JPH0626812B2 - Method for determining the fully closed position of the mold - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for determining the fully closed position of a mold.

[Prior Art] Conventionally, a fully closed position of a mold is determined by using a sensor such as a limit switch or a proximity switch, and finely adjusting a mounting position and sensitivity of the sensor.

[Problems to be Solved by the Invention] However, in the method of determining the fully closed position of the mold by finely adjusting the mounting position and sensitivity of the sensor, 0.1 mm is required.
It was difficult to adjust with a high degree of accuracy, and it was not possible to accurately determine the fully closed position of the mold. Further, due to the heat of the resin or the heat of adjusting the temperature of the mold, there is a difference in the expansion of the metal between the cold state and the hot state, so that the detection position changes. Further, there is a drawback in that variations occur depending on the person who adjusts the mounting position and sensitivity of the sensor.

Therefore, an object of the present invention is to provide a method for automatically determining the fully closed position of a mold with high accuracy and according to the state of the mold.

[Means for Solving Problems] A method for determining a fully closed position of a mold according to the present invention detects a relative position of a movable mold with respect to a fixed mold and drives the movable mold to move the fixed mold to the fixed mold. The relative position when the movable mold is closed and the movable mold is stationary is stored as a stationary position, and the next fully closed position is determined from the stored average value of the plurality of past stationary positions. It is characterized by

[Operation] Since the average value of past stationary positions is set as the fully closed position of the mold, the fully closed position of the mold is automatically corrected according to the state of the molding machine, especially the mold, and the accurate mold is obtained. The fully closed position of can be determined.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

Referring to FIG. 2, a mold according to the present invention has a fixed mold 12 attached to a fixed platen 11 and a movable mold 14 attached to a movable platen 13, and the movable platen 13 is attached to a tie bar 15. By sliding along an actuator 16 described later, the fixed mold 12 and the movable mold 14 are opened and closed and the mold is clamped.

In this embodiment, there are four tie bars 15 (two on each side), and each tie bar 15 between the fixed platen 11 and the movable platen 13 has a relative position to the movable platen 13, that is, a movable mold 14. A sensor 17 for detecting the relative position of the fixed mold 12 to the fixed mold 12 is attached. The relative position detected by each sensor 17 is supplied to the mold clamping control device 18 as a position signal PS. The mold clamping control device 18 causes the position indicator 19 to display the position signal PS as a digital value. As the sensor 17, a differential transistor, a potentiometer, or the like is used.

Further, in the mold clamping control device 18, the normal mold clamping width A is set by the setting switch 20. Here, the normal mold clamping width A means that the fixed mold 12 and the movable mold 14 are, as shown in FIG.
It is a width that can be considered that the mold is normally clamped at the stationary position P in which the movable platen 13 is stationary by normally closing the foreign matter without being pinched between them. In addition, this stationary position P
Range of normal mold clamping width A centered on (P-C to P + B)
Is called the normal mold clamping range.

Therefore, the operator (operator) can operate the setting switch 20 while taking into consideration the mounting position of each sensor 17 and the allowable size of the foreign matter sandwiched between the fixed mold 12 and the movable mold 14. The normal mold clamping width A can be freely set. The normal mold clamping width A set from the setting switch 20
Is also displayed as a digital value on the position indicator 19 by the mold clamping control device 18.

The mold clamping control device 18 also sends a mold clamping control signal DC to the mold clamping drive device 21 based on the position signal PS and the normal mold clamping range according to a flowchart described later. Mold clamping drive
21 is the above-mentioned actuator according to the mold clamping control signal DC
The movable platen 13 is moved to the tie bar 15 by driving 16.
Slide along.

Although not shown, the mold clamping control device 18 includes a ROM storing a program corresponding to the above-mentioned flowchart and the RO.
According to the program stored in M, processing is performed based on the position signal PS and the normal mold clamping range, and the mold clamping control signal DC
It has a processor (CPU) for generating the data, a RAM storing data necessary for processing by the CPU, and a timer for time monitoring. The RA used in this embodiment
The M has a battery backup, and the data stored therein is not erased even when the power is turned off.

Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG.

It is assumed that the fixed mold 12 and the movable mold 14 are open as shown in FIG.

In this state, first, the mold clamping control device 18 determines that the mold clamping control signal DC
As a result, a high-speed low-pressure mold closing signal and subsequently a low-speed low-pressure mold closing signal are generated to close the movable mold 14 and the fixed mold 12. Position signal PS (stationary position) from each sensor 17 when the movable mold 14 and the stationary mold 12 are normally closed and the movable platen 13 is stationary without foreign matter being sandwiched between them.
The operator confirms with the position indicator 19, and the stationary position and the normal mold clamping width A (plus side allowable value B and minus side allowable value C)
Set with the setting switch 20. The mold clamping control device 18 sets the stationary position set by the setting switch 20 as the fully closed position of the mold, stores the normal mold clamping width A in the RAM, and determines the mold closed position and the normal mold of this mold. The normal mold clamping range is calculated from the clamping width A and stored in the RAM. Then, the mold clamping control device 18 generates a mold opening signal as the mold clamping control signal DC and returns the movable platen 13 to the lowest position, that is, the initial state (the state shown in FIG. 2). In the present embodiment, the stationary position is stored in the RAM four times corresponding to each sensor 17, but at the initial setting, the stationary position set by the setting switch 20 is stored in all four times.

After this initial setting, the mold clamping control device 18 automatically performs the mold clamping operation of the movable mold 14 and the fixed mold 12 as described below.

First, the mold clamping control device 18 generates a high-speed low-pressure mold closing signal as a mold clamping control signal DC, as shown in FIG. 3, so that the movable platen 13 approaches the fixed platen 11 (upward in FIG. 2).
Move fast to.

When the distance between the movable mold 14 and the fixed mold 12 reaches a predetermined distance, the mold clamping control device 18 generates a low speed low pressure mold closing signal as a mold clamping control signal DC, and further moves the movable platen 13 to the fixed platen. Move slowly toward 11 (step 100).

The mold clamping control device 18 monitors the position signal PS from each sensor 17, and checks whether this position signal PS is within the normal mold clamping range stored in the RAM (step 101).
And 102). As a result of this check, if the position signal PS exceeds the normal mold clamping range (YES in step 101), the mold clamping control device 18 judges that it is abnormal and generates a stop signal as the mold clamping control signal DC, and the movable platen 13 To stop the movement (step 103).

On the other hand, the position signal PS is out of the normal mold clamping range (step 10
2), if the predetermined time T has elapsed from the start of the low speed low pressure mold closing (time T in FIG. 3) (YES in step 104), the mold clamping control device 18 determines that the movable mold 14 and the fixed mold 12 are connected. It is determined that a foreign object is sandwiched between them, and a stop signal is generated as the mold clamping control signal DC to stop the movement of the movable platen 13 (step 103).

Here, as the predetermined time T, the movable mold 13 and the fixed mold 12 are separated from each other after the movable platen 13 starts the low speed low pressure mold closing operation.
A time that is slightly longer than the time required for the movable platen 13 to normally close and the movable platen 13 to stand still without foreign matter being caught between them is selected.

If the position signal PS is within the normal mold clamping range (step
Even if the answer of 102 is YES, the movable platen 13 does not stop (step 105).
No.), and when the predetermined time T has elapsed from the start of the low-speed low-pressure mold closing (YES in step 104), the mold clamping control device 18 has a foreign object sandwiched between the movable mold 14 and the fixed mold 12. Then, a stop signal is generated as the mold clamping control signal DC to stop the movement of the movable platen 13 (step 103).

On the other hand, the position signal PS is within the normal mold clamping range (YES in step 102) before the predetermined time T has elapsed from the start of the low-speed low-pressure mold closing (NO in step 104), and the movable platen 1
When 3 is stopped (YES in step 105), the mold clamping control device 18 determines that the mold closing operation is normally completed,
A high-pressure mold clamping signal is generated as the mold clamping control signal DC, and the movable mold
14 and the fixed die 12 are clamped to a high pressure (step 106).
At the same time, the mold clamping control device 18 determines the fully closed position (normal mold clamping range) of the new mold in the cycle of the next process as follows (step 107).

First, the CPU of the mold clamping control device 18 stores the position signal PS from each sensor 17 in the RAM as a new stationary position (at this time, the information of the oldest stationary position is erased), and this RA
The average value of the stationary positions of the past four times (four cycles) stored in M is calculated. The calculated average value is stored in the RAM as the fully closed position P of the new mold for the next cycle. The CPU of the mold clamping control device 18 also determines a new normal mold clamping range from the newly obtained fully closed position P of the mold and the normal mold clamping width A set by the setting switch 20 and stored in the RAM. , RAM.

In this way, the stationary position of the movable platen 13 in the past cycle is stored, and the average value of the stored stationary positions of the number of past cycles is obtained. Since the obtained average value is used as the fully closed position of the new mold in the next cycle, the fully closed position of the mold is automatically corrected according to the condition of the mold, and the accurate fully closed position of the mold is obtained. You can decide.

[Effect of the Invention] As is clear from the above description, according to the present invention, the average value of a plurality of past stationary positions is set as the fully closed position of the mold.
There is an effect that the fully closed position of the die can be automatically corrected according to the state of the die and an accurate fully closed position of the die can be always determined.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining a method for determining a fully closed position of a mold according to an embodiment of the present invention, FIG. 2 is a diagram showing a configuration of a mold clamping device to which the present invention is applied, and FIG. It is a figure which shows an example of the time passage of the position signal from the sensor used in order to demonstrate invention. 11 …… Fixed platen, 12 …… Fixed mold, 13 …… Movable platen, 14 …… Movable mold, 15 …… Tie bar, 16 …… Actuator, 17 …… Sensor, 18 …… Clamping control device, 19 ......
Position indicator, 20 ... Setting switch, 21 ... Mold clamping drive device.

Claims (1)

[Claims] 1. The relative position of a movable mold with respect to a fixed mold is detected, and the movable mold is driven to close the fixed mold and the movable mold, and the movable mold stands still. A method for deciding a fully closed position of a die, characterized in that a relative position is stored as a stationary position, and a next fully closed position is determined from an average value of a plurality of stored still positions in the past.