JPH0618318A - Weight measuring apparatus - Google Patents

Abstract

PURPOSE:To improve the measuring efficiency of a measuring apparatus. CONSTITUTION:Weight sensor 20(1,1)-20(4,4) are arranged in four columns and four rows on the transfer surface of a weighing conveyor. Weight signals of there weight sensors are input to a synthesizing/processing part 28 via a multiplexer 26 and an A/D converter 27 of a weight synthesizing device 25. The synthesizing/processing part 28 detects the load range of articles carried onto the weighing converyor for every article, and obtain the sum of the weight signals from the weight sensors in the load range every time the load range is moved, therby calculating the weight of each article.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weighing device for weighing the weight of articles.

[0002]

2. Description of the Related Art For example, a conveyor type weighing apparatus shown in FIG. 14 has been conventionally used for weighing articles during transportation. This weighing device is configured to detect the weight of the article W carried on the weighing conveyor 2 from the pre-stage conveyor 1 by the weighing machine 3 while the article W is transported on the weighing conveyor 2.

[0003]

However, in such a weighing device, if the loading of the next article is started before the weighing of the previous article is completed, accurate weighing cannot be performed. The article must be carried from the pre-stage conveyor 1 to the weighing conveyor 2 at an interval equal to or longer than the time obtained by dividing the sum of the length Lc of the weighing conveyor 2 and the article length Lw by the transport speed V, and the weighing device has a large capacity. It was restricted.

Further, not only with such a conveyor type weighing device, but also with a weighing device for manually placing an object to be weighed on a weighing table to obtain the weight, while weighing one item, the next item Weighing must be awaited, and it took a lot of labor and time to weigh many articles continuously. Therefore, it has been strongly desired to realize a weighing device having higher capacity.

An object of the present invention is to provide a weighing device that solves this problem.

[0006]

In order to solve the above-mentioned problems, the weighing device of the present invention is arranged at a predetermined pitch on a weighing surface for weighing an object to be weighed, and the object to be weighed on the weighing surface is arranged. A plurality of weight sensors each outputting a weight signal corresponding to the load, based on the weight signals from the plurality of weight sensors, within a weighing region formed by the plurality of weight sensors,
Load area detection means for detecting a load area formed by a weight sensor that simultaneously receives the load of one object to be weighed, and a weight sensor within the load area detected by the load area detection means. And a weight calculation means for calculating the sum of the weight signals for each load region to obtain the weight of each object to be weighed.

[0007]

With the above construction, in the weighing apparatus of the present invention, when one article to be weighed is loaded on the plurality of weight sensors, the load formed by the weight sensor receiving the weight of the articles to be weighed at the same time. The area is detected for each object to be weighed,
The weight of each weighing object is detected from the sum of the weight signals of the weight sensors included in the load area.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a weighing conveyor 10 of one embodiment, and FIG. 2 is a sectional view taken along the line AA of FIG.

In this weighing conveyor 10, a driving roller 14 and a driven roller 15 are supported in front of and behind side plates 12 and 13 provided upright on both sides of a base 11, and a conveyor belt 16 is stretched between both rollers. ing.

A sensor support plate 17 is horizontally arranged between the driving roller 14 and the driven roller 15.

Both ends of the sensor support plate 17 have side plates 12 and 13.
16 weight sensors 20 (1,1) to 20 (4,4) are arranged in 4 rows and 4 columns on the upper surface 17a thereof.

Each of the weight sensors 20 (1,1) to 20 (4,
The mechanical structure 4) has a supporting portion 20 formed in a concave shape when viewed from the side, as shown in FIG. 3 as one of them 20 (i, j).
a and a deformable portion 20b supported on both ends of the supporting portion 20a.
And a T-shaped load portion 20b for applying a force that pushes down the center of the deformable portion 20b.

On both upper and lower surfaces of the deformable portion 20b,
Resistor elements Ra to Rd whose resistance values change according to the degree of deformation of the deformable portion 20b are attached.

As shown in FIG. 4, each of the resistance elements Ra to Rd has a series circuit of Ra and Rc and a series circuit of Rd and Rb connected in parallel to a power supply line, and an intermediate voltage V between Ra and Rc.
_The differential amplifier 2 calculates the voltage difference between the intermediate voltage V ₂ between ₁ and Rd and Rb.
It is detected in 1.

The output of the differential amplifier 21 is adjusted in advance so as to be zero when there is no load on the weight section 20c.

When a load is applied to the load portion 20c from above and the center of the deformable portion 20b is pushed downward, the resistance values of the resistance elements Ra and Rb change in the same direction, for example, in the increasing direction, and Rc and Rd are opposite. Changes to decrease.

Therefore, one of the intermediate voltages V ₁ drops,
The other intermediate voltage V ₂ rises, the voltage difference increases, and a differential output corresponding to the weight is output from the differential amplifier 21.

The conveyor belt 16 forming the measuring surface of this measuring device is made of an extremely lightweight material, and
As shown in FIG. 2, in the state where the article is not loaded,
The back surface 16a of the conveyor belt 16 and the load portion 2 of each weight sensor
The tension and the like are set in advance so that a slight gap is generated between the upper surface of the transport belt 0c and the upper surface of the transport belt 16 and all the load is transmitted to the weight sensor side when there is an article on the transport surface 16b of the transport belt 16.

The drive motor 2 is attached to one side plate 13.
3 is attached, and the drive roller 14 transmits the rotational force of the drive motor 23 to the conveyor belt 16 by the drive belt 24 that is stretched between the drive roller 14 and the drive motor 23.

Each of the weight sensors 20 (1,1) to 20 (4,
The weight signal (4) (differential output signal) is output to the weight synthesizer 25 as shown in FIG.

The weight synthesizer 25 includes a multiplexer 26 for selecting a weight signal, an A / D converter 27 for converting the weight signal from the multiplexer 26 into a digital signal,
It is composed of a synthesizing unit 28 for synthesizing the digital signals from the A / D converter 27 and detecting the weight of the articles carried into the weighing conveyor 10.

The synthesizing processing unit 28 detects a load area formed by a weight sensor that simultaneously receives the load of the articles completely carried on the weighing conveyor, and a load area detection processing section 28a for detecting the load area for each article. The weight calculation processing section 28b for calculating the total weight signal of the weight sensor in the applied load region and calculating the weight of the article.

6 and 7 are flow charts showing the processing procedure of the synthesizing processing unit 28.

The operation of one embodiment will be described below with reference to this flowchart.

The synthesizing processing unit 28 is a first processing unit for handling the case where an article longer than the length L of the load portion 20c of each weight sensor in the conveying direction and longer than 3L is carried in at an interval of L or more.
It has a second processing routine.

That is, in the first processing routine shown in FIG. 6, after the variable i is initialized to "1", the four weight sensors 20 (i, 1) to 20 (i, 4) in the i-th column are initialized. At least one weight signal among the weight signals reaches a predetermined level Wo higher than the noise level, and Ts time has elapsed,
The weight outputs of all the weight sensors from the first column to the i-th column are checked (steps 1 to 3).

For example, as shown in FIG. 8A, the tip of an article Wa having a length of 2 L or less has the weight sensor 2 in the first row.
0 (1, 2), 20 (1, 3) is carried in, and after the weight signal exceeds a predetermined level Wo as shown in FIG. The weight signals of all the weight sensors 20 (1,1) to 20 (1,4) in the first row are checked immediately before the signal reaches the weight sensor in the second row.

Next, it is judged whether or not the rear end of the article Wa has passed over the weight sensor in the first row, and if it has not passed, the value of i is increased by "1" and the process proceeds to step 2. The operation of returning is repeated (steps 4 to 5).

In the state of i = 2, as shown in FIG.
The tip of a has the weight sensors 20 (2, 2), 20 in the second row.
After being loaded onto (2, 3) and Ts has passed, 2
All weight sensors 20 (1,1) to 2 in the first and second rows
Weight signals of 0 (1,4), 20 (2,1) to 20 (2,4) are checked.

In this state, the weight sensor 20 in the first row is
Since the weight values of (1,2) and 20 (1,3) are sufficiently large with respect to zero, the trailing edge is not detected, and the value of i becomes “3” as it is.

With i = 3, as shown in FIG. 10, the tip of Wa of the article is the weight sensor 20 (3, 2) in the third row,
When the Ts time has passed after being loaded onto 20 (3,3),
All weight sensors 20 (1, 3) from the third row to the first row
The weight signals 1) to 20 (3,4) are checked.

At this time, the weight sensor 20 (1,
Since the outputs of 1) to 20 (1,4) are zero, the article W
It is detected that the rear end of a is in the second row. That is, the first carried-in article W by the processing of steps 1 to 5
It is detected that the load area of a is in the range of the third row and the second row.

When the rear end row i _e is detected, the second processing routine is started in preparation for the next carried-in article, and
The weight calculation process after step 6 is started. That is, i
The total sum S of the weight signals from the column to the column i _e (= 2) is calculated and the value is stored (steps 6 and 7).

This value S is determined by the four weight sensors 20 (2,
2), 20 (2,3), 20 (3,2), 20 (3,
3) corresponds to the weight value of the article Wa subjected to the distributed load.

Next, if the values of i and i _e are incremented by "1" and i has not reached "5", as in step 2, one of the weight signals in the i-th column sets W ₀ . Wait until you come (steps 8-10).

In the state of i = 4, as shown in FIG. 11, the tip of the article Wa has the weight sensors 20 (4, 2), 20.
When Ts elapses after reaching (4, 3), all the weight signals from the i (= 4) th column to the i _e (= 3) th column are added in the same manner as above, and the value S is stored, and the step S is stored. Return to 8 (step 11).

Here, i = 5, and the average value of S is the article W.
The weight value of a is output, and the weighing process of this article Wa is completed (step 12).

On the other hand, as shown in FIG. 11, the process for the next article Wb carried in at intervals of one row or more for the weight sensor is performed by the second process routine in exactly the same manner as the first process routine. Done. This second processing routine uses the variable k instead of the variable i, and executes the first after the detection of the trailing edge sequence.
Since the processing routine is completely the same as the first processing routine except that the processing routine is started, the description thereof will be omitted.

In this way, the articles sequentially carried into the weighing conveyor 10 at intervals of L or more are weighed and carried out.

Although 16 weight sensors are arranged in 4 rows and 4 columns in this embodiment, the present invention is not limited to this embodiment.
The arrangement of the weight sensor is arbitrary, including 1 row N columns and N rows 1 column. Further, in this embodiment, each time the load region moves with the movement of the article, the sum of the weight signals is obtained, and the weight of the article is detected by the average value of the sums.
The weight may be detected by the first total sum without performing the average value calculation.

Further, in this embodiment, the case where the load area of the article is detected by detecting the leading end row and the trailing end row of the articles carried in at intervals of L in the carrying direction has been described. As described above, the two articles W are loaded side by side with a space of L or more along the direction orthogonal to the transport direction.
It is also possible to measure c and Wd.

In this case, the load area for each article may be detected by measuring the leading edge row, trailing edge row and non-loaded row of each article, and the weighing may be performed.

Further, in the above-mentioned embodiment, the sum of the weight signals of all the weight sensors in the load area is obtained. However, since the weight sensors in the first and fourth rows do not receive the load of the article, these The weight signal of the row weight sensor may be omitted.

Further, in the above embodiment, the case where the article is loaded on one surface with respect to the weighing surface and the weight sensors which simultaneously receive the load of the article are adjacent to each other have been described. For example, as shown in FIG. In the case of weighing the articles We loaded on the weighing surface with two (or more) surfaces separated by L or more, even if the weight value of the next row of the tip row is zero in advance, If the non-load sequence is not determined, the same processing as described above can be performed.

In the above embodiment, the weighing conveyor 10 is used.
Multiple weight sensors were arranged on the lower surface of the conveyor belt to detect the weight of the articles conveyed on the conveyor belt, but it is possible to slide on the plurality of weight sensors by inertia when carrying in regardless of the conveyor belt. Alternatively, the transport mechanism may be omitted, and a manual type weighing device may be used in which a plurality of articles are simply placed at intervals of one weight sensor.

[0047]

As described above, in the weighing device of the present invention, a plurality of weight sensors are arranged on the weighing surface, and a weight sensor which simultaneously receives the load of the object to be weighed is formed based on the weight signal. The load area to be weighed is detected for each object to be weighed, and the sum of the weight signals of the weight sensors in that load area is calculated to detect the weight of each item on the weight sensor. Instead, the weight of each article can be detected simply by leaving an interval for one weight sensor, and remarkably high-speed weighing becomes possible.

Further, the weight of each article placed at an arbitrary position in an arbitrary order at intervals of one weight sensor,
Since it can be weighed independently, it has the effect that it can be used for various purposes such as store scales.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a side view showing a main part of one embodiment.

FIG. 4 is a circuit diagram of a main part of one embodiment.

FIG. 5 is a block diagram showing a configuration of a main part of one embodiment.

FIG. 6 is a flowchart illustrating an example of a processing procedure of a main part of the embodiment.

FIG. 7 is a flowchart illustrating an example of a processing procedure of a main part of the embodiment.

FIG. 8 is a schematic plan view for explaining the operation of the embodiment.

FIG. 9 is a schematic plan view for explaining the operation of the embodiment.

FIG. 10 is a schematic plan view for explaining the operation of the embodiment.

FIG. 11 is a schematic plan view for explaining the operation of the embodiment.

FIG. 12 is a schematic plan view for explaining another embodiment of the present invention.

FIG. 13 is a schematic side view for explaining another embodiment of the present invention.

FIG. 14 is a schematic side view showing a configuration of a conventional device.

[Explanation of symbols]

 10 Weighing Conveyor 11 Base 12, 13 Side Plate 14 Drive Roller 15 Driven Roller 16 Conveyor Belt 20 (1,1) to 20 (4,4) Weight Sensor 20a Support 20b Deformation 20c Load 25 Weight Synthesizer 26 Multiplexer 27 A / D converter 28 Synthesis processing unit 28a Load area detection unit 28b Weight calculation unit

Claims (1)

[Claims] 1. A plurality of weight sensors, which are arranged at a predetermined pitch on a weighing surface for weighing an object to be weighed and which output a weight signal corresponding to the load of the object to be weighed on the weighing surface, respectively. Based on the weight signal from the weight sensor, the load region formed by the weight sensor receiving the load of one weighing object at the same time within the weighing region formed by the plurality of weight sensors is defined as each weighing object unit. And the weight region detection means for detecting the total of the weight signals of the weight sensors in the load region detected by the load region detection means are calculated for each load region to obtain the weight of each object to be weighed. And a weighing device having means.