JP3001228B2 - Method of controlling die clamping force of die casting machine - Google Patents

Description

The present invention relates to a method for controlling a mold clamping force of a die casting machine.

[Prior Art] In a die-casting machine having a toggle-type mold clamping mechanism, a situation may occur in which the mold clamping force increases due to thermal expansion of the mold during operation, or the mold cannot be clamped.

To prevent this, appropriate control of the mold clamping force is required.

Control of the mold clamping force of a tie scat machine having a toggle mold clamping mechanism is performed by a die height device. And
To adjust the mold clamping force, the change in the tie bar elongation is detected with a measuring instrument, etc., and the mold clamping force is found.The casting operator constantly monitors this and discovers any abnormalities. However, since the adjustment is performed by rotating the tie bar nut to adjust the die height device, the adjustment operation requires a lot of time and labor. Therefore, from the viewpoint of speeding up this adjustment work and saving labor, a method of automatically adjusting the die height device by controlling the die height device by combining the tie bar elongation detector, the die height device and the microcomputer, and controlling the mold clamping force of the die casting machine. It has become adopted. Japanese Patent Publication No. 58-55860 discloses a method of automatically controlling the die clamping force of the die casting machine.

[Problem to be Solved by the Invention] In a conventional mold clamping force control method for a die casting machine, which is a combination of a tie bar elongation detector, a die height device, and a microcomputer, an abnormal upper limit of mold clamping force for judging abnormality of the clamping force. When the abnormal state is not less than the lower limit of the mold clamping force or below the lower limit of the abnormal mold clamping force, a control method in which neither the casting nor the compensation of the mold clamping force is performed is adopted. Some control methods employ a control method for correcting a mold clamping force.

In such a conventional method of controlling the mold clamping force, in the case of a control method in which neither the casting nor the compensation of the mold clamping force is performed in an abnormal state as in the former case, the mold clamping force at the start of the operation of the die casting machine, that is, at the start of the casting cycle. When presetting (moving the die height device in advance so that the mold clamping force is close to the target mold clamping force)
The mold clamping force must be preset by the AND error method, which requires time and labor. Also, in the case of a control method in which casting is not performed even in an abnormal state as in the latter case, but the mold clamping force is always corrected, the abnormal state is caused by biting in a mold in a mold, an abnormality in a tie bar elongation detection sensor, (Other abnormalities include:
Abnormalities in the die height sensor, abnormalities in the control of the die height motor, and the like. ) Etc., even if the mold clamping force is in an abnormal state, the compensation is performed even though the mold clamping force should not normally be corrected, so the abnormal state is expanded. .

Therefore, in such a case, there is a problem that the setting of the mold clamping force is performed again after removing the cause of the abnormality such as removal of the burrs stuck in the mold and inspection of the tie bar elongation detection sensor.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and has as its object to provide a method of presetting a mold clamping force at the time of presetting a mold clamping force of a die casting machine, and a method of presetting a mold clamping force. The control method for keeping the force within a certain range is set continuously and automatically, and when presetting the mold clamping force, the mold clamping force is automatically corrected at all times. When an abnormal state occurs, a machine or the like does not automatically perform automatic correction, but a worker or the like confirms the abnormal state and removes the cause of the abnormality, thereby providing a control method.

[Means for Solving the Problem] In order to achieve the above object, a method for controlling a mold clamping force of a die casting machine according to the present invention provides a method for controlling a mold clamping force set value and whether or not to correct the mold clamping force. An upper limit and a lower limit of the allowable range of the judgment and an abnormal upper limit and a lower limit of the mold clamping force for judging abnormality of the mold clamping force are provided, and the mold clamping force measured immediately after the start of the operation of the die casting machine is within the allowable range. If the mold clamping force exceeds the upper limit or the mold clamping force lower limit before entering, an alarm is issued and casting is not performed.After opening the mold, only the difference between the measured mold clamping force and the set value Automatic correction of the mold clamping force is performed.If the mold clamping force falls below the upper limit or falls below the lower limit of the mold clamping force after entering the allowable range, an alarm is issued and neither the casting nor the mold clamping force is automatically compensated. The cause of the abnormality is confirmed and removed.

[Operation] The mold clamping force control method of the present invention configured as described above includes:
At the time of presetting to set the mold clamping force of the die casting machine at the start of the casting cycle, even if the mold clamping force is in an abnormal state, priority is given to the correction of the mold clamping force, and it works to enable automatic presetting, and If the mold clamping force falls within the set allowable range even once even after the start of the casting cycle, if the mold clamping force becomes abnormal, an alarm is issued and the casting is stopped to correct the mold clamping force. It works to wait for removal of the cause of the abnormal state without performing any processing such as.

[Embodiment] An embodiment will be described with reference to the flowchart of FIG. 1. When the control method of the present invention is started after setting the mold clamping force in FIG. The setting of N = 0 is performed. Thereby, the mold clamping in the block 2 is performed.

Next, in block 3, the elongation of each tie bar during mold clamping is detected. Block 3 in Block 4
The mold clamping force is calculated from the measured value of. In block 5, it is determined whether or not the mold clamping force obtained in block 4 is equal to or greater than a specified abnormal upper limit of the clamping force or equal to or less than an abnormal lower limit of the abnormal clamping force.

If the result of the comparison determination in block 5 is NO, that is, if the mold clamping force is not equal to or higher than the abnormal upper limit value or equal to or lower than the abnormal lower limit value, casting is not signaled and casting is performed, and the process directly proceeds to block 6, The mold clamping force obtained by the calculation is stored in the buffer. Then, the process proceeds to block 7, where the average value of the predetermined number of mold clamping forces is obtained. In this case, when the past data does not reach the predetermined number of times, that is, when the average value of the predetermined number of times cannot be obtained, the average value for the number of times of measurement (when the number of times of measurement is one, the value is obtained).

In block 8, it is determined whether the average value or the like obtained in block 7 is within the allowable range of the upper limit and the lower limit set as a criterion for determining whether to correct the mold clamping force. If YES here, that is, the average value is the upper limit, lower limit,
Is within the allowable range, the flag N is set to 1 in block 11, and the process returns to immediately after the start again to perform the mold clamping of block 2, and the same processing as described above is performed. Block 8
If the determination is NO, that is, if the average value is outside the allowable range of the upper limit and the lower limit, proceed to block 9 and open the mold so that it falls within the allowable range. As described above, by combining the tie-bar elongation detector, the die height device, and the microcomputer, the die height device is automatically adjusted to correct the mold clamping force.

Then, in block 10, the mold clamping force data of the calculation result stored in the buffer in block 6 is cleared, and the process returns to immediately after the start again to perform mold clamping of block 2.

On the other hand, if the result of the comparison determination in Block 5 is YES, that is, if the mold clamping force is equal to or higher than the abnormal upper limit value of the clamping force or equal to or lower than the abnormal lower limit value of the abnormal clamping force, the process proceeds to Block 12 and an alarm is output. It warns that the mold has bitten a foreign object and the casting work is stopped and blocked
Proceeding to 13, whether the mold clamping force within the allowable upper and lower limits set as the criterion for determining whether to correct the mold clamping force after the die casting machine to be controlled starts the casting cycle It is determined whether or not.

When the result of the determination in block 13 is NO, that is, when it is determined that the casting cycle has not been within the allowable range even after the start (flag N =
0) proceeds to block 6 and after the mold clamping force obtained by the calculation is stored in the buffer, the same as described above, "the mold clamping force that has never been within the allowable range is set to be within the allowable range. Processing is performed in the order of block 7 and block 8,
It is returned immediately after the start of the casting cycle again, and the block 2 is clamped.

If the result of the determination in block 13 is YES, that is, if it is determined that the casting cycle is within the allowable range after starting (flag N = 1), the flow proceeds to block 14 to correct the mold clamping force. Is not performed. Since the die-casting machine is in a casting stopped state, the cause of the abnormal state must be eliminated by the casting operator. Therefore, after the burrs are caught in the mold, the burrs are removed, and if the tie bar elongation detection sensor is abnormal, the burrs are inspected and replaced, and then the casting cycle is restarted and the processing procedure from the beginning is repeated. Will be.

[Effect of the Invention] As described above, the method of controlling the mold clamping force of the die casting machine according to the present invention automatically corrects the mold clamping force to a predetermined value by the processing procedure described in the embodiment, and furthermore, this processing procedure is Since it is repeated according to the casting cycle, the required mold clamping force can always be maintained within the set range, and the compensation of the mold clamping force when presetting the mold clamping force at the start of the operation of the die-casting machine is a manual operation. It is done automatically without depending. In addition, since it is determined that the mold clamping force has become abnormal due to biting of a burr, abnormality of a detection sensor, or other causes, the process does not automatically correct the mold clamping force. Is achieved, which has an effect on the quality control of the die-cast molded product, and can improve the efficiency of the casting operation.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a processing procedure of an embodiment of the control method of the present invention.

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B22D 17/26 B29C 45/66

Claims (1)

(57) [Claims] A method for controlling a mold clamping force of a toggle link type die casting machine for automatically adjusting a mold clamping force by using a die height device for controlling the mold clamping force. The upper and lower tolerances for determining whether or not to make corrections, and the upper and lower limits of abnormal clamping force for determining the normal state of clamping force, are set, and the operation of the die casting machine is started. Measure the force, if the measured mold clamping force does not exceed the mold clamping force abnormal upper and lower limits, calculate the average value of a predetermined number of consecutive times, whether or not the average value is within the allowable range When the average value is within the allowable range, the operation of the die casting machine is repeated, and when the average value exceeds the allowable range, the mold clamping force is automatically corrected by the difference between the average value and the set value. , The measured mold clamping force exceeds the upper or lower limit of the abnormal mold clamping force If an alarm is issued, the casting is stopped, and if the mold clamping force abnormality exceeds the upper or lower limit and the cycle starts after the cycle starts, and the average value of the measured clamping force is within the allowable range, this mold is removed. Calculate the average value including the measured value exceeding the upper or lower limit of the clamping force abnormality, and when the average value exceeds the allowable range, perform automatic correction of the mold clamping force by the difference between the average value and the set value, and It is characterized in that the mold clamping force is not automatically corrected if the average value of the measured clamping force is within the allowable range after the cycle start that exceeds the upper or lower limit of the abnormal clamping force. Die casting machine clamping force control method.