JPS62286658A - Control method of die clamping force for forming machine - Google Patents

Abstract

PURPOSE:To keep good condition fop the die clamping force at every cycle by adjusting the die clamping force at the next cycle under consideration of changing degree of the die clamping force in accordance with the changing degree of the die temp. during the former cycle, based on the die clamping force during the former cycle. CONSTITUTION:At the first time of continuously forming, the die clamping force is adjusted at the desirable value, and the die clamping force is measured by a detecting instrument, built in the column 8. Whether this value is in the range of the standard value or not, is judged, and in case of being not in the range, it is readjusted to be in the range. Next, lubricant, etc., is supplied on the die and the die clamping is executed, and then the die clamping force FL1 and the die temp. just before injection start are started to measure, and after their confirmation, a series of operation is executed. And the die temp. for one cycle is measured and stored to operate rising degree of the all-round die temp. during the next cycle. Next, expansion and shrinkage of the die according to the changing degree of the temp., based on the die clamping force FL1 and the above-mentioned operating value, are found and then based on this value, rising degree of the all-round die clamping force during the next cycle is operated. Then, whether the max. die clamping force during the one cycle is in the permissible max. die clamping force of the forming machine or not, is judged.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention manages mold clamping force in a molding machine having a trouble molding and clamping mechanism such as a die casting machine or an injection molding machine. It is about the method.

[Prior Art] Fig. 2 shows a mold clamping mechanism of a molding machine such as a die casting machine, in which a movable platen 4 equipped with a movable mold 2 is connected to a fixed platen 3 equipped with a fixed mold 2 in a cylinder. A toggle mechanism 6 is activated by the mold clamping cylinder 5 attached to the platen 7.
By extending the column 8 and receiving the reaction force by the column 8 connecting the fixed platen 3 and the cylinder platen 7,
The movable mold 2 is brought into and out of contact with the fixed mold 1 so that the clamping force, that is, the mold clamping force can be overcome.

8a is a column nut, 9 is a machine base of 16° [Problems to be solved by the present invention] In die casting machines and injection molding machines, the mold temperature at the start of injection is relatively low, and the injection operation is By repeating this process, the mold temperature gradually increases.When the mold clamping force at the start of injection is raised close to the functional limit, and when the mold clamping force is adjusted, the mold temperature increases during repeated injection operations. Expansion of the mold due to the rise in mold temperature -L increases the mold clamping force, ■ Toggle 6 cannot be fully extended and the required mold clamping force cannot be obtained, ■ The power of mold clamping cylinder 5 is dependent on the platen and Uncertainty factors such as layer movement and friction of the toggle are expected and there is a margin, so there is a capacity limit.Secondly, mold clamping force is generated, which adversely affects the machine and mold, and reduces the durability of each. This causes problems such as a significant decrease in

Also, in order to avoid the troublesome adjustment of mold clamping force,
When the mold temperature is low just before the start of the machine operation, the mold clamping force may be set a little lower so that the maximum mold and clamping force can be obtained while the mold temperature is stable. In that case, insufficient mold clamping force at the start of injection may easily cause rupture or cause problems such as hot water blowing.

[Means for Solving the Problems] The present invention is intended to improve the above-mentioned drawbacks, and the mold clamping force for each cycle is adjusted to the best condition from the start of the machine operation. The purpose is to manage and coordinate.

In the present invention, the mold clamping force before the start of injection is detected using an existing detector, and based on this, it is determined whether or not to enter the injection process, and the first molding cycle is started. The mold clamping force of a cycle is determined by detecting the change in mold temperature during the previous cycle with a mold temperature detector, converting it into a mold clamping force increase rate, and adjusting the existing mold clamping force adjustment device by taking this into account. Adjustments were made.

[Operation] By detecting the mold clamping force before the start of injection, it is possible to judge whether the mold clamping force necessary to start injection is secured, and also to prevent the occurrence of paris and hot water blowing.

I do.

It also detects the rate of change in mold temperature from the start of injection to the time before the start of mold opening and due to spray operation, converts it into a mold clamping force increase rate, and adjusts the maximum mold clamping force that the machine has for the next cycle. Since this is used as a standard for the purpose of the test, abnormalities in the mold clamping force can be prevented.

[Example] Next, the invention will be explained in more detail with reference to examples shown in the drawings.

In general, the change in mold temperature yEI when no mold clamping force adjustment is performed is as shown in the one-mold temperature T diagram over time in FIG. 1(a), and during one cycle, J! ! The mold temperature TL+ is the lowest before the start of injection immediately after the first tightening, and the mold temperature T gradually increases from the start of injection. Immediately before moving to the opening operation, the mold temperature THI is generally the highest, then the mold temperature begins to decrease, and due to the spray operation after the mold opening, the mold temperature suddenly begins to decrease, and the next After mold clamping 1
From the start of the next injection, the mold temperature T gradually increases again. In that case, the mold temperature TL2 immediately before the start of injection immediately after the next mold clamping is generally higher by TDl than the gold Δ1j temperature TL+ before the start of injection immediately after the previous mold clamping, and the mold temperature T is as shown in Fig. 1. As shown in (a), the waveform is captured every cycle,
Moreover, it tends to gradually become υj. Figure 1 (
In a) TLI, Tl2, Tl3.

...... is the mold temperature immediately after mold clamping and before the start of injection in each cycle, T) (I, Tl-12, "rH: +
,... is the maximum temperature of the mold during each cycle, Tu
p+, Tup2, -99. -3 is the maximum temperature of the mold during each cycle THI, rH2, ... and the initial minimum temperature of the mold TLI, Tl2, ...
・Difference between Tdovnl, Tdown2,...
... is the maximum temperature THI of the mold during each cycle, r
H2, 1 at the mold temperature at the end of each cycle.
The initial minimum temperature of the mold for the next cycle TL2, Tl3,
The difference between -..., TOI, TD2, -... is Tl2- TLI, Tl3- Tl2,..., respectively.
...is shown.

Money! If the temperature rises or falls by -L, the mold expands and contracts by that amount, and the thickness of the mold becomes thicker or thinner, so the mold clamping force increases or decreases by that amount.

Therefore, the state of change in mold clamping force corresponding to the mold temperature curve in Figure 1(a) is shown by the solid line in the time E-mold clamping force edge diagram in Figure 1(b). This is a curve. Figure 1(b)
In, FLI, FL2, Flj.

...... is the initial mold, clamping force, Fl-1 during each cycle
1.FH2.

FH3, ... is the maximum mold clamping force during each cycle, F
up+.

F up2 , --- is FHI -FLI,
Fl-12-Fl-2, -..., Fdawnl
, Fdown2 , ... is FHI Fl
2, FH2-FL3, ・”..., For
, FO2, ------ is FL2- FLI
.

FL3- FL2 ,..., also, Fm
ax is the maximum allowable mold clamping force of the molding machine, Fl-1, FL is,
These values indicate the upper and lower limits of the initial mold clamping force base 8FA value for determining whether or not the initial mold clamping force is within the desired mold clamping force range prior to the first cycle operation.

If the mold clamping force is not fully adjusted after the mold clamping force is initially set, as the mold temperature increases with each cycle,
The mold clamping force during mold clamping eventually reaches the maximum allowable mold clamping force Fm of the molding machine.
This would be dangerous as it would exceed the ax.

Therefore, in the present invention, if it is determined that the mold clamping force exceeds the maximum allowable mold and clamping force Fmax of the molding machine during the next mold clamping, the mold clamping force is slightly reduced immediately before the mold clamping of the first cycle. Adjust the mold clamping force to ensure that it does not exceed the allowable maximum mold clamping force Fmax. Even so, in the event that the mold clamping force exceeds the molding machine's maximum mold clamping force FLAX during mold clamping, the initial mold clamping force of the first cycle will be relatively greatly reduced, and the initial Ensure that the mold clamping force falls within the upper and lower limits of the standard value.

When actually controlling and managing the mold clamping force, for example, it is done as shown in Figures 3 (a) and (b), or as shown in Figures 4 (a) and (b). do.

As shown in FIGS. 3(a) and 3(b), when starting M-continuation molding, the mold clamping force is first adjusted to a desired mold clamping force. Then, the mold clamping force detection device built into the column 8 measures the mold clamping force FQ before the start of injection, and this mold clamping force F□ is the upper limit FH of the predetermined initial mold clamping force reference value. and the lower limit Fl is automatically determined.

If the mold and clamping force Fo are not within the desired range, open the mold and adjust the mold clamping force again until the mold clamping force FO reaches the desired value FH, F.
Make sure it is between L. If the mold clamping force FO is between the desired values FH and FL, the mold is opened, a lubricant or the like is sprayed onto the gap part of the mold, and the mold is clamped again.

Immediately before the start of injection, the mold clamping force FLI is measured, and the mold temperature T is also started to be measured. In this case, the mold temperature T
is measured at a location where the temperature is approximately the same as the average temperature of the mold. When the mold clamping force FLI and the mold temperature T are confirmed to be constant, an injection command is issued, and injection starts, ends, cures the product in the mold cavity, opens the mold,
Product extrusion, take 11! , spray and perform normal molding operations.

On the other hand, if the mold temperature T starts to be measured immediately before injection starts, the mold temperature T during one cycle from injection completion, mold opening, spraying, and mold clamping to just before the next injection starts.
are determined continuously or discontinuously and stored in a microcomputer.

and ■ Initial minimum temperature TLI of the mold during the cycle.

The maximum temperature THI is detected, and the mold temperature TL2, which is slightly smaller than the mold temperature at the end of one cycle, that is, the initial minimum temperature of the mold during the next cycle, is detected, and each of these temperatures TLI is detected.

From THI and Tl2, ■The rising temperature of the mold during the cycle TL [PI = Tl-11-TLI, lower'f4
Temperature T dawn = T)+1 -Tu,ffi combined temperature riseff1To+ = Tup+ -Tdowr++
Calculate.

Next, based on the previous mold clamping force FLI and the above calculated value, the expansion and contraction of the mold with the degree of temperature change is determined, and based on that, the maximum mold 1 clamping force FHI during one cycle and the mold clamping force at the end of one cycle are determined. force, that is, the initial mold force during the next cycle, the mold clamping force FL2, which is equal to the minimum mold clamping force. Calculate the total mold clamping force '2 Shengtang Fo+ = FL2- FLI.

Then, the maximum allowable mold and clamping force FLax of the molding machine are set, and it is determined whether the maximum mold clamping force FHI during one cycle is less than or equal to the clamping force Fmax. Frnax-Fs+
If ≧O, the total mold clamping force increase during one cycle FJ F
Ol is F! It is determined whether it is less than or equal to Iax - FHI.

If For is less than F mat -FH1, the next mold clamping operation will start, but if For becomes stronger than Fmax - FHI, the maximum mold clamping force FH2 in the next cycle will be the maximum allowable mold clamping force Fmax of the molding machine. Since it is expected that the initial mold clamping force FL2 of the first cycle will exceed F
t, + -For + (Fmaz -FHI) so that FH2 becomes the same as Fmax, and then the next mold clamping is performed.The rJA adjustment condition at this time is shown in Fig. 1 (b). , indicated by dotted line A.

On the other hand, if the maximum mold clamping force FHI during one cycle exceeds the allowable maximum mold clamping force Fmax of the molding machine, open the mold once and set the initial mold clamping force FL2 of the next cycle to The fgl adjustment state at this time, in which adjustment is made to the intermediate value, that is, (FHIF1)/2, and then the next mold clamping is performed, is illustrated by the dotted line B in FIG. 1(b).

Then, the operations after mold clamping are constantly repeated.

In addition, in a device where the mold clamping force T is 100ton, for example, TH=L030ton, TL=990ton
.

Set Tmax = l 100 tons.

FIGS. 4(a) and 4(b) are views of another embodiment showing only the steps after mold clamping in FIGS. 753(a) and 4(b). Third
In Figures (a) and (b), the maximum mold clamping force FHI during one cycle was calculated by taking into account the rising temperature Tupl of the mold, but in Figures 4 (a) and (b) ), the maximum mold clamping force FHI during one cycle was measured by a mold clamping force detection device built into column 8, and the value FHI was directly used for calculations and comparisons.

That is, in FIGS. 4(a) and 4(b), as shown, the initial mold clamping force FLI during one cycle and the initial minimum temperature TL+ of the mold are constant at A1, and the maximum mold temperature during mold clamping is The mold temperature TL2 at the end of the clamping force FH1,L cycle is measured, and the difference between the mold temperature TL2 at the end of one cycle and the initial minimum temperature TLI is determined between the start of the current cycle and the start of the next cycle. Calculate the estimated mold clamping force increase FD+, and then compare FHI with Fmax and change Fo+ to Fw in the same way as shown in Fig. 3 (a) and (b).
ax -Fl-11 and based on the result, the initial mold clamping force FL2 for the next cycle is set to 21! J Adjust.

In this case, in the unlikely event that the maximum mold clamping force FH during one cycle
When I exceeds the maximum allowable mold clamping force Fmax of the molding machine,
Instead of adjusting the initial mold clamping force FL2 of the next cycle to an intermediate value between FH and FL, it is also possible to adjust it to the initial mold clamping force FLO of the time before the previous cycle.

In this way, the maximum mold clamping force FHI during one cycle
It is efficient to use the molding machine with , FH2, ... as close as possible to the maximum allowable mold clamping force FIIIax, and even if molding is repeated continuously, the mold clamping force remains constant. It is safe because it does not become larger than necessary.

In the above embodiment, the changes in mold temperature and mold clamping force were calculated and compared based on , but this was done based on the rate of change and rate of change in mold temperature and mold clamping force. It's okay.

Furthermore, the maximum and minimum values of the mold temperature and mold clamping force for each cycle can be directly detected using a peak hold device using the LSI 5.

In addition, when measuring the mold temperature, instead of inserting a thermometer such as a thermostat in the mold and measuring it directly, it is possible to measure the mold temperature by keeping the outlet temperature of the cooling water of the mold constant. It is also possible to indirectly make the state of change constant.

[Effects of the Invention] In the present invention, the criteria for determining whether to adjust the mold clamping force are as follows:
is based on the degree of change in mold temperature during the previous cycle.In order to obtain the estimated degree of change in mold clamping force, the mold clamping force for each cycle is relatively accurately approached to the maximum allowable mold clamping force of the actual machine. Can drive. Therefore, molding can be performed continuously after an efficient and effective mold clamping force is maintained, and the mold clamping force does not exceed the allowable maximum mold clamping force of the molding machine during molding. Even if you exceed 10,000, you will only exceed it by a small amount, and the next time immediately,
Since the mold clamping force is adjusted, the mold clamping force does not become larger than necessary and there is no need to apply excessive force to the molding machine.
It is safe and does not damage the mold clamping mechanism. On the other hand, since the mold clamping force does not become too small, it is possible to suppress the occurrence of paris from the start of the first injection, and also to prevent the risk of boiling.

[Brief explanation of drawings]

The drawings are for explaining the present invention, and FIG. 1(a) is a time-mold temperature diagram, FIG. 1(b) is a time-mold clamping force diagram, and FIG. 2 is a more conventional diagram. Front view showing an example of a mold clamping device of a molding machine used in
4(a) and 4(b) are diagrams showing flow sheets for different mold clamping force adjustments, respectively. 1...Fixed type, 2...Movable type, 5...
・Mold clamping cylinder, 6... Toggle mechanism, 8...
Column, TLI, TL2...initial minimum temperature of the mold during each cycle, To+, TO2...total temperature rise of the mold for each cycle, FLI, FL2...initial mold clamping force of each cycle , THI, TH2... Maximum mold clamping force during each cycle 5TDI, TD2... Estimated amount of increase in mold clamping force between each cycle, Fmax... Maximum allowable mold clamping force of the molding machine. Patent applicant: Ube Industries, Ltd. Part 3 (b) Rope 4 Figure (q) Part 4 (b)

Claims (2)

[Claims] (1) In a molding machine with a mold clamping mechanism, the next mold clamping is performed based on the mold clamping force during the previous cycle, taking into account the degree of increase in mold clamping force according to the state of change in mold temperature during the previous cycle. A mold clamping force management method in a molding machine that adjusts the force. (2) In a molding machine with a mold clamping mechanism, when adjusting the next mold clamping force, calculate the total temperature rise of the mold during the previous cycle between the start of the previous cycle and the start of the next cycle. When converted into an estimated increase in clamping force, if the estimated increase in mold clamping force during the previous cycle is larger than the difference between the maximum allowable mold clamping force of the molding machine and the maximum mold clamping force during the previous cycle, The set mold clamping force immediately before the start of injection is determined from the mold clamping force immediately before the start of injection in the previous cycle, based on the estimated increase in mold clamping force during the previous cycle, and the maximum allowable mold clamping force of the molding machine and the highest mold during the previous cycle. A mold clamping force management method in a molding machine that reduces the clamping force by the difference in clamping force.