JPH10122940A - Multiple balance device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To weigh various kinds of luggage of different lengths using the same device and to enhance the measuring efficiency in terms of time. SOLUTION: Two conveyor balances 11, 12 having load cells or the like and differing in length are arranged in series along a conveyor line, and an input conveyor 13 and an output conveyor 14 are placed, respectively, upstream and downstream of the conveyor balances 11, 12. Photoswitches 15, 16, 17 for detecting the presence of luggage A are provided in front of and behind the conveyor balance 11. Further, the output values of the conveyor balances 11, 12 and the outputs of the photoswitches 15, 16, 17 are connected to a computation means, where the output of the conveyor balances 11, 12 are combined in accordance with a measurement sequence, so that medium-length luggage A is weighed by only the upstream conveyor balance 11 and short luggage A is weighed by only the downstream short conveyor balance 12, while for long luggage A the total of the weights measured by the upstream and downstream conveyor balances 11, 12 is used as its weight measurement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple weighing apparatus for individually weighing different loads that are successively conveyed.

[0002]

2. Description of the Related Art In a situation where a large number of loads having various lengths are successively conveyed on a conveyor line in a state close to a presser, individual loads are accurately weighed without stopping. Is extremely difficult.

One countermeasure is to use a conveyor weigher capable of high-speed response and weigh the baggage in progress one by one quickly. This is a general technical requirement commonly required for high-speed automatic weighing. Therefore, detailed description is omitted.

A conventional example using a conveyor scale having a single measuring range will be described with numerical examples for easy understanding. FIG. 4 is an explanatory diagram in the case where relatively long packages are weighed using the conventional apparatus. It is assumed that the luggage A sent for weighing is conveyed via a carry-in conveyor 1 onto a conveyor weigher 2 having a length L = 80 cm, for example, and discharged from a discharge conveyor 3. After the photo switch 4 for position detection provided at the front end of the conveyor scale 2 shifts from light shielding to light transmission, an effective minimum distance S of, for example, 10 cm suitable for weight detection is measured during traveling. However, when the baggage length X is 70 cm or more, there is a high possibility that the tip of the baggage A will be erroneously weighed by the conveyor scale 2 on the discharge conveyor 3, so that a baggage of 70 cm or more cannot be measured correctly. .

FIG. 5 shows an example in which relatively short packages are weighed by the conventional apparatus, and is conceptually similar to the case of FIG. However, during the weighing operation, the preceding luggage A ′ needs to be completely separated from the conveyor scale 2, and for this purpose, the photo switch 5 provided at the rear end of the conveyor scale 2 is blocked by the preceding luggage A ′. The weighed value after the transition from to the light transmission must be adopted as the measured value. If the distance G between the loads is 35 cm, the load length X is less than 20 cm, and if the distance G is 25 cm, there is a possibility that two loads having the load length X less than 40 cm are simultaneously weighed on the same conveyor scale 2. Is large and correct measurement cannot be expected.

In this case, the size of the maximum length Xmax of the load A that can be measured by the conveyor scale 2 will be examined. In FIG. 4, a condition for preventing the preceding or succeeding package A 'or package A "from being incorrectly weighed together with the package A on the same conveyor scale 2, that is, a condition" package interval G≥minimum transport distance S required for weight detection ". Below, while the tip of the luggage A is passing through a traveling portion of, for example, S = 10 cm indicated by a bold line effective for measurement,
Assuming that the weighing value is obtained from the conveyor weigher 2, as can be understood from FIG.
Is given by the following equation. Xmax = LS (1)

In this case, the distance G between the packages is G
Since any size may be used as long as the condition of ≧ S is satisfied,
The maximum length Xmax of the load is the actual length L of the conveyor scale 2
And only the distance S, for example, the maximum length Xmax = 80 cm
It is determined that −10 cm = 70 cm.

Next, when the minimum length Xmin of the load that can be measured is obtained, as shown in FIG. 5, it is greatly affected by the distance G between the loads, and expressed by the following equation (2). Xmin = L + S-2G (2)

For example, the distance G before and after the load A is 35
cm, the length L = 80 cm, and the distance S = 10 cm, the minimum length Xmin is 20 cm according to the equation (2).

[0010] As described above, the minimum length Xmin of the weighable baggage A is greatly influenced by the interval G. When the interval G is large, short and small packages can be weighed, but wasteful time increases in measurement. The temporal measurement efficiency decreases, and the number of measurements per unit time hardly increases. If the distance G before and after the baggage A is not equal, the smaller distance G is used.
Applies to equation (2).

Equations (1) and (2) show the length L, distance S, and distance G.
By substituting the example of the real number, the measurable area relating to the baggage length X and the interval G can be illustrated. FIG. 6 shows that the length L of the conveyor scale 2 is 80 cm, the measured traveling distance S is 10 cm, and the distance G is
Is given in the range of 10 cm or more, the area of the weighable baggage length X is shown by hatching in relation to the interval G.

For example, when the interval G is regulated to 25 cm, the baggage length X that can be correctly measured is 40 cm of the straight line a.
~ 70cm, 70cm or more, of course, 40
Even small packages less than a centimeter cannot be weighed correctly. Regarding how to select the interval G when the luggage length X is determined, for example, in order to correctly measure the luggage A with the luggage length X = 25 cm, the interval G is set to 32.5 cm with reference to the straight line b. It is understood that the regulation must be performed so as to fall within the above range.

The actual number of the parameters of the apparatus may be slightly changed according to the actual situation.
When the distance S, the interval G, the baggage length X, and the like are simultaneously changed proportionally, the size of the model size changes, but the basic characteristics do not change.

[0014]

The performance of a high-speed weighing machine or a sorter is generally expressed by the number of measurement processes per unit time. Therefore, in the following description in this specification, the evaluation will be made with emphasis on the measurable number per unit time as the evaluation criterion of the high speed.

Specifically, as the transport speed is increased, or the pitch D of the load (center-to-center distance or load length X + interval G)
The more you pack, the more your ability increases. The automatic weighing technology required for increasing the transport speed is included in the general technical conditions and will not be particularly discussed here. The explanation focuses on the problem.

Conveyor scale 2 using the same numerical example as in FIGS. 4 and 5 has a transfer speed of 100 c within a weighable range.
Calculating the weighing capacity in the case of m / sec gives the following table. In this table, the reciprocal of the capacity corresponds to the pitch P (cm) at the time of transportation, and the pitch P is the sum of the load length X (cm) and the interval G (cm). The capacity (pieces / second) does not double, but increases at most by about 30%.

Luggage length X Minimum gap G Minimum pitch P Maximum capacity 10 40 50 2.00 20 35 55 1.82 30 30 60 1.67 40 26 65 1.54 50 20 70 1.43 60 15 76 1.33 70 10 80 1.25

As is clear from this table, in the conventional non-stop weighing device using one conveyor scale 2, when the transport interval G of the load A is selected to be small in order to increase the weighing capacity, the weighing is performed. The baggage length X to be obtained is set only in a relatively large range, and there is a possibility that two small baggage A can be simultaneously placed on the conveyor scale 2, so that correct weighing cannot be performed. On the other hand, luggage length X
If the distance G is selected to be large in order to enable the measurement of short and small packages A having a small size, there is a contradiction that a decrease in the weighing capacity cannot be avoided.

An object of the present invention is to improve the above-mentioned problems of the conventional apparatus using a single balance, to measure various types of packages, both long and short, using the same apparatus, and to improve the time measurement efficiency. It is an object of the present invention to provide a novel multiple weighing device capable of preventing a decrease in weighing capacity.

[0020]

In order to achieve the above object, a multiple weighing apparatus according to the present invention is an apparatus for individually weighing loads of luggage conveyed one after another. Are arranged in series and adjacent to each other, and an arithmetic means for adding the outputs of these load measuring means by an arbitrary combination is provided.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. In the embodiment, FIG.
As shown in FIG. 2, two conveyor scales 11 and 12 each having a load cell or the like for load measurement and a transport roller or the like as transport means and having different lengths are arranged in series and adjacently along the conveyor line. , The upstream and downstream sides of these conveyor scales 11 and 12
3 and a discharge conveyor 14 are arranged. Photo switches 15 and 16 for detecting the presence or absence of baggage A and obtaining a measurement timing are provided at the front of the conveyor scale 11 on the upstream side, at the boundary between the conveyor scales 11 and 12, and at the rear of the conveyor scale 12, respectively. , 17 are provided. Further, the output values of the conveyor scales 11, 12 and the photo switches 15, 1
The outputs of 6 and 17 are connected to arithmetic means (not shown). In this arithmetic means, based on the measurement sequence, the outputs of the conveyor scales 11 and 12 are combined to obtain the weight value of one package A. I have.

Based on the approximate combination of the baggage length X and interval G, that is, the output of the photo switches 15, 16, and 17, the arithmetic means automatically selects an appropriate measurement sequence.
Each package A to be measured is efficiently weighed by any one of the methods (a) to (c).

(A) The intermediate-length luggage A is weighed by the conveyor weigher 11 on the upstream side. (b) The short package A is weighed by the short conveyor scale 12 on the downstream side. (c) For the long baggage A, the sum of the weights of the upstream conveyor weigher 11 and the downstream conveyor weigher 12 is used as the measurement value.

In order to facilitate understanding of the operation, for example, the length L1 of the conveyor scale 11 is set to 80 cm as in the conventional apparatus.
It is assumed that the length L2 of the conveyor weigher 12 is half that of 40 cm. FIG. 1 is an explanatory view assuming a case of weighing a package A in a medium-sized cardboard box, which is often used in practical use. As shown, the length L1 of the upstream conveyor scale 11 is 80 cm.
If the distance G is regulated to 30 cm or more, the luggage of 30 cm to 70 cm can be weighed by the upstream conveyor weigher 11 without using the downstream conveyor weigher 12 for weighing purposes.

In this case, the timing of taking out the weighing signal may be a measurement sequence based on various algorithms. After the rear end of the package A crosses the photo switch 15 and shifts from light-shielding to light-transmitting, the effective distance S = 10c.
It is a principle to maintain m.

FIG. 2 shows a case where a short package A is weighed.
If the gap G is secured to a predetermined size, even if two packages are simultaneously loaded on the conveyor scale 11, only a single package A is loaded on the conveyor scale 12, and the package length X is 30.
The weight of the baggage A of not more than 1 cm can be accurately measured by the conveyor scale 12.

FIG. 3 shows a case where a long baggage A is measured. A baggage A having a baggage length X of 70 cm to 110 cm can be measured by using the sum of the output values of the conveyor scales 11 and 12 as a weight value. it can.

Which conveyor scale is used to measure a specific load A depends on the algorithm.
17 and the maintenance time of the weighing signal, etc. If the interval G is secured to a predetermined size, the packages A having different package lengths X are mixedly loaded on the conveyor line. However, it is needless to say that the weight of each load A can be measured without any problem.

Further, in this embodiment, by changing the algorithm, that is, the measurement sequence, the weighing of the package A is not necessarily limited to the above (a) to (c). Long baggage A is a conveyor scale 11
Not only can the measurement be carried on both the conveyor scales 11 and 12, and the short luggage A can be measured by the conveyor scale 1
The measurement can be performed in a state of being placed on only one or both of the conveyor scales 11 and 12. In this way, the measured values can be averaged, and the shorter the baggage, the greater the number of times of weighing and the more accurate the measured values.

In the embodiment, two conveyor weighers having different lengths are used. However, although the range that can support the baggage length X is small even if the conveyor scales of the same length are used,
It is clear that the processing capacity is improved as compared with the conventional example.

Alternatively, more conveyor scales can be used. For example, if three conveyor scales having different lengths of 50 cm, 40 cm, and 30 cm are arranged in this order, the combination of the lengths of the conveyor scales is as follows. 30cm, 40cm, 50cm, 70cm, 9
It becomes 0 cm and 120 cm, and the space G between the packages can be further reduced and transported. Of course, in this case, the number of photo switches also needs to be increased to, for example, four.

When two conveyor weighers are arranged, either the long or short conveyor weigher may be arranged on the upstream side. However, if all three conveyor weighers have different lengths, the length may be increased toward the upstream or downstream side. By arranging in order, the combination of the conveyor lengths becomes more uniform. When the number is four or more, how to arrange them may be appropriately considered in consideration of the length of the conveyor scale.

Also, the judgment of which conveyor weigher output is to be used is not limited to the use of a photo switch, but an ultrasonic switch, a proximity switch, a mechanical switch, a television camera, or the like may be used as other baggage detecting means. Can also be used. Also, if the speed information of the conveyor is obtained using a rotary encoder or the like, the number of the above-mentioned baggage detecting means can be reduced. Furthermore, without using the above-described baggage detecting means, if the conveyor speed is taken into consideration, or if a known baggage length is available, a measurement sequence is created by an algorithm based on the change in the output of the conveyor scale, and the individual baggage is created. It is also possible to weigh.

Incidentally, the load measuring means is not limited to the conveyor scale as in the embodiment, but may be one in which load measuring means is added to a transport roller.

[0035]

As described above, in the multiple weighing apparatus according to the present invention, a plurality of load measuring means are arranged in series and adjacent to each other, and a weight detected by a single or a plurality of load measuring means is determined in advance. Based on the appropriate measurement sequence thus determined, the weight of individual packages can be determined. As a result, as compared with the case where weighing is performed using only a single balance, not only can the range of the length of individual packages that can be measured be expanded, but also the intervals can be shortened to increase the number of weighed items per unit time.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment.

FIG. 2 is an explanatory diagram when weighing short packages.

FIG. 3 is an explanatory diagram when weighing long packages.

FIG. 4 is an explanatory view of a conventional example in which relatively long packages are weighed.

FIG. 5 is an explanatory diagram of a conventional example when weighing relatively short and small packages.

FIG. 6 is an explanatory diagram illustrating a measurable area with respect to a luggage length and an interval.

[Explanation of symbols]

 11, 12 Conveyor scale 13 Carry in conveyor 14 Carry out conveyor 15, 16, 17 Photo switch

Claims (7)

[Claims] 1. An apparatus for individually weighing loads of luggage conveyed one after another, in which a plurality of load measuring means having a conveying means are arranged in series and adjacent to each other, and the output of each of these load measuring means is arbitrarily set. A multi-scale weighing apparatus comprising a calculating means for adding by a combination of the following. 2. The apparatus according to claim 1, wherein said calculating means selects said load measuring means to be used by said load detecting means, and obtains the weight of said load in combination with an output of said load measuring means. Continuous weighing device. 3. The load calculating means selects the load measuring means to be used by the load detecting means and the speed detecting means, and obtains the weight of the load in combination with the output of the load measuring means. 5. The multiple weighing device according to 4. 4. The multiple weighing apparatus according to claim 2, wherein said baggage detecting means is a photo switch. 5. The multiple weighing apparatus according to claim 1, wherein said load measuring means has a length along a conveying direction. 6. The multiple weighing apparatus according to claim 5, wherein the load measuring means has different lengths along the transport direction. 7. The multiple weighing apparatus according to claim 6, wherein said load measuring means are arranged in order of length.