Roller conveyor device, controller, and mechanical device abnormality detection method

Patent metadata

Field	Value
Publication number	US-9926140-B2
Application number	US-201414786409-A
Country	US
Kind code	B2
Filing date	Apr 30, 2014
Priority date	Apr 30, 2013
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

There is provided a roller conveyor that has a function capable of specifying a failure part or a defective part. When a signal for executing a failure detection operation is transmitted from a host controller ( 50 ) to each zone controller ( 10 ), each zone controller ( 10 ) immediately activates the corresponding motor-incorporating roller ( 5 a ). Then, after a certain time, the motor-incorporating roller ( 5 a ) is stopped. A pulse interval thereafter is detected by a pulse interval monitoring program ( 36 ) to determine whether a delay phenomenon has occurred. The delay phenomenon is a phenomenon in which the pulse signal generation interval is temporarily extended.

First claim

The invention claimed is:

1. A roller conveyor comprising:
a frame;
a plurality of rollers attached to the frame, at least one of the rollers being a motor-incorporating roller including therein a roller body and a motor that causes the roller body to rotate;
a pulse signal generation unit that generates a pulse signal in accordance with rotation of a rotor of the motor-incorporating roller; and
a failure detection function that detects abnormality of the roller conveyor,
the failure detection function detecting a pulse signal interval when the rotation of the motor-incorporating roller is caused to be stopped by a signal from a controller and detecting occurrence of a delay phenomenon in which a maximum pulse signal interval becomes at least a predetermined interval before the motor-incorporating roller comes to stop.

2. The roller conveyor as defined in claim 1 ,
wherein the roller conveyer monitors the pulse signal interval until the number of the generated pulse signal interval reaches the number smaller than the number of the pulse interval generated before the pulse signal stops by a predetermined number to determine whether the delay phenomenon has occurred during the monitored period.

3. The roller conveyor as defined in claim 1 ,
wherein the roller conveyer monitors the pulse signal interval until the number of the generated pulse signal intervals reaches a certain number after energization to the motor-incorporating roller is stopped to determine whether the delay phenomenon has occurred during the monitored period.

4. The roller conveyor as defined in claim 1 , further comprising a characteristic phenomenon detection function of detecting occurrence of a characteristic phenomenon in which the pulse signal temporarily extends the interval and then shortens the interval, and then comes to stop of generation.

5. The roller conveyor as defined in claim 1 ,
wherein the roller conveyor is divided into a plurality of control zones,
one or a plurality of the motor-incorporating rollers are provided in each of the control zones, and
the roller conveyor comprises a controller for controlling the motor-incorporating rollers of each of the control zones or a plurality of the control zones.

6. The roller conveyor as defined in claim 1 , further comprising a plurality of controllers and a host controller for the controllers,
wherein information about the pulse signal interval is transmitted from each of the controllers to the host controller in accordance with an instruction of the host controller.

7. The roller conveyor as defined in claim 5 ,
wherein the controller includes:
an interval detection unit that detects the pulse signal interval; and
a selection unit that selects the maximum one of the pulse intervals detected by the interval detection unit, and
wherein information about the maximum interval is transmitted to a host controller to determine whether the delay phenomenon has occurred in the host controller.

8. The roller conveyor as defined in claim 1 , further comprising an alarm unit that notifies generation of looseness in attachment of the motor-incorporating roller to the frame on the condition that the delay phenomenon has occurred.

9. The roller conveyor as defined in claim 8 ,
wherein an alarm content of the alarm unit changes depending on the degree of the delay phenomenon.

10. The roller conveyor as defined in claim 1 ,
wherein the failure detection function detects a switching interval from a rise or a fall of any pulse signal to a rise or a fall of another pulse signal as the pulse signal interval to detect occurrence of the delay phenomenon in which the pulse signal switching interval becomes a certain interval or more before the motor-incorporating roller comes to stop.

11. The roller conveyor as defined in claim 1 ,
wherein whether the delay phenomenon has occurred is determined by comparing any pulse signal interval nw with an immediately preceding pulse signal interval mw and by determining whether a difference between the pulse signal interval nw and the immediately preceding pulse signal interval mw is equal to or more than a threshold TS, and
when the motor-incorporating roller is rotated on the condition that there is no looseness in attachment of the motor-incorporating roller and a pulse signal interval immediately before power supply to the motor-incorporating roller is stopped is defined as a reference interval ts, the threshold TS is three to ten times the reference interval ts.

12. The roller conveyor as defined in claim 1 ,
wherein whether the delay phenomenon has occurred is determined by comparing any pulse signal interval nw with an immediately preceding pulse signal interval mw and by determining whether a difference between the pulse signal interval nw and the immediately preceding pulse signal interval mw is a predetermined ratio or more on the basis of the immediately preceding pulse signal interval mw or the specific pulse signal interval nw.

13. The roller conveyor as defined in claim 1 ,
wherein the rotor of the motor-incorporating roller has a permanent magnet and a plurality of poles,
wherein the roller conveyor comprises:
a plurality of signal generation units that detects approach/departure of the poles to generate a signal, several of the signal generation units simultaneously generating signals when the motor rotates; and
a pulse generation circuit that generates a pulse corresponding to each of the signal generation units in accordance with a signal corresponding to each of the signal generation units, and
wherein the roller conveyor detects the pulse signal interval without distinguishing which of the signal generation units generates the pulse signal interval.

14. A controller for controlling a motor-incorporating roller having a roller body and a brushless motor therein, the brushless motor including a signal generation unit that generates a signal in accordance with a rotation position of a rotor so as for the controller to switch current to be supplied to a stator of the brushless motor in accordance with the signal,
the controller comprising;
a pulse generation circuit that generates a pulse in accordance with a signal generated by the signal generation unit;
an interval detection unit that detects an interval of pulse signals generated by the pulse generation circuit;
a selection unit that selects a maximum one of the pulse intervals detected by the interval detection unit; and
a transmission unit that transmits information about the selected maximum interval to the outside that can be processed to identify an abnormality of a function of the motor-incorporating roller.

15. A method for detecting abnormality of a function of a machine,
the machine using a motor-incorporating roller including a roller body and a motor therein, the motor-incorporating roller rotating the roller body by rotation of the motor,
the method comprising:
generating a pulse signal in accordance with rotation of the motor in the motor-incorporating roller;
detecting a pulse signal interval when rotation of the motor-incorporating roller is caused to be stopped by a signal from a controller; and
determining abnormality of a function of the machine on the condition that the pulse signal interval reaches at least a predetermined maximum interval before the motor-incorporating roller comes to stop.

16. The method as defined in claim 15 ,
wherein the method monitors the pulse signal interval until the number of the generated pulse signal interval reaches the number smaller than the number of the pulse interval generated

Assignees

• Itoh Denki Co Ltd

Inventors

• Itoh Kazuo
• Tachibana Toshiyuki
• Nagai Yoshinori
• SAYAMA Shinji

Classifications

• H02P6/12

  Monitoring commutation; Providing indication of commutation failure · CPC title

• G01D5/145

  influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06) · CPC title

• G01M99/00

  Subject matter not provided for in other groups of this subclass · CPC title

• B65G23/08 Primary

  with self-contained driving mechanisms, e.g. motors and associated gearing · CPC title

• B65G43/00

  Control devices, e.g. for safety, warning or fault-correcting · CPC title