JP2020006646A - Safety device for large injection molding machine - Google Patents

Abstract

To provide a safety device for a large injection molding machine that reliably detects that no worker is left inside a safety door.SOLUTION: A safety device 13 includes two sets of optical sensors 14, 15, an IC card reader/writer 17, and a controller. Two sets of optical sensors are provided adjacent to each other in the vicinity of a safety door 9 and detect whether an operator has entered the inside of the safety door or exited outside when passing through the safety door. At this time, when the operator causes the IC card reader/writer to read an IC card possessed by each operator, the controller checks whether a normal state is recorded, and an appropriate state, that is, [exit state] or [approach state] is written to the IC card. In this way, the controller checks whether the operator has entered or exited normally, and counts the number of operators staying inside the safety door. Thus, permission for driving a large injection molding machine is determined.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a safety device for a large injection molding machine that requires an operator to enter the mold clamping device for maintenance during maintenance of the mold clamping device such as mold replacement.

  As is well known, an injection molding machine includes a mold clamping device for clamping a mold, an injection device for melting an injection material and injecting it into the mold. In a mold clamping device of an injection molding machine, there are various maintenance operations such as replacement of a mold, and such maintenance operations involve danger. Therefore, safety measures are taken for the mold clamping device, the entire mold clamping device is covered with a housing, and a safety door is provided in an opening secured for maintenance work. The safety door can be opened only when the injection molding machine is stopped. Alternatively, the injection molding machine stops while the safety door is open. When the safety door is open, for example, as described in Patent Literature 1, the servomotor is not driven because the power of the servomotor is cut off. That is, each device cannot operate. Therefore, as long as the safety door is opened, the operator can safely perform maintenance on the mold clamping device.

JP 2014-19144 A

  As described above, in the injection molding machine, the safety door is provided in the mold clamping device, and maintenance in the mold clamping device must be performed with the safety door opened. When the safety door is open, the servomotor is not driven by the interlock, so it can be said that the safety of the worker is sufficiently ensured. However, there are problems. Specifically, there may be a situation where the safety door is closed during maintenance. In the case of an injection molding machine in which the interval between the tie bars is wide, for example, when the interval between the tie bars exceeds 1200 mm, the maintenance of the mold clamping device must be performed by an operator entering the mold clamping device. Then, the worker enters the inside of the safety door completely, and the safety door may be closed even while the worker is performing maintenance on the mold clamping device. In particular, in the case of a large injection molding machine, a plurality of workers may enter the mold clamping device, and there is a high possibility that workers are left behind. If it is attempted to secure the safety only by the interlock based on the open / close state of the safety door, the safety cannot be secured. Therefore, a standard is required for a large injection molding machine not only to secure safety by opening and closing the safety door but also for additional safety measures. As an injection molding machine provided with additional safety measures, for example, an injection molding machine in which a safety mat provided with a weight detection sensor is provided inside a safety door is known. If the worker is standing on the safety mat, the controller is notified that the worker is inside the safety door, and the injection molding machine cannot operate. However, since the safety mat is made of a resin material, if the molten resin falls from an injection device or a mold, the safety mat is damaged. Therefore, it cannot be provided immediately below the mold clamping device. That is, even though the safety mat can be provided in a quasi-dangerous area such as near the mold clamping device, it cannot be provided in a dangerous area such as the inside of the mold clamping device, and safety cannot be completely secured. As an alternative, safety treads may be provided. However, both safety mats and safety treads are dangerous because workers stand on tie bars and the like, and 100% safety cannot be ensured. There is also a method of providing a sensor for detecting the presence or absence of a worker by radiating a laser in the mold clamping device and detecting the laser. However, if there is a blind spot in the mold clamping device, the worker may not be detected by the sensor, and this is not completely safe. On the other hand, there is a method of ensuring safety by operation. For example, a padlock is provided at the main breaker or the emergency stop push button so that the main breaker cannot be entered or the emergency stop push button cannot be released. After confirming that no workers remain in the mold clamping device, manually release the padlock. Then, the main breaker turns on and the injection molding machine can be driven. However, when checking whether or not an operator remains in the safety door, there is a case where a check is omitted or a check is forgotten. Depending on the method of ensuring safety through operation, safety cannot always be ensured.

  Therefore, the present invention, in a large injection molding machine, even if the safety door is closed while the worker is in the mold clamping device, mechanically detects that the worker is left behind It is an object of the present invention to provide a safety device for a large-sized injection molding machine which ensures safety and prevents driving of the injection molding machine when safety cannot be ensured.

  In order to achieve the above object, the present invention is configured as a safety device provided with two sets of optical sensors in a large-sized injection molding machine. Each set of optical sensors includes a light emitting device that emits a light beam and a light receiving device that receives the light beam. The two sets of optical sensors are provided adjacent to each other in the vicinity of the safety door provided in the mold clamping device, and the timing of the interruption when the worker passes through the safety door causes the worker to move inside the safety door. Detects whether the vehicle has entered or exited. The controller of the large injection molding machine is configured to count the number of workers staying inside the safety door based on signals from the two sets of optical sensors and determine permission to drive the large injection molding machine. . Further, the safety device is provided with an IC card reader / writer inside the safety door, and is configured to read / write the exit / enter state recorded on the IC card possessed by each worker.

That is, the invention according to claim 1 is designed such that, when maintenance is performed on the mold clamping device, the safety door provided on the mold clamping device is opened, and an operator enters the mold clamping device to perform the maintenance. A safety device for a large-sized injection molding machine, wherein the safety device includes two sets of optical sensors, each of which includes a light emitting device for emitting light and a light receiving device for receiving the light. And the interruption is detected. The two sets of optical sensors are provided adjacent to each other in the vicinity of the safety door. It is configured to detect whether the worker has entered the inside of the safety door or has exited the outside, and the controller of the large-sized injection molding machine is based on signals from the two sets of optical sensors. Counting the number of workers staying inside the safety door, and permitting the operation of the large-sized injection molding machine after confirming that the number of workers is zero. It is configured as a machine safety device.
According to a second aspect of the present invention, in the safety device according to the first aspect, the safety device includes an IC card reader / writer provided inside the safety door, and each of the workers has the IC card reader / writer. The exit / entry state recorded in the IC card is read and written by the IC card reader / writer, and is configured as a safety device for a large injection molding machine.
According to a third aspect of the present invention, in the safety device according to the second aspect, the controller can be switched to any one of an entry check mode, an exit check mode, and a standby mode. When the two sets of optical sensors detect the entry of a worker into the inside of the safety door, the mode is switched to an entry check mode, and the IC card reader / writer switches the IC card within a predetermined time. The presence or absence of reading is checked, and if there is a reading and the exit state is recorded on the IC card, it is rewritten to the entry state and switched to the standby mode. When the IC card in the entry state is read, it is rewritten to the exit state and switched to the exit check mode. A safety device for a large injection molding machine, wherein the two sets of optical sensors check whether or not the worker has left within a predetermined time, and switch to a standby mode when the leaving is detected. Is configured as

  As described above, according to the present invention, when performing maintenance on the mold clamping device, the safety door provided on the mold clamping device is opened, and the operator enters the mold clamping device to perform the large injection. It is intended for safety devices of molding machines. According to the invention, the safety device comprises two sets of optical sensors, one set each comprising a light emitter emitting a light beam and a light receiver receiving the light beam so that when the light beam is interrupted, the interruption is detected. The two sets of optical sensors are provided adjacent to each other in the vicinity of the safety door, and the worker enters the inside of the safety door due to a shift in the shutoff timing when the worker passes through the safety door. It is detected whether the user has left or has left. Since the detection is performed by the two optical sensors, the entry and exit of the worker can be confirmed accurately and reliably. The controller of the large injection molding machine counts the number of workers staying inside the safety door based on the signals from the two sets of optical sensors. Therefore, it is possible to reliably detect that there is no worker in the mold clamping device and to start driving the large-sized injection molding machine. According to another aspect of the present invention, a safety device includes an IC card reader / writer provided inside a safety door, and an exit / entry state recorded on an IC card possessed by each worker is provided by the IC card reader.・ It is designed to be read and written by a writer. Therefore, by checking the exit / entry state of the IC card, it is possible to more accurately determine whether or not an operator is staying in the mold clamping device, and an effect of increasing safety is obtained. According to still another invention, the controller can be switched to any one of three modes of an entrance check mode / exit check mode / standby mode. When the controller is in the standby mode, the controller uses two sets of optical sensors. When the entry of the worker into the inside of the safety door is detected, the mode is switched to the entry check mode, the presence or absence of reading of the IC card is checked within a predetermined time by the IC card reader / writer, and the IC card is read and exits the IC card. If it is recorded, it is rewritten to the entry state and switched to the standby mode. If the IC card reader / writer reads the entered IC card in the IC card reader / writer during the standby mode, it is rewritten to the exit state and exits. After switching to the check mode, the worker is left by the two sets of optical sensors within a predetermined time. Whether or not to to check, exit is configured to switch to standby mode if it is detected. If such a case deviates from the normal operation, it can be judged that everything is abnormal, and the number of workers staying in the mold clamping device can be reliably and accurately grasped. The drive of the large injection molding machine can be started.

FIG. 2 is a perspective view showing a part of a mold clamping device of a large-sized injection molding machine according to an embodiment of the present invention including a mold according to the embodiment of the present invention, a safety door, and a safety device according to the present embodiment. is there. It is a front view showing the safety device of the large-sized injection molding machine concerning an embodiment of the invention. 5 is a table showing a relationship in which a mode changes according to an event that occurs in the controller of the safety device according to the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described. The large-sized injection molding machine 1 according to the present embodiment includes the mold clamping device 2 and an injection device not shown in the drawing, although the vicinity of the mold clamping device 2 is shown in FIG. The mold clamping device 2 according to the present embodiment includes a fixed platen 4, a movable platen 5 that is opened and closed with respect to the fixed platen 4, a mold clamping housing (not shown), the fixed platen 4 and the mold clamping housing. .., And a toggle mechanism. The present invention is directed to a large-sized mold clamping device 2 in which a worker enters the mold clamping device 2 during maintenance, and the mold clamping device 2 according to the present embodiment is also formed in a large size.

  Although the entirety of the mold clamping device 2 is covered by a casing (not shown) to ensure safety, the casing is provided with a safety door 9. The safety door 9 is slidably opened and closed, and an operator opens the safety door 9 and enters the mold clamping device 2. The large-sized injection molding machine 1 includes a controller (not shown). When the safety door 9 is opened, the controller stops supplying power to the motor so that the large-sized injection molding machine 1 is not driven. Inside the safety door 9, a safety mat 11 is laid in a predetermined range. The safety mat 11 includes a pressure-sensitive sensor, detects the weight of the worker when the worker is present, and notifies the controller that the worker is inside the safety door 9. Therefore, even if the safety door 9 is closed while the worker is left inside the safety door 9, the worker is detected by the safety mat 11 and the controller stops supplying power to the motor. This enhances safety. However, the safety mat 11 is made of resin, and is broken when the molten resin falls or the like. Therefore, the safety mat 11 cannot be laid directly below the mold clamping device 2 and cannot be detected when the worker has entered the center of the mold clamping device 2. As an alternative measure, safety treads are being prepared, but safety treads cannot ensure 100% safety as described above. Thus, the large-sized injection molding machine 1 according to the present embodiment ensures substantially complete safety by the safety device 13 according to the present embodiment described below.

  The safety device 13 according to the present embodiment includes two sets of optical sensors, that is, first and second sets of optical sensors 14 and 15, an IC card reader / writer 17, and a controller of the large-sized injection molding machine 1. I have. The first and second sets of optical sensors 14 and 15 may be directed to light beams having other wavelengths, but in the present embodiment, each of the first and second sets of optical sensors 14 and 15 is constituted by a light emitter emitting infrared light and a light receiver receiving this infrared light. If infrared light is blocked, it is detected. 1 and 2 show only the light receiver. As shown in FIGS. 1 and 2, the first and second sets of optical sensors 14 and 15 are provided near the safety door 9 and slightly adjacent to each other in the horizontal direction. Because of such a slight offset, when the worker enters the inside through the safety door 9, it is first detected by the first set of optical sensors 14 by the passage of the worker, and immediately thereafter, the second set Is detected by the optical sensor 15. Conversely, when the worker exits outside the safety door 9, it is first detected by the second set of optical sensors 15, and shortly thereafter by the first set of optical sensors 14. That is, the first and second sets of optical sensors 14 and 15 detect whether the worker enters the safety door 9 or exits the safety door 9 when passing through the safety door 9. Can be.

  The IC card reader / writer 17 is a device that reads and writes information on an IC card possessed by each worker. The IC card reader / writer 17 is provided horizontally apart from the first and second sets of optical sensors 14 and 15. Specifically, it is provided near the mold clamping device 2. Accordingly, when the worker enters the safety door 9 through the safety door 9, the IC card is read by the IC card reader / writer 17 after the entry is detected by the first and second sets of optical sensors 14 and 15. Will be done. Both the first and second sets of optical sensors 14 and 15 and the IC card reader / writer 17 are connected to the controller of the large injection molding machine 1.

  The safety device 13 according to the present embodiment counts the number of workers entering and exiting the safety door 9 so that no workers are left inside the safety door 9 before driving the large-sized injection molding machine 1. Can be reliably detected. The controller can be switched between three modes to check for worker entry and exit. Normally, the standby mode M0 is set, and when the worker enters the safety door 9, the mode is switched to the entry check mode M1, and the first and second sets of optical sensors 14, 15 and the IC card reader / writer 17 are used. Is checked to see if the worker has entered normally. When the worker exits from the safety door 9, the mode is switched to the exit check mode M2, and the signals from the first and second sets of optical sensors 14, 15 and the IC card reader / writer 17 are checked, and the worker is normally operated. It is checked whether or not you have left.

  With reference to the table of FIG. 3, a description will be given of a process when the worker enters and leaves the safety door 9. This table summarizes the contents processed by the controller according to the events E1 to E5 that occur when the controller is in the predetermined modes M0 to M2, and the mode switching, and can also be called a mode transition table. . When the large-sized injection molding machine 1 is first stopped after operation, the safety door 9 is closed and no worker is inside the safety door 9. At this time, the controller is in the standby mode M0. Each worker has his or her own IC card, and the "exit state" is recorded in the IC card. When the safety door 9 is opened and the worker enters the safety door 9, the first and second sets of optical sensors 14 and 15 detect the worker's entry (event E1). Then, the controller switches the mode to the entry check mode M1. The worker causes the IC card reader / writer 17 to read the IC card within a predetermined time after entering the safety door 9. That is, the controller obtains the information of the IC card within a predetermined time from the event E1. When the controller confirms that the "exit state" is recorded on the IC card (event E3), it is determined that the IC card is normal, and the IC card reader / writer 17 rewrites the information of the IC card to obtain the "entry state". . Then, the mode is switched to the standby mode M0. The controller counts up the number of workers inside the safety door 9. A plurality of workers can enter the safety door 9 in a similar procedure, and the controller can count the exact number of workers who have entered.

  When the worker is about to leave, the controller is in the standby mode M0. First, the worker causes the IC card reader / writer 17 to read his / her IC card. The "entry state" should be written on the IC card of the worker who has entered, and this is read (event E4). The controller writes the "exit state" to the IC card by the IC card writer 17, and switches to the exit check mode M2. The worker exits the safety door 9 within a predetermined time. Then, the leaving of the worker is detected by the first and second sets of optical sensors 14 and 15 within a predetermined time (event E5). The controller determines that the worker has exited normally, switches the mode to the standby mode M0, and reduces the number of workers remaining in the safety door 9. When all the workers leave the safety door 9 in the same manner, the number of workers remaining in the safety door 9 becomes zero, and the controller permits the large injection molding machine 1 to be driven.

  The table of FIG. 3 also describes a case where it is determined that an abnormality has occurred in the entry and exit of the worker. There are two events that cause an error when in the standby mode M0. Specifically, when the IC card is read by the IC card reader / writer 17 and the "exit state" is read (event E3), the exit is detected by the first and second sets of optical sensors 14 and 15 ( An error occurs when the event E5) occurs. The former event occurs when the "exit state" is recorded on the IC card instead of the "entering state" in spite of the fact that the worker is inside the safety door 9. The latter event occurs when the worker attempts to leave the IC card without reading the IC card into the IC card reader / writer 17. There are four events that cause an error when in the entry check mode M1. First, an error occurs when the first and second sets of optical sensors 14 and 15 detect the entry of a worker (event E1). This is because the next worker is trying to enter even though the entry check of other workers has not been completed. Next, an error occurs when the IC card is not read within a predetermined time from the entry detection by the first and second sets of optical sensors 14 and 15 (event E2). This is because the workers do not follow the correct procedure for entry. When the "entry state" is read from the IC card (event E4), an error occurs. This is because the "exit state" should be recorded on the IC card possessed by the worker who intends to enter. An error also occurs when the leaving of the worker (event E5) by the first and second sets of optical sensors 14 and 15 is detected. There are four events that cause an error when in the exit mode M2. First, an error occurs when the first and second sets of optical sensors 14 and 15 detect the entry of a worker (event E1). This is because another worker is trying to enter while the worker is leaving. Next, an error occurs when the IC card is read and the device is in the "exit state" (event E3). This is because another worker is trying to enter while checking the leaving of the worker. If the "entry state" is read from the IC card (event E4), an error occurs because another worker is about to leave during the exit check. If the first and second sets of optical sensors 14 and 15 do not detect the exit within a predetermined time after the worker reads and writes the IC card at the time of exit (event E5), this is also determined to be an error. When such an error is detected in the large injection molding machine 1, the controller prohibits the driving of the large injection molding machine 1. Prohibition is continued until the error state is released. The administrator confirms that there is no person in the mold board, determines that it is in a safe state, and performs error cancellation processing.

DESCRIPTION OF SYMBOLS 1 Large injection molding machine 2 Mold clamping device 4 Fixed plate 5 Movable plate 7 Tie bar 9 Safety door 13 Safety device 14, 15 First and second set of optical sensors 17 IC card reader / writer

Claims (3)

A safety device for a large injection molding machine, which is designed to open a safety door provided in the mold clamping device when maintenance is performed on the mold clamping device, and to allow an operator to enter the mold clamping device and perform the operation. ,
The safety device includes two sets of optical sensors,
Each set of optical sensors is composed of a light emitting device that emits a light beam and a light receiving device that receives the light beam.
The two sets of optical sensors are provided adjacent to each other in the vicinity of the safety door, and the worker enters the inside of the safety door due to a shift in the timing of shutting off when the worker passes through the safety door. Is detected whether it has left or outside.
The controller of the large injection molding machine counts the number of workers staying inside the safety door based on signals from the two sets of optical sensors, and the permission of driving the large injection molding machine is A safety device for a large-sized injection molding machine, wherein the safety device is implemented after confirming that the value has become zero.   2. The safety device according to claim 1, wherein the safety device includes an IC card reader / writer provided inside the safety door, and the escape / recording recorded on an IC card carried by each of the workers. A safety device for a large injection molding machine, wherein the entry state is read and written by the IC card reader / writer. 3. The safety device according to claim 2, wherein the controller is configured to be switched to one of three modes of an entry check mode, an exit check mode, and a standby mode,
When the two sets of optical sensors detect the entry of a worker into the inside of the safety door during the standby mode, the mode is switched to the entry check mode, and the IC card reader / writer sets the IC within a predetermined time. Check the presence or absence of reading of the card, and if there is a reading and the exit state is recorded on the IC card, rewrite it to the entering state and switch to the standby mode,
When the IC card reader / writer reads the entering IC card while in the standby mode, the IC card is rewritten to the exit state and switched to the exit check mode. A safety device for a large injection molding machine, characterized in that it checks whether or not a worker has left, and switches to a standby mode when the leaving is detected.

Images