JP2007192603A - Method and device for detecting level difference of conveyer table - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for detecting level difference of a pass line automatically in real time. <P>SOLUTION: The level difference of the pass line is detected, based on the load current of electric motor of each roller at the time of transferring a carrying matters, wherein the transfer tables are constituted of roller groups individually having driving electric motors. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a transport table for detecting a difference in roller level of a transport table of a system composed of a plurality of rollers and driving each roller by an electric motor installed in one to one on each roller. The present invention relates to a level difference detection method and apparatus.

  Conventionally, roller tables have been widely used in industry for conveying articles such as steel plates. In this transport roller table, it is required to form a flat pass line by matching the horizontal levels of the rollers.

  The difference in the level of the transport table pass line is caused by the trouble that the motor torque is not transmitted to the transported object, which increases the load on other motors, and in some cases the transport becomes impossible due to insufficient torque, or the transported object meanders. It is because it becomes the cause of.

  However, each roller constituting the roller table inevitably undergoes a difference in horizontal level between the rollers as a result of surface wear due to repeated use. Therefore, using the factory's regular maintenance date, etc., periodically measure the roller diameter or pass line level to check the level difference of the pass line, and if there is a level difference, replace the roller. We perform measures such as doing.

  Various techniques for detecting the horizontal level of a roller in a roller table have been proposed so far. For example, Patent Literature 1 discloses a technique referred to as “a roller level measurement method and apparatus for a roller table”. In this technique, a carriage having a sliding surface with a length extending over at least three rollers is placed on a roller table, and a measurement reference plane parallel to the sliding surface is provided above the sliding surface of the carriage. , And measure the shortest distance from the measurement reference plane to the roller peripheral surface under the carriage for all the rollers located under the carriage, and measure the inclination angle of the carriage sliding surface with respect to the horizontal plane. Based on this, the relative horizontal level difference of the roller peripheral surface in the roller group under the carriage is calculated.

Patent Document 2 discloses a technique called a “roller table pass line measurement system”. This technology includes a roller position detection unit that detects the position of the roller, a plurality of non-contact distance meters, an inclinometer that measures the inclination of the apparatus body, an inclination correction unit that calculates the relative height of the roller, and a roller The present invention relates to a pass line measuring apparatus capable of moving on a roller table having height correction means for calculating the height correction data.
JP-A-10-132551 JP-A-9-210672

  However, in the techniques described in Patent Document 1 and Patent Document 2, a specific device such as a carriage having a sliding surface extending over the roller at the bottom or a path line measuring device that can move on the roller table must be provided. In addition, there is a problem that the measurement needs to be performed at a timing when the conveyed object is not on the roller table, and the measurement cannot always be performed.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a level difference detection method and apparatus for a transport table that automatically and in real time detects a level difference of a pass line.

  The invention according to claim 1 of the present invention is the level difference detection method for a transport table constituted by a group of rollers each having a drive motor, and the load on the motor of each roller when transporting a transported object. A level difference detection method for a transport table, wherein a level difference of a pass line is detected based on a current value.

  The invention according to claim 2 of the present invention is the transfer table level difference detection method according to claim 1, wherein the load current value is zero or a no-load current value. A level difference detection method for a transfer table, characterized in that it is determined that there is a level difference in the pass line when the load current value of the electric motor located at 0 exceeds zero or a no-load current value.

  According to a third aspect of the present invention, there is provided a level difference detection device for a transport table configured by a group of rollers each having a driving motor, and a current detector that detects a load current of the motor. A level difference detection device for a transport table, comprising: a comparator that collects load current values and compares and calculates the current values.

  Further, the invention according to claim 4 of the present invention is the level difference detection device for a transfer table according to claim 3, wherein the comparator has a load current value of zero or a no-load current value of the motor. A level difference detection device for a transfer table, characterized in that when a load current value of a motor located before and after the motor exceeds zero or a no-load current value, it is determined that there is a level difference in a pass line. is there.

  Since the present invention detects the motor load current of each roller at the time of conveyance and compares it with the motor load current of other rollers, it detects the level difference of the pass line caused by roller wear or the like. It is possible to detect the level difference of the pass line in an appropriate and real time. As a result, it is possible to eliminate the trouble that the conveyance becomes impossible due to insufficient motor torque and the trouble that the conveyed object meanders.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 4 is a flowchart showing an example of the processing procedure of the present invention.

  First, load current values of the motors that drive the table rollers that are transporting the object to be conveyed among the electric motors installed on each roller of the conveying table rollers are collected by a current detector (load current). Value collection (Step01)).

  Next, it is examined whether there is any collected load current value that is zero or no load current value. As for the no-load current value, the no-load current value of each motor is measured in advance, and this value is compared with the load current value (determination 1 (Step 02)).

  When the load current value is zero or no load current value in Step 02 (in the case of Yes), the load current values of the motors before and after the corresponding motor are examined. That is, it is checked whether the front and rear motors have zero or a load current value exceeding the no-load current value (determination 2 (Step 03)).

  FIG. 1 is a diagram schematically showing a case where there is no level difference between pass lines. Since there is no level difference in the pass line, all the rollers 2 are in contact with the conveyed product 1, and at this time, the load current corresponding to the conveyance of the conveyed product 1 is uniform in each electric motor that drives each roller. Is flowing.

  On the other hand, FIG. 2 is a diagram schematically illustrating a case where a level difference occurs in the pass line. In FIG. 1 or FIG. 2, 1 is a conveyed product, 2 is a table roller, 2a is a worn table roller, 2b is a roller immediately before the worn table roller, and 2c is a roller immediately after the worn table roller. FIG. 2 shows an example in which the roller 2a is worn. When the roller diameter is reduced, only the roller is not in contact with the conveyed product 1. At this time, the load current value of the roller 2a is zero or only the no-load current value. On the other hand, naturally the load electric current according to conveyance of the conveyed product 1 flows into the electric motor of rollers other than the roller 2a which was abraded.

  If the current value of the front and rear motors is zero or exceeds the no-load current value, there is a transported object on the front and rear rollers, that is, there is naturally a transported object on the target roller located between the front and rear rollers. It is what you think. However, nonetheless, the load current of the target roller is zero or the no-load current value means that the roller and the transported object are not in contact, that is, the pass line is lowered due to wear of the roller (pass It is determined that there is a line level difference (Step 04). This determination may be made, for example, by notifying the operator like a display with a level difference (Step 05). In Step 02 or Step 03, if the determination is No, it is determined that there is no pass line level difference (Step 06).

  In this way, fluctuations in the pass line level are determined using the motor current during conveyance, so that the level difference can be detected automatically and immediately, which enables quick and appropriate countermeasures before conveyance travel occurs. Can be done.

  Examples of the present invention will be described below. FIG. 3 is a diagram showing the configuration of a system according to an embodiment of the present invention. In the figure, 1 is a conveyed product, 2 is a table roller, 3 is an electric motor, 4 is a current detector, 5 is a comparator, and 6 is a display.

  A current detector 4 for detecting the load current of each motor 3 of the table roller 2 is installed, and the current value detected by each detector is taken into the comparator 5. The comparator 5 performs processing / judgment in the processing flow of FIG.

  When the load current value of the electric motor that drives the roller 2 that is conveying the conveyed product 1 is zero or only the no-load current, the electric current value of the rollers positioned before and after the corresponding roller is compared. At that time, when the current value of the electric motors of the front and rear rollers is zero or exceeds the no-load current value, the conveyed product 1 is present on the front and rear rollers, that is, the conveyed product 1 is also present on the corresponding roller. Conceivable. However, nonetheless, if the load current of the corresponding roller is zero or no load current, it is judged that the roller and the conveyed product are not in contact, that is, the pass line is lowered due to roller wear or the like. To do.

  In this way, when it is determined that the pass line is lowered, the display 6 displays that there is a level difference and notifies the operator.

It is a figure which shows typically the case where there is no level difference in a pass line. It is a figure which shows typically the case where a level difference arises in a pass line. It is a figure which shows the structure of the system which is one Example of this invention. It is a flowchart which shows the example of a process sequence of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conveyed object 2 Table roller 2a The worn table roller 2b The roller 2c just before the worn table roller 2c The roller just after the worn table roller 3 Electric motor 4 Current detector 5 Comparator 6 Display

Claims (4)

In a level difference detection method for a transport table composed of a group of rollers having individual drive motors,
A level difference detection method for a transport table, characterized in that a level difference of a pass line is detected based on a load current value of the electric motor of each roller when a transported object is transported. In the level difference detection method of the conveyance table of Claim 1,
There is an electric motor whose load current value is zero or no load current value,
A method for detecting a level difference in a transport table, wherein when a load current value of a motor located before and after the motor exceeds zero or a no-load current value, it is determined that there is a level difference in a pass line. In a level difference detection device for a transport table composed of a group of rollers having individual drive motors,
A current detector for detecting a load current of the motor;
A level difference detection device for a transport table, comprising: a comparator that collects, compares and calculates the detected load current values. In the level difference detection apparatus of the conveyance table of Claim 3,
In the comparator, the load current value is zero or a no-load current value of the motor,
A level difference detection device for a transfer table, characterized in that when a load current value of an electric motor positioned before and after the electric motor exceeds zero or a no-load current value, it is determined that there is a level difference of a pass line.

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