JPH03291532A - Weight selecting device - Google Patents

Abstract

PURPOSE:To set measurement timing corresponding to an article to be tested by carrying the article to be tested in prior to selective conveyance and calculating its carry-in time and carry-out time. CONSTITUTION:When a setting mode is indicated to the weight selecting device 10, a weighing conveyor 4 is driven at a specific speed and a carry-in sensor 13 decides the start of the carrying-in operation of the article to be tested and a sampling means 14 receives the carrying-in start signal and closes a sampling switch 15 for a specific time after specific measurement timing and a zero correcting means 12 stores a memory circuit 16 with a weighing signal after the weight of the conveyor 4 itself is subtracted for correction. Then a selection decision part 18 calculates the mean value of weighing data stored in the circuit 16 by a mean arithmetic means 19, makes dynamic corrections by a correcting means 20 so that the mean value becomes equal to the stationary weight of the article, and compares the correction output with previously set upper and lower limit values by a comparing means 21 to output the comparison result as a decision signal to a selecting conveyor 2. Simultaneously, a measurement timing determining means 17 calculates the measurement start timing and measurement end timing from the detected carrying-in time and carrying-out time.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application Field of the Present Invention The present invention relates to a weight sorting device that weighs articles during transportation and performs sorting judgment on the articles.

Conventional technology> On the production line, the weight of the product is measured while it is being transported on the line, and
In order to sort out defective products, a weight sorting device @3 shown in Fig. 5 is installed. In FIG. 5, the weight Φ of the article W carried from the carry-in conveyor 1 to the weighing conveyor 4 of the weight sorting circuit 3 is measured by a weighing device 5, and the weighing signal is inputted to the sorting determination section 6.

As shown in FIG. 6, the sorting determination unit 6 receives a weighing signal that rises as the article is carried in, calculates the weight of the article based on the stable weighing signal when a predetermined timing TS has elapsed since the article has been carried in, and performs sorting based on the weight. A determination is made and the determination result is output to the sorting conveyor 2. The sorting conveyor 2 sorts and conveys the articles from the weighing conveyor 4 to a conveying route according to the determination result.

Note that this measurement timing varies depending on the length and weight of the articles or the conveyor speed, so the articles to be sorted are carried into the weighing conveyor 4 in advance, and the weighing signals from the weighing device 5 are recorded on an external recording device 7 such as an XY plotter. A measurement timing that is considered to be stable is determined from the recorded signal waveform diagram and set in the selection determination section 6.

<Problems to be Solved> However, in order to set the measurement timing, connecting the external recording device 7 as described above and finding the measurement timing from the recorded waveform diagram takes a lot of time. It becomes necessary. Particularly on lines where product types are frequently changed, wasted time due to this setting work will have a large negative impact on production efficiency.

The present invention has solved this problem II! The purpose is to provide a sorting device.

<ii! Means for Solving the Problem〉 Weighing signal storage means for storing weighing signals from a measuring instrument for test articles that are carried onto a conveyor on a trial basis, and a time taken from the start of carrying the test articles to the conveyor until the completion of carrying them. transport time detection means for detecting the transport time from the start of transport of the test article to the transport conveyor to the completion of transport from the weighing data stored in the weighing signal storage means, the detected transport time and and measurement timing calculation means for calculating measurement timing based on the transport time.

Therefore, the weighing signal corresponding to the test article carried in on a trial basis prior to sorting and conveyance is stored in the weighing signal storage means, the carry-in time and the conveyance time are calculated, and the measurement timing corresponding to this article is calculated. Ru.

Examples of the present invention> An embodiment of the present invention will be described below based on one drawing.

FIG. 1 is a block diagram showing the configuration of a weight sorting device 10 according to an embodiment.

In FIG. 1, 11 is an A/D converter for digitally converting a weighing signal, and 12 is a zero correction means for subtracting and correcting the weight of the weighing conveyor 4 itself from the weighing signal.

Reference numeral 13 denotes a carry-in sensor that detects the start of carrying the first item into the weighing conveyor 4, and is composed of, for example, a pair of light emitters and receivers.

Reference numeral 14 denotes a sampling means that receives a signal from the carry-in sensor 13 indicating the start of carry-in, closes the sampling switch 15 for a predetermined time after a predetermined measurement timing, and stores the weighing signal from the zero correction means 12 in the memory circuit 16.

Measurement timings (measurement start timing and measurement end timing) determined by the measurement timing determining means 17 in the setting mode are set in advance in the sampling means 14.

Reference numeral 18 denotes a sorting/determination section, which includes an average calculation means 19 that calculates the average value of the weighing data during the measurement timing stored in the memory circuit 16, and a dynamic correction unit that corrects this average value to be equal to the static weight of the article. It is comprised of means 20 and comparison means 21 which compares this correction output with upper and lower limit values preset in upper and lower limit setting means 22 and outputs the comparison result to the sorting conveyor 2 as a determination signal.

Next, the operation of this weight sorting trick If10 will be explained based on the flowchart of FIG.

When the setting mode is instructed to the weight sorting device 10, the weighing conveyor 4 is driven at a predetermined conveyance speed, and an instruction is given to carry in the first item (step 1.2).

Here, the test article (static weight W
s) When it is determined by the detection signal of the carry-in sensor 13, the timer is started, the sampling switch 15 is closed, and the weighing data is sequentially stored in the memory circuit 16 as shown in FIG. 3-5).

This weighing signal is stored until the timer reaches a predetermined time T11 (slightly longer than the longest time until the carried-in article is completely discharged from the weighing conveyor 4), but during this time, the carried-in article is completely discharged from the weighing conveyor 4. The carry-in time Ta is stored (steps 6 to 8).

When a predetermined time TII has elapsed from the start of carrying in the goods, the weighing data that is equal to or closest to the initial value WO of the weighing data stored in the memory circuit 16 is found from among the weighing data stored near the end of carrying out, and The time, that is, the transport time Tz during which the article is on the weighing conveyor 4 is calculated (step 9).

Next, the sum of a predetermined delay time α determined by the article length, conveyor length, and conveyor speed is determined as the measurement start timing TS from the start of carrying in the article, and from the time when carrying out the article is completed, this 13 The timing that goes backward by the time is determined as the measurement end timing Te (
Step 10.11).

Next, among the measurement data stored in the memory circuit 16,
The average value Wa of the weighing data stored during the measurement timing (TS, Te) is calculated, and if this average value Wa is not within the allowable weight range determined for the stationary IWS, proceed to step 2. Returning, a carry-in instruction is given for the article, and if it is within the allowable range, a correction coefficient for dynamic correction is calculated (steps 12 to 14).

Note that the correction coefficient of this dynamic correction is
The calculation structure is such that the corrected weight approaches the static weight little by little every 111 feeds, and if the corrected weight Wh matches the static weight after performing the above process several times, then the The measurement timing (TS, Te) when TS becomes maximum among the articles carried in is finally fixed in the sampling means 14, and the optimal measurement timing for this article is determined (step 15, 16).

In this way, after setting the correction coefficient for dynamic correction and the measurement timing (TS, Te>) in the sampling means 14, when the selection mode is designated, the process is performed as shown in the flowchart of FIG. Weighing conveyor 4 is driven at a predetermined speed. Carrying-in sensor 1
When the arrival of the first item is detected by the detection signal from 3, a timer is started, and when this time reaches TS, the sampling switch 15 is closed and the weighing data is stored (steps 1 to 5).

When the timer reaches Te, the average value Wa of the weighing data sampled between TS and Te is calculated, and the dynamically corrected correction type IWh is subjected to selection judgment against the upper and lower limit values as the weight value of the initial item, and its The judgment result is output to the sorting conveyor 2, and the process returns to step 2 (step 6 to
9).

Upon receiving the determination signal, the sorting conveyor 2 selectively conveys the articles to a conveyance route according to the determination result.

Thereafter, each time an article is carried into the weighing conveyor 4, the same sorting determination process as described above is performed, and the article is sorted.

Other embodiments of the present invention> In the above embodiments, the measurement timing <Ts, Te
) was carried out at a timing when the articles were almost at the center of the weighing conveyor 4, but this was due to the fact that the interval between the articles carried in was larger than the length of the conveyor, or the length of the articles was longer than the length of the conveyor. In other words, the timing is such that measurement is possible even under unfavorable conditions where the period during which the weighing signal is stable is extremely short, and if selection under such conditions is not necessary, weighing The measurement timing may be set at a timing when the signal is more stable (when the article is closer to the sorting conveyor 2 than the center).

In the above embodiment, the correction coefficient for dynamic correction was set during the measurement timing setting, but this does not limit the present invention, and these settings may be made separately. Good too.

Furthermore, in the embodiment described above, the average value was calculated after storing the sampled metric data in the memory circuit 16 in the sorting mode, but the average value is calculated by sequentially integrating the sampled metric data. It's okay.

In addition, in the embodiment described in IIfJ, the time Ta of the article is detected by the signal from the carry-in sensor 13 using a light emitter/receiver etc. arranged on the carry-in side of the Mtl conveyor 4, but the memory circuit 16 The delivery time may be determined from the stored weighing data.

Effects of the Present Invention> As described above, the weight sorting device of the present invention transports and weighs the test article, stores the weighing signal, and determines the measurement timing based on the transport time and loading time calculated from the weighing data. Since it is configured to calculate and set the measurement timing suitable for the article, it is possible to set the measurement timing suitable for the article in a short time without using an external recording device and by simply transporting the article for a test.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a flowchart showing the processing procedure of the embodiment, and FIG.
The figure is a diagram for explaining the measurement timing determination procedure of one embodiment, and FIG. 4 is a flowchart showing another processing procedure of one embodiment. FIG. 5 is a block diagram showing the configuration of a conventional device, and FIG. 6 is a waveform diagram showing an example of a measurement signal. 4...Weighing conveyor, 5...Measuring device,
10... Weight sorting device, 11... A/
D converter, 12...Zero correction means, 13...
... Carrying-in sensor, 14... Sampling means, 15... Sampling switch, 16...
. . . Memory circuit, 17 . . . Timing determining means, 18 . . . Selection determination unit.

Claims (1)

[Scope of Claims] A measuring device is provided that outputs a weighing signal corresponding to the weight of the article carried into the conveyor, and a measuring signal from the measuring device is provided at a measurement timing when a predetermined period of time has elapsed from the start of carrying the article into the conveyor. In a weight sorting device that determines the weight value of an article based on a weighing signal and performs a sorting judgment on the article based on the weight value, a weighing signal from the scale for the test article carried onto the conveyor on a trial basis is stored. carrying-in time detecting means for detecting the carrying-in time from the start of carrying the test article to the conveyor until the completion of carrying the test article to the carrying conveyor; transport time detection means for detecting transport time from the start of transport of the test article to the completion of transport; and measurement timing calculation means for calculating the measurement timing based on the detected transport time and transport time, A weight sorting device that measures the weight of articles at different measurement timings.