JP3648059B2 - Molding machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a molding machine such as an injection molding machine or a die casting machine, more particularly, to techniques clamping pressure of the low pressure clamping stroke in the mold clamping operation (load pressure) to be monitored.
[0002]
[Prior art]
In a molding machine having a molding die such as an injection molding machine, when high pressure clamping is performed to generate a clamping force in a state where foreign matter is interposed between the stationary mold and the movable mold, Since this leads to damage to the mold and also causes molding defects, a low-pressure mold clamping process for detecting whether foreign matter is present on the mold release surface may be provided before the high-pressure mold clamping process. Many.
[0003]
Ideally, the set pressure in the above-mentioned low pressure mold clamping process for detecting foreign objects is ideally low pressure mold clamping in the absence of foreign objects (normal condition) between the stationary mold and the movable mold. It is desirable to have a value that is about the same as or slightly higher than the peak value of the clamping pressure (load pressure) measured during the process. Even if it exists on the mold release surface, the movement of the movable mold is blocked by the resistance from the foreign matter.
[0004]
[Problems to be solved by the invention]
By the way, the mold clamping pressure (load pressure) in the low-pressure mold clamping process is different in each mold due to the sliding load of the guide pins and angular pins of the mold. It is necessary to determine the pressure appropriately.
[0005]
However, conventionally, since there was no means for detecting the peak value of the clamping pressure in the low pressure clamping process, the set pressure in the low pressure clamping process was set to a rough value with a margin. In order to eliminate this point, the operator reads the mold clamping pressure during the low pressure clamping process using an analog pressure meter, and determines the set pressure value during the low pressure clamping process based on this. Although it is also attempted to do it, it is difficult to accurately read the peak value of the measured mold clamping pressure from the fluctuation of the pointer with an analog pressure meter, and the set pressure in the low pressure mold clamping process was also given a margin It tends to be set to a rough value.
[0006]
The present invention has been made in view of the above points. The object of the present invention is to make it possible for an operator to accurately recognize the peak pressure of the actually measured clamping pressure during the low pressure clamping process, and thereby the low pressure clamping. The object is to realize a molding machine that can easily and surely determine an appropriate pressure in the process.
[0007]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a low-pressure mold clamping process for detecting whether or not foreign matter exists on the mold release surface before the movable mold touches the fixed mold. In the molding machine configured to enter a high pressure mold clamping process for generating a predetermined mold clamping force after the low pressure mold clamping process, the set pressure value of each process of the mold clamping including the low pressure mold clamping process is stored. Pressure setting storage means, pressure detection means for measuring the clamping pressure in the low pressure clamping process, peak pressure detection means for detecting the peak pressure in the low pressure clamping process section from the actual pressure output by the pressure detection means, and a display processing means for displaying on the display screen of the display device a peak pressure in the low-pressure clamping stroke segment in the previous shot peak pressure detecting means outputs, the set pressure value in the low-pressure clamping stroke segment, solid The peak value of the clamping pressure measured during the low-pressure clamping process when there is no foreign object between the side mold and the movable mold (normal condition), or just slightly above that The value is corrected automatically by the machine itself.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory diagram showing a simplified overall control system and a simplified mold opening / closing system mechanism in an injection molding machine according to an embodiment of the present invention.
[0009]
In FIG. 1, 1 is a fixed die plate, 2 is a fixed die mounted on the fixed die plate 1, 3 is a movable die plate, 4 is a movable die mounted on the movable die plate 3, and 5 is a movable die. A toggle link mechanism for driving the plate 3 back and forth, 6 is a rotation-linear motion conversion mechanism for driving the crosshead of the toggle link mechanism 5 back and forth, and 7 is rotated by a rotating part of the rotation-linear motion conversion mechanism 6. This is an electric servo motor that serves as a drive source for clamping (opening / closing) molds.
[0010]
Further, 11 is a microcomputer (system controller) that controls operation and display control of the entire machine (injection molding machine), 12 is a sensor group composed of a large number of sensors provided in each part of the machine, and 13 is each part of the machine. A driver group composed of a large number of driver circuits for driving and controlling a large number of driving sources disposed in the machine, 14 is a key input device disposed on the front of the machine, and 15 is adjacent to the key input device. For example, a color CRT display, a color LCD, or the like. The sensor group 13 includes a torque sensor 12a that detects a torque value (that is, a mold clamping pressure (load pressure) corresponding to the torque value) from the drive current value of the electric servo motor 7. The driver group 13 includes a servo driver circuit 13a that drives and controls the electric servomotor 7.
[0011]
The microcomputer 11 in FIG. 1 performs control of the entire molding process such as weighing operation, injection operation, mold opening / closing operation, ejection operation, calculation / storage processing of measured data, non-defective / defective product determination processing, abnormality determination processing, etc. Various processing such as calculation / determination processing or display control processing of the output image of the display device 15 is executed. The microcomputer 11 is actually composed of a ROM having various I / O interfaces, a control program stored therein, a RAM in which various data and flags are read and written, an MPU (microprocessor), and the like. Although various processes are executed by various programs, in the present embodiment, the following description is given on the assumption that the molding condition setting storage unit 21, the molding process control unit 22, the actual measurement value storage unit 23, and the display processing unit 24 are provided. Do. The actual value storage unit 23 includes a low-speed mold clamping peak pressure detection unit 23a.
[0012]
The molding condition setting storage unit 21 stores various operating condition values input by the key input device 14 and the like in a rewritable form. The operating condition values include, for example, the tightening force, the relationship between the screw position and screw speed during the metering stroke, the screw retraction speed, and the back pressure, the suck back control condition, and the injection speed from the start of injection to the holding pressure switching. Condition, primary injection pressure condition, secondary pressure (holding pressure) switching condition, holding pressure condition from holding pressure switching time to holding pressure end time, band heater temperature of each part, mold closing (clamping) stroke (position) And speed control conditions, mold clamping force (pressure), mold opening stroke (position) and speed control conditions, pressure, eject control conditions, and the like.
[0013]
The molding process control unit 22 is based on the molding process control program created in advance and the set condition value stored in the molding condition setting storage unit 21, and the sensor group 12 (position sensor) disposed in each part of the machine. The driver group 13 (motor driver, heater driver, etc.) while referring to the data from the actual value storage unit 23 that captures measurement information from the pressure sensor, temperature sensor, etc.) in real time and the clocking information from the built-in clock. Etc.), the corresponding drive source is driven and controlled to execute a series of molding steps.
[0014]
In the actual measurement value storage unit 23, all actual measurement data of monitor items set in advance during continuous automatic operation is captured over a predetermined number of consecutive shots. Monitor items to be imported include: (1) time monitoring item, (2) position monitoring item, (3) rotational speed monitoring item, (4) speed monitoring item, (5) pressure monitoring item, (6) temperature monitoring item, (7) Power monitoring items and the like, and the important items of the molding operation condition setting items described above are substantially overlapped.
[0015]
The low pressure clamping peak pressure detecting portion 23a of the measured value storage unit 23, from the output value of the torque sensor 12a for detecting the torque value from the driving current value of the electric servomotor 7 (clamping pressure), described later detecting a peak pressure of the measured clamping pressure in the low pressure clamping stroke segment, so as to store it in a predetermined memory area.
[0016]
The display processing unit 24 creates display image data of a designated display mode based on a display image creation / control program created in advance in response to an instruction for calling a display image in a mode desired by an operator using the key input device 14. .
[0017]
That is, when a call instruction for a predetermined display image by the operator arrives, the data conversion processing means of the display processing unit 24 reads the information from the information stored in the molding condition setting storage unit 21 or the actual measurement value storage unit 23 as necessary. Data for use in displaying the display mode image is extracted, and these are converted into a form corresponding to the designated display mode of the display mode image. For example, if the designated display mode is a graphic image of a certain process, the extracted data is converted into image data that has been drawn at a predetermined enlargement / reduction ratio, or there is a designated display mode. If it is the operation state setting image of the process, the extracted data is converted into numerical image data. Then, the generation processing data by these data conversion processing means is taken into the display image data generation means of the display processing unit 24. On the other hand, the display mode image is displayed from a large number of characters, symbols, graphic figures, ruled line data, etc., which are fixed data for the mode image, which are created and stored in advance in the display fixed data storage means of the display processing unit 24. Data to be used is extracted, taken into the display image data generation means, and synthesized as display image data together with the generation processing data of the data conversion processing means. As a result, the display image data generating means generates image data for the designated display mode, which is sent to the display device 15 according to a command from the display processing unit 24, and is displayed on the display screen of the display device 15. The image data in the predetermined mode is displayed.
[0018]
FIG. 2 is a diagram illustrating an operation example of a mold clamping (mold closing) process in the injection molding machine according to the present embodiment. In the example shown in FIG. 2, the mold clamping process from the mold clamping start position (mold opening completion position) to the mold clamping completion position is as follows: low speed mold clamping process → high speed mold clamping process → low pressure mold clamping process → high pressure mold clamping process According to the position of the movable mold 4 (movable die plate 3), the process is divided into four stages and controlled so as to shift sequentially. And speed and pressure are set for each of the low-speed mold clamping process, the high-speed mold clamping process, the low-pressure mold clamping process, and the high-pressure mold clamping process, and each process is controlled by speed feedback control according to the position. It is executed by controlling the speed of the electric servo motor 7 so as to coincide with the speed set value.
[0019]
Here, the pressure setting value of each process of the low speed mold clamping process, the high speed mold clamping process, the low pressure mold clamping process, and the high pressure mold clamping process functions as an upper limit regulation value (upper limit regulation torque value). This is to prevent output of a pressure value (torque value) higher than this. Therefore, the pressure setting value is set to a sufficiently smaller value than the other strokes in the low pressure mold clamping process, which is the mold protection section, for detecting whether or not foreign matter is present on the mold release surface. The
[0020]
In the present embodiment, in the initial setting state after mold replacement, since it is difficult to set a proper value of pressure set value of the low-pressure mold clamping stroke from the beginning, in the initial stage, the low-pressure mold clamping stroke The pressure set value (upper limit value) is set to a rough and large value. The test run in this state, the actual clamping pressure at the low pressure clamping stroke segment (actual drive torque) detected by the torque sensor 12a, the measured from the torque sensor 12a at low pressure clamping stroke segment the torque data, stores incorporated into the measured value storing unit 23, the in the low pressure type clamping peak pressure detecting unit 23a, and detects the peak pressure of the measured clamping pressure in the low pressure clamping stroke segment, this Remember.
[0021]
In the present embodiment, the peak pressure of the measured clamping pressure at a low pressure mold clamping stroke segment detected as described above, it is to be displayed in the display image for the mold opening and closing condition setting. FIG. 3 is a view showing a display image for setting the mold opening / closing conditions displayed on the display screen of the display device 15.
[0022]
In the mold opening / closing condition setting display image shown in FIG. 3, a mold opening / closing control condition setting field 31 and an ejection control condition setting field 32 are provided. The mold opening control condition setting field 33 and the mold clamping control condition setting field 34 are divided. Then, on the lower side of the setting column 34 of the mold clamping control conditions, though display column 35 of the peak pressure of the measured clamping pressure in the low pressure clamping stroke segment is provided on the display section 35, the low pressure in the previous shot The peak pressure in the mold-clamping stroke section is displayed (here, the pressure is shown in% display with respect to the rated torque of the electric servomotor 7).
[0023]
Thus, while displaying the image for the mold opening and closing condition setting, why providing a display column 35 of the peak pressure of the measured clamping pressure at a low pressure mold clamping stroke interval, the value in the display column 35 column peak pressure operator while checking, on the same display image, a pressure setting section 34a of the low-pressure mold clamping stroke in setting column 34 of the mold clamping control conditions, in order to be able to modify the pressure setting of the low-pressure mold clamping stroke . That is, after confirming that it is the peak value of the clamping pressure measured during the low-pressure clamping process in the absence of foreign matter between the fixed mold and the movable mold (normal condition), the peak display column 35 displayed peak pressure comparable the column pressure, or a value of a greater extent than it negligible, is adapted to set the pressure setting section 34a of the low-pressure mold clamping stroke. Accordingly, variable it is possible to set the pressure setpoint of the low pressure clamping stroke Easy ensure proper ones, I hereinafter, and can increase the foreign object detection accuracy, the mold being damaged It can be avoided as much as possible.
[0024]
In the example shown in FIG. 3, while displaying an image for mold opening and closing condition setting, is provided with the display section 35 of the peak pressure in the low pressure clamping stroke segment, and alternatively to the display section 35, FIG. 4 As shown in FIG. 4, a display column 41 of a graph of measured mold clamping pressure in the low pressure mold clamping process may be provided. Display of such graphic data, the display processing unit 24, by referring to the measured torque data (measured clamping pressure data) in the low pressure mold clamping stroke segment stored in the measured value storage unit 23, easily To be realized. Then, as shown in FIG. 4, when performing a graphical representation of the measured clamping pressures, that the operator of the peak pressure can readily visible, set to ones proper pressure setting value of the low-pressure mold clamping stroke Can do.
[0025]
In the above-described embodiment, the example in which the electric servo motor is used as the drive source for opening and closing the mold has been described. However, the present invention can also be applied to a configuration using a hydraulic cylinder as the drive source for opening and closing the mold. Needless to say.
[0026]
Furthermore, in the embodiment described above, also be, but modification of set pressure in the low pressure clamping stroke segment and so the operator makes the machine (the microcomputer 11) itself performs automatically corrected, no problem.
[0027]
【The invention's effect】
As described above, according to the present invention, the operator can accurately visually confirm the peak pressure of the actually measured mold clamping pressure during the low-pressure mold clamping stroke, so that the set pressure in the low-pressure mold clamping stroke can be determined easily and reliably. Therefore, the foreign object detection accuracy can be increased, and damage to the mold can be avoided as much as possible.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a simplified overall control system and a simplified mold opening / closing system mechanism in an injection molding machine according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing an operation example of a mold clamping (mold closing) process in an injection molding machine according to an embodiment of the present invention.
FIG. 3 is an explanatory view showing a display image example for setting a mold opening / closing condition in an injection molding machine according to an embodiment of the present invention.
FIG. 4 is an explanatory diagram showing a graph display example of an actual measured mold clamping pressure in a low pressure mold clamping process, which is displayed in a display image for mold opening / closing condition setting in an injection molding machine according to an embodiment of the present invention. .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fixed die plate 2 Fixed side metal mold 3 Movable die plate 4 Movable side metal mold 5 Toggle link mechanism 6 Rotation-linear motion conversion mechanism 7 Electric servo motor 11 Microcomputer (system controller)
12 sensor group 12a torque sensor 13 driver group 13a servo driver circuit 14 key input device 15 display device 21 molding condition setting storage unit 22 molding process control unit 23 actual measurement value storage unit 23a low-speed mold clamping peak pressure detection unit 24 display processing unit 35 low-speed Display column 41 for peak pressure in the clamping stroke section Display column for a graph of measured clamping pressure in the low-speed clamping stroke section

Claims (2)

Before the movable side mold touches the fixed side mold, a low pressure mold clamping process is provided for detecting whether or not there is a foreign substance on the mold release surface. After the low pressure mold clamping process, a predetermined process is performed. In a molding machine designed to enter a high pressure mold clamping process for generating mold clamping force,
Pressure setting storage means for storing a set pressure value of each process of the mold clamping including the low pressure mold clamping process;
Pressure detecting means for measuring the clamping pressure in the low pressure clamping process;
A peak pressure detecting means for detecting a peak pressure in a low pressure mold clamping stroke section from an actually measured pressure output by the pressure detecting means;
Display processing means for displaying on the display screen of the display device the peak pressure in the low pressure mold clamping stroke section in the previous shot output by the peak pressure detection means,
The set pressure value in the low-pressure mold clamping stroke section is the peak value of the mold clamping pressure measured during the low-pressure mold clamping stroke when there is no foreign object between the fixed mold and the movable mold (normal condition). A molding machine characterized in that the machine itself automatically corrects it to a value of the same level or slightly above it. In claim 1,
An electric servo motor is used as a driving source for opening and closing the mold, and the pressure detecting means detects a current value of the electric servo motor and calculates a torque value, thereby detecting a measured pressure corresponding to the current value. A molding machine characterized by that.

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