JPH04303717A - Belt scale - Google Patents

Abstract

PURPOSE:To improve the accuracy of the instantaneous conveyance amount of a belt scale. CONSTITUTION:The outputs of a weight measuring part 3 during one rotation of a belt 2 are sampled at a specified interval corresponding to the rotating speed of a belt conveyer. The result is especially stored in a zero-point register 8. A selector 9 gives the instruction for reading applicable zero-point correcting values Zo-Zn to the zero-point register 8 in response to the rotating position of the belt 2. These parts are provided. The measured weight value from the weight measuring part 3 is corrected by the zero-point correcting value which is read with the zero-point register 8 from time to time in response to the rotating position of the belt conveyer, and the very accurate instantaneous amount of conveyance is obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt scale for determining the amount transported by a belt conveyor.

0002

2. Description of the Related Art A belt scale is constructed as shown in FIG. A weighing section 3 is provided on the outgoing path of the belt conveyor 1 that transports the conveyed items, and the weighing section 3 supports the rotating belt 2 from below and measures the load acting on the working length.
The indicator 4 receives pulses P from a pulse generator 5 that generates pulses P in synchronization with the rotation of the belt 2 as rotational speed information, and receives occasional weight values A from the weighing section 3 as load factor information. Calculating the cumulative weight of transported items.

Since the weighing section 3 measures the weight via the belt 2, the zero point fluctuates due to variations in the thickness of the belt 2 in the circumferential direction. Points are corrected.

The output of the weighing section 3 when the belt conveyor is operated in a no-load condition with no conveyed material placed on the belt 2 is as follows:
For example, as shown in FIG. 4, the zero point fluctuates due to variations in the thickness of the belt 2 in the circumferential direction. Therefore, the indicator 4 integrates the weight values during the period in which the belt 2 rotates an integral number of times, and calculates the average value Z of the integrated values.
During operation with a conveyed object placed on the belt 2, the value obtained by constantly subtracting the average value Z from the occasionally measured weight value A of the weighing section 3 is processed using rotational speed information to obtain the cumulative weight value of the transported object. is being calculated.

[0005]

[Problem to be Solved by the Invention] As described above, since the zero point is corrected using a constant average value Z regardless of the rotational position of the belt 2, the instantaneous accuracy of the cumulative weight value of the conveyed object is currently poor. It is.

SUMMARY OF THE INVENTION An object of the present invention is to provide a belt scale that can improve the accuracy of the instantaneous transport amount of conveyed objects compared to conventional belt scales.

[0007]

[Means for Solving the Problems] The belt scale of the present invention measures the load acting on the belt of a belt conveyor in a weighing section, and processes the weight value of the weighing section using information on the rotational speed of the belt conveyor. In the belt scale for determining the amount transported by the belt conveyor, a zero point register that samples and specifically stores the output of the weighing section during one revolution of the belt at predetermined intervals according to the rotation speed of the belt conveyor; The present invention is characterized in that a selector is provided for instructing reading of the zero point correction value corresponding to the zero point register in accordance with the rotational position of the belt.

[0008]

[Operation] According to this configuration, the zero point correction value corresponding to each rotational position of the belt is written in the zero point register, and the zero point correction value read from the zero point register according to the rotational position of the belt conveyor is written. Since the cumulative weight value of the transported object is calculated while correcting the weight value measured by the weighing section from time to time, the accuracy of the calculated instantaneous transport amount is improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. It should be noted that the same reference numerals are given to the parts having the same functions as in FIG. 3 showing the conventional example.

A sensor 7 is provided near the belt 2 of the belt conveyor to detect marks made on the belt 2, specifically protrusions 6, and the sensor 7 detects when the belt 2 has made one rotation. . The indicator 4 has a zero point register 8.
and a selector 9 are provided.

During operation, the belt conveyor is operated under no load. In this state, the zero point register 8 is set to the write state. When the sensor 7 detects the protrusion 6, the selector 9 is reset by the reset signal R, and the selector 9 selects the first slot 8 of the zero point register 8.
The current weighing value Zo (see FIG. 2) of the weighing section 3 is written in o. Every time a specified number of pulses P from the pulse generator 5 are counted, the selector 9 sequentially transfers the current weight values Z1, Z2, . . . , Zn to the second slots 81, . . . of the zero point register 8. ..., write to the n-th slot 8n.

[0012] When transporting an object, the zero point register 8 is set to the read state. When the sensor 7 detects the protrusion 6, the selector 9 reads out the content Zo of the first slot 8o of the zero point register 8 and supplies it to the subtracter 10 as a subtracted number. The subtractor 10 is supplied with the measured values of the weighing section 3 as the subtracted number. Every time the selector 9 counts a specified number of pulses P from the pulse generator 5,
In order, the second slot 8o of the zero point register 8,...
, the n-th slot 8n is instructed to read, and the subtracter 10
The subtraction number is switched to Z1, Z2, . . . , Zn.

In this way, the output Aou of the subtracter 10
At time t, a zero point correction value corresponding to the occasional rotational position of the belt 2 is read out from the zero point register 8 to generate a weight value that has been accurately zeroed, and this is displayed as an instantaneous transport amount, for example.

Further, the weight value of the output Aout is processed using speed information determined by the number of pulses P generated in the output of the pulse generator 5 per unit time to calculate the transport amount, and this is integrated.

In the above embodiment, data at one point of the belt 2 is written in the zero point register 8, but data at each rotational position during an integral number of rotations of the belt 2 is collected for each rotational position. By writing the average value of the data collected for each rotational position into the slot of the zero point register 8, the accuracy of the instantaneous transport amount is further improved.

[0016]

As described above, according to the present invention, the load acting on the belt of the belt conveyor is measured by the weighing section, and the weight value of the weighing section is processed using information about the rotational speed of the belt conveyor. A belt scale for determining the amount transported by a belt conveyor includes a zero point register that samples and stores the output of the weighing section during one revolution of the belt at predetermined intervals according to the rotation speed of the belt conveyor; and a selector that instructs the zero point register to read out the corresponding zero point correction value according to the rotational position of the zero point register.
If the zero point correction value corresponding to each rotational position of the belt is written in the zero point register, the weight value of the weighing section can be calculated from time to time using the zero point correction value read from the zero point register according to the rotational position of the belt conveyor. can be corrected to obtain an extremely accurate instantaneous transport amount.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a belt scale of the present invention.

FIG. 2 is an explanatory diagram of zero point correction values at each rotational position of the belt of the same apparatus.

FIG. 3 is a configuration diagram of a belt scale.

FIG. 4 is an explanatory diagram of zero point correction values in a conventional belt scale.

[Explanation of symbols]

1 Belt conveyor 2 Belt 3. Weighing section 4 Indicator 5 Pulse generator 8 Zero point register 9 Selector 10 Subtractor

Claims (1)

[Claims] 1. A belt that measures the load acting on the belt of a belt conveyor with a weighing section, processes the weighed value of the weighing section with information on the rotational speed of the belt conveyor, and calculates the amount transported by the belt conveyor. On the scale, the belt is 1
A zero point register that samples and stores the output of the weighing section during rotation at predetermined intervals according to the rotational speed of the belt conveyor, and a zero point correction that corresponds to the zero point register according to the rotational position of the belt. A belt scale equipped with a selector that instructs reading of values.