JP2014076546A - Emergency stop method for injection molding machine, and injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection molding machine which can be stopped reliably in an emergency with a low probability of malfunction.SOLUTION: An injection molding machine is equipped with an acoustic microphone. In the acoustic microphone, acoustic detection processing to detect voice is implemented, and if a sound of an acoustic pressure higher than a specified acoustic pressure threshold value is detected in the acoustic detection processing, the injection molding machine is brought into an emergency stop. The acoustic detection processing can be implemented only for a specified period of time from a mold closing step of a molding cycle consisting of a mold closing step, an injection step, a cooling step, a mold opening step and a protrusion step, or can be implemented only in the mold closing step, or only in the mold closing step and the injection step of the molding cycle. The acoustic detection processing may also be implemented only for a specified number of the mold cycles from start-up of the injection molding machine.

Description

  The present invention relates to an emergency stop method for an injection molding machine and an injection molding machine having a predetermined emergency stop function.

  As is well known in the art, an injection molding machine includes a mold clamping device that clamps a mold, an injection device that measures and injects molten resin into a mold that has been clamped, and a projection device that projects a molded product. Configured and controlled by a controller. The molding cycle is carried out as follows. That is, in the mold closing process, the mold clamping device is driven to close the mold and clamp the mold. In the injection process, the screw provided in the heating cylinder of the injection device is driven in the axial direction to inject the molten resin into the mold. The molten resin is injected into a cavity in the mold. In the cooling process, the molten resin in the cavity is cooled and solidified. In the initial stage of the cooling process, that is, after the injection process, a pressure holding process for driving the screw to apply pressure to the molten resin is also appropriately performed. In the cooling step, a metering step of weighing the molten resin for the next molding cycle is also performed after the pressure holding step. That is, in the measuring step, the resin material is supplied to the heating cylinder and the screw is driven to rotate, and the molten resin is measured at the tip of the screw. When the molded product is cooled and solidified, the mold clamping device is driven in the mold opening process to open the mold, and the ejector device is driven in the projecting process to eject the molded product. That is, a molded product is obtained. Thereafter, the molding cycle is carried out in the same manner.

  In the injection molding machine, various devices are driven in this way in the molding cycle. However, when foreign matter adheres to the mold, it is necessary to stop the injection molding machine promptly so as not to damage the mold. In addition, the injection molding machine needs to be stopped urgently when it is noticed that there is an error after changing the injection condition or when the operator feels some danger. Thus, in order to ensure safety, the injection molding machine is provided with a function that can be stopped in an emergency, such as an emergency stop button. When the emergency stop button is pressed, the injection molding machine stops promptly even during the molding cycle.

Japanese Patent No. 3619985 JP 2009-166996 A Japanese Patent No. 4817312

  Patent Document 1 describes an injection molding machine that is not directly related to the present invention but has a function of recognizing an operator's voice. In this injection molding machine, when various setting information is set in the controller, a predetermined operator switch is turned on to start voice recognition. The operator then utters desired setting information toward the controller of the injection molding machine. Then, the controller understands the content and inputs it as setting information.

  Patent Document 2 describes an emergency stop device that recognizes a voice and stops an escalator. The device recognizes the escalator passenger's voice and can identify pre-registered recognized speech languages such as “stop”, “stop”, “dangerous”, for example. Upon recognizing that these recognized speech languages are uttered, the emergency stop device promptly stops the escalator. This ensures passenger safety.

  Patent Document 3 describes an emergency stop system that can be applied to robots such as household chores support robots at home, elderly self-support robots, and nursing robots. In this system, the audio sound signal input from the sound input unit is processed by a predetermined filter function to determine whether it is a human scream. And if it is judged that it is a scream, the robot is stopped urgently. Therefore, when the robot user feels danger and raises a scream, the robot can be safely stopped.

  An emergency stop button provided on a conventional injection molding machine can also be used to stop the injection molding machine urgently. Therefore, when an abnormality is found, the emergency stop button can be operated to stop the injection molding machine and protect the mold, or to ensure the safety of the operator. In other words, safety can be secured. However, there are some problems. Specifically, when an emergency occurs or a person feels danger, the muscles become stiff and the body is stiff, trying to unconsciously take a defense posture. Or, when an emergency situation occurs, the judgment power is paralyzed for a moment, forgetting the presence of the emergency stop button, or the position of the button is not known. In such a case, the operation of the emergency stop button may be delayed and the emergency stop of the injection molding machine may be delayed, or the injection molding machine may continue to operate without operating the emergency stop button. In other words, the emergency stop button that requires the operator's operation does not necessarily ensure safety. Humans can utter speech consciously or unconsciously, even if their bodies are stiff due to the emergence of an emergency or their judgment is paralyzed. Therefore, it is conceivable that the injection molding machine is urgently stopped using a voice, and it is possible to refer to Patent Documents 1 to 3. However, even if the techniques described in these documents are simply adopted, there seems to be a problem. Specifically, the speech recognition technology described in Patent Document 1 is excellent in that it can recognize the content of speech and input setting information according to the content, but there is no guarantee that speech recognition will be successful, and emergency Occasional voices may be screams whose contents cannot be understood. If so, there is no guarantee that an emergency stop can be ensured. The emergency stop device described in Patent Document 2 also has a problem because it can be stopped only by a specific recognized speech language registered in advance. The emergency stop system described in Patent Document 3 seems promising because it can recognize human screams. However, in order to identify whether or not it is a human scream, the audio-acoustic signal is processed by a predetermined filter function. This process is a process that is carried out to extract whether or not a voice is generated by a person by extracting a sound pressure of a predetermined range of frequencies from the audio-acoustic signal. There are individual differences, and the voice uttered in an emergency may be different from the voice uttered normally. Then there is no guarantee that the screams can be recognized reliably. In other words, there is no guarantee that the injection molding machine can be stopped urgently.

  It is also necessary to consider the characteristics or conditions specific to the injection molding machine. In factories where injection molding machines are installed, cranes and other industrial machines are also installed. When a function that is simply stopped by voice is incorporated in an injection molding machine, there is a possibility that the injection molding machine may stop urgently due to malfunction caused by noise generated by a crane or other industrial machine. Therefore, it is necessary to pay attention to the noise of the factory where the injection molding machine is installed. An injection molding machine also has a characteristic that abnormality is likely to occur at the start of operation. For example, if the injection conditions are changed, the problem is often noticed in the first one or first few molding cycles. On the other hand, when the molding cycle is stabilized, there is a characteristic that an abnormality hardly occurs. There are other characteristics as well. Specifically, the process of damaging the mold or exposing the operator to danger is limited to some processes in the molding cycle. For example, a mold closing process for closing the mold can be given. As described above, the injection molding machine has unique characteristics, and there is a problem when an emergency stop function by voice is simply incorporated into the injection molding machine without considering these.

  An object of the present invention is to provide an injection molding machine that solves the above-described problems. Specifically, the injection molding machine has a low possibility of malfunction and can reliably stop the injection molding machine in an emergency. It aims to provide a molding machine.

  In order to achieve the above object, the present invention provides an audio microphone in an injection molding machine. Then, voice detection processing for detecting voice is performed in the voice microphone, and when a sound having a sound pressure exceeding a predetermined sound pressure threshold value is detected in the voice detection processing, the injection molding machine is urgently stopped. And this voice detection process may be carried out for a predetermined time from the mold closing process among the molding cycles consisting of the mold closing process, the injection process, the cooling process, the mold opening process, and the protruding process. Of these, only the mold closing process or only the mold closing process and the injection process may be performed. Furthermore, the voice detection process may be performed only during a predetermined number of molding cycles from the start of operation of the injection molding machine.

Thus, in order to achieve the above object, the invention according to claim 1 is an injection molding which includes an audio microphone and repeatedly performs a molding cycle including a mold closing process, an injection process, a cooling process, a mold opening process, and a protruding process. In the machine, the voice detection process for detecting the voice in the voice microphone is performed, and when the sound having a sound pressure exceeding a predetermined sound pressure threshold is detected in the voice detection process, the injection molding machine is urgently stopped. It is configured as an emergency stop method for an injection molding machine.
According to a second aspect of the present invention, in the method according to the first aspect, the voice detection process is performed for a predetermined time from the mold closing step in the molding cycle, and the emergency stop of the injection molding machine is performed. Configured as a method.
According to a third aspect of the present invention, in the method according to the first aspect, the sound detection process is performed only in the mold closing process or only in the mold closing process and the injection process in the molding cycle. It is comprised as an emergency stop method of the injection molding machine.
According to a fourth aspect of the present invention, in the method according to any one of the first to third aspects, the voice detection processing is performed only during a predetermined number of molding cycles from the start of operation of the injection molding machine. The present invention is configured as an emergency stop method for an injection molding machine.
The invention according to claim 5 includes an audio microphone, and is configured as an injection molding machine in which the emergency stop method according to any one of claims 1 to 4 is performed.

  As described above, according to the present invention, when the sound detection process for detecting the sound is performed in the sound microphone, and the sound with the sound pressure exceeding the predetermined sound pressure threshold value is detected in the sound detection process, the injection molding machine is urgently Is configured to stop. Therefore, even if the body is stiff in an emergency, the injection molding machine can be stopped by detecting the operator's scream. In an emergency, the volume of the scream increases. However, in the present invention, since the determination is made only by the sound pressure level, the injection molding machine can be stopped urgently without erroneously recognizing the scream as noise. According to another invention, the voice detection process is configured to be performed for a predetermined time from the mold closing process in the molding cycle, and according to another invention, the voice detection process is performed only in the mold closing process of the molding cycle. Or it is comprised so that it may implement only in a mold closing process and an injection process. In other words, in these inventions, the voice detection process is performed only for a process with a high degree of risk in the molding cycle. Then, erroneous operation can be prevented. For example, the injection molding machine continues to operate normally even if a large noise occurs in the factory during a cooling process with a low degree of danger. According to another invention, the sound detection process is configured to be performed only during a predetermined number of molding cycles from the start of operation of the injection molding machine. When changing the injection conditions in an injection molding machine, there is a high possibility of damaging the mold or damaging various devices if the conditions are incorrect. However, you will notice the error in the molding cycle immediately after the start of operation or the operation. It is during several molding cycles from immediately after the start. In other words, it is highly necessary to make an emergency stop during several molding cycles from the start of operation. According to the present invention, since the voice detection process is performed only during a predetermined molding cycle after the start of operation that requires a high emergency stop, the safety is high, and the injection molding machine is not accidentally stopped due to the noise of the factory. Can be. In other words, the possibility of malfunction can be greatly reduced while ensuring maximum safety.

It is a figure explaining the emergency stop method of the injection molding machine which concerns on embodiment of this invention, The (a)-(c) is the timing which implements the audio | voice detection process of the emergency stop method which concerns on each different embodiment. FIG. It is a figure explaining the process of the injection molding machine when noise generate | occur | produces when performing the audio | voice detection process and when not implementing.

  Embodiments of the present invention will be described below. In this specification, the emergency stop method of the injection molding machine according to the first to third embodiments will be described. However, the injection molding machine according to this embodiment that implements these emergency stop methods is also a conventional injection machine. Similar to the molding machine, it includes a mold clamping device for clamping a mold, an injection device for melting a resin material and injecting the mold into a mold that has been clamped, and a protruding device for ejecting a molded product.

  In the injection molding machine according to the present embodiment, an audio microphone is provided in a controller that controls each device. This voice microphone is a microphone to which external sound including the voice of the operator is input, and can measure the sound pressure level of the sound.

  As shown in FIG. 1A, the injection molding machine according to the present embodiment also implements a molding cycle including each process. That is, the molding cycle includes a mold closing process in which the mold is closed and clamped by the mold clamping device, and a screw provided in the heating cylinder in the injection device is driven in the axial direction to clamp the mold. An injection process for injecting the molten resin into the cavity formed in the mold, a cooling process for waiting until the molten resin is cooled and solidified in the mold, a mold opening process for opening the mold, and a molded molding And a projecting process for projecting the product. Such a molding cycle is repeated. The cooling process includes a pressure holding process in which the resin is applied by driving the screw in the axial direction so that the molten resin shrinks due to cooling and defects such as sink marks are not generated in the molded product, and the next molding cycle. For this purpose, there is also included a metering step in which a resin material is supplied to the heating cylinder and the screw is rotated to melt the resin and measure it in front of the screw.

  In the emergency stop method according to the first embodiment of the present invention, the voice detection process described below is performed for a predetermined time T from the start of the molding cycle in each molding cycle. This time T is set in the controller by the operator, and an arbitrary time is set. In the present embodiment, the time T is set so as to include a part of the mold closing process, the injection process, and the cooling process in which the molding cycle is started. In the first embodiment, the voice detection process is performed only for three molding cycles from the start of operation of the injection molding machine. In FIG. 1A, time zones in which voice detection processing is performed are indicated by reference signs A1, A2,. In the present embodiment, the number of times is three, but this number can also be set arbitrarily. For example, the voice detection process may be performed only for one molding cycle after the operation of the injection molding machine is started, or may be performed only for several molding cycles. Furthermore, it may be performed in all molding cycles.

  The voice detection process is a process for monitoring the sound pressure level of the sound input in the voice microphone, and monitors whether or not a sound pressure threshold value that is a predetermined threshold value is exceeded. Then, when a sound having a sound pressure level exceeding the sound pressure threshold is detected, the injection molding machine is urgently stopped. When the sound detection process is not performed, the sound pressure level of the sound input to the sound microphone is not monitored. The sound pressure threshold value can also be set to an arbitrary value by the operator in the controller.

  FIG. 2 shows a state in which various noises including the screaming voice of the operator are generated in the time zones A1, A2, and A3 during the voice detection process and the other time zones B1 and B2. . In the time zone A1 immediately after the start of operation, the noise in the factory temporarily increases, but the injection molding machine does not stop because the sound pressure threshold is not exceeded. In the time zone B1, a telephone ringing sound and a crane running sound are generated and these sound pressure levels exceed the sound pressure threshold value. However, since the voice detection process is not performed, the injection molding machine does not stop. Similarly, the injection molding machine does not stop because the voice detection processing is not performed even when the operator's conversation or the forklift running sound exceeds the voice threshold in the time zone B2. In the time zone A3 during the voice detection process, the operator senses danger and raises a scream, and the sound pressure level of the scream exceeds the sound pressure threshold. Then, the injection molding machine will stop urgently.

  FIG. 1A shows an emergency stop method according to the second embodiment. In the second embodiment, the voice detection process is performed only for a specific process in the molding cycle. Specifically, in the second embodiment, the voice detection process is performed only in the mold closing process and the injection process. The periods of the voice detection target are indicated by reference signs A1 ', A2', A3 '. As described above, the process to be subjected to the voice detection process is set in the controller, but can be arbitrarily set by the operator. For example, only the mold closing process can be performed. Also in the present embodiment, the voice detection process is performed only for three molding cycles from the start of operation of the injection molding machine, but the number of times is the first embodiment. Any number of times can be set in the same manner as the emergency stop method according to. That is, the voice detection process may be performed only in one molding cycle from the start of the operation of the injection molding machine, or may be performed only in several molding cycles. Furthermore, it may be performed in all molding cycles.

  FIG. 1 (c) shows an emergency stop method according to the third embodiment. In the third embodiment, the voice detection process is always performed regardless of the molding cycle process. It is carried out in all molding cycles. Therefore, whenever a sound having a sound pressure exceeding the sound pressure threshold is detected, the injection molding machine is urgently stopped.

  The emergency stop method for the injection molding machine according to the embodiment of the present invention can be variously modified. For example, although it is a modification of the emergency stop method according to the third embodiment, for the first few molding cycles from the start of operation, the voice detection process is performed regardless of each step of the molding cycle, For subsequent molding cycles, the voice detection process may be stopped. Further, in the emergency stop methods according to the first and second embodiments, it has been described that only one value is set as the sound pressure threshold value for determining emergency stop, but this differs for each molding cycle. A sound pressure threshold may be set. For example, in the first molding cycle after the start of the operation of the injection molding machine, the sound pressure threshold value is set to a small value, and in each of the second molding cycle and the third molding cycle, the sound pressure threshold value is sequentially increased. It can also be set as. In this way, in the first molding cycle, it is possible to reliably detect a scream and make an emergency stop, while in the second and subsequent molding cycles, it is possible to prevent a malfunction that causes an emergency stop by picking up noise. .

    A1, A2 Time zone for voice detection processing

Claims (5)

  In an injection molding machine that includes an audio microphone and repeatedly performs a molding cycle including a mold closing process, an injection process, a cooling process, a mold opening process, and a protruding process, an audio detection process for detecting audio in the audio microphone is performed, An emergency stop method for an injection molding machine characterized in that an emergency stop of the injection molding machine is performed when a sound having a sound pressure exceeding a predetermined sound pressure threshold is detected in the voice detection process.   The method according to claim 1, wherein the voice detection process is performed for a predetermined time from the mold closing step in the molding cycle.   The method according to claim 1, wherein the voice detection process is performed only in the mold closing process or only in the mold closing process and the injection process in the molding cycle. .   The method according to any one of claims 1 to 3, wherein the voice detection process is performed only during a predetermined number of molding cycles from the start of operation of the injection molding machine. Emergency stop method. An injection molding machine comprising an audio microphone, wherein the emergency stop method according to any one of claims 1 to 4 is performed.

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