JPS584772B2 - Butsupin Hansou Souchiniokel Zero Tenchi Yousei Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention extracts the instantaneous weight applied within a certain section of an article conveying device (for example, a belt conveyor) with an electrical generator of a size proportional to the weight, and digitally converts the voltage. At the same time, the amount of movement of the transport device is extracted as a pulse per unit length proportional to the travel distance, and after multiplying the two pick-up signals, the results are integrated to calculate the total weight of the transported article. The present invention relates to a device for adjusting the error weight to zero when there is no conveyed article on the belt in an article transporting device designed to determine the weight.

In general, an instantaneous weight measuring device for an article conveying device called a belt scale presses a load detection port roller provided on the device against the conveying belt, and measures the load applied to the roller using a differential transformer or a strain gauge type. Since the configuration is such that the load voltage is extracted through a load-voltage converter such as a load cell, even when there is no transported article on the conveyor belt, the weight of the belt itself and When the weight of the attached object attached to the belt is added, the load converter constantly outputs a voltage signal with a certain value proportional to the weight, and this value is integrated in the integrator.

By the way, this integrated value is an error weight that is added to the net weight of the object to be measured, so in order to remove these error weights, the integrated value of the integrator is It is necessary to perform zero adjustment in advance so that the value is zero.

From the above, in the present invention, the belt of the conveying device is rotated an integer number of times in an idle state, and the weight that is the error output by the integer number of rotations is memorized, and the stored value is used as an error correction value during the weighing operation. The present invention aims to provide a highly accurate conveying device that does not include weight errors.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and operation of an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In the figure, 1 is a load converter that generates a voltage signal Δe of a magnitude proportional to the instantaneous weight of the article being carried by the conveyor, and this converter 1 has a load detection port that comes into pressure contact with the conveyor belt. It consists of a weighing machine equipped with a weighing rod, a differential transformer that converts the displacement of the load into an electrical signal, and a load-to-voltage converter such as a strain gauge type rotocell.

2 is a pulse transmitting device that transmits a pulse signal PL per unit length proportional to the conveying distance of the conveying device, for example,
This is a pulse generator that has a foil that is pressed into contact with a conveyor belt and driven in contact with it.

Therefore, the voltage signal Δe output from the load converter 1
is the following adder circuit 3 and analog/disicle converter 4
(hereinafter referred to as an A-D converter), the digital signal PW
is converted into , and inputted to the multiplication device 5, where the multiplication PWxPL (that is, instantaneous weight signal The total weight is then input to the totalizer 6, and the total weight corresponding to the conveyed amount is determined.

In the configuration and operation described above, except for the adder circuit 3, this is a commonly used and well-known belt scale.

Next, we will explain each block related to zero point adjustment, which is the object of the present invention, added to the above configuration. 8 is a counter that counts the number of pulses transmitted from the pulse transmitter 1.

Further, this counter 8 has a configuration in which the set value is preset by setting a certain value to the setting device 9.
When the count value reaches this set value, a signal P1 for a constant count value is input to the next control circuit 12.

Further, in this control circuit 12, when the signal P1 is inputted, the arithmetic unit 7 performs an operation of dividing the result integrated in the arithmetic unit 7 by the number of pulses counted by the counter 8, and the result is , is stored in the next storage circuit 10 using the control signal P3 from the control circuit 12.

The stored result is further converted into an analog signal △E through the next digital-to-analog converter 11, and then input to the adder circuit 3, which outputs the output signal △e from the load converter 2.
addition is performed.

That is, in this adder circuit 3, if the output polarity from the digital-to-analog converter 11 is positive, a negative value whose polarity is inverted is added, and conversely, if the output polarity is negative, a positive value is added. The output from the load converter 2 is corrected for tilting on the plus side or the minus side, and the state of the correction is integrated in the integrating device 6, resulting in highly accurate measurement that does not include errors. will be carried out.

As described above, in the present invention, the conveying device is rotated an integer number of times when it is empty, and the integral value of the voltage signal Δe outputted for the integer number of rotations is added to the adding circuit 3 with the polarity reversed, and the load is Since it is configured to subtract the error from the content from converter 1,
There are excellent effects in that errors can be corrected very well, net weight can be easily measured, and high accuracy can be measured.

[Brief explanation of drawings]

FIG. 1 is a control block diagram showing the configuration of the present invention. 1...Pulse transmitter, 2...Load converter, 3...Addition circuit, 4...A-D
Converter, 5... Multiplication device, 6... Integration device, 7... Arithmetic device, 8... Counter, 9... Setting device, 10... memory circuit, 11... D-A converter, 12...
control circuit.

Claims (1)

[Claims] 1 A load converter that generates a load voltage signal with a magnitude proportional to the instantaneous weight of the article being transported by the conveyance device, and an analog converter that converts the load voltage signal into a digital signal.
A digital converter and a pulse transmitting device that transmits a pulse signal per unit length proportional to the conveying distance of the conveying device are provided, and the instantaneous weight value and unit time each output from the transmitting device and the load converter are In an article conveyance device equipped with a multiplier that multiplies the hit pulse and an integrator that calculates the total conveyed weight by accumulating the output of the multiplier, the empty space when no article is placed on the conveyance device. A digital calculation device that integrates the output of the analog-to-digital converter for operation and a counter that counts the number of pulses sent from the pulse generator are installed, and the count value of the counter reaches a certain value. Then, the arithmetic unit is provided with a division function for stopping the integration and dividing the result of the integration by the number of pulses of the counting, a memory circuit for storing the division result, and converting the digital value stored in the memory circuit into an analog value. Digital to convert
An analog converter, and an adder circuit that adds the analog output of the digital/analog converter and the output of the load converter are configured to control input switching to the arithmetic unit, storage circuit, and digital/analog converter. 1. A zero point adjustment device for an article conveying device, characterized in that it is configured with a control device that performs the following functions.