JPS5988656A - Apparatus for inspecting thermosetting resin - Google Patents

Abstract

PURPOSE:To accurately and rapidly detect the fluidized and cured state of the resin in each part of a mold, by detecting resin pressure during fluidization, a plunger falling speed and a fluidized leading end position. CONSTITUTION:A resin tablet thrown in a mold 1 is pressed by a plunger 3 to be converted to molten resin and carried to a cavity 7 through a gate 6. Pulse voltage is outputted from a pulse generator 16 by the order of a microcomputer 14 to cyclically open and close the electromagnetic relief valve 17 of a molding machine. Resin pressure and the displacement of the plunger 3 are detected by pressure detectors 8, 9, 10 and a displacement detector 11 and the data in the following state of pressure change is stored in a computer 14. At the point of time when the signal from the pressure detector 10 is not followed to the signal of the pulse generator 16, the computer 14 performs the operation of viscosity and a gate seal state on the basis of the stored data and the result thereof is outputted by a printer 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thermosetting resin inspection device for detecting the flow and sanding state of resin in a resin mold.

[Prior art]

Conventionally, in order to detect the fluidity of a thermosetting resin, the value of the minimum melt viscosity measured by a Koka type flow tester or the value of the flow distance in a spiral flow mold has been used. The former uses a very thin nozzle (・, the viscosity is calculated by flowing the resin under constant pressure conditions,
The heat transfer state is thicker (different than that in the actual mold),
It was of little use in predicting the flow state inside the mold. In addition, since the latter method detects the flow distance of the resin in a flow path with an extremely small cross-sectional area, the heat transfer state is significantly different from that in the actual mold, and the supporting spiral flow length is However, it is not possible to quantitatively predict the ease of filling the resin in the mold.

On the other hand, as a means to examine hardenability, hot plate method < J I
8 K 5905), kinilastometer, hot hardness measurement of molded products, etc. In the hot plate method, the upper pressure resin is placed on a hot plate, the resin is stirred with a metal rod, and the time until the metal rod becomes immovable is measured, and this time and the hardening of the resin in the mold are measured. It is impossible to know the relationship with the state.In addition, the plastic coder method uses a measuring device to detect the phase change from liquid to solid caused by curing of the resin as a torque change, but this result also The relationship with the hardening state of the resin inside the mold is not clear.Furthermore, the hot hardness of molded products is measured inside the mold, but this measurement value is not measured until after the mold is opened. This has the drawback that the measurement error varies depending on the elapsed time, and the process by which the resin is assimilated from the liquid cannot be understood.

As mentioned above, with conventional methods, although it is possible to make a relative comparison of the fluidity and curing properties of resins, the actual flow in the mold,
It was not possible to grasp the relationship with the curing state, and even if the characteristic values of the resin were within the specifications using the conventional methods described above, it was not possible to grasp the relationship with the reality that the quality of the molded product would change significantly. . As mentioned above, in the past, there was no appropriate management method for resins, which resulted in poor product yields, which was a major obstacle in improving reliability.

[Purpose of the invention]

The object of the present invention is to overcome the above-mentioned drawbacks of the prior art.
It is an object of the present invention to provide a thermosetting resin inspection device that can accurately and quickly detect the state of flow and hardening of resin in each part of a mold.

[Summary of the invention]

In order to achieve the above [I-ya1', the present invention is constructed as follows. In other words, it is possible to quantitatively detect the flow and hardening state of the resin in the metal channel, which has a structure that is almost similar to that of an actual mass-produced mold. By using a pressure detector installed in the mold to detect the falling speed of the resin pressure detector during flow and the position of the flow tip, the above detection values can be used to determine whether the runner is not filled with light or has a poor appearance. It is possible to calculate the resin viscosity of the part and the resin viscosity of the cavity part that is associated with the occurrence of poor wire alignment. Also.

After filling the cavity with resin, we can directly examine the resin curing condition at the gate, which is closely related to the occurrence of voids inside the molded product. As mentioned above, this invention clarifies the causes of defects in molded products, which were unknown in the conventional method, and enables not only lot management of materials but also the selection of new resins and the optimization of molds. The above measurement results can be fed into the flow path design.

[Embodiments of the invention]

In the following - the invention will be explained on the basis of the drawings.

Figure 1 shows the overall configuration of an embodiment of the present invention.
't1 This v8 fat tablet (shown in the figure) is pushed by the plunger 6, and from the melted resins 4 and 1, the runner 5
．． It passes through Gate 6 and is transported to Kibitei 7. Resin pressure detectors 8*9y10 are embedded in the bottom runner 5 and cavity 7 of the plunger 6, respectively.

The pressure of the flowing resin is converted into an electric signal, and the displacement of the plunger 5 is also converted into an electric signal by a displacement detector 11. These signals are converted into digital signals by a digital voltmeter 16 via an amplifier 12, and stored in a control/arithmetic microcomputer 14. The data cannot be stored in the external storage device 15 if the storage capacity of the -1 microcon beater 14 is small.

When the cavity is completely filled with resin, the microcomputer 14 instructs the resin generator 16 to output a pulse voltage of a predetermined waveform, and the pulse voltage is passed through the amplifier 12'.

The electromagnetic relief valve 17 of the molding machine is opened and closed periodically.

This oil pressure change is detected by resin pressure detectors 8, 9, and 10, and q! Data of the tracking state of the pressure change of rs is stored in the microconbeater 14 or the external memory device 15. When the signal from the resin pressure detector 10 inside the cavity no longer follows the signal from the pulse generator 16, the microcomputer 14 stops the operation of the pulse generator 16, returns to the reset state, and saves the stored data. Based on this, calculations are performed on the viscosity and gate seal state, and the results are outputted by the printer 18.

Next, the operation of the present invention will be specifically explained with reference to FIGS. 2 to 6. FIG. 2 shows the profile of the measured values of the resin pressure detectors 8, 9, 10 and the displacement detector 11 of the plunger 3 from the time when the filling of the resin into the mold 1 is started until it is completed. A method for calculating the viscosity of the resin in the runner 5 and cavity 7 will be described below with reference to FIG. Here, -Pp*PR*"C indicates the indicated values of the resin pressure detectors 8, 9, and 10 provided at the bottom of the plunger 5, the runner 5, and the cavity 7, respectively, and 2 indicates the displacement detector 11 of the plunger 5. indicates the indicated value.

Let us now describe the method for calculating the viscosity of the resin in the runner 5, assuming that the values of Pp+PB and Z at time t2 are respectively PP2 m ''R2t Z2.The viscosity η of the resin in the runner 5 is calculated by the following equation.

riB= (PP2-PR2)/'βRQ...
(1) Here, β is a constant determined from the distance from the bot 2 to the resin pressure detector 9 of the runner 5 and the cross-sectional shape of the runner 5. Further, Q is the resin flow rate and can be determined from a linear equation.

Here, C1 is the step time when analog data is digitized, Zl*Z3 is the displacement data of the plunger 5 stored before and after t2, and AP is the cross-sectional area of the plunger 6. Therefore, by the time the transfer of the resin is completed, the viscosity of the resin in the runner 5 until the transfer is completed can be calculated using the values of P P + P R,Z stored every other time. Note that the above calculation is instructed to be performed from the point where the value of PR begins to appear. ts indicates the time when the resin transfer is completed, and since the value of Z does not change after this time (Zs=Zs+1), the flow JiQs immediately before the resin transfer is completed can be determined by the following equation.

Note that when Zs:Zs+1 is reached, Zs is set as the displacement at the time of completion of resin transfer, and a command is given to calculate the flow rate of resin immediately before completion of transfer using equation (6).

Next is the viscosity of the resin in cavity 7. is obtained from the following equation.

ηc=Pcs/'Ic11QB----=----(4) Here, PC8 is the indicated value of the resin pressure detector 10 in the cavity Z immediately before the transfer is completed, and β is the value measured from the resin pressure detector 10 to the cavity Z A constant 7 is determined depending on the distance to the end of the cavity 7 and the cross-sectional shape of the cavity 7, and Qs can be found from the above equation (6). Therefore, using the memorized values of Pcs, Qs, and the previously calculated β. V. can be calculated.

At the point in time when Z B =Z B +1 in FIG. 2, the microcomputer 14 issues a command to the pulse generator 16 to change the oil pressure of the plunger 6 sinusoidally. This state is shown in FIG. 6, which compares the blog files of the PP and PC. As shown in the figure, the pressure amplitude PPm of PP maintains a substantially constant value, while the pressure amplitude PCm of PC gradually decreases, indicating that the gate 6 is completely cured at te.

It should be noted that the absolute value of PC becomes smaller as time passes, and this is because the curing shrinkage of the resin becomes more noticeable. FIG. 4 is an enlarged version of FIG.
5 indicates the upper and lower ends of the pressure amplitude of PP+PC, respectively, and this time is synchronized with the pulse generator 16, and the pressure at each point of count 1-1 is stored in the microconbeater 14. and PPm#PCm in 11
and pressure amplitude ratio α=”am/′)′ Pm is calculated by the following formula.

(PPm) tl = Pp2-(Ppt+Pps)
/2 ・・・・・・・・・・・・(5)(PCm)t1
=PC2(PCI+PC5)/2 --(6)αt1
= (Pcm) t1/CPpm) tl
・・・・・・・・・-(7) Similarly, t2. t3・
PPm*PCm+α at the time of... is determined. When the pulse generator 16 reaches Pcm-〇, the microcomputer 14 stops the operation of the pulse generator 16 and (
The calculation results of equations 1) to (7) are printed out from the printer 18.

Table 1 compares the spiral flow length and gel time (hot plate method) of two lots of conventional bioconductor fixing resin. Resin lot) B has slightly worse fluidity and hardenability than A, but both are within the specifications, and it is unclear how this difference relates to the occurrence of defects in conventional methods. It is unclear. Figure 5 shows
This is a comparison of the void occurrence rate and the average amount of gold wire chamfer for each resin lot, and it can be seen that in lot B, both the voids and the gold wire bending are at a very poor level.

Table 2 compares the viscosity of the resin in the runner 5 and cavity 7 investigated according to the present invention for each resin lot. From this result, it can be seen that the viscosity of the 30 t lot is more than 1.5 times higher than that of the A lot. From this value, it can be seen that the viscosity of the lunch 5 portion is this high. , the resin flows extremely tightly inside the mold 1, and in mass production molds, the curing reaction proceeds without completing the transfer of the resin within the set time, resulting in a state where sufficient pressure is not applied inside the cavity Z. In addition, in B lot, cavity 47
K',,': It was found that because the viscosity of the J6 resin became higher, the force for bending the gold wire became thicker, and the amount of gold wire bending increased.

FIG. 6 is a plot of the value of α obtained according to the present invention against time, and the time in which the resin pressure at the bottom of the Veg Granger 5 is applied to the inside of the cavity Z is shorter in lot B than in lot A.

It was found that α also decreased rapidly.

Therefore, it became clear that it was easy to harden at the gate 6 and pressure was transmitted into the cavity Z (in lot B, the voids were crushed).

〔Effect of the invention〕

In the conventional method, the above-mentioned differences in void level and gold wire bending amount from resin lot to resin lot were unclear, but with this invention, for the first time, it was possible to quantitatively determine the cause.

In other words, according to the present invention, not only the fluidity and curing properties of the resin are checked when the resin is received, but also the mechanism of defective molded products is clarified, which facilitates the development of the resin.
Since the measurement results can be fed back to the optimal setting of molding conditions and the optimal design of the flow path specifications of the mold, the yield and reliability of molded products can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of an embodiment of the present invention, Fig. 2 is an explanatory diagram of the viscosity of the resin, and Figs. Explanatory diagram for, 5th
The figure shows a comparison diagram of failure occurrence states between resin lofts, and FIG. 6 shows a comparison diagram of resin lofts in gate seal states measured and calculated according to the present invention. Explanation of symbols 1...Mold 3...Plunger 4...
・Resin 5...Runner 6...Gelt
7... Cavity 8.9.10... Resin pressure detector 11... Plunge kilometer displacement detector 12, 12'... Amplifier 14... Microcomputer 16... Pulse generator 17... Electromagnetic Relief valve Fig. 7/σ Fig. 2 Fig. B

Claims (1)

[Claims] (A plurality of resin pressure detectors are provided in the mold consisting of a re-cavity, a gate, and a runner, and a displacement detector is provided in the plunger of the molding machine, and when the resin is flowing inside the mold, A thermosetting resin inspection device characterized by having a function of monitoring the signals output by each of the above detectors and calculating the resin viscosity of the cavity and launch portion from the monitored values. (2) Having the above calculation function. At the same time, after filling the resin into the cavity, the relief valve opening of the plunger of the molding machine is varied in a pulsed or periodic manner to calculate the pressure amplitude of the resin pressure or the pressure amplitude of the resin pressure and hydraulic pressure for one hour. The thermosetting resin inspection device according to claim 1, having the function of: