JPH0698656B2 - Method and device for setting optimum allowable value of monitoring data of injection molding machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for setting an optimum allowable value of monitoring data in an injection molding machine, and in particular, monitoring data during injection molding and measurement data of molded products. Correlation is calculated by statistical processing and corrected and set so that the allowable value of the monitoring data with respect to the allowable value of the data of the molded product that is a good product is optimal, and the appropriate allowance for the monitoring data for molding the good product is obtained. The present invention relates to a method and an apparatus for setting an optimum allowable value of monitoring data that allows easy setting of values.

[Conventional technology]

In today's automatic control of injection molding machines such as computers, defective products may be produced in large quantities depending on the preset molding conditions.
There is a need to automatically control the quality of molded products. In particular,
In each molding process of injection molding, in order to always maintain a constant quality of the product, in the molding process (molding process) such as factors (molding conditions etc.) that are directly related to each other and the operating condition of the injection molding machine. It is necessary to control each of the various factors to be optimal.

Therefore, in injection molding, the step that directly determines the quality of the molded product is the injection step, and this injection step is divided into three steps: filling, holding pressure, and cooling / solidification.
Furthermore, in addition to these three steps, there are the steps of plasticizing the material in the heating cylinder and measuring.

However, the program control of the injection process is performed by plasticizing and kneading the molding material in the injection process, then filling the mold with the molten material, and then cooling and solidifying the molded product to determine the state of the molten material. The control is set to be optimal for obtaining good quality.

Therefore, the program control that is generally put into practical use at present is injection speed control, injection pressure (holding pressure) control, mold cavity internal pressure control, automatic switching control from injection speed control to injection pressure, It covers control of cushion amount, plasticizing / measuring process, and mold clamping process.

In controlling such various processes, the monitoring data set in the control device is constantly compared with the values of the monitoring data executed by the control device, and the monitoring data set so that a predetermined goodness is molded is corrected. Control is performed.

However, a molded product does not always obtain an appropriate allowable value depending on the molding conditions in the molding process, and it is necessary to correct the molding setting allowable value. Therefore, in the past, the data values obtained by executing monitoring data such as filling time, measuring time, cushion position, barrel temperature in the injection molding process were monitored in the control device, and the measured data of the molded product was compared with these monitoring data. In relation to (weight, other data), allowable values of molding conditions for various moldings to obtain a non-defective product are empirically obtained, and these are manually set by the operator on the display device.

[Problems to be Solved by the Invention]

However, when a defective molded product is generated, the operator empirically corrects and sets the allowable values for various moldings while observing the measured data of the molded product, so the operation requires time. During this period, stopping the machine reduces the operating rate, which hinders productivity. In addition, since the molding conditions are empirically determined, individual differences occur, which makes it difficult to be versatile.

Therefore, the object of the present invention is to obtain the correlation between the measurement data of the molded product that is a non-defective product and the monitoring data for obtaining the non-defective product by statistical processing, and display this correlation in the form of a graph together with this graph. It is possible to correct the allowable value of the monitoring data of the injection molding machine, and further to obtain the arithmetic expression for the correlation, and to set the allowable value of the monitoring data manually or automatically, thereby forming a good product. An object of the present invention is to provide a method and an apparatus for setting an optimum allowable value of monitoring data of an injection molding machine, which can easily correct the allowable value of monitoring data in a short time.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the optimum allowable value setting method of the monitoring data of the injection molding machine of the present invention is based on the monitoring data sampled by the control device during the molding process of the injection molding machine and the measurement data of the molded product, respectively. In the method of setting the allowable value, correcting the allowable value of the execution monitoring data corresponding to this, and setting the optimum allowable value of the monitoring data of the injection molding machine that performs injection molding, the measured data of the molded product and various monitoring data The correlation is calculated by statistical processing, and the calculation formula for this correlation is calculated. This calculation formula is stored in a storage medium, and the correlation between the measured data of the molded product that is a good product and the monitoring data that is various good products. Is displayed on the display device as a graph, and execution monitoring data during injection molding is based on this correlation graph. It is characterized by modifying the allowable value of.

In this case, the correlation between the measured data of the molded product and various kinds of monitoring data is calculated by statistical processing to obtain an arithmetic expression of the correlation and an allowable value of each data, and the arithmetic expression and the allowable value are stored in a storage medium. And remember
The correlation between the measured data of the molded product that is a non-defective product and the monitoring data that is various non-defective product is displayed in a graph on a display device, and the monitoring data for the allowable value of the measured data that is the non-defective product of the molded product is displayed based on the arithmetic expression. The allowable value can be automatically set, and the allowable value of the execution monitoring data during injection molding with respect to the allowable value of the monitoring data can be monitored and corrected.

Further, the apparatus for implementing the optimum allowable value setting method for the monitoring data described above determines the correlation between the measurement data of the molded product molded by the injection molding machine and the monitoring data sampled during the injection molding. Based on the above, the allowable value of the monitoring data is corrected, and the optimum allowable value of the monitoring data is set to perform injection control.The optimum allowable value setting device of the monitoring data of the injection molding machine detects the injection state in the injection molding process. In order to do so, a detection unit provided at each predetermined position of the injection molding machine, an automatic measuring machine that measures the injection molded product, a drive control unit that controls each drive unit of the injection molding machine, and sampling from the detection unit. The permissible value of the execution monitoring data is input, and the command signal processed based on the permissible value is output to each of the drive control units. The control device is a non-defective product memory for storing measurement data of a non-defective molded product measured by an automatic measuring device and monitoring data corresponding to the measurement data, and the non-defective molded product. While obtaining the correlation between the measurement data of and the monitoring data that is a good product by statistical processing,
A function calculator that obtains a formula for this correlation,
A central processing unit that stores the arithmetic expression in a storage medium, a display device that graphically displays the correlation on a screen, an allowable value of measurement data of a molded product measured based on the arithmetic expression, and an allowance of monitoring data. The calculated value is compared with the permissible value of the sampled execution monitoring data, and the permissible value of the execution monitoring data is corrected based on the graph displayed on the display device to set the optimum permissible value of the monitoring data. It is characterized in that it is composed of an arithmetic unit.

In this case, the control device, a non-defective product data memory that stores the measurement data of the molded product that is a non-defective product measured by the automatic measuring device, and the monitoring data sampled from each detection unit corresponding thereto, and the non-defective product. A function calculator that calculates the correlation between the measured data of the molded product and the monitoring data that is a non-defective product by statistical processing, and that calculates a calculation formula from the correlation, and a central processing unit that stores the calculation formula in a storage medium. , A display device that graphically displays the correlation and the allowable value on the screen, and converts the allowable value of the measured data of the molded product that is a good product into the allowable value of the monitoring data based on the arithmetic expression. The permissible value of the execution monitoring data sampled for the value is compared and calculated, and the graph displayed on the display device is displayed. Execution unit that corrects the allowable value of the monitoring data and sets the optimum allowable value of the monitoring data, and the allowable value setting that automatically sets the allowable value of the monitoring data converted by this arithmetic unit It can be composed of parts.

[Action]

According to the method and apparatus for setting the optimum allowable value of the monitoring data of the injection molding machine according to the present invention, at the time of injection molding, the correlation between the measurement data of the molded product that is a good product and the monitoring data that obtains various good products is statistically calculated. It is possible to easily correct the permissible value of the execution monitoring data sampled at the time of injection molding on the basis of the graph showing this correlation on the display device.

Further, an arithmetic expression is obtained from the correlation, and the allowable value of the monitoring data for the measured data of the good molded product which is statistically obtained based on the arithmetic expression is manually or automatically set, and this is displayed together with the graph. Displayed on the device, based on the graph showing these correlations and the allowable value of the monitoring data, correct the allowable value of the execution monitoring data during injection molding and set the optimum allowable value of the monitoring data in a short time. It can be carried out.

〔Example〕

Next, an embodiment of an optimum allowable value setting method and apparatus for monitoring data of an injection molding machine according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block circuit diagram showing an embodiment of an apparatus for carrying out an optimum allowable value setting method for monitoring data of an injection molding machine according to the present invention. In FIG. 1, reference numeral 10 indicates an injection molding machine. The injection molding machine 10 includes a barrel 12, a screw 14 that is inserted into the barrel 12 so as to be rotatable and axially advanceable and retractable, and the screw 14. A pair of injection cylinders 18 that move back and forth in the axial direction via the bearing unit 16,
It basically comprises a hydraulic motor 20 that rotationally drives the screw 14.

In the injection molding machine 10 configured as described above, the raw material (resin) supplied from the hopper (not shown) is melted by the heat of the heater arranged in the barrel 12 and the shearing heat of the resin caused by the rotation of the screw 14. Then, the molten resin having reached a predetermined amount is filled in the mold 22 by the injection cylinder 18 via the screw 14. In this way, the molten resin filled in the mold 22 is pressurized by the mold clamping device 24,
It is molded into a product with a predetermined shape. After that, the molded product can be automatically taken out by releasing the mold.

In this case, the hydraulic motor 20, which is the drive unit, the injection cylinder 18, and the mold clamping device 24, the servo valves 26, 28, 30 as the drive control unit, respectively, the rotation speed of the screw 14, the moving speed of the injection cylinder 18, and The opening / closing position and opening / closing speed of the mold clamping device 24 are controlled.

Further, a detection unit for detecting the injection state is provided at a position corresponding to each drive unit of the injection molding machine 10. That is, the hydraulic motor 20 is provided with a sensor 32 (for example, a rotary encoder, a tachogenerator, a potentiometer, or the like) for detecting a rotation state, and the bearing unit 16 detects a movement position thereof. Position sensors 34, 36 (eg limit switches, proximity switches, magnetic scales, etc.)
Is provided. Further, a pressure sensor 38 for detecting the injection pressure is provided for the injection cylinder 18. Further, a temperature sensor 40 for detecting the temperature of the molten resin in the barrel 12 is provided on the injection side wall of the barrel 12.

In FIG. 1, reference numeral 42 is a control device, 44 is a central processing unit (hereinafter referred to as CPU) of the control device 42, and 46 is an input circuit. Therefore, the input circuit 46
Is connected to each of the above-mentioned sensors and inputs execution monitoring data monitored in the injection molding process.

Reference numeral 48 indicates an output circuit, and servo valves 26 and 2 are respectively provided.
8, 30 and the alarm output device 50 and the timer 52 are connected, and the signals processed in the control device 42 are output.

Reference numeral 56 indicates an input device (hereinafter referred to as a keyboard) for manually inputting set values and the like, and reference numeral 60 indicates a CRT for controlling a display device 58 (hereinafter referred to as CRT).
A control circuit is shown.

Further, reference numeral 62 indicates a storage device composed of a storage medium. The storage device 62 includes a non-defective product data memory 64, a monitoring data memory 66, and a molded product measurement data memory.
A 68 and a tolerance setting device 70 are provided. However,
The non-defective product data memory 64 stores measurement data and monitoring data of each molded product during molding of a non-defective product, and allowable values thereof. Also, the monitoring data memory
66 stores various execution monitoring data in the injection process input from the input circuit 46 and the calculated allowable value. Furthermore, the measurement data memory of the molded product
68, the measurement data of the molded product measured by the automatic measuring device 54 including an automatic weighing device for weighing the weight and the like of the molded product and an automatic measuring device for measuring the dimensions and the like is input from the input circuit 46 and The permissible value is calculated from, and the obtained permissible value is stored. Then, the allowable value setting device 70 obtains an allowable value based on the correlation between the measurement data and the monitoring data of the molded product at the time of molding a non-defective product, sets the allowable value, and executes the monitoring in the arithmetic unit described later. It is arranged to compare the data and modify its tolerance and set this automatically.

An arithmetic expression can be obtained in the function calculator 72 from the correlation between the measurement data of the molded product which is a non-defective product stored in the non-defective product data memory 64 and the monitoring data. The graph of the correlation obtained based on the arithmetic expression obtained by the function calculator 72 is displayed on the screen of the CRT 58 via the CRT control circuit 60. In this way, based on the graph of the correlation displayed on the screen of CRT58, comparing the allowable value for the monitoring data and the allowable value for the execution monitoring data,
These are input-corrected on the screen by manual operation with the keyboard 56.

Further, the allowable value of the execution monitoring data stored in the monitoring data 66 and the allowable value stored in the allowable value setter 70 are compared in the calculation unit 74 based on the graph of the correlation and corrected. In addition to determining the allowable value, it is determined whether each execution monitoring data is within the allowable value range.

In this case, the execution monitoring data at the time of injection molding is constantly monitored by the calculation unit 74, and when the execution monitoring data is out of the allowable value range, an alarm is output by the alarm output circuit 50 via the output circuit 48. .

In the control device 42 described above, all of the address data bus 76
Is connected to the CPU 44 via the, and data processing is performed in this CPU 44.

Next, a graph of the correlation displayed on the screen of the CRT 58 will be described with reference to FIGS. 2 and 3.

In the graph shown in FIG. 2, the vertical axis Y represents the measured data (weight, size, other data) of the molded product, and the horizontal axis X represents the monitoring data (filling time, weighing time, take-out time, cycle time, cushion amount). , Speed / pressure switching position, injection start position, screw rotation speed, barrel temperature, and other data), the graph Y = f (X) of the correlation at the time of molding a good product by statistical processing is CRT58. Displayed on the screen. Then, based on this graph, the measured data of the injection-molded product is compared with each monitoring data in the injection process, and the manual operation by the keyboard 56 on the screen of the CRT58 is performed so that the data becomes a good product. Correct the allowable value of monitoring data by.

In addition, the CRT5
Based on the graph displayed on the screen of 8, the allowable value ΔX of the monitoring data with respect to the allowable value ΔY of the measured data of the molded product is automatically set, and the allowable value of the execution monitoring data is calculated by the calculation unit 74 with respect to this allowable value. The tolerances are compared and corrected by manual or automatic operation, which sets the optimum tolerance for monitoring data (3rd
Figure).

Next, the operation of the apparatus of this embodiment described above will be described based on the flowchart shown in FIG.

When the molded product is obtained in step 1, various kinds of monitoring data in the injection process are sent from the input circuit 46 via the data bus 76 by the control device 42 in step 2.
Input to the monitoring data memory 66 of the controller 42,
Remembered. At the same time, in step 3, the weight, size, and other data of the molded product are automatically measured and input from the input circuit 46 via the data bus 76 to the measured data memory 68 of the molded product and stored. Next, in step 4, it is determined whether the product is good or bad, and the measured data of the molded product that is a good product is obtained along with the monitoring data in step 2 in step 5 to obtain the correlation Y = f (X) by the function calculator 72, This in step 6
Display as a graph of correlation on the screen of CRT58.

Next, in step 7, it is selected whether the allowable value is manually set or automatically set. In the case of manual,
In step 8, based on the correlation graph
The allowable value of the monitoring data is corrected by manually operating the keyboard 56 on the screen of the CRT58.

If automatic setting is selected, in step 9, the allowable value of the measured molded product data is calculated by the calculation unit 74.
Calculated by the above, and this value is input and stored in the measurement data memory 68 of the molded product, and is automatically set. The allowable value of the data of this molded product is calculated as the allowable value of the monitoring data based on the graph of the correlation in step 10, and the allowable value is input and stored in the allowable value setting device 70 in step 10 and is automatically set. To do.

In this way, in step 11, whether or not the execution monitoring data monitored during the molding of the product is within the range of the tolerance value modified in step 8 or the tolerance value modified in step 11 is determined. The arithmetic unit 74 constantly monitors (step 12), and the alarm output circuit 50 displays an abnormal state via the output circuit 48 even if the value is outside the allowable range. Further, if this monitoring data is out of the allowable range, in step 13, a good molded product can be obtained.

In this way, according to the present invention, it is possible to easily set the optimum conditions in the injection molding process for molding a good product.

〔The invention's effect〕

As is apparent from the above-described embodiments, according to the optimum allowable value setting method of the monitoring data of the injection molding machine according to the present invention, the monitoring data sampled by the controller during the molding process of the injection molding machine and the measurement of the molded product are performed. In the method of setting the optimum allowable value of the monitoring data of the injection molding machine that performs injection molding, determine the allowable value from the data and correct the allowable value of the execution monitoring data corresponding to it. While obtaining the correlation with the monitoring data by statistical processing,
The calculation formula for this correlation is calculated, this calculation formula is stored in a storage medium, and the correlation between the measured data of a molded product that is a good product and various monitoring data that is a good product is displayed graphically on a display device. By correcting the allowable value of the execution monitoring data at the time of injection molding based on the relationship graph, it is possible to easily set the optimum allowable value of the monitoring data in the injection process in a short time.

In addition, as a device that implements the method for setting the optimum allowable value of the monitoring data described above, the correlation between the measurement data of the molded product molded by the injection molding machine and the monitoring data sampled during the injection molding is determined. Modify the allowable value of the execution monitoring data based on the relationship, set the optimum allowable value of the monitoring data and perform injection control.Set the optimum allowable value of the monitoring data of the injection molding machine. From the detection unit, a detection unit provided at each predetermined position of the injection molding machine to detect, an automatic measuring machine that measures the injection molded product, a drive control unit that controls each drive unit of the injection molding machine, and the detection unit. Input the allowable value of the sampled execution monitoring data, and send the command signal processed based on the allowable value to each drive control unit. And a control device that applies force, wherein the control device stores a measurement data of a molded product that is a non-defective product measured by an automatic measuring device, and a non-defective product data memory that stores monitoring data corresponding to the measured data, and the molding product that is the non-defective product. While obtaining the correlation between the measurement data of the product and the monitoring data that is a non-defective product by statistical processing, a function calculator that obtains an arithmetic expression for this correlation, a central processing unit that stores the arithmetic expression in a storage medium, A display device that graphically displays the correlation on the screen, and compares the allowable value of the measured data of the molded product measured based on the arithmetic expression and the allowable value of the monitoring data with the allowable value of the sampled execution monitoring data. Calculate and correct the allowable value of the execution monitoring data based on the graph displayed on the display device. By configuring with an arithmetic unit that sets the optimum allowable value of the monitoring data, the allowable value of the monitoring data is always automatically corrected even if the molding conditions change in time series, and this is stored, set, and monitored. As a result, a product having stable quality can be molded.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be applied to a production machine other than an injection molding machine, for example. Within the scope of the spirit of
Various design changes can be made.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block circuit diagram showing an embodiment of an apparatus for carrying out an optimum allowable value setting method for monitoring data of an injection molding machine according to the present invention, FIG. 2 and FIG. FIG. 4 is a graph showing the correlation between the measured value of the molded product obtained by the invention and the monitoring data, and FIG. 4 is a flow chart showing the implementation of the method of the present invention in the embodiment shown in FIG. 10 …… Injection molding machine, 12 …… Barrel 14 …… Screw, 16 …… Bearing unit 18 …… Injection cylinder, 20 …… Hydraulic motor 22 …… Mold, 24 …… Clamping device 26, 28, 30… … Servo valve, 32 …… Sensor 34, 36 …… Position sensor, 38 …… Pressure sensor 40 …… Temperature sensor, 42 …… Control device 44 …… CPU (Central processing unit), 46 …… Input circuit 48 …… Output circuit, 50 …… Alarm output circuit 52 …… Timer, 54 …… Automatic measuring device 56 …… Keyboard (input device), 58 …… Display device (CR
T) 60 …… CRT control circuit, 62 …… Memory device 64 …… Good product data memory, 66 …… Monitoring data memory 68 …… Measurement data memory, 70 …… Allowable value setter 72 …… Function calculator, 74… … Calculator 76 …… Address data bus

Claims (4)

[Claims] 1. An allowable value is determined from monitoring data sampled by a control device during a molding process of an injection molding machine and measured data of a molded product, and the allowable value of corresponding execution monitoring data is corrected and injection is performed. In the method of setting the optimum allowable value of the monitoring data of the injection molding machine that performs molding, the correlation between the measured data of the molded product and various monitoring data is calculated by statistical processing, and the calculation formula for this correlation is calculated. This arithmetic expression is stored in a storage medium, and the correlation between the measured data of non-defective molded products and the monitoring data of various non-defective products is displayed in a graph on the display device. Optimal tolerance of monitoring data of injection molding machine characterized by correcting tolerance of execution monitoring data Setting method. 2. A correlation between a measured data of a molded product and various monitoring data is calculated by statistical processing to obtain an arithmetic expression of the correlation and an allowable value of each data, and the arithmetic expression and the allowable value are calculated. In addition to being stored in a storage medium, the correlation between the measured data of a molded product that is a non-defective product and various monitoring data that is a non-defective product is displayed in a graph on a display device, and the measured data of the molded product that is a non-defective product is calculated based on the arithmetic expression. 2. The injection molding machine according to claim 1, wherein an allowable value of the monitoring data with respect to the allowable value of is automatically set, and the allowable value of the execution monitoring data at the time of injection molding with respect to the allowable value of the monitoring data is monitored and corrected. How to set the optimum allowable value for monitoring data. 3. A correlation between measurement data of a molded product molded by an injection molding machine and monitoring data sampled during injection molding is defined, and an allowable value of execution monitoring data is corrected based on this correlation. The optimum tolerance value setting device for the monitoring data of the injection molding machine that sets the optimum tolerance value of the monitoring data and controls the injection is installed at each predetermined position of the injection molding machine to detect the injection state in the injection molding process. Input the allowable value of the execution monitoring data sampled from the detection unit, the automatic measuring machine that measures the injection-molded product, the drive control unit that controls each drive unit of the injection molding machine, and the allowable value. And a control device that outputs a command signal processed based on a value to each of the drive control units, wherein the control device is an automatic measurement device. A non-defective product data memory that stores the measured data of the measured non-defective molded product and the corresponding monitoring data, and a statistical correlation between the measured data of the non-defective molded product and the non-defective monitoring data. While obtaining by processing,
A function calculator that obtains a formula for this correlation,
A central processing unit that stores the arithmetic expression in a storage medium, a display device that graphically displays the correlation on a screen, and an allowable value of measurement data of a molded product measured based on the arithmetic expression and an allowance of monitoring data. The calculated value is compared with the permissible value of the sampled execution monitoring data, and the permissible value of the execution monitoring data is corrected based on the graph displayed on the display device to set the optimum permissible value of the monitoring data. An optimum allowable value setting device for monitoring data of an injection molding machine, which is configured by a calculation unit. 4. The non-defective product data memory for storing the measured data of the non-defective molded product measured by the automatic measuring device and the monitoring data sampled from each detection unit corresponding thereto, A function calculator for obtaining the correlation between the measurement data of the molded product that is a good product and the monitoring data that is a good product by statistical processing, and a calculation unit for calculating a calculation formula from the correlation, and a central procedure for storing the calculation formula in a storage medium. A device, a display device that graphically displays the correlation and the allowable value on the screen, and converts the allowable value of the measured data of the molded product that is a good product to the allowable value of the monitoring data based on the arithmetic expression, and The permissible value of the execution monitoring data sampled with respect to the permissible value is compared and calculated, and the graph displayed on the display device is calculated. Execution unit that corrects the allowable value of the monitoring data and sets the optimum allowable value of the monitoring data, and the allowable value setting that automatically sets the allowable value of the monitoring data converted by this arithmetic unit The optimum permissible value setting device for monitoring data of an injection molding machine according to claim 3, wherein the optimum allowable value setting device comprises: