JP4824879B2 - Unloader abnormality diagnosis method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily narrow the abnormal place of an ejector assembly down and to diagnose both of abnormality due to too much load and abnormality due to too little load to perceive trouble beforehand. SOLUTION: Trial operation is performed to set the upper and lower limit values of the load torque of a servo motor. At the time of automatic operation, the load torque of the servo motor is detected and the detected value is set as history and renewed by the set number of times to be recorded. When the detected value of load torque is not more than the lower limit value, load is diagnosed to be abnormally lowered in a moving mechanism and a part becoming the candidate of a too little load factor is displayed along with history data. When the detected value of load torque is not less than the upper limit value, load is diagnosed to be abnormally increased in the moving mechanism and a part becoming the candidate of a too much load factor is displayed along with history data.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for diagnosing abnormalities in various parts of a machine in a take-out machine that takes out various processed products from various processing machines.
[0002]
[Prior art]
For example, a take-out machine for an injection molding machine is configured to move a chuck in and out of the molding machine, and to remove a resin molded product from a mold and take it out of the machine. Since the unloader operates in linkage with the molding machine, an abnormality or failure of the unloader greatly affects the operating rate of the molding machine. Therefore, conventionally, the current value of the motor provided in the chuck moving mechanism is monitored, and when an overcurrent flows, it is determined that an excessive load has occurred in the moving mechanism, and the operation of the machine is stopped, and the process The method of prompting early recovery by displaying an alarm indicating that there was an abnormality in the system was used.
[0003]
[Problems to be solved by the invention]
However, the conventional abnormality diagnosis method has the following problems.
(1) Although it can be specified in which process the abnormality has occurred, it has not been possible to specify in detail in which part of the process the abnormality has occurred.
(2) Although abnormalities due to overload, such as guide seizure and bearing damage, can be diagnosed, abnormalities due to underload, such as belt breakage and shaft breakage, cannot be diagnosed.
(3) When the abnormality is diagnosed, there are many cases where the parts have already been damaged, and the failure cannot be detected in advance.
[0004]
The object of the present invention is to provide an abnormality diagnosis method that solves the above-mentioned problems, can identify in detail the abnormality location of the unloader, can diagnose both abnormalities due to overload and underload, and can detect a failure in advance. It is in.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the abnormality diagnosis method for the unloader according to the present invention is the load information of the chuck moving mechanism (limited to the load torque of the motor) in the unloader that moves the chuck in and out of the processing machine and takes out the workpiece. .) Is detected, and the detected value is compared with the preset upper and lower limit values. When the detected value is less than or equal to the lower limit value, parts that cause an underload due to cutting or breakage that are candidates for an underload factor are displayed. When the detected value is equal to or higher than the upper limit value, a part that is an overload factor candidate and that generates an overload due to seizure or contact is displayed.
[0006]
Here, the processing machine includes various machines such as a machine tool and a surface processing machine in addition to the injection molding machine. Processed products include various products or semi-finished products such as sheet metal molded products, machined products, and surface processed products in addition to resin molded products. The chuck for taking out the processed product is not particularly limited, and examples include a chuck that adsorbs the processed product by evacuation and a chuck that holds the processed product by opening and closing the claw.
[0007]
The “chuck moving mechanism” is a mechanism for moving the chuck into and out of the processing machine. In the case of a take-out machine in which the chuck moves in a plurality of directions, a plurality of moving mechanisms are provided for each direction, and abnormality diagnosis is performed in a required part or all of the mechanisms.
[0008]
The “load information” of the chuck movement mechanism means the load on each part of the mechanism, such as the load acting on the actuators such as motors and air cylinders provided in the mechanism, or the load acting on power transmission parts such as belts and chains. Contains information that can be detected as a quantity value. For example, the load torque of the motor can be detected from the current value or the number of revolutions inversely proportional to it, or the tension of the belt can be detected using a tension meter.
[0009]
The “upper limit value and lower limit value” define a normal range of the load acting on each part of the moving mechanism, and is set in the storage device as an electric quantity value that can be compared with the detected value of the load information. When setting each value, the operator can also input manually based on the operation program and experience value of the processing machine, but the upper limit value and the lower limit value are set in that data suitable for the actual operation status can be acquired. It is preferable to set based on an execution value of trial operation.
[0010]
“Parts that are candidates for an underload factor and generate an underload by cutting or breakage ” are not particularly limited, and examples thereof include a belt, a shaft, and a coupling. “Parts that generate an excessive load due to seizure or contact as a candidate for an excessive load factor” are not particularly limited, and examples thereof include a guide, a bearing, and a belt cover. However, these candidate parts are all representative, and in implementation, they are appropriately selected in consideration of the possibility and frequency of abnormality based on the specific configuration of the chuck moving mechanism.
[0011]
In addition, the abnormality diagnosis method of the present invention is characterized in that a history of load information is recorded and history data is displayed at any time in order to more specifically identify an abnormality location. For example, the load information for the past several times or several hours is updated and stored in the storage device, and is displayed on the display device together with the candidate parts when an abnormality occurs. Alternatively, only the peak value may be extracted from the load information, and long-term history data over the past few days or months may be recorded.
[0012]
In this case, it is preferable to transmit the history data to a remote host computer via a communication line so that the abnormality of the unloader can be diagnosed at a remote location. Not only history data but also control data such as various setting values and communication data with a processing machine may be added to the transmission data. Examples of the communication line include a local communication line using a LAN and a wide area communication line using the Internet. As a transmission / reception device, a cellular phone with mail can also be used.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in a take-out machine for an injection molding machine will be described with reference to the drawings. As shown in FIG. 1, the main frame 2 of the take-out machine 1 is fixed on an injection molding machine 3 so as to extend in the left-right direction. A left and right moving body 4 is supported on the main frame 2, and a subframe 5 that is long in the front-rear direction is fixed to the left and right moving body 4. The sub-frame 5 supports a back-and-forth moving body 6, and the back-and-forth moving body 6 supports a vertically moving body 8. A revolving body 9 is supported on the vertically moving body 8, and a plurality of chucks 10 are mounted on the revolving body 9. And the chuck | zipper 10 moves to the front-back, up-down, and the left-right direction, extracts the resin molded product from the metal mold | die 11 of the molding machine 3, and takes it out of the machine.
[0014]
The front-rear moving mechanism of the chuck 10 includes a front-rear moving body 6, a guide 19 that guides the front-rear moving body 6, a servo motor 20 with a speed reducer that drives the front-rear moving body 6, and the power of the servo motor 20 is moved back and forth. The belt 21 is transmitted to the body 6. As shown in FIG. 2, the moving mechanism in the left-right direction of the chuck 10 includes a left-right moving body 4, a guide 13 that guides the left-right moving body 4, a servo motor 14 with a speed reducer that drives the left-right moving body 4, and a servo. The belt 15 and the pulleys 16, 17, and 18 transmit the power of the motor 14 to the left and right moving body 4.
[0015]
As shown in FIG. 3, a double speed mechanism that drives the vertical moving body 8 at a high speed is adopted as the vertical movement mechanism of the chuck 10. The vertical moving body 8 is formed in a columnar shape and is supported by the elevating body 23 via the guide 22. The lifting / lowering body 23 is supported by the front / rear moving body 6 through a guide 24 and is driven by a servo motor 25 with a speed reducer through an end belt 26. A vertically long endless belt 27 is stretched on the elevating body 23, a part of one side thereof is coupled to the longitudinally moving body 6 by a joint 28, and a part on the opposite side is coupled to the vertically movable body 8 by a joint 29. Yes. The endless belt 27 is rotated by the movement of the elevating body 23, and the vertical moving body 8 is driven at a speed twice that of the elevating body 23 by the rotation of the endless belt 27.
[0016]
Note that a double speed mechanism using two actuators, that is, a servo motor and an air cylinder, may be employed as the vertical movement mechanism of the chuck 10. In the turning mechanism of the chuck 10, the turning body 9 is driven by a servo motor 30 (see FIG. 1). In each mechanism, LM guides (linear motion guides) using rolling guides are used for the guides 13, 19, 22, and 24, and toothed belts are used for the belts 15, 21, 26, and 27. Instead of a belt, it is possible to use a chain or a ball screw.
[0017]
The servo motors 14, 20, 25, 30 of each mechanism are servo-controlled by the control device of the unloader 1. For example, in the vertical movement mechanism of the chuck 10, as shown in FIG. 4, the control device 31 controls the servo motor 25 via the servo control unit 32, and based on the signal from the encoder 33 attached thereto, The moving amount and speed of the moving body 8 are detected. Further, the control device 31 has a function of detecting the load torque of the servo motor 25 based on the rotation speed (encoder signal), the load current value, or the supply voltage value. The control device 31 is connected to an input device 35 for inputting various set values, a storage device 36 for storing set values, detection values, and the like, and a display device 37 for displaying stored data, alarms, and the like. .
[0018]
The take-out machine 1 configured as described above takes out the molded product in the order of steps shown in FIGS. During the molding operation of the molding machine 3, the chuck 10 stands by at the origin position O above the mold 11. When the molding machine 3 finishes one shot and a take-out start command is issued after the mold is opened, first, the vertical moving body 8 is lowered, the forward moving body 6 is moved forward, and the chuck 10 is moved forward. Hold the molded product. Next, {circle around (4)} the back and forth moving body 6 moves backward, {circle around (5)} the up and down moving body 8 rises to the origin position O, and the unloader 1 outputs a mold clamping start command to the molding machine 3. Subsequently, (6) the left and right moving body 4 moves out of the machine, (7) the turning body 9 turns to change the orientation of the chuck 10, (8) the up and down moving body 8 descends, and (9) the chuck 10 releases the part. Thereafter, (10) the vertically moving body 8 is raised, (11) the revolving body 9 is swung to restore the orientation of the chuck 10, (12) the left and right moving body 4 is moved into the machine, and the chuck 10 is moved to the origin position O. Return to.
[0019]
Next, an abnormality diagnosis method for the unloader 1 will be described. As shown in FIG. 7, at the start of operation of the unloader 1, a trial operation (manual operation) for one cycle is executed (step S1). Here, the load torque of the servo motors 14, 20, 25, and 30 that drive the left and right moving body 4, the front and rear moving body 6, the vertical moving body 8, and the turning body 9, that is, standard load information that can normally execute each process. Is detected for each process, plus or minus allowable values are added to these execution values, and the upper limit value and the lower limit value of the load torque during automatic operation are set in the storage device 36 (step S2). If it carries out like this, the load information optimal for an actual driving | running condition can be set automatically also as the inspection of each part at the time of an operation start. The upper limit value and the lower limit value may be set as a percentage of the execution value.
[0020]
In the automatic operation, substantially the same diagnostic program is executed for each process (excluding the gripping and releasing process of the molded product). First, when the start command of the process is confirmed based on the end signal of the previous process (step S11), the servo motors 14, 20, 25, 30 are driven (step S12), and the moving bodies 4, 6, 8, 9 Are moved in each direction. As shown in FIG. 8, when a preset acceleration time has elapsed from the start of the process (step S13), the load torque of the servo motors 14, 20, 25, 30 is detected by the control device 31 (step S14). The detected value is stored in the storage device 36 (step S15). Note that the load torque may be detected at a position away from the process start position by a preset distance.
[0021]
Subsequently, the detected value of the load torque is compared with the lower limit value set in the trial operation (step S16), and if it is equal to or higher than the lower limit value, it is compared with the upper limit value (step S17). If the detected value is less than or equal to the upper limit value, it is diagnosed that the load torque is normal, the servo motors 14, 20, 25, 30 are continuously driven, the load torque is monitored, and the detected value is recorded as a history for a set number of times. Updated and recorded. When the moving bodies 4, 6, 8, 9 reach the end of the stroke, an end command is confirmed based on a signal such as a limit switch (step S18), and the servo motors 14, 20, 25, 30 are stopped ( Step S19), the process ends normally.
[0022]
On the other hand, when the detected value of the load torque is equal to or lower than the lower limit value, it is diagnosed that the load is abnormally lowered in the moving mechanism, and an alarm signal for informing the underload is output (step S20). The servo motors 14, 20, 25, 30 are immediately stopped (step S19). In response to this alarm signal, the display device 37 displays parts that are candidates for underload factors in the process on the display device 37. For example, as shown in FIG. 9, in the case of the chuck ascending process, the endless belt 26 and the endless belt 27 (slip, cut), the reducer shaft of the servo motor 25 (breakage), the coupling (damage), etc. A plurality of candidate parts that generate an error are displayed together with a part number and abnormality content.
[0023]
When the detected value of the load torque is equal to or higher than the upper limit value, it is diagnosed that the load is abnormally increased in the moving mechanism, and an alarm signal for notifying the excessive load is output (step S21). The display device 37 displays parts that are candidates for an overload factor in the process. For example, as shown in FIG. 10, in the case of the chuck ascending process, a plurality of excessive loads such as inner and outer LM guides 22 and 24 (baking), a reduction gear bearing (breakage) of the servo motor 25, a belt cover (contact), etc. The candidate parts are listed together with the part number and the content of the abnormality.
[0024]
Therefore, the following effects can be obtained.
(A) From the two alarm display screens, it is possible to narrow down to the parts level what kind of abnormality has occurred in which part of which process, and to specify it in detail, and to shorten the time until recovery, that is, down time.
(B) It is possible to accurately diagnose not only an abnormality caused by an excessive load such as a seizure of a guide or a bearing breakage but also an abnormality caused by an excessive load such as a belt breakage or a shaft breakage.
(C) By strictly setting the upper limit value and the lower limit value, an abnormality can be found before the component breaks down, and measures for avoiding the failure can be taken early.
(D) As shown in FIG. 8, the abnormality diagnosis can be performed over a long period in a section where the load torque is stable (constant section of the moving body).
[0025]
As shown in FIGS. 9 and 10, the display device 37 includes an up scroll button 39 and a down scroll button 40 for displaying all candidate parts, a front button 41 and a next button 42 for switching screens, A transmission button 43 for starting the transmission program is provided. Then, when the next button 42 is pressed on the alarm display screen, as shown in FIG. 11, the history data for the set number of times executed in the past is displayed. The history data includes a load torque detection value, date, product number, upper and lower limit values, etc., and is displayed in a list from the latest data.
[0026]
Therefore, the following effects can be obtained.
(E) By comparing the history data with the candidate parts on the previous screen when an abnormality occurs, it is possible to narrow down the abnormal parts and abnormal parts in more detail.
(F) The history data is displayed at any time, the change of the load torque can be collated, and the life of the parts can be predicted, which is useful for pre-maintenance.
(G) History data can be accumulated as technical data for new product development.
[0027]
When the transmission button 43 is pressed, a transmission program is started, and a diagnostic file including data necessary for a dedicated engineer at a remote site to examine the abnormality, such as history data, various setting values, communication data with the molding machine 3, etc. Is automatically created. This file is transmitted to a remote host computer using a LAN or the Internet via a local area or wide area communication line by a transmission / reception device (not shown) attached to the unloader 1.
[0028]
Therefore, the following effects can be obtained.
(H) The abnormality of the unloader can be diagnosed in detail while the user or a full-time engineer of the manufacturer is in a remote place.
(I) It is not necessary for a manufacturer's full-time engineer to visit the site, and the cost for after-sales service can be saved.
(J) Replacement parts or preparation parts can be quickly arranged according to the diagnosis result.
(K) If an e-mail mobile phone is used as a transmission / reception device, the take-out machine can be recovered at an early stage wherever a dedicated engineer is.
(L) By using this system at the time of starting production of a new molded product or when a program abnormality occurs, the manufacturer can promptly deliver a new or modified program to the user.
[0029]
In addition, this invention is not limited to the said embodiment, For example, it can also be suitably changed and embodied as follows, for example in the range which does not deviate from the meaning of invention.
(1) As shown in FIG. 12, the time (or distance) from the start of the process until the maximum load torque is generated is set, the load torque is detected at the point x at which this set time has elapsed, and the detected value is the upper limit Diagnose the load abnormality at the initial stage of the process by comparing with the value and the lower limit.
(2) As shown in FIG. 13, two detection points x, y (time or distance) are set in the middle of the constant velocity section, the average value of the load torque in this section is obtained, and the average value is set to the upper limit value and Diagnose load abnormalities in the middle of the process by comparing with the lower limit.
(3) The abnormality diagnosis method of the embodiment is applied to a take-out machine that takes out various processed products from various processing machines such as a machine tool, a surface processing machine, a packing machine, and a food processing machine.
[0030]
【The invention's effect】
As described above in detail, according to the abnormality diagnosis method according to the present invention, the parts that are candidates for the underload factor and the parts that are candidates for the overload factor are displayed separately. Both an abnormality caused by a load and an abnormality caused by an underload can be diagnosed, and an excellent effect is obtained in that a failure can be detected in advance.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an entire take-out machine in which an abnormality diagnosis method of the present invention is implemented.
FIG. 2 is a front view showing a horizontal movement mechanism of the chuck in the take-out machine.
FIG. 3 is a front view showing a vertical movement mechanism of a chuck in the take-out machine.
FIG. 4 is a block diagram showing an abnormality diagnosis system for the unloader.
FIG. 5 is a process explanatory diagram of the unloader.
FIG. 6 is a time chart showing the operation of the moving object.
FIG. 7 is a flowchart showing an embodiment of the abnormality diagnosis method according to the present invention.
FIG. 8 is a load torque diagram of a servo motor for supplementarily explaining the diagnosis method.
FIG. 9 is a front view of a display device showing an underload alarm display screen.
FIG. 10 is a front view of a display device showing a display screen of an overload alarm.
FIG. 11 is a front view of a display device showing a display screen of history data.
FIG. 12 is a load torque diagram showing an example of changing the abnormality diagnosis timing.
FIG. 13 is a load torque diagram showing another example of changing the abnormality diagnosis timing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Unloader 3 Injection molding machine 4 Left-right moving body 6 Back-and-forth moving body 8 Vertically-moving body 9 Revolving body 10 Chuck 14 Servo motor 15 Belt 19 Guide 20 Servo motor 21 Belt 22 Guide 24 Guide 25 Servo motor 26 Ended belt 27 Endless belt 30 Servo Motor 31 Control Device 32 Servo Control Unit 33 Encoder 35 Input Device 36 Storage Device 37 Display Device 43 Send Button

Claims (4)

In the unloader that moves the chuck in and out of the processing machine and takes out the processed product,
Detecting a load torque of the motor of the chuck moving mechanism, compared with the upper limit value and the lower limit value preset detection values, when the detected value is below the lower limit, the undersized load factor candidates, under-load by cutting or breakage An abnormality diagnosis method for an unloader, characterized in that when a detected value is equal to or greater than an upper limit value, a component that causes an excessive load due to seizure or contact is displayed as a candidate for an excessive load factor.   The abnormality diagnosis method for an unloader according to claim 1, wherein the upper limit value and the lower limit value are set based on an execution value of trial operation.   The abnormality diagnosis method for an unloader according to claim 1 or 2, wherein a history of load torque of the motor is recorded and the history data is displayed at any time.   4. The abnormality diagnosis method for an unloader according to claim 3, wherein the history data is transmitted to a remote host computer via a communication line.

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