Control device for conveying equipment

Abstract

To provide a control device for a transport device that allows for the prior determination of maintenance schedules. [Solution] The extraction machine 20 has multiple electric motors 23a, 26a, and 28a. The extraction machine control device 200 measures the effective load rate for each of the multiple electric motors 23a, 26a, and 28a and determines whether any of the effective load rates have exceeded a threshold. If it is determined that the effective load rate of any of the electric motors 23a, 26a, or 28a has exceeded a threshold, maintenance information prompting maintenance is displayed on the touch panel 40a on the manufacturing information input screen or the mold information input screen.

Description

Technical Field

[0001] The present invention relates to a control device for a conveying device.

Background Art

[0002] Conventionally, a monitoring device has been proposed that detects the load of a motor of a machine tool, compares the detected value with an upper limit value, and displays it on a monitor when the upper limit value is exceeded. Such a monitoring device is described in, for example, Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, it has been considered to apply such a monitoring method to a take-out robot that takes out a molded product from a molding machine. However, if the load of the motor of the take-out robot exceeds the upper limit value, it means that the operation of taking out the molded product from the molding machine fails. In this case, generally, it is necessary to stop the molding machine and the take-out robot to remove the molded product and replace the parts of the take-out robot. That is, there is a problem that maintenance for restoration takes time and production stops until the maintenance is completed.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a control device for a conveying device that can grasp the maintenance timing in advance.

Means for Solving the Problems

[0006] A control device for a conveying device that solves the above problems is a control device for a conveying device that conveys a workpiece, wherein the conveying device has one or more motors, and each motor is provided with a load measuring unit that measures the effective load ratio of the motor, a determination unit that determines for each motor whether the effective load ratio or the increase in the effective load ratio exceeds a predetermined threshold, and an output unit that, if it is determined that the effective load ratio or the increase in the effective load ratio exceeds a predetermined threshold for any of the motors, causes a notification unit to output maintenance information prompting maintenance.

[0007] This makes it possible to know in advance when maintenance will be required for the conveying equipment. [Brief explanation of the drawing]

[0008] [Figure 1] Perspective view of a Cartesian robot. [Figure 2] Side view of the molding machine and the extraction machine. [Figure 3] A block diagram showing the functions of the molding machine control device and the extraction machine control device. [Figure 4] A schematic diagram of the display screen for the effective load factor. [Figure 5] A schematic diagram of the manufacturing information input screen. [Figure 6] A schematic diagram of the mold information input screen. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the "control device for conveying equipment" described herein will be explained with reference to the drawings. Figures 1 and 2 show a molding machine 10 and a removal machine 20 which serves as a conveying device for removing molded products from the molding machine 10.

[0010] First, let's describe the molding machine 10. The molding machine 10 has a main body 11 that extends in the X direction, and a fixed platen 12 and a movable platen 13 that are positioned opposite each other at an appropriate distance in the middle of the main body 11. Four tie bars 14 that extend along a predetermined X direction are horizontally mounted at the four corners of the fixed platen 12 and the movable platen 13. A movable platen 15 is supported on the tie bars 14 so as to be able to move relative to the fixed platen 12 in the X direction.

[0011] A fixed mold 31 is attached to the fixed mounting platen 12a provided on the fixed platen 12, and a movable mold 32 is attached to the movable mounting platen 15a provided on the movable platen 15, opposite to the fixed mold 31. The combination of the fixed mold 31 and the movable mold 32 constitutes the mold 33.

[0012] Furthermore, the movable platen 15 is connected to the operating shaft of a clamping member 16, such as a hydraulic cylinder or a reciprocating feed screw member, which is provided on the main body 11. The movable platen 15 is moved as the clamping member 16 operates, causing the movable mold 32 to perform a mold closing or mold opening operation relative to the fixed mold 31.

[0013] An injection unit 17 is provided on the main body 11 on the fixed platen 12 side. When the movable mold 32 is closed, the injection unit 17 injects molten synthetic resin into the mold 33 from an injection cylinder 17a that is pressed against the back surface of the fixed mold 31, thereby forming a molded resin product.

[0014] As shown in Figure 3, the molding machine 10 includes a molding machine control device 100. The molding machine control device 100 includes a processor 101 as hardware, a storage unit 102 such as memory and storage, and a communication bus 103 connecting the processor 101 and the storage unit 102. The storage unit 102 provides, for example, a work area for temporary use when the processor 101 is performing processing. The storage unit 102 also stores various programs and data for the processor 101 to read and execute.

[0015] Next, the extraction machine 20 will be described. As shown in Figures 1 and 2, the extraction machine 20 is fixed to the upper surface of the fixed platen 12 of the molding machine 10. The extraction machine 20 in this embodiment is, for example, a gantry loader. More specifically, the travel frame 21 of the extraction machine 20 is provided in a straight line so as to extend in the Y direction perpendicular to the X direction. A first traveling body 22 is supported on the upper part of the travel frame 21 so as to be movable in the Y direction. The first traveling body 22 is configured to reciprocate in the Y direction by a first moving mechanism 23 (see Figure 3), such as a feed screw mechanism, a belt mechanism, or a rack and pinion mechanism. The first moving mechanism 23 has a first electric motor 23a, such as a numerically controllable servo motor, and is driven by the first electric motor 23a.

[0016] The first traveling body 22 is provided with front and rear frames 24 that extend linearly in the X direction. The front and rear frames 24 have a length such that their ends reach the open movable mold 32. The second traveling body 25 is supported on the front and rear frames 24 so as to be movable in the X direction. The second traveling body 25 is configured to reciprocate in the X direction by a second moving mechanism 26 (see Figure 3), such as a lead screw mechanism, belt mechanism, or rack and pinion mechanism. The second moving mechanism 26 has a second electric motor 26a, such as a numerically controllable servo motor, and is driven by the second electric motor 26a.

[0017] The second traveling body 25 is provided with upper and lower frames 27 that extend linearly in the Z direction (vertical direction). The upper and lower frames 27 are supported on the second traveling body 25 so as to move up and down. The upper and lower frames 27 have a length such that when lowered, their lower ends reach between the open molds 33. The upper and lower frames 27 are configured to reciprocate in the Z direction by a third moving mechanism 28 (see Figure 3), such as a feed screw mechanism, belt mechanism, or rack and pinion mechanism. The third moving mechanism 28 has a third electric motor 28a, such as a numerically controllable servo motor, and is driven by the third electric motor 28a.

[0018] At the lower end of the upper and lower frames 27, a chuck 29 having a plurality of suction pads, gripping claws that open and close, etc. is attached. The chuck 29 is provided with an operating mechanism 30 (see FIG. 3) such as an air cylinder or an electric motor. By operating a plurality of suction pads, gripping claws that open and close, etc. (suction operation, opening and closing operation) by these operating mechanisms 30, one or more molded products can be gripped by the chuck 29.

[0019] As shown in FIG. 3, the take-out machine 20 has a take-out machine control device 200. The take-out machine control device 200 includes a processor 201 as hardware, a storage unit 202 such as a memory and a storage, and a communication bus 203 that connects the processor 201 and the storage unit 202. The storage unit 202 provides, for example, a work area for temporary use when the processor 201 performs processing. In addition, the storage unit 202 stores various programs and data for the processor 201 to read and execute.

[0020] Further, the take-out machine 20 has a controller 40 as an information input unit and a notification unit. The controller 40 has a touch panel 40a that outputs (displays) various information and can input various instructions. The controller 40 is connected to the take-out machine control device 200 by wire or the like, and is configured to be able to input and output various information to and from the take-out machine control device 200.

[0021] Next, the functions of the molding machine control device 100 and the take-out machine control device 200 will be described. First, the function of the take-out machine control device 200 will be described. The processor 201 of the take-out machine control device 200 has a function of controlling the take-out of the molded product. This function is realized by the processor 201 executing the program stored in the storage unit 202.

[0022] When an operator inputs the number of molded products to be manufactured to the controller 40 via the touch panel 40a, the controller 40 inputs the number of products to be manufactured to the extraction machine control device 200. The processor 201 of the extraction machine control device 200 stores the input number of products in the storage unit 202. The processor 201 also notifies the molding machine control device 100 of this number of products and has it store it in its storage unit 102. Note that the number of products may be replaced with the manufacturing time.

[0023] Furthermore, if the number of units manufactured is stored (i.e., if the number of units manufactured is 1 or more), the processor 201 reads the control information for the extraction machine 20 stored in the storage unit 202. The control information for the extraction machine 20 includes information necessary to control the extraction machine 20, such as the stopping position of the chuck 29, the moving speed, and the timing of the start of movement. More specifically, it includes information such as the drive sequence of the first to third electric motors 23a, 26a, and 28a, rotational speed, output torque, acceleration time, constant speed time, deceleration time, drive start timing, drive stop timing, and the gripping and release timing of the molded product by the operating mechanism 30.

[0024] The control information for the extraction machine 20 is determined by operator teaching and stored in the memory unit 202. The control information for the extraction machine 20 is determined for each mold 33 attached to the molding machine 10, and the control information for the extraction machine 20 is stored in the memory unit 202 for each mold 33. Each mold 33 is assigned an identification number as mold information to identify the mold 33, which is attached to the surface of the mold 33. The memory unit 202 stores the control information associated with this identification number.

[0025] The identification number of the mold 33 attached to the molding machine 10 is set (stored) in the memory units 102 and 202 as the identification number indicating the current mold 33 when the mold 33 is attached to the molding machine 10 (during replacement, etc.). The processor 201 reads the control information of the extraction machine 20 associated with the identification number currently set in the memory unit 202. In the following, the identification number currently set (stored) in the memory units 102 and 202 as the identification number indicating the mold 33 attached to the molding machine 10 may simply be referred to as the "currently set identification number".

[0026] The processor 201 of the extraction machine control device 200 controls the extraction machine 20 to extract molded products from the mold 33 based on the control information of the extraction machine 20 that it has read, once it receives a mold opening signal from the molding machine control device 100 indicating the completion of the mold opening operation, until the input production quantity becomes zero. The processor 201 then subtracts the number of extracted molded products from the production quantity and updates the production quantity stored in the memory unit 202.

[0027] Next, the functions of the molding machine control device 100 will be described. The processor 101 of the molding machine control device 100 has functions such as controlling the opening and closing operation of the mold 33 and controlling the injection unit 17. These functions are realized by the processor 101 executing programs stored in the memory unit 102.

[0028] The processor 101 of the molding machine control device 100 reads control information for the molding machine 10 from the storage unit 102 if the stored number of production units is 1 or more. The control information for the molding machine 10 includes information necessary for opening and closing control of the mold 33 and injection control. More specifically, the control information for the molding machine 10 includes information related to opening and closing control, such as the opening and closing speed of the mold 33, the opening and closing timing, and the stopping position of the movable mold 32 (i.e., stroke length). In addition, the control information for the molding machine 10 includes information related to injection control, such as the amount of resin to be injected, the injection timing, and the injection speed.

[0029] The control information for the molding machine 10, like the control information for the extraction machine 20, is determined by teaching by an operator and stored in the memory unit 102. The control information for the molding machine 10 is determined for each mold 33 attached to the molding machine 10, and the control information for the molding machine 10 is stored in the memory unit 102 in association with the identification number of the mold 33.

[0030] The processor 101 of the molding machine control device 100 controls the mold clamping member 16 to close the mold 33 according to the control information of the molding machine 10 corresponding to the set identification number, if the number of products to be manufactured is 1 or more. After the mold closing operation is completed, the processor 101 controls the injection unit 17 to inject resin into the mold 33 according to the control information of the molding machine 10. After the injection is completed, the processor 101 of the molding machine control device 100 controls the mold clamping member 16 to open the mold 33 according to the control information of the molding machine 10. Then, when the mold opening operation is completed, the processor 101 of the molding machine control device 100 inputs a mold opening signal to the extraction machine control device 200 to notify it of this. As a result, the resin molded product is extracted from the mold 33 by the extraction machine 20 as described above. The processor 101 also deducts the number of products manufactured from the number of molded products manufactured and updates the number of products stored in the memory unit 102.

[0031] From this point onward, the molding machine control device 100 repeatedly performs a series of processes (opening / closing control and injection control) until the input (stored) production quantity becomes zero. Note that the above-described process flow is just one example, and the order and content of the processes may be changed as appropriate, as long as molding and removal of molded products are performed continuously until the production quantity becomes zero.

[0032] By the way, if any one of the electric motors 23a, 26a, or 28a in the extraction machine 20 malfunctions (delays, stops, etc.), it becomes impossible to properly extract the molded products, and the entire extraction process comes to a halt. For this reason, it is necessary to identify signs of malfunction in the electric motors 23a, 26a, or 28a before they occur and to perform maintenance at the appropriate time. For this reason, this embodiment is configured as follows.

[0033] The processor 201 measures the effective load ratio for each electric motor 23a, 26a, and 28a while the extraction machine 20 is in operation. The effective load ratio is the ratio of the effective value of the torque output over a predetermined period (e.g., 15 seconds) to the rated torque. The effective load ratio is expressed as a percentage, with the rated torque set to 100%. Torque can be calculated, for example, using the torque constant and the current flowing through each electric motor 23a, 26a, and 28a. Therefore, the processor 201 functions as a load measuring unit.

[0034] Then, as shown in Figure 4, the processor 201 displays the measured effective load ratio of each electric motor 23a, 26a, and 28a on the touch panel 40a of the controller 40, and stores it in the storage unit 202 in association with the identification number being set.

[0035] Furthermore, if the measured effective load rate of the first electric motor 23a exceeds a first threshold for the first electric motor 23a, the processor 201 decides to display maintenance information prompting maintenance of the first electric motor 23a on the touch panel 40a. The first threshold is defined for each mold 33 and is stored in association with an identification number. In other words, the control information (control content) of the extraction machine 20 is defined for each mold 33, and how the first electric motor 23a is controlled is predetermined for each mold 33. For this reason, the initial value of the effective load rate can also be determined for each mold 33. The initial value corresponds to the value measured immediately after maintenance of the extraction machine 20, and is the value measured when the effective load rate is expected to be at its lowest.

[0036] On the other hand, it is known that as the first electric motor 23a deteriorates with use, the effective load ratio increases from its initial value, and malfunctions (such as delays or stopping) occur when it exceeds a certain value (for example, 90%). For this reason, a first threshold for the effective load ratio is determined, and maintenance information is displayed in advance before a malfunction occurs. The first threshold is preferably a value greater than the initial value but less than the value at which a malfunction occurs, and is determined based on experiments and empirical rules.

[0037] Furthermore, similar to the first electric motor 23a, the processor 201 decides to display maintenance information for the second electric motor 26a if the measured effective load rate of the second electric motor 26a exceeds the second threshold, and to display maintenance information for the third electric motor 28a if the measured effective load rate of the third electric motor 28a exceeds the third threshold. The second and third thresholds are determined in the same way as the first threshold and are stored in the storage unit 202 in association with identification numbers. Therefore, the processor 201 functions as a determination unit.

[0038] Next, the timing for displaying the effective load rate and maintenance information will be explained. When manufacturing molded products, the touch panel 40a of the controller 40 displays a manufacturing information input screen, and the operator inputs the number of products to be manufactured. The extraction machine 20 and the molding machine 10 then enter an automatic operation state until the number of products manufactured reaches zero, continuously manufacturing and extracting molded products. As shown in Figure 4, during automatic operation, the processor 201 measures the effective load rate of each electric motor 23a, 26a, and 28a, and displays the measured effective load rate in the respective columns 300a to 300c on the touch panel 40a.

[0039] When an operator enters the number of units to be manufactured on the manufacturing information input screen, the processor 201 determines whether the effective load ratio of each electric motor 23a, 26a, and 28a stored in the memory unit 202 exceeds the first to third thresholds, respectively. The processor 201 uses the most recent value stored during manufacturing as the effective load ratio for this determination. If any of the effective load ratios of each motor exceeds a threshold, the processor 201 displays maintenance information for the electric motor 23a, 26a, and 28a that has exceeded the threshold. For example, if the effective load ratio of the first electric motor 23a exceeds the first threshold, as shown in Figure 5, when the number of units to be manufactured is entered in a predetermined field 310 on the manufacturing information input screen 301 displayed on the touch panel 40a, the processor 201 displays maintenance information 302 for the first electric motor 23a.

[0040] Furthermore, when the mold 33 is replaced, the touch panel 40a displays a mold information input screen, the user enters an identification number indicating the mold 33 attached to the molding machine 10, and this is set in the memory units 102 and 202 as the identification number of the current mold 33.

[0041] Therefore, when the operator inputs an identification number indicating the mold 33 after replacement, the processor 201 reads out the effective load ratio of each electric motor 23a, 26a, and 28a that is stored in association with that identification number. This effective load ratio is the most recent value of the effective load ratio measured the last time that the mold 33 identified by the identification number was attached to the molding machine 10 to manufacture a molded product.

[0042] The processor 201 then determines whether each read effective load rate exceeds the first to third thresholds. If any of the first to third thresholds are exceeded, the processor 201 displays maintenance information for the electric motors 23a, 26a, and 28a that have exceeded the threshold.

[0043] For example, as shown in Figure 6, when an identification number is entered into a predetermined field 320 on the mold information input screen 303 displayed on the touch panel 40a, if the effective load rate of the first electric motor 23a stored in association with that identification number exceeds a first threshold, maintenance information 304 for the first electric motor 23a is displayed. For this purpose, the processor 201 functions as an output unit.

[0044] According to the above embodiment, the following effects are achieved.

[0045] (1) The processor 201 measures the effective load ratio for each of the electric motors 23a, 26a, and 28a, and determines for each motor whether the measured effective load ratio exceeds the first to third thresholds. If the processor 201 determines that the effective load ratio of any of the electric motors 23a, 26a, or 28a exceeds the first to third thresholds, it outputs maintenance information prompting maintenance to the touch panel 40a. This makes it possible to know the signs of a malfunction in the electric motors 23a, 26a, or 28a before a problem occurs.

[0046] (2) If the effective load rate exceeds the threshold, when the number of products to be manufactured is entered on the manufacturing information input screen, the processor 201 causes maintenance information to be output on the manufacturing information input screen. This makes it possible to display maintenance information at the time when the number of products to be manufactured is entered in order to start the manufacturing of molded products. This makes it easier to attract the attention of the worker and ensures that maintenance is reliably performed.

[0047] (3) When the identification number of the replacement mold 33 is entered on the mold information input screen, if any of the effective load rates measured when the replacement mold 33 was previously used exceeds the first to third thresholds, the processor 201 outputs maintenance information on the mold information input screen. This makes it possible to display maintenance information at the time the identification number is entered in order to replace the mold 33 and set the control information for the extraction machine 20. This makes it easier to attract the attention of the operator and ensures that maintenance is performed.

[0048] (modified version) Some of the configurations in the above embodiment may be modified. The following describes some modified examples with altered configurations. In the above embodiment, the transition of the effective load ratio over time may be displayed in a graph. This makes it easy to understand how the effective load ratio is increasing.

[0049] In the above embodiment, maintenance information may be displayed at any time when each effective load rate exceeds the first to third thresholds. For example, maintenance information may be displayed when each effective load rate exceeds the first to third thresholds. In the above embodiment, it was determined whether each effective load factor exceeded the first to third thresholds. However, it is also possible to determine whether the increase in each effective load factor from its initial value (i.e., the difference from the initial value) exceeds the respective threshold.

[0050] In the above embodiment, the first to third threshold values ​​may differ for each mold 33. In this case, the first to third threshold values ​​can be stored in association with the identification number being set. Also, the first to third threshold values ​​may differ or be the same for each electric motor 23a, 26a, and 28a.

[0051] In the above embodiment, if the effective load rate exceeds the first to third thresholds, the maintenance information may prompt a change in the control information of the electric motors 23a, 26a, and 28a. In other words, it is known that the effective load rate can be suppressed by changing the output torque, rotational speed, acceleration time, etc., of the electric motors 23a, 26a, and 28a. Therefore, if maintenance cannot be performed immediately, the control information may be changed to suppress the effective load rate. The change in control information may be performed by an operator or by the processor 201.

[0052] In the above embodiment, the motors provided in the extraction device 20 are not limited to electric motors 23a, 26a, and 28a, but may be changed as desired. For example, a motor for controlling the attitude of the chuck 29 (motor for the pivot axis or rotation axis) may be provided. The effective load rate of each of these motors may also be measured, and it may be determined whether or not a threshold has been exceeded. If it has been exceeded, maintenance information may be displayed.

[0053] The conveying device in the above embodiment is not limited to the extraction machine 20 for removing molded products, but can be arbitrarily changed to any device that conveys workpieces. For example, the conveying device may be a palletizing device that performs palletizing. [Explanation of Symbols]

[0054] 10... Molding machine, 20... Extraction machine, 33... Mold, 40... Controller, 100... Molding machine control device, 101... Processor for molding machine control device, 200... Extraction machine control device, 201... Processor for extraction machine control device.

Claims

1. In a control device for a workpiece transport device, The transport device has one or more motors, Each of the motors is provided with a load measuring unit for measuring the effective load ratio of the motor, A determination unit that determines for each motor whether the effective load ratio or the increase in the effective load ratio exceeds a predetermined threshold, A control device for a transport device, comprising: an output unit that, when it is determined that the effective load ratio or its increase exceeds a predetermined threshold in any of the motors, outputs maintenance information to the notification unit prompting maintenance.

2. The control device for a transport device according to claim 1, which prompts a change in the control content for the motor that has been determined to have exceeded a threshold in the maintenance information.

3. The aforementioned conveying device is a removal machine for removing molded products from the molding machine. It has a controller with a touch panel, When the number of molded products to be manufactured or the manufacturing time is input via the controller, the extraction machine enters an automatic operation state until the number of molded products to be manufactured reaches the input number, or until the operating time of the extraction machine reaches the input manufacturing time. The control device for a transport device according to claim 1, wherein the output unit, when determined by the determination unit, causes maintenance information to be output on the manufacturing information input screen of the touch panel in which the number of units manufactured or the manufacturing time is input.

4. The aforementioned conveying device is a removal machine for removing molded products from a molding machine. It has a controller with a touch panel, The controller is configured to display a mold information input screen that accepts input of mold information to identify the mold installed after replacement when the mold attached to the molding machine is replaced. The control device for a transport device according to any one of claims 1 to 3, wherein the output unit outputs maintenance information on the mold information input screen when mold information is input to the mold information input screen, and the determination unit determines that the effective load rate or its increase value measured when the replaced mold identified by the mold information was last used exceeds a predetermined threshold.

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