows a standard flow in which no abnormalities are found when collecting performance data.

As shown in this figure, injection molding is started under molding condition A, and after time (or number of shots) T1 has elapsed under molding condition A, it is changed to molding condition B, and under molding condition B, time T, After the lapse of time, the molding condition is changed to C, and after the time T has elapsed under this molding condition C, the molding condition is changed to the new molding condition, and continuous molding is repeated under this molding condition.

In this case, if the time T is O, then the molding conditions A-
Molding condition C - molding condition, and molding condition B can also be skipped.

The above-described molding conditions at startup are stored in the startup-time molding condition storage section 10-5 of the control device 10 described above.

Changes in molding conditions in these injection molding machines are performed automatically without an operator.

Next, a method for automatically changing molding conditions in the injection molding machine of the present invention will be explained.

In this case, a method for automatically changing molding conditions that is suitable for cases where abnormalities are likely to occur when actual data is collected will be described.

(1) First, when injection molding is started, the data stored in the molding condition storage section 10-5 at startup is read out, injection molding is performed under the molding condition A described above, and then The performance data is stored in the performance data storage section 10-2. It is determined whether to proceed to the next stage by comparing the stored data with the commanded data.

(2) Next, when proceeding to the next stage, set the time (or number of shots) according to the basic molding conditions using timer 10-6.
After the TI has elapsed, the molding condition is changed to B, injection molding is performed under this molding condition B, and the performance data at that time is stored in the performance data storage section 10-2.

It is determined whether to proceed to the next stage by comparing the stored data with the commanded data.

(3) Next, when proceeding to the next step, set the time (or number of shots) on timer 10-6 according to the basic molding conditions.
After Tz has elapsed, the molding condition is changed to C, injection molding is performed under this molding condition C, and the performance data at that time is stored in the performance data storage section 10-2.

It is determined whether to proceed to the next stage by comparing the stored data with the commanded data.

(4) Next, when proceeding to the next stage, set the time (or number of shots) on timer 10-6 according to the basic molding conditions.
After Ts has elapsed, the molding conditions are changed to normal injection molding, and continuous molding is repeated under these molding conditions. The performance data at that time is stored in the performance data storage section 10-2.

In this way, the actual performance data can be stored and the transition to the next molding condition can be executed while checking the actual performance data.

Therefore, the molding results are continuously stored, and if it is determined that there is an abnormality, an alarm is issued by the alarm device 18, and control is performed such as automatically changing the molding conditions to those before the change.

When the start-up is completed and the normal molding state is reached, for example, if there is an upward trend of 7 consecutive points as shown in FIG. A signal can be sent to 18 to issue an alarm. This point is described in detail in Japanese Patent Application No. 169645/1983 proposed by the inventor of the present invention. Further, as described above, control such as automatically changing the molding conditions at the seven consecutive points described above can be performed.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, according to the present invention, the following effects can be achieved.

(1) Certain basic molding conditions and molding and monitoring conditions for the start-up molding stage are set in advance, and after molding starts, the molding conditions are automatically set while collecting performance data in the memory of the electronic control device. Changes have been made to ensure smooth molding at start-up.
It is possible to prevent the occurrence of defective products. Therefore, it is possible to reduce the waste of resin and the cost required for product discrimination.

(2) Basic molding conditions and molding and monitoring conditions for the start-up molding stage are stored in the memory of the electronic control unit, and the molding stage at start-up is executed while checking the monitoring conditions. As a result, it is possible to respond quickly and to improve control functions.

(3) After transitioning to normal injection molding, if, for example, seven consecutive shots show an upward or downward trend, the conditions related to the performance data showing that trend will be automatically changed to prevent the failure. Manufacturing of non-defective products can be eliminated. Further, significant labor savings can be achieved.

(4) Manipulate molding condition parameters! (For example, how much to change the holding pressure) can be arbitrarily set by the operator in advance, for example, in percentage units, thereby enabling high-quality injection molding to be performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an injection control device of an injection molding machine to which the present invention is applied, FIG. 2 is a flowchart showing a standard method for automatically changing molding conditions in the injection molding machine of the present invention, and FIG.
Figure 4 shows monitoring conditions (judgment conditions) and molding conditions used for automatic change of molding conditions in the injection molding machine of the present invention.
The figure shows molding condition parameters and their manipulated variables, and FIG. 5 is a diagram showing an example of monitoring when there are seven continuous rise points during normal injection molding. l... Injection cylinder, 2... Screw, 3... Hydraulic motor for screw rotation, 4... Mold, 5... Digital displacement detector, 6... Speed detector, 7...・Screw tachometer, 8.9...pressure regulator, lO...electronic control device! , 1O-1...CPU (central processing unit),
10-2... Actual data storage unit (RAM), 10-
3... Storage unit (ROM) for molding conditions and monitoring conditions, 1
0-4...Interface section, 10-5...Storage section (ROM) for molding conditions at startup, 10-6...Timer (counter), 10-7...Monitoring conditions and molding parameters Conversion unit (table) with the manipulated variable, 10-8・
・・Operation amount storage unit (ROM) for molding parameters, 11
...input/output device, 12...screw rotation speed regulator,
13.17... Servo valve, 14... Screw back pressure U
! 4-node regulator, 15... holding pressure regulator, 16... injection speed regulator. Patent applicant: Sumitomo Heavy Industries, Ltd.
Patent attorney Masanobu Kato (1 other person) Figure 2 6-6A-7n-6y'L-57L-4yt-J X
-27L-/Le rL: Shit v. pardon

Claims (1)

[Claims] Injection molding is performed while referring to the data stored in the memory of the electronic control unit for molding conditions and monitoring conditions at the time of start-up.
Molding in an injection molding machine, characterized in that performance data is collected in the memory of an electronic control device, and while referring to the data, the injection molding is performed under the next molding condition to reach the normal injection molding stage. How to automatically change conditions.