JPH07311073A - Weighing device - Google Patents

Abstract

PURPOSE:To provide a weighing device which can automatically adjust the timing for starting the processing of weighing signals when a conveyor in which a taking conveyor and a weighing conveyor are made to overlap each other is used. CONSTITUTION:A computing means 30 computes the time required for an article M to pass the overlap portion R between a weighing conveyor 12 and a taking conveyor 14, according to such parameters as conveyor velocity V, the length L of the article, and the length A of the overlap, and so the timing for starting the processing of weighing signals can be adjusted automatically through the detection of the article M by a sensor 8. A weighing signal processing circuit 38 starts processing of the weighing signals from the adjusted timing and can obtain data on the weight of the article M which show measured values.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a conveyor in which an intake conveyor and a weighing conveyor are overlapped with each other,
The present invention relates to a weighing device that weighs articles while they are being transported.

[0002]

2. Description of the Related Art Generally, when a large number of produced articles are continuously weighed, the articles are fed from the take-in conveyor to the weigh conveyor and the weigh conveyor is loaded while the articles move on the belt of the weigh conveyor. A weighing device for measuring the weight of a weight detector (load cell) to obtain the weight of an article is often used.

In this type of apparatus, vibration occurs when an article is transferred from the take-in conveyor to the weighing conveyor or the belt conveyor itself, so that the vibration load is superimposed on the weight of the article. Therefore, the weighing signal output from the weight detector is A / D converted and digitally filtered by a digital filter (low-pass filter) to remove these relatively high-frequency vibration components, so that the accurate weight of the article can be obtained. measure. In this case, the data of the weighing signal taken out from the digital filter is constantly sampled at a predetermined cycle, and is fetched as weighing data indicating an accurate weight value of the article after a predetermined timing from the start of weighing. This timing is set as follows.

FIG. 4 shows a state in which the articles M are weighed. The article M moves on the conveyor as shown by M (a) to M (c). The detection sensor 8 is arranged at the upstream end of the weighing conveyor 2. First, the article M is sent from the take-in conveyor 4 to the weighing conveyor 2 and the leading edge of the article M is detected by the detection sensor 8 (state of M (a)). After that, until the whole article is transferred to the weighing conveyor 2 (state of M (b)),
Since the article M is also on the take-in conveyor 4, it cannot be used as a weighing signal. Then, from the time when the entire article is transferred to the weighing conveyor 2 (state of M (b)) until the leading end of the article M reaches the downstream end of the weighing conveyor 2 (state of M (c)), that is, , The weighing signal while the entire article is only on the weighing conveyor 2 is adopted.

When the velocity of the measuring conveyor is V and the length of the article is L, the detection sensor 8 detects the article M (M (a)).
The measurement signal is adopted at a timing delayed by (L / V) from the state (1).

Therefore, in order to output the weighing signal of the article M by this weighing conveyor 2, if the length of the weighing conveyor 2 is X, the response time of the digital filter is F, and the sampling time of the data is S, ( X / V)-(L /
It is necessary to satisfy the conditional expression of V) ≧ (F + S).
For example, if the filtering time F is 180 msec and the sampling time S is 20 msec, 200 msec or more is required to output the weighing signal.

If the weighing conveyor speed V, the weighing conveyor length X, the article length L, and the sampling time S are set, the filtering time F is calculated using this conditional expression.
It is also possible to select a digital filter that can output the weighing signal by calculating

[0008]

However, the conventional device has the following problems. If the item to be weighed is of a type that is soft and easily sticks to the belt (for example, raw ham), the item may get caught in the transit area when moving from the intake conveyor to the weighing conveyor. Many. In order to prevent this, the intake conveyor and the weighing conveyor may be overlapped.

In this case, since the weight of the article is on the both conveyors during the time when the article passes through the overlapping portion, it cannot be used as a weighing signal, and the above conditional expression cannot be applied as it is. Further, when there are many types of articles to be weighed and the lengths of the articles are different, it is necessary to change the length of the overlapping portion according to the length of the articles.

Therefore, in the conveyor in which the take-in conveyor and the weighing conveyor are overlapped, if the kinds of articles to be weighed are different, the conveyor speed, the length of the articles, and the length of the overlapping portion are correspondingly There is a problem that it is complicated because it is necessary to design the timing for starting the processing of the weighing signal.

The present invention solves the above-mentioned problems, and when a conveyor in which a take-in conveyor and a weighing conveyor are overlapped is used, the processing start timing of the weighing signal can be automatically adjusted. Is intended to provide.

[0012]

In order to achieve the above object, a weighing device of the present invention is provided with a weighing conveyor that conveys and weighs articles, and is arranged so as to overlap with the weighing conveyor in the conveying direction and take in the articles. At least one of the following parameters: a take-in conveyor to be delivered to the weighing conveyor by means of a sensor, a detection sensor arranged at the upstream end of the weighing conveyor to detect the presence of an article moving on the weighing conveyor, a conveyor speed, an article length, and an overlap length. Input means for inputting one, storage means for storing each of the above parameters, operation means for calculating the timing at which the article passes through the overlapping portions of both conveyors and the entire article transfers to the weighing conveyor, based on each of the parameters, And weighing signal processing for starting weighing signal processing from the above timing to obtain weighing data indicating a weighing value It has a road.

[0013]

According to the present invention, the calculating means is the conveyor speed,
Based on each parameter of the article length and the overlap length, the transit time for the article to pass through the overlapping part of the weighing conveyor and the take-in conveyor is calculated, so the processing start timing of the weighing signal is automatically detected from the detection of the article by the detection sensor Can be adjusted to. The weighing signal processing circuit can start the processing of the weighing signal from the adjusted timing to obtain the weighing data of the article indicating the weighing value.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration diagram of a weighing device according to an embodiment of the present invention. This apparatus includes a weighing conveyor 12, a take-in conveyor 14, a weight detector (load cell) 16 and a detection sensor 8. In the plan view of FIG. 1A, the weighing conveyor 12 is a thin belt conveyor 12-1, 1
2-2 is an assembly, and the intake conveyor 14 is an assembly of thin belt conveyors 14-1 to 14-3. The distance between the narrow belt conveyors 12-1 and 12-2 is almost equal to the width of each of the thin belt conveyors 14-1 to 14-3, and the distance between the thin belt conveyors 14-1 to 14-3 is also small. It is almost equal to the width of the belt conveyors 12-1 and 12-2.
And the thin belt conveyors 14-1 to 14 of the intake conveyor
-3 is a thin belt conveyor 12 of the weighing conveyor in the transport direction.
-1, 12-2 and the front end portions thereof are overlapped with each other, and both conveyors 12, 14 have an overlap portion R. Detection sensor 8 such as photoelectric sensor
Is placed at the upstream end of the weighing conveyor 12 to prevent two articles M from getting on the weighing conveyor 12, and the articles M transferred from the take-in conveyor 14 onto the weighing conveyor 12.
Is detected and a detection signal D is output.

In the front view of FIG. 1 (B), the measuring conveyor 12 has a motor M with the driving roller J1 and the driven roller J2 of the thin belt conveyors 12-1 and 12-2 being common.
Each belt can be moved at the same time by driving 1. The weighing conveyor 12 is loaded on a weight detector (load cell) 16 via a frame (not shown) that supports the rollers J1 and J2, and conveys and weighs the article M. In the take-in conveyor 14, the driving rollers J3 of the thin belt conveyors 14-1 to 14-3 and the driven roller (not shown) on the upstream side are commonly used, and the belts are moved simultaneously by the driving of the motor M2. The take-in conveyor 14 takes in the article M and transfers it to the weighing conveyor 12. In this figure, the speed of the take-in conveyor 14 and the weighing conveyor 12 is V, the length of the article M is L, and the length of the overlapping portion R is A.

FIG. 2 shows the configuration of the signal processing system of the above-mentioned weighing device. This device comprises an arithmetic means 30, a memory means 32, an input means 34 such as a ten-key pad, a weighing signal processing circuit 38,
An A / D converter 40 and a digital filter 42 are provided.

The operation of this device will be described below. First,
At least one of each parameter of the conveyor speed V, the article length L, and the overlap length A is input by operating the input means 34. These input parameters V, L,
A is stored in the storage means 32.

FIG. 3 shows a state in which the articles M are weighed while moving M (1) to M (3) on the conveyor having the overlapping portion R. First, the article M is the take-in conveyor 1
4 is fed to the weighing conveyor 12 at a speed V, and the tip of the sensor is detected by the detection sensor 8 (state of M (1)).
After this, the time until the rear end of the article M passes through the overlap portion R (state of M (2)), that is, the overlap passage time T, is the state in which the article M is also on the take-in conveyor 14. Therefore, it is not adopted as a weighing signal.

2 receives the detection signal D from the detection sensor 8 of FIG. 3 based on the respective parameters V, L and A stored in the storage means 32, and the articles are transferred to both conveyors 12, The timing at which the entire article passes through the overlapping portion R of 14 and transfers to the weighing conveyor 12, that is, the overlapping passage time T is calculated.

Here, the position of the center of gravity of the article M is 1 / L of the length L.
If the position is 2, the length A of the overlapping portion R is
The overlap passage time T for the article M to pass through is T = (L + A) / V (1)

Thereafter, from the time when the entire article is transferred to the weighing conveyor 12 (in the state of M (2)) to the downstream end of the weighing conveyor 12 (in the state of M (3)), that is,
The weighing signal while the article M is only on the weighing conveyor 12 is adopted. Therefore, this weighing conveyor 12
Therefore, in order to output the weighing signal of the article M, if the response time of the digital filter is F and the sampling time of the data is S, the conditional expression of ((X / V) −T) ≧ (F + S) must be satisfied. Will be required.

On the other hand, the weighing signal measured by the weight detector 16 is A / D converted by the A / D converter 40, and the high frequency signal is removed by the digital filter 42 (filtering signal). The filtering signal is constantly sampled by the weighing signal processing circuit 38 at a predetermined cycle. Then, the article M is detected by the detection sensor 8.
After being detected, the timing is automatically delayed by the overlap passage time T calculated by the equation (1), the filtering signal is taken in by the weighing signal processing circuit 38, and the weighing data is generated to start the weighing. The weighing data of the article showing the value will be obtained.

[0023]

As described above, according to the present invention, the arithmetic means passes the articles passing through the overlapping portions of the weighing conveyor and the intake conveyor on the basis of the parameters of the conveyor speed, the article length and the overlap length. Since the time is calculated, the processing start timing of the weighing signal can be automatically adjusted from the detection of the article by the detection sensor. The weighing signal processing circuit can start the processing of the weighing signal from the adjusted timing to obtain the weighing data of the article indicating the weighing value. Accordingly, it is possible to provide the weighing device that automatically adjusts the processing start timing of the weighing signal when the conveyor in which the intake conveyor and the weighing conveyor are overlapped is used.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a weighing device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a signal processing system of the weighing device.

FIG. 3 is a diagram showing a moving state of an article.

FIG. 4 is a diagram showing a conventional weighing state of an article.

[Explanation of symbols]

8 ... Detection sensor, 12 ... Weighing conveyor, 14 ... Intake conveyor, 30 ... Calculation means, 32 ... Storage means, 34 ... Input means (numeric keypad), 38 ... Weighing signal processing circuit, M ... Article

Claims (1)

[Claims] 1. A weighing conveyor that conveys and weighs articles, a pickup conveyor that overlaps the weighing conveyor in the feeding direction, takes in articles and transfers them to the weighing conveyor, and an upstream end of the weighing conveyor A detection sensor for detecting the presence of an article transferred onto the weighing conveyor, an input means for inputting at least one of the parameters of conveyor speed, article length and overlap length, storage means for storing the above-mentioned parameters, and each of the above-mentioned parameters Based on the above, calculation means for calculating the timing at which the article passes through the overlapping parts of both conveyors and the entire article transfers to the weighing conveyor, and the weighing data indicating the weighing value by starting the processing of the weighing signal from the above timing. A weighing device equipped with a weighing signal processing circuit.