JP2010137931A - Driving control device for conveyor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving control device for a conveyor capable of easily and efficiently controlling the driving of the conveyor body by performing proper power supply control of an induction electric motor and of easily and inexpensively adapting itself to a conveyor body of different functions. <P>SOLUTION: The conveyor body 13 carries chips generated by cutting work of metal. When clogging of the chips is caused, a load is applied to the induction electric motor 12, increasing its driving current. When a detecting value of a current detector becomes a limit current value or more, it is determined that the value is the limit current value or more by a microcomputer, and power supply to the induction electric motor 12 by an inverter is stopped, and the power supply is also performed in a reversal mode by the inverter after a predetermined time, and the induction electric motor 12 is reversed. Thus, the clogging of the chips clogged in a chip conveyor body 13 can be removed, and inconvenience such as burning damage of the induction electric motor 12 can be properly avoided by maximally utilizing torque of a conveyor. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive control device for a conveyor that controls a power supply state to an induction motor in a conveyor such as a chip transfer device that conveys an object supplied to the conveyor body in a certain direction by driving the conveyor body by an induction motor. .

Conventionally, as this type of drive control device, for example, as shown in Patent Document 1, a conveyor main body provided with drive means, an electric switch that performs forward / reverse rotation and stop of the conveyor by switching / interrupting electrical connection, 2. Description of the Related Art A chip conveyor is known that includes a control device that controls switching / interconnection of switch connections and an overload detection means that detects overload of the conveyor. In this chip conveyor, the control device controls the time length and operation sequence of each operation, the counting device for counting the number of forward / reverse recovery operations of the conveyor, and the detection signal of the overload detection device. Is stopped, and it is determined whether or not the count number of the counting means has reached a predetermined number. And control means to perform.
Japanese Patent Laid-Open No. 61-173893

  However, in the above chip conveyor, an overcurrent flowing through the electric motor is detected as overload detection means, but the overcurrent is not clearly shown. For this reason, if the overcurrent is too small, the driving force of the motor cannot be used efficiently, and if the overcurrent is too large, the load applied to the motor is increased, which may cause unnecessary damage to the motor. In addition, an analog sequencer or digital computer is operated as a control device by a control program. For this reason, it is necessary to prepare a program for each type of conveyor with different standards. There is a problem that the control cost becomes expensive due to lack. Furthermore, since it is necessary to prepare a control device for each of a plurality of types of conveyors, the control of the plurality of conveyors cannot be performed in a concentrated manner, and the control becomes complicated and the control cost is further increased. There is also a problem.

  Here, the relationship between the rotational speed of the induction motor, the torque, and the drive current will be described with reference to FIG. The induction motor rotates at a steady speed N that is smaller by the slip s than the synchronous speed, and the drive current at that time is Iu and the load torque is Tu. When the load applied to the induction motor increases, the rotational speed starts to decrease and the load torque T decreases after reaching the maximum torque Tm, but the drive current I continues to increase as the rotational speed decreases. Such an increase in the drive current I adds an excessive load to the motor, leading to problems such as a decrease in durability of the motor and burning.

  In consideration of the characteristics of the induction motor, the present inventor determines that the drive current at the time when the maximum torque Tm is generated is the upper limit current Im, and stops driving the motor when the drive current increases to the limit current Im. As a result, it has been found that it is possible to prevent a decrease in durability of the induction motor due to overloading, a problem such as burnout, and the most effective use of the torque of the induction motor, and the present invention has been conceived. Therefore, the present invention enables simple and efficient drive control of the conveyor body by performing appropriate power feeding control on the induction motor, and can also easily and inexpensively cope with the conveyor body having different functions. An object of the present invention is to provide a drive control device for a simple conveyor.

  In order to achieve the above object, a feature of the present invention is that the conveyor main body is driven by the induction motor, thereby controlling the power supply state to the induction motor in the conveyor that conveys the material supplied to the conveyor main body. Then, by changing the power supply state from the power source to the induction motor, the power supply changing means capable of switching the drive state of the induction motor to one of normal rotation, stop, and reversal, and the drive current of the induction motor are detected. Current detection means, input means for inputting power supply conditions such as a limit current value that is a drive current value at the time of maximum torque generation of the induction motor, storage means for storing the power supply conditions input by the input means, and current detection The drive current value detected by the means is read and compared with the limit current value stored in the storage means to determine whether or not the drive current value is equal to or greater than the limit current value. A current value determining means; and a power supply control means for stopping the induction motor by the change control of the power supply state of the power supply changing means in response to the determination result of the current value determining means that exceeds the limit current value. .

  In the present invention, for example, in the case of a conveyor that transports luggage at an airport or the like, if the luggage is clogged while the conveyor body is being driven, an excessive load is applied to the induction motor and the drive current increases. If the drive current continues to increase and the detection value of the current detection means becomes equal to or greater than the limit current value that is the current value when the maximum torque of the induction motor is generated, it is determined by the current value determination means to be equal to or greater than the limit current value. In response to this, the power feeding control means stops the induction motor by changing the power feeding changing means, and the conveyor body is automatically stopped, so that the caught luggage can be removed. In the present invention, when an excessive load is applied to the conveyor body, as a condition for stopping the induction motor that drives the conveyor body, the limit current value of the induction motor is adjusted when the maximum torque is generated, thereby driving the induction motor. While making full use of the force, it is possible to reliably avoid problems such as a decrease in durability and burnout of the motor caused by an excessive current flowing through the induction motor, and the conveyor can be driven efficiently. In addition, according to the present invention, setting and changing of power supply conditions such as a limit current value can be easily performed by the input means without complicated procedures such as change of the control program. As a result, the drive control device Can be easily mounted and driven on conveyors of various applications and standards, so that the cost required for the drive control device can be greatly reduced.

  Further, in the present invention, the power supply control means stops the induction motor by the change control of the power supply state of the power supply change means, then reverses the induction motor for a predetermined time, and then stops and returns to normal rotation again. Can be. Thereby, for example, in the case of a chip conveyor that transports chips generated by metal cutting, when clogging of chips occurs in the conveyor body and the detected value of the current detecting means exceeds the limit current value, the power supply control means However, by the change control of the power supply changing means, it is possible to reverse the induction motor for a predetermined time after stopping the normal rotation, and to return to the normal rotation state after the stop. In this way, by turning the induction motor in the inverted state, the conveyor body can be reversed to easily remove the clogged chips. In addition, when the clogging of the chip cannot be removed by one reversing operation, the clogging can be automatically removed by repeating forward rotation / stop / inversion. In the present invention, as in the first aspect of the invention, when an excessive load is applied to the conveyor body, as a condition for stopping the induction motor that drives the conveyor body, the limit current value of the induction motor is set when the maximum torque is generated. By combining them, it is possible to reliably avoid problems such as a decrease in durability and burnout of the induction motor while making maximum use of the rotational force of the induction motor, and to drive the conveyor efficiently and inexpensively.

  Further, in the present invention, temperature detection means for detecting the surface temperature of the induction motor is provided, the limit surface temperature value of the induction motor is input by the input means, stored in the storage means, and the temperature detected by the temperature detection means A detection value is read and compared with the limit surface temperature stored in the storage means, and surface temperature determination means for determining whether or not the temperature detection value is equal to or higher than the limit surface temperature is provided. Control for changing the power supply state of the power supply change means in response to receiving the determination result of either the determination result that is greater than or equal to the limit current value from and the determination result that is greater than or equal to the limit surface temperature from the surface temperature determination means Thus, the induction motor can be stopped. Thereby, as a condition for stopping the induction motor when an excessive load is applied to the conveyor body, the limit surface temperature can be referred to in addition to the limit current value, so the stop control of the induction motor can be more reliably performed, Safer drive control of the induction motor is ensured.

  Further, it is preferable that the power supply changing means is an inverter. Thereby, by changing the frequency, the rotation speed of the induction motor can be controlled, and the forward / stop / reverse switching of the conveyor can be smoothly adjusted.

  In the present invention, it is preferable that the power supply control means, the current value determination means, and the storage means are constituted by a microcomputer. As a result, the drive control device can be configured in a compact manner, including the use of an inverter, and the limit current value and the like can be easily set by the input means. As a result, the drive control device can be easily and inexpensively attached to conveyors of various uses and standards.

  In the present invention, the input means can be a manual switch input. This is convenient because it is possible to easily set and change the power supply conditions and the like by manual input as necessary near the conveyor installed at the work place.

  In the present invention, the input means can be a personal computer. This is convenient because the power supply conditions and the like can be easily set and changed at a remote location without going to the work site where the conveyor is installed.

  In the present invention, a personal computer may be used as a common input unit, and data may be input in parallel to power supply control units of a plurality of conveyor driving devices. As a result, it is possible to set power supply conditions, etc., and change work for multiple conveyors of different types and functions installed in a wide factory, using a single computer. The management effort is greatly reduced.

  According to the present invention, when an excessive load is applied to the conveyor body, as a condition for stopping the normal rotation of the induction motor that drives the conveyor body, the induction motor is adjusted so that the limit current of the induction motor is adjusted when the maximum torque is generated. While making full use of the rotational force of the electric motor, it is possible to reliably avoid problems such as reduced durability and damage of the induction motor, and to drive the conveyor efficiently and inexpensively. In addition, according to the present invention, the setting of power supply conditions such as limit current values and the change thereof can be easily performed by the input means regardless of complicated procedures such as a change of the control program. Since it can be easily mounted and driven on conveyors of different uses and standards, the cost required for the drive control device can be greatly reduced. In addition, as a condition for stopping the induction motor, by making it possible to refer to the limit surface temperature in addition to the limit current value, the stop control of the induction motor can be performed more reliably, and the induction motor can be controlled more safely. Can be secured.

  Further, by using an inverter as the power supply changing means, the rotation speed of the induction motor can be controlled, and the rotation speed of the conveyor can be freely adjusted. Further, by configuring the power supply control means, current value determination means, and storage means with a microcomputer, the drive control device can be made compact, including the use of an inverter, and the input means can limit the current limit value, etc. Therefore, the drive control device can be easily mounted and driven on conveyors of various uses and standards. Further, in the present invention, by setting the input means as a manual switch input, it is convenient because the power supply conditions and the like can be easily set and changed as necessary near the conveyor installed at the work place. .

  Further, in the present invention, by using a personal computer as the input means, it is convenient because the power supply conditions and the like can be easily set and changed at a place away from the work site where the conveyor is installed. In addition, it is possible to manage multiple conveyors of different types and functions from a single personal computer by using a personal computer as a common input means and enabling data input to the storage means of multiple conveyor drive devices. Management effort is greatly reduced.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 is a schematic diagram showing a schematic configuration of a chip conveyor that is an example of a conveyor that conveys objects in a predetermined direction according to the first embodiment, and FIG. 2 is a circuit mainly showing a drive control device of the chip conveyor. The configuration is shown by a block diagram, and FIG. 3 shows the circuit configuration of the display unit by a block diagram. The chip conveyor 10 is configured to carry chips by receiving power from the 200v commercial power supply 11 and driving the conveyor body 13 by the induction motor 12, and the power supply state to the induction motor 12 is controlled by the drive control device 15. To do. The chip conveyor 10 conveys chips generated during metal processing by the conveyor main body 13, but when a chip clogging occurs on the way, the conveyor main body 13 is stopped and the conveyor main body 13 is moved for a predetermined time. A cycle of reversing, further stopping, and then returning to normal rotation is performed at least once, so that clogging of chips in the conveyor body 13 is automatically removed.

  The drive control device 15 includes an inverter 16 connected to a power supply line that supplies power to the induction motor 12 from the commercial power supply 11, a current detector 17 that detects a drive current output from the inverter 16 to the induction motor 12 in two phases, A control unit 21 that controls the drive of the inverter 16 in response to a current detection result from the current detector 17, a display unit 31 that is connected to the control unit 21 and displays a current value, and the like, and is connected to the other control unit 21. It comprises an analog external input 29, an external input 41, an external output 42, a personal computer 39, an external input 37 connected to the display unit 31, an external output 38, and the like. The control unit 21 and the display unit 31 are accommodated in a control box 19 provided in the vicinity of the conveyor body 13.

  The control unit 21 is provided with connectors CN1 to CN8 and is connected to each part of the drive control device 15 via each connector. The control unit 21 is provided with a microcomputer 22 composed of ROM, RAM, CPU, I / O and the like, and is supplied with a predetermined DC voltage by a power supply circuit 23 connected from the commercial power supply 11 via the connector CN1. Power is supplied. In the control unit 21, the integration circuit 24 connected to the connectors CN2 and CN3, the high-speed communication circuit 25 connected to the connector CN4, the low-speed communication circuit 26 connected to the connector CN6, and the connector CN7 are connected. The input circuit 27 and the output circuit 28 connected to the connector CN8 are provided and connected to the microcomputer 22, respectively.

  A current detector 17 is connected to the connector CN2. The current detector 17 is composed of, for example, a Hall element. Connected to the connector CN3 is an analog external input 29 for performing external input for changing the rotation speed of the induction motor 12 during normal rotation and reverse rotation. An analog voltage value input from the connector CN3 is input to the microcomputer 22 after the noise is removed by the integrating circuit 24. The above-described inverter 16 is connected to the connector CN4. The inverter 16 switches the power supply state to the induction motor 12 based on a control signal input from the microcomputer 22 through the high-speed communication circuit 25 so as to be one of forward rotation drive, stop, and reverse drive. A display unit 31 is connected to the connector CN5. Power is supplied from the power supply circuit 23 and display is performed based on a control signal from the microcomputer 22.

  The display unit 31 includes a display circuit 32 connected to the connectors CN9 and CN12, and a display board 33 which is a visual display means such as an LED or an LCD is connected to the display circuit 32. The connector CN9 is connected to the microcomputer 22 through the connector CN5 of the control unit 21. The display circuit 32 inputs a digital signal from the microcomputer 22 and displays it on the display board 33. Further, a shift register 34 is connected to the display circuit 32, and an input circuit 35 and an output circuit 36 are connected to the shift register 34. An external input 37 for manually inputting initial settings such as a power supply condition to the setting induction motor 12 is connected to the input circuit 35 via the connector CN10. The output circuit 36 is connected via a connector CN11 to an external output 38 for displaying a lamp or the like. Further, an emergency stop input 48 described later is connected to the connector CN12, and the emergency stop input is displayed on the display board 33 through the display circuit 32.

  A personal computer 39 is connected to the connector CN6. Like the external input 37, the personal computer 39 sets power supply conditions for the induction motor 12, but can be performed from a place away from the site where the conveyor body 13 is installed. Connected to the connector CN7 is an external input 41 such as a remote controller for performing a command such as normal rotation / reversal or operation start / stop of the induction motor 12 by remote operation from the outside. Input to the computer 22. The connector CN8 is connected to an external output 42 such as a red lamp, a green lamp, a relay, and a rotating lamp for outputting the control state of the microcomputer 22, and a digital signal from the microcomputer 22 passes through the output circuit 28. Input to the external output 42.

  The control unit 21 is provided with a setting start switch 43. The setting start switch 43 is a manual switch provided in the control box 19 and directly connected to the microcomputer 22. The setting start switch 43 enables an initial setting manual input by the external input 37 in the on state, and disables the manual input in the off state. As shown in FIG. 4, the display unit 31 and the external input 37 are arranged on the front surface of the control box 19. The external input 37 includes a setting switch 44, a normal rotation switch 45, a reverse switch 46, a stop reset switch 47, and an emergency stop switch 48.

  The setting switch 44 is as shown in FIG. Switching between a manual position, an inching position, and an automatic position can be performed by turning the lever 44a. The manual position is a position where the setting parameter item is changed. The inching position is set when driving. The automatic position is a position where the setting parameter is changed. The forward switch 45 and the reverse switch 46 are push button switches, and change setting parameter items and numerical values. The stop reset switch 47 is a push button switch that stops the operation of the induction motor 12 or resets the setting conditions. The emergency stop switch 48 is a switch for stopping the operation when an emergency situation occurs during the operation of the induction motor 12. The parameter setting by the external input 37 is performed at the position where the control box 19 of the chip conveyor 10 at the work place is installed when the induction motor 12 is stopped, and is displayed on the display plate 33 of the display unit 31. It is done while looking at the numbers. The external output 38 is a lamp indicating a set state provided in the forward rotation switch 45, the reverse switch 46, the stop reset switch 47, and the emergency stop switch 48.

  Next, the setting contents of parameters by the external input 37 will be described. First, the lever 44a of the setting switch 44 is switched to the manual position, the parameter is set to the stop set current by the forward rotation switch 45 and the reverse switch 46, and then the lever 44a is switched to the automatic position, and the forward rotation switch 45 and the reverse switch 46 are pressed. The stop current value when the maximum torque is generated is set. Similarly, the contact output time at the time of current detection is set. Similarly, the inverter communication operation is operated at high and low frequencies, the automatic operation mode is reversed operation, the automatic operation start condition is determined by the panel switch, the standby time until startup, the green lamp display time at the start of operation, automatic Number of retries during operation, green lamp blinking at the start of operation, buzzer ringing time at the start of operation, start-up current detection start delay time, normal rotation speed, red lamp display time at current detection stop, red at current detection stop Lamp blinking, buzzer time when current detection is stopped, automatic reverse operation time, automatic reverse operation speed, selection of normal operation after stop current is reached in post-stop condition during automatic reverse operation, current value calibration range, inching inverter operation frequency, Settings such as the operation time after detection of current during forward rotation are performed.

  Next, the operation of the chip conveyor 10 will be described. First, when the power supply 11 is turned on, after the start standby time has elapsed, power is supplied to the induction motor 12 through the inverter 16 based on the control of the microcomputer 22, and the conveyor motor 13 rotates as the induction motor 12 rotates forward. Is started, and the conveyance of the chips generated by cutting the metal put into the conveyor body 13 is started. When a load is applied to the conveyor main body 13 due to clogging of the chips during the transfer of the chips due to the rotation of the conveyor main body 13, the torque of the induction motor 12 increases. When the clogging of the chip is not eliminated, the torque becomes maximum, and the driving current of the induction motor 12 correspondingly becomes the limit current value. When the limit current is detected by the current detector 17, the power supply from the inverter 16 is stopped under the control of the microcomputer 22 accordingly. As a result, the rotation of the induction motor 12 stops, and the rotation of the conveyor body 13 driven by the induction motor 12 stops.

  Subsequently, based on the control of the microcomputer 22, an inversion command is sent to the inverter 16, and an inversion signal is output from the inverter 16 over a predetermined time. In response to this, the induction motor 12 starts reversal, and the conveyor main body 13 reverses, so that the clogging of the chips into the conveyor main body 13 can be easily removed. After the conveyor main body 13 is reversed for a predetermined time, the inverter 16 stops supplying power based on the control of the microcomputer 22 and the reverse of the conveyor main body 13 is stopped. Subsequently, based on the control of the microcomputer 22, a normal rotation command is sent to the inverter 16, and a normal rotation signal is output from the inverter 16. In response to this, the induction motor 12 starts normal rotation, and the conveyor body 13 is returned to the normal rotation state. Thereby, when the clogging of the chip is not eliminated, the induction motor 12 is further repeatedly stopped, reversed, and normally rotated. By performing such a normal rotation-stop-reverse drive cycle of the induction motor 12 at least once, chips jammed in the conveyor body 13 are automatically removed.

  As described above, in the embodiment, when the chip is clogged in the conveyor main body 13 that conveys the chip generated by the metal cutting process, a load is applied to the induction motor 12 and the drive current increases to increase the current. When the detected value of the detector 17 exceeds the limit current value, the microcomputer 22 stops the power supply from the inverter 16 to the induction motor 12, and after a predetermined time, the inverter 16 supplies power in the inversion mode. Invert the induction motor 12. As a result, the chip conveyor main body 13 changes from normal rotation to reverse, and chip clogging can be automatically removed by repeating such reverse normal rotation. In the present embodiment, as a condition for stopping the conveyor main body 13, the limit current value of the induction motor 12 is matched when the maximum torque is generated, so that the durability of the induction motor 12 is reduced while the maximum rotational force of the conveyor is utilized. It is possible to appropriately avoid problems such as burnout and burnout, and to drive the conveyor efficiently and inexpensively.

  Further, in the present embodiment, setting and changing of the power supply conditions such as the limit current value can be easily performed manually at the work site by the external input 37 without using complicated procedures such as changing the control program. . As a result, the drive control device 15 can be easily mounted and driven on conveyors of various uses and standards, so that the cost required for the drive control device 15 can be greatly reduced. Further, by using the inverter 16 as the power supply changing means, the rotational speed of the induction motor 12 can be controlled by changing the frequency of the drive current, and the rotational speed of the conveyor body 13 can be freely adjusted. Further, by using the microcomputer 22 as the power supply control means, the drive control device 15 including the inverter 16 can be configured in a compact manner. In the embodiment, the power supply condition can be set or changed using the personal computer 39 instead of the external input 37. This is convenient because power supply conditions can be easily set and changed at a location away from the work site where the chip conveyor 10 is installed.

Next, a first modification of the present embodiment will be described.
As modification 1, as shown in FIGS. 2 and 5, a plurality of induction motors 12 </ b> B to 12 </ b> X, conveyor bodies 13 </ b> B to 13 </ b> X, and drive control devices 15 </ b> B to 15 </ b> X having the same or different standards for one conveyor are used. This PC can be connected in parallel to the CN 6 of each of the drive control devices 15A to 15X, with the conveyor as an extension unit, and a single personal computer 39 as a common power supply condition setting / changing means. As a result, data such as power supply conditions can be collectively input to each of the drive control devices 15A to 15X by a single personal computer 39. As a result, for a plurality of conveyors of different types and functions installed in a wide factory, power supply conditions and the like can be set and changed by a single personal computer 39. Conveyor management effort is greatly reduced.

Next, a second modification of the present embodiment will be described.
As a second modification, as shown in FIG. 6, a current limiting relay (SSR) 51 is used in place of an inverter as a power supply changing means. The current limiting relay 51 is connected to the microcomputer 22 through the connector CN8 on the output side of the output circuit 28 without using the high-speed communication circuit 25. Thereby, the change control of the electric power feeding to the induction motor 12 can be performed similarly to the first embodiment. However, in the case of the current limiting relay 51, since the speed change control cannot be performed like the inverter 16, the normal rotation, stop, and reverse operation of the conveyor body 13 cannot be smoothly switched. A magnet switch MG can be used in place of the current limiting relay 51.

Next, Example 2 will be described with reference to FIG.
In the second embodiment, the load 53 is a combination of the induction motor 12 and the conveyor body 13, and a temperature detector 54 for detecting the surface temperature is attached to the case of the induction motor 12. The temperature detector 54 is connected to the connector CN2 in parallel with the current detector 17, and is connected to the microcomputer 22 through the integration circuit 25. In the second embodiment, in addition to the setting of the parameter that is a condition for supplying power to the induction motor 12 by the external input 37, the drive current of the induction motor 12 becomes excessive, and the motor 12 when the current approaches the limit current value is used. A predetermined limit surface temperature value is input as the surface temperature of the case, and is stored in the RAM which is a storage unit of the microcomputer 22. The other configuration is the same as the configuration shown in FIG. 2 of the first embodiment, and a description thereof will be omitted.

  In the second embodiment, when the conveyor body 13 starts to rotate as the induction motor 12 rotates forward, the detection value from the temperature detector 54 and the detection value from the current detector 17 are input to the microcomputer 22. The When a load is applied to the conveyor main body 13 due to clogging during chip conveyance by the rotation of the conveyor main body 13, the torque of the induction motor 12 increases, the drive current increases, and the surface temperature of the case also increases. . When the detected value of the drive current reaches the limit current value or the detected surface temperature of the case reaches the limit surface temperature, the power supply from the inverter 16 is stopped under the control of the microcomputer 22 accordingly. . As a result, the rotation of the induction motor 12 is stopped, and the rotation of the conveyor body 13 driven by the induction motor 12 is stopped. Thereafter, as in the first embodiment, based on the control of the microcomputer 22, the induction motor 12 is reversed for a predetermined time, and then stopped and returned to normal rotation.

  As described above, in the second embodiment, as a condition for stopping the induction motor 12 when an excessive load is applied to the conveyor body 13, in addition to detecting that the drive current has reached the limit current value, the temperature Since the limit surface temperature by the detector 54 can be referred to, the stop control of the induction motor 12 can be more reliably performed, and further safe driving of the induction motor 12 is ensured. In the second embodiment, the inverter 16 is used. However, instead of this, a current limiting relay SSR or a magnet switch MG can be used. In this case, as in the second modification, the high-speed communication circuit is used. It is necessary to connect from the output side of the output circuit 28 without using 25.

  In addition, in the structure of the said Example 2, it can be set as the heating furnace provided with the heater, the heating apparatus, etc. as the load 53 instead of an induction motor and a conveyor main body. In this case, the upper limit value and the lower limit value of the current for driving the heater are set by the external input 37, and the upper limit temperature and the lower limit temperature of the heater are set. Thereby, the temperature control of the heater can be performed by the heater current and the heater temperature, and efficient driving is possible while preventing the heater from being overheated. In particular, it is convenient because a large number of heaters having different heating conditions can be collectively managed by a microcomputer.

  In each of the above embodiments, forward rotation / stop / reverse drive is performed as power feeding control of the induction motor. However, it is possible to omit the reverse drive and perform only normal rotation and stop. Moreover, in the said Example, although the example applied to the chip conveyor which conveys a chip as a conveyor was shown, this invention is applicable not only to this but to the conveyor which conveys various things. For example, when a load is transported by a conveyor at an airport or the like, and the conveyor is clogged with a load, the conveyor is automatically stopped by catching the load. be able to. In this case, it is not necessary to reverse the conveyor body. Further, when the escalator becomes excessive and the driving current of the induction motor exceeds the limit value, the movement of the escalator is automatically stopped to ensure the safety of the operation. In addition, what was shown in each said Example is an example, It is also possible to implement in various changes in the range which does not deviate from the meaning of this invention.

  In the present invention, when an excessive load is applied to the conveyor body, as a condition for stopping the induction motor that drives the conveyor body, the limiting current value of the induction motor is adjusted when the maximum torque is generated. While making the best use of it, it is possible to appropriately avoid problems such as reduced durability and burnout of induction motors, and to drive conveyors efficiently and inexpensively. Adopting an inverter and microcomputer, power supply conditions By using a manual switch input or a personal computer for setting or changing the drive control device, it is useful because the drive control device can be easily mounted and used on conveyors of various applications and standards.

It is a block diagram which shows schematic structure of the chip conveyor which is Example 1 of this invention. It is a circuit diagram which shows the drive control apparatus of a chip conveyor in detail. It is a circuit diagram which shows the display part of a drive control apparatus in detail. It is a model diagram which shows the setting switch etc. of a control block. It is a circuit diagram which shows the drive control apparatus of the chip conveyor which is the modification 1 in detail. It is a block diagram which shows the structure of the chip conveyor which is Example 2. FIG. It is a graph which shows the relationship between the rotational speed of an induction motor, a torque, and a drive current. It is a circuit diagram which shows the drive control apparatus of the chip conveyor which is Example 2 in detail.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Chip conveyor, 11 ... Power supply, 12 ... Induction motor, 13 ... Conveyor body, 15 ... Drive control apparatus, 16 ... Inverter, 17 ... Current detector, 21 ... Control part, 22 ... Microcomputer, 31 ... Display part, 37 ... External input, 39 ... PC.

Claims (8)

By driving the conveyor body with an induction motor, a drive control device for the conveyor that controls the power supply state to the induction motor in the conveyor that conveys the object supplied to the conveyor body,
By changing the power supply state from the power source to the induction motor, the power supply changing means capable of switching the induction motor to one of the normal rotation, stop, and reverse drive states;
Current detection means for detecting the drive current of the induction motor;
Input means for inputting power supply conditions such as a limit current value that is a drive current value at the time of maximum torque generation of the induction motor;
Storage means for storing power supply conditions input by the input means;
Current value determination means for reading the drive current value detected by the current detection means and comparing it with the limit current value stored in the storage means, and determining whether the drive current value is equal to or greater than the limit current value; ,
And a power supply control means for stopping the induction motor by changing the power supply state of the power supply change means in response to a determination result that the current value determination means determines that the current value is greater than or equal to the limit current value. Drive control device.   The power supply control means, after stopping the induction motor by the power supply state change control of the power supply change means, further reverses the induction motor for a predetermined time, and then stops and returns to normal rotation again. The drive control apparatus of the conveyor of Claim 1 characterized by the above-mentioned. Providing a temperature detecting means for detecting the surface temperature of the induction motor, inputting a value of a limit surface temperature of the induction motor by the input means, and storing it in the storage means;
Surface temperature determination means for reading the temperature detection value detected by the temperature detection means and comparing it with the limit surface temperature stored in the storage means, and determining whether the temperature detection value is equal to or higher than the limit surface temperature. Provided,
The power supply control means has received a determination result that is earlier than the determination result that is greater than or equal to the limit current value from the current value determination means and the determination result that is greater than or equal to the limit surface temperature from the surface temperature determination means. The conveyor drive control device according to claim 1, wherein the induction motor is stopped by a change control of a power supply state of the power supply change unit.   The conveyor drive control device according to any one of claims 1 to 3, wherein the power supply changing means is an inverter.   5. The conveyor drive control device according to claim 1, wherein the power supply control unit, the current value determination unit, and the storage unit are configured by a microcomputer. 6.   6. The conveyor drive control device according to claim 1, wherein the input means is a manual switch input.   The conveyor control device according to any one of claims 1 to 5, wherein the input means is a personal computer.   8. The conveyor drive control device according to claim 7, wherein the personal computer can be used as a common input means and can be input to storage means of a plurality of conveyor drive devices.

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