JPS6043294B2 - Mold opening/closing operation control system in resin molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold opening/closing operation control system in resin molding.

This type of control method controls the molded product to be completely ejected from the mold, confirms that there is no residual resin in the mold, and then performs the next resin molding process. It is used to control the system to stop.

As such a control method, there is a method using a residual resin confirmation device using a contact type with the product using a limit switch.

However, since this method involves direct contact with the product, it may not be possible to detect the product properly depending on the shape of the product, and continuous use may easily damage the device. For this reason, there are non-contact confirmation devices that use a weighing scale or electrostatic type, but gravimetric confirmation devices have a slow response time and are susceptible to external influences such as vibration and wind. There is a problem that it is easy to receive.

Electrostatic type confirmation devices have problems in that they cannot detect resins that have no or weak chargeability, and they also cannot detect small-sized products. Electrostatic type devices have no directivity and are therefore susceptible to external disturbances. Therefore, the purpose of the present invention is to provide a non-contact method that does not come into contact with the product, is stable and reliable, can be used semi-permanently, is applicable to all resins, and is capable of detecting small objects. The object of the present invention is to provide a control system that has directivity and is less susceptible to external disturbances.

Another purpose is to develop a device that is more reliable than the electrostatic type when picking up multiple pieces.
In order to achieve the above object, the present invention focuses on the fact that all substances emit infrared rays (that is, radiant energy) from their surfaces, and by detecting such infrared rays, the presence or absence of residual resin is confirmed. take a method.

In other words, all substances with a temperature above absolute o degrees (O' -273 degrees Celsius) emit infrared rays from their surfaces, and the infrared rays travel in a straight line at the same speed as light, but this infrared rays, or radiant energy, The amount of emitted increases as the temperature rises, and at the same time it differs depending on the substance even at the same temperature, so the difference in infrared rays between these substances is used for confirmation. This emission ratio, which differs depending on the substance, is called the radiance, and it is 1.0 for a black body, which is an ideal heating element.
On the other hand, it is determined by what ratio of energy is released at the same temperature. Such a radiance is, for example, about 0 for plastic and about 0.60 for 95N iron.
Therefore, since synthetic resins and metals are significantly different, they can be used. Therefore, when using this principle to check molded products, if the measurement area is treated as a spot and the difference in radiance of that area is detected, it is possible to detect whether or not resin remains within the spot. Become.

This is because, as mentioned above, at the same temperature, the temperature of the resin is detected to be about 1.5 times that of the mold. For such confirmation, it is sufficient to measure the spot at a known infrared temperature, but while an infrared thermometer must absolutely display the temperature, the present invention Since it is sufficient to detect the difference between the mold and the resin, it is sufficient to detect the relative temperature difference, and the apparatus can be simplified.

Hereinafter, an example of implementation of the present invention will be described with reference to the drawings. As shown in FIG. 1, this method can be embodied as a device that uses a sensor 3 to spot-detect whether or not a product 2 made of synthetic resin remains in a mold 1.

This spot is designated by the symbol S. As the sensor 3, Thermo Spot◆Sensor'VSS manufactured by Japan●Sensor Corporation can be used. Such a sensor 3 is convenient because the size of the spot S can be arbitrarily changed using a lens, and it can be disposed at an arbitrary distance from the position of the mold 1, which is the object to be detected. Of course, it is also possible to change the size of the spot S depending on this distance. Furthermore, the sensor 3 does not need to display an absolute temperature, but may be any sensor that can detect a relative temperature difference. In this respect, it is much more advantageous in terms of cost than those that require precise temperature display. The energy detected by the sensor 3 enters the input section 41 of the device 4 in FIG. 2 as an input signal.

This device 4 issues control commands based on signals from the sensor 3, and its block diagram is shown in FIG. This device 4 cuts the mold temperature component from the temperature detection of the sensor 3, which is an input signal, extracts only the energy component due to the resin, and outputs various control signals by comparing this energy component. . Now, to explain with reference to the block diagram of Fig. 3, the detected temperature detected by the sensor 3 is as follows.
It enters the input terminal as a temperature signal t, which is first input to the amplifier 5.

This signal t is amplified by the amplification part GAIN of the amplification device 5, and the input below the temperature a of the mold 1 is cut by the cut deposit EVEL, and only the energy generated by the resin is taken out as an output. . Note that the input to the amplifier 5 can be visually confirmed on the monitor 6, and although the level has not yet been cut, the operation by the input and the level cut position can be visually confirmed. The meter of this monitor 6 is also indicated by the reference numeral 6 in FIG. In this way, the level-cut output by the cut publication EVEL is not output because if only the detected temperature of the mold 1 is input as the input t, all of it will be cut.

At this time, the comparator 7 outputs a low level signal t''.
is output. When resin remains in the mold 1, the corresponding amount of energy enters the comparator 7 as an output signal, and the comparator 7 generates a high ● level signal t''.These signals t'' are sent to the flip-flop circuit FF. -1 to relay RY-1. Signal t'' is also input to detection indicator lamp 42 to clearly indicate detection. Relay RY-1
is for issuing a mold closing command, but it is set so that while the output is being output, that is, while there is resin, relay RY-1 does not work and the mold closing command is not issued. In order to prevent blank firing, this relay RY-1 is set to operate and issue a mold closing command only when the state changes from no output to present and then to no output. When mold 1 is filled with resin and molding is completed, the mold is opened and the product is taken out.
The next molding process begins, and when the mold is opened, the molding machine issues a mold opening completion signal f, which is input to the device 4'.

This signal f is generated by two timers TM-1 and T to prevent a mold closing command from being issued before the product is ejected.
It plays the role of operating M-2. In other words, when the mold opening is completed and the product is normally discharged, relay RY-1 may issue a mold closing signal in order to proceed to the next process, but even if the product is not discharged, the time is As the temperature decreases over time, it is detected as a change from no output to output to no output, which may cause relay RY-1 to operate and issue a mold closing command, so this is prevented. Further, the timers TM-1 and TM-2 each operate to issue an operation command for the take-out machine (robot) in the event of an abnormality, and also to command an interlock, as will be described in detail below. That is, the mold opening completion signal f is input to timer TM-1 and timer TM-2 as shown in FIG.

Since the time of timer TM-1 is set shorter than the time of timer TM-2, the set time of timer TM-1 first elapses, but even after this time, the product is not ejected and the mold opening completion signal f is emitted. When continues to be input, the mold opening completion signal f is input to the relay RY-2 via the timer TM-1, the flip-flop circuit FF-2, etc., and the relay RY-2 is activated. At this time, a take-out command is issued to issue a robot operation command.
If the product is not discharged despite the robot's operation command, an interlock is activated after the set time of timer TM-2 has elapsed to prevent the mold closing signal from being issued.
In other words, even if the time set by the timer TM-2 has elapsed, if there is a mold opening completion signal f due to some product remaining, this is configured to issue an interlock command via the flip-flop circuit FF-4. be. When the product is properly discharged, the device 4 issues a mold closing command c to cause the molding machine to close the mold 1 and perform molding.This signal c is sent to the automatic mold opening/closing circuit of the molding machine. Put it in the series.

As described above, this signal is generated by relay RY-1. When the molding machine completes mold closing, the molding machine issues a mold closing completion signal e, and when this signal is input to the device 4, all controls are reset to prepare for the next operation.

In addition, if the unloader is used only in abnormal situations, the unloader operating circuit should be connected to the unloader operating circuit only if you want to configure the unloader to operate when the product does not fall when the product is normally automatically dropped. You can put it in and make it work.

The operation in such a case will be described later using FIGS. 8 and 9. Since the configuration of the device 4 is as described above, the operation of this device will now be explained separately in normal and abnormal conditions with reference to FIG. 4 and subsequent figures.

First, FIG. 4 is an operation chart showing the operation when the take-out machine is not used and the molding is performed normally.

In the figure, a is the temperature input of the temperature signal t'', b is the mold opening completion signal F, c is the timer TM-1, d is the timer TM-2, and e is the mold closing command signal C..f from the relay RY-1. Each shows the operation of the mold closing completion signal e.After the previous process is completed normally and a new process starts, the mold 1 is closed.Shortly after the mold closing completion signal e is input, the mold 1 is closed. The mold 1 is filled with resin and a temperature input t'' enters the device 4.

This is at time T1 in the figure. As mentioned above, the temperature input t is cut by the amount of the mold 1, but what functions as a signal is the signal t'' emitted by the comparator 7 due to the input amount due to the energy of the resin. When the mold 1 is opened, a mold opening completion signal f is input from the molding machine.This is at time T2 in the figure.This signal f is simultaneously inputted by the timer T.
Since the timers TM-1 and TM-2 are input, each timer TM-1 and TM-2 starts operating at the same time point T2 and continues to operate for the set time. When the molded product is normally discharged from the mold 1, the resin disappears from the spot S, the sensor 3 no longer detects the energy of the resin, and the temperature input level becomes low level. At this time T3, the state changes from no temperature input t'' to some state to no state, so relay RY-1
is activated and a type-closing bond is emitted. As a result, mold 1
When the mold is closed, a mold closing completion signal f is issued from the molding machine at time T4, and the above-described cycle is repeated again. In the figure, F indicates one cycle. Timer T
Although M-1 and TM-2 stop operating after their respective set times have elapsed, they do not particularly function under normal conditions. FIG. 5 is an operation chart during normal operation when the take-out machine is always used to take out products.

In the figure, b'' is a diagram showing the operation b'' of the take-out machine, and the take-out machine starts operating at the same time point T2 as the input of the mold opening completion signal f starts. At the time when this take-out machine enters the spot S, that is, at time T2'', which is slightly delayed from time T5, the sensor 3 is blocked by this and the detection is cut off, so the signal t
'' will no longer be input. However, since the take-out machine operates while the mold opening completion signal f is input, the signal f will continue to be input unless the take-out machine is fully operated and there is no end.
Therefore, at time T3 when the input of this signal f stops, relay RY
-1 reads the change from no signal to signal to no signal and issues a mold closing command. Other operations are the same as those shown in FIG. 4. Next, a case where there is an abnormality in the molding operation, that is, a case where the product is not discharged from the mold 1 or a case where the mold 1 is blank-shot without resin being filled will be described.

FIG. 6 is an operation chart in such an abnormal case when the take-out machine is not used.

Figure 6 A and a'' both show temperature input, where a is mold 1
This shows the case of empty firing without resin entering.

Therefore, the sensor 3 does not sense the resin temperature, and the chart remains flat at zero level (low level). a
'' is a case where the product is not discharged, and in this case, the temperature input continues after the time T1 when the resin enters.

In both cases A and a'', even if the mold 1 is opened and the mold opening completion signal f is input at time T2, the mold opening completion signal f continues to be input.

In case a, there is no product to be discharged to begin with, so it cannot be taken out, while in case a'', it cannot be taken out due to some abnormality.At this time,
Two timers TM-1 and TM-2 start operating at the same time point T2 when the input of the mold opening completion signal f starts. When the take-out machine is in use, timers TM-1 and TM-2 start operating. When using the take-out machine, use the timer TM-
When the operation of step 1 is completed, the relay RY-2 issues a take-out command as described above and instructs the robot (take-out machine) to operate, but in the case of this Fig. 6, since such a take-out machine is not used, the timer TM Even after the set time of −1 is completed, the product is not taken out and the mold opening completion signal f does not stop.
(An example of operating the take-out machine when the timer TM-2 expires will be described later with reference to FIG. 8). Therefore, timer T
At time T5 when the set time of M-2 is completed, the mold opening signal f is transmitted to the timer TM-2 and the flip-flop FF-3,
Interlock command is issued by operating relay RY-2 via FF-4 or the like. This interlock causes the device to stop. The operation of the interlock is shown in figure d''. When interlocked, it
Displayed by 5. During this time, no signal for activating relay RY-1 is detected, so no mold closing command is issued. Next, with reference to FIG. 7, an abnormal situation in an example in which a take-out machine is always used to take out products will be described.

A and a'' in the figure each indicate the temperature signal input in the case of blank punching and the case in which the molded product is not discharged,
This is the same as in FIG.

However, at point a'' in Fig. 7, the take-out machine starts working at the time T when the input of the mold opening completion signal f'' starts, and at this time, the arm of the take-out machine temporarily enters the spot S detected by the sensor 3. , the temperature of the spot S decreases, and the temperature input becomes zero during the period a'' in the figure. At this time, the temperature input temporarily changes from absent to present to absent, so if it is not a blank firing, the relay RY- 1 will be activated and a mold closing command will be issued,
In order to avoid this, the mold closing command is configured to be connected to the circuit after the unloading machine returns. (This is the same as in Figure 5). In the case of the figure, the take-out machine works after time T2'', but if the product cannot be taken out by the take-out machine due to some abnormality, the mold closing completion signal f continues to be input, and the result is the same as in the case of Fig. 6. timer TM-2
“After the set time is completed, it will be interlocked.

While Fig. 7 shows the case where the product is always discharged by the take-out machine, Fig. 8 shows the case where the product is automatically dropped, and the take-out machine is not normally used.
This shows the case where the unloading machine is operated only when the product cannot be discharged due to automatic dropping.

Under normal conditions, at the same time as the input of the mold opening completion signal f starts, the product should fall from the mold and the temperature input should become low level at time T5 (see Figure 4), but such discharge is not normal. , the mold opening completion signal f continues to be input, and as a result, at the end of the set time of timer TM-1 T6
Relay RY-2 is activated and a command to operate the takeout machine (robot) is issued.

When the take-out machine operates, the temperature input goes to a low level at one point as described above, but at this time, the same configuration as above is used to prevent relay RY-1 from operating, and the take-out machine discharges the product. Only then will relay RY-1 issue a mold closing command. When the unloading machine discharges the product, a mold closing command is issued at time T7, this is completed, the mold closing completion signal stops being input, and one cycle is completed. The above is a case where the product is discharged by the unloading machine, but the unloading command is issued at T6 at the end of the set time of timer TM-1, and the product is not discharged even though the unloading machine is activated. It is shown in FIG.

In this case, since the mold opening completion signal f continues to be input even after the take-out machine returns, the interlock will eventually function at the end of the set time of the timer TM-2. The low level time b'' of the temperature input by the take-out machine and the temporary mold closing signal f'' caused by the temperature input are the same as described above. (
As above, during f'', the takeout machine is not returned, so no command is actually given.) As mentioned above, by using this device 4, normality or abnormality in each state is detected, It is possible to control the opening and closing operations of the mold.

In Fig. 4, 42 is a connection to the power supply, 43 is a mounting bracket, 44 is a detection indicator lamp, 45 is an interlock indicator lamp, 46 is a level setting dial, 47 is a sensitivity adjustment, and 48 is a timer TM. -1 is the Terama setting dial, and 49 is the time setting dial of the timer TM-2. As mentioned above, in the present invention, whether or not resin remains in the mold used for resin molding is determined by detecting the temperature of the mold at a spot, and cutting the temperature of the mold from the detected temperature. Since the mold opening/closing operation control is characterized by determining the presence or absence of residual resin and controlling the next process, it is a non-contact type that does not come into contact with the product, thus improving stability and reliability. Rich and can be used semi-permanently.

Moreover, it is applicable to all resins, and even small-sized ones can be detected. In addition, it has good directivity and is not easily affected by external disturbances, and can be applied more reliably than before even in the case of multiple captures. It should be noted that, as a matter of course, the present invention is not limited to the above-described embodiments.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram schematically showing how the method of the present invention is applied. FIG. 2 is an example of a device to which the method of the present invention is applied, and FIG. 3 is a block diagram of the device. 4 to 9 are charts showing the operation in each state of this example.
1...Mold, 2...Resin (product), 3...Sensor, 4...Device, S...Spot.

Claims (1)

[Claims] 1 In order to detect whether or not resin remains in the mold used for resin molding, the temperature of the mold for molding is detected at a spot, and the temperature of the mold is cut from the temperature detection, thereby removing the residual resin. A mold opening/closing operation control method for resin molding, which is characterized by determining the presence or absence of a metal mold and controlling the next process.