JPS6123032A - Method of supplying articles to be weighed to weighing machine - Google Patents

Abstract

PURPOSE:To provide a desired weighing time and accuracy by supplying articles with a capacity ensuring feeder in the beginning of weighing, stopping said feeder before a certain time and supplying the articles only with an accuracy ensuring feeder to provide a standard for setting the capacity and controlling the running of both feeders. CONSTITUTION:On an exhaust port of a storage tank hopper 1 are provided a capacity ensuring feeder 2 and a accuracy ensuring feeder 3. The capacities (ton/ hour) of both feeders are set from the tolerance, time, etc. of weighing. Next, for a method of running suitable for the capacity and accuracy of the feeders 2, 3 are supplied articles only by the feeder 2 or by both feeders 2, 3 in the beginning of supply. Before a certain time t, the feeder 2 is stopped to supply the article only with the feeder 3 which is stopped to complete the weighing when the actually measured value of a weighing machine reaches the value of weighed value minus fall error of the feeder 3. Thus, a desired time and accuracy of weighing can be easily attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a method for feeding grain, feed, etc. into a weighing machine.

[Conventional technology and its problems]

In the recent transport industry, the era has passed when it was sufficient to transport the required amount within the required time, and accuracy in transport time and transport amount is now required.

In particular, there is a strong demand for this in the supply of objects to be weighed by weighing machines.

Therefore, in recent years, when feeding to weighing machines, feeders of different sizes are used. Initially, the large capacity feeder is used, and then only the small capacity feeder is used.
A method of supply has been adopted.

However, this method only uses large and small feeders with different capacities; there is no guideline for setting the capacity of each feeder, and the feeding time (weighing time) and weighing time are It does not optimize accuracy. That is, in order to improve accuracy, for example, the feeding time of only the small capacity feeder was simply lengthened.

[Problem that the invention attempts to solve]

This invention takes the above points into consideration and aims to provide a method for supplying objects to be weighed to a weighing machine that optimizes the supply time and satisfies accuracy.

[Means for Solving the Problems and Their Effects] In order to achieve the above-mentioned problems, in this invention, at the beginning of supply, the maximum weight is fed by a capacity guarantee feeder that can feed the maximum weight within the required time, and the feeder From a certain period of time before the feed is completed by the feeder, continuous feeding is performed only by the accuracy guarantee feeder with a capacity smaller than (weighing tolerance x number of times of measurement value conversion of the weighing machine 7 seconds), and during the above certain period of time, This setting is made so that even if the maximum head error and measurement error of the guarantee feeder occur, the measurement value will not be exceeded when the feeder stops.

That is, as shown in FIGS. 1 and 2, this invention provides two feeders 2 at the outlet of the storage tank hopper 1.
, 3, one side 2 is a capacity guarantee feeder, the other side 3
is used as a feeder for accuracy assurance. Since the former is for large-volume supply, a set of tanks as shown in Figure 2 is sufficient without taking precision into account, but as shown in the figure, the latter is preferably a screw feeder or other suitable for small-volume supply. Furthermore, the accuracy guarantee feeder 3 is provided with a damper 5 that instantly closes its discharge port using an air cylinder 4 or the like to prevent errors other than the head error that can be estimated in advance from occurring. In the figure, 6 is the screw feeder drive motor, 7
is the cylinder for driving the damper feeder.

Next, we will set the capacity of both feeders 2 and 3. First, the capacity of feeder 2 for capacity guarantee Q + r [On/hov
r) is calculated and set using the following formula (■).

Q1=T÷M×60 minutes XK1 ・・・・・・・・・・・・
・・・・・・・ ■Here, T: Maximum measurement value (ton) M: Maximum measurement time (minutes) ±S: Measurement tolerance (K9) K: The coefficient 1 is based on the measurement tolerance S. In order to increase the accuracy of the weighing error, it is necessary to reduce the capacity of the accuracy guarantee feeder 3, which increases the weighing time and makes it impossible to complete the weighing within the predetermined time. To shorten a large amount of supply time by increasing the capacity of a guarantee feeder 2.

Table 1 shows an example of the relationship between accuracy and machining. However, it is not limited to this table.

Table 1 Next, the capacity Q2(to”/
hovr) is calculated and set using the following equation (2).

G2<(S x 60 seconds x 60 minutes x K 3)/1 ooo
・・・・・・・・・■(Dividing by 1000 is to
(to make n) Ka is a value obtained by dividing the number of conversions (sampling) of the actual measurement value of the weighing machine itself by a certain number. Normally, the number of sampling times is electronic and is about 3 to 6 times per second, and if the weighing machine and feeder operate at the normal timing for each sampling, G2 < Sx (number of sampling times) x 60 seconds x 60 minutes. This is a good thing, but
Since the timing is difficult to match, it is made into a coefficient (Ka) so that it may be shifted by one time.If the number of samplings is 3 to 6, then Ka is, for example, 2 to 5.

Therefore, the capacity Q2 of the feeder 3 is set to be smaller than (metering tolerance S x number of sampling times), and desired accuracy can be obtained.

Furthermore, although this is an operating method that suits the capacity and accuracy of feeders 2 and 3, at the beginning of supply, large supply and small picture feeders 2 and 3 are operated simultaneously, and a certain supply amount switching optimum value T2 (to
At step n), only the large capacity feeder 2 is stopped, and thereafter only the small capacity feeder 3 is used to supply the object to be weighed up to the specified amount, and the process is completed. T2 is calculated and set using the following equation (2).

T2 = T (QI X (2/35QQ to a-)
, , , , , , , , , , ■ 2 is a certain period of time to stop the large capacity feeder 2 before the set required time until the end of measurement has elapsed. 1 is set so that even if the maximum head error and weighing error (occurred when the sampling timing shifts) of the capacity guarantee feeder 2 occurs, the end weighing value will not be exceeded when the feeder 2 stops ( conditions). For example, let a be 2 seconds. Here, if you try to improve the accuracy, the feeder 3 will inevitably have to reduce its capacity, and the operation time will become longer, making it impossible to clear the required time. Therefore,
As shown in Table 1, K is highly accurate (the smaller it is, the shorter the operation time of the small capacity feeder 3 is. However,
Make sure that the above conditions are met.

With this configuration, when the meter is started, it is supplied by only the capacity guarantee feeder 2 or both feeders 2 and 3,
For a certain period of time (previously, the capacity guarantee feeder 2 is stopped and only the accuracy guarantee feeder 3 is supplied, and when the actual measurement value of the weighing machine becomes the value obtained by subtracting the head error of the feeder 3 from the measured value, the accuracy guarantee feeder 2 is stopped and the accuracy guarantee feeder 3 is supplied. Stop feeder 3 and finish weighing.

Next, examples will be described.

〔Example〕

20 (weighing from 1 to 2000F for a single type (1 cumulative) 1
If the accuracy is within 17 minutes for each product type, the sampling frequency of the weighing machine shall be 4 times/second.

The feeder 2 for capacity guarantee is about 50% larger than the maximum weighing value (2000P) and feeds 3000P/min, and the feeder 3 for accuracy guarantee feeds 1009P/min. 2 seconds before the maximum weighing value supply time (40 seconds), only feeder 3 will supply.

Ql-3000y-/min-507/sec-12.59
/ 1/4 second Q2 = 1005'/minute - 1,67P/second =
0.42 g/1/4 sec i) 2000. P measurement time T2 = 2000 50 X 2 = 1900F feeder 2 operation time: 1900÷50=38f'J
Feed amount of feeder 3 up to this time 38 x 1.67 = 63.46 F) 38 after starting measurement
Since (1900+63.5)-1963,52 has been weighed in seconds, feeder 3 feeds the rest. At this time, if the head error of feeder 2 is ignored, the remaining weighing time is (2000-1963,5)/1.67-21
．． It will be 85 seconds. In reality, it stops at an amount less the head error of the feeder 3. If the head error of the feeder 2 is included, a larger amount will be supplied, and the time to complete metering will be shorter.

Therefore, the total weighing time is 38+21.85=59.8
It will be 5 seconds, which will be less than 1 minute. Here, the final weighing time (seconds)
In the above, the error is 0.42P when the timing of the operation of the feeder 3 and the timing of the actual measurement of the weighing machine is shifted by one time, and is 0.81' even if the timing is shifted by two times, and the accuracy of 1·f is guaranteed.

1i) 20oF measurement time T2 = 200 50
Supply amount: 2xt, 57-3.34 (g) Remaining weighing time: 96.66 ÷ 1.67 = 57.88 (sec) Total weighing time: 2 + 57.88 = 59.88 (sec) [
Effects] As described above, the present invention provides a guideline for capacity setting and operation control of the capacity guarantee feeder and the accuracy guarantee feeder, so that desired measurement time and measurement accuracy can be easily obtained.

[Brief explanation of drawings]

1 and 2 are schematic cutaway front views of each embodiment of the present invention. 2... Feeder for capacity guarantee, 3... Feeder for accuracy guarantee.

Claims (2)

[Claims] (1) When feeding objects to be weighed into a weighing machine using a feeder and weighing them, at the beginning of the feeding, feed the object using a feeder that guarantees the ability to feed the maximum weight value within the required time, and from a certain period of time before the feeder completes feeding. teeth,
Continuous feeding is performed only by an accuracy guarantee feeder with a capacity smaller than (weighing tolerance x number of times of measurement value conversion of the weighing machine/second), and the above-mentioned fixed time is the maximum value of the head error and weighing error of the capacity guarantee feeder. A method for supplying objects to be weighed to a weighing machine, characterized in that the feeder is set so as not to exceed a weighed value when the feeder stops even if the feeder stops. (2) As the accuracy of the above measurement tolerance increases,
The method for supplying objects to be weighed to a weighing machine according to claim 1, characterized in that the capacity of the capacity guarantee feeder is increased.