JPH0663512A - Weight selecting device - Google Patents

Abstract

PURPOSE:To detect abnormality of a sensor for detecting optically a fact that an article is carried into a weighing conveyor. CONSTITUTION:When an article carried into a weighing conveyor 11 from a carrying-in conveyor 1 is detected by a carrying-in sensor 12 of an optical sensor 12, a timer circuit 14 is actuated, a switch 15 is closed at a stable measuring timing by a weighing signal of a weigher 11a, and a weight value of the article is inputted to a deciding circuit 16 and selected and decided. A comparator 23 of a weight variation deciding part 21 outputs a signal for showing whether the weighing signal exceeds a reference value R or not. An abnormality detecting circuit 30 detects abnormality of the carrying sensor 12 by a signal of the carrying-in sensor 12 and a signal from the comparator 23, outputs an abnormality signal to an alarm circuit 40 and the deciding circuit 16, reports the abnormality, and also, decides the article to be a defective article.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weight sorting apparatus which conveys an article on a weighing conveyor, detects the weight value of the article, and determines the article selection based on the detected weight value.

[0002]

2. Description of the Related Art In order to efficiently sort the weight of articles,
Conventionally, the weight sorting apparatus 10 shown in FIG. 10 has been used.

The weighing conveyor 11 of the weight sorting device 10 is
A weight signal corresponding to the load of the article W carried in from the carry-in conveyor 1 is output from the weighing machine 11a to the selection determination unit 13.

A carry-in sensor 12 for optically detecting the carry-in of the article W is provided on the carry-in side of the weighing conveyor 11. The carry-in sensor 12 is composed of a pair of light-emitters (not shown) that are arranged to face each other across an article-carrying path, and the light-receiver is in a non-light-receiving state while the article is between the light-emitters and the sensor output. Becomes a high level (hereinafter referred to as H level), and when the article is not between the light emitter and the light receiver, the light receiver enters a light receiving state, and the sensor output becomes a low level (hereinafter referred to as L level).

Therefore, when an article W of a predetermined length is carried in from the carry-in conveyor 1 to the weighing conveyor 11, the output of the carry-in sensor 12 is shown for a predetermined time H as shown in FIG.
The level becomes a level, and the weight signal from the weighing machine 11a increases during this period as shown in FIG. 7B, and the article W becomes stable after being completely transferred to the weighing conveyor 11.

The selection determination unit 13 activates the timer circuit 14 at the rise of the output of the carry-in sensor 12, outputs the signal shown in FIG. 11C at the timing Ts when the weight signal stabilizes from the rise, and switches the switch. 15 is closed, and a stable weight signal corresponding to the weight of the article W is input to the determination circuit 16. The determination circuit 16 performs the selection determination of the input weight signal according to a predetermined selection criterion, sends the determination result to a sorting machine (not shown) of the sorting conveyor 2, and sends the determined finished product to a route according to the determination result. Distribute.

In this way, the articles W carried into the weight sorting apparatus 10 are successively subjected to the sorting judgment, are sent to the sorting conveyor 12, and are sorted according to their weight.

[0008]

However, as described above, in the weight sorter in which the carry-in sensor 12 detects the carry-in of articles, if the carry-in sensor itself fails,
Since the carried-in goods are carried out one after another without being inspected, the worker must constantly monitor them.

In particular, the carry-in sensor 12 is often variably adjusted in height position and direction according to the size and shape of the article, and may be damaged due to handling during the work, and its fixing is insufficient. In some cases, the light emitting / receiving axis may change.

Therefore, when an abnormality of the carry-in sensor is detected,
It is necessary to perform alarm generation and line stop processing.

Abnormalities of the carry-in sensor 12 include continuous output of a signal indicating a light-shielding state and continuous output of a signal indicating a light-receiving state regardless of the passage of an article. As indicated by the dotted line in (a) of 11, when the light-shielding state continues, the sensor abnormality can be detected by determining whether the H level time of the sensor output has continued for a predetermined time or longer.

However, even if the sensor output is kept at the L level for a long time, it cannot be determined whether the article carry-in is regulated by the preceding line or the abnormality of the carry-in sensor itself. This abnormality could not be detected other than the provision of a sensor. An object of the present invention is to provide a weight sorting device that solves this problem.

[0013]

Means for Solving the Problems In order to solve the above-mentioned problems, a weight sorting apparatus of the present invention relates to a weighing conveyor that outputs a weight signal corresponding to the load of the conveyed articles while conveying the articles, and the weighing conveyor. A carry-in sensor that optically detects the carry-in of the article, and a selection judgment of the carry-in article based on the weight signal of the weighing conveyor when a predetermined timing has elapsed after receiving a signal indicating the article carry-in from the carry-in sensor. In a weight sorting device having a sorting determining means for performing, the weight signal of the weighing conveyor determines the weight change determining means for determining whether or not there is a change due to the loading of articles to the weighing conveyor, and a signal from the loading sensor. An abnormality detection unit that detects an abnormality of the carry-in sensor based on the determination result of the weight change determination unit is provided.

[0014]

With the above construction, in the weight sorting apparatus of the present invention, if the weight change determining means outputs the determination result indicating the article loading even when the loading sensor does not output the signal indicating the article loading, It is detected that the carry-in sensor is abnormal.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a weight sorting device 20 of one embodiment. In addition, in FIG. 1, the weighing conveyor 11, the carry-in sensor 12, and the selection determination unit 13 are the same as those of the conventional device 1 described above.
Since it is the same as 0, the same reference numerals are given and the description is omitted.

The weight signal from the weighing device 11a of the weight sorting device 20 is sent to the sorting determination unit 13 and the weight change determination unit 2.
It is input to 1.

The weight change determination unit 21 includes a reference value setter 22.
The reference value R preset in the table and the weight signal are compared by the comparator 2
3, the H level signal is output while the weight signal exceeds the reference value R. As the reference value R, for example, the article W
The value of about 1/2 or ⅓ of the average weight of is measured in advance, and the output of the comparator 23 is about half that on the weighing conveyor 11 when the article W is carried out from the carry-in conveyor 1. It is at the H level during the period from the transfer to the selection conveyor 21 until the transfer to the selection conveyor 21 by about half.

The output of the comparator 23 and the output of the carry-in sensor 12 are input to the abnormality detection circuit 30. When the output of the comparator 23 becomes H level, the abnormality detection circuit 30 checks the state of the carry-in sensor 12 and detects whether the carry-in sensor 12 is abnormal.

FIG. 2 shows an example of the circuit configuration of the abnormality detection circuit 30. The abnormality detection circuit 30 inputs the output of the carry-in sensor 12 and the output of the comparator 23 to the AND circuit 31 and outputs the logical product output of the AND circuit 31 into two flip-flops (hereinafter,
Input to the D terminals of 32 and 33. One F
F32 latches the level of the D terminal at the falling edge of the input clock, and the other FF33 D at the rising edge of the input clock.
Latch the pin level.

The timer circuit 34 is activated at the rising edge of the output of the comparator 23 and outputs the H level signal of the time width Tr to the FF.
Input to the clock terminals 32 and 33. Timer circuit 34
The timer time (Tr) of is set in the reference time setter 35 in advance. This time Tr is predetermined by the article length L and the conveyor speed V, and is slightly longer than the time when the article W passes through the carry-in sensor 12 (for example, 1.
2 L / V) is preset.

Therefore, the inverted output of the FF 33 is set to the H level only when the output of the carry-in sensor 12 is in the L level at the rising timing of the output of the comparator 23,
The output of the FF 32 is set to the H level when the output of the carry-in sensor 12 is in the H level at the falling timing of the output of the timer circuit 34. These two states are abnormal states of the carry-in sensor 12, and the H-level output of the OR circuit 36, which is the logical sum of the output of the OR circuit 36, the output of the FF 32, and the inverted output of the FF 33, causes an alarm as a sensor abnormality signal. It is output to the circuit 40 and the determination circuit 16.

When the alarm circuit 40 receives an H-level abnormal signal from the abnormality detection circuit 30, it outputs an alarm sound (or light) to notify the sensor abnormality. Further, the determination circuit 16 outputs a selection determination signal for excluding from the line all passing articles as defective on the sorting conveyor 2 while receiving the sensor abnormality signal.

Next, the operation of the weight sorting device 20 will be described with reference to FIG.
And the timing chart of FIG.

When the article W starts to be carried in from the carry-in conveyor 1 onto the weighing conveyor 11 at t _0, the output of the carry-in sensor 12 rises and the weight signal from the weighing machine 11a is sent as shown in FIG. 3 (a). It increases as shown in FIG.

At t _{1 when the} weight signal exceeds the reference value R,
The output of the comparator 23 rises as shown in (d) of the figure, and in synchronization with this, the AND circuit 31 of the abnormality detection circuit 30.
And the output of the timer circuit 34 in FIG.
It rises like (f).

If there is no abnormality in the carry-in sensor 12, its sensor output falls at the time t ₂ when the article W is completely transferred onto the weighing conveyor 11, and the output (e) of the AND circuit 31 is synchronized with this. Fall down. As described above, the timer time Tr of the timer circuit 34 is such that the article W has the loading sensor 1
2 is set longer than the time required to pass through, the timer output (f) is, falls at t ₃ later than time t _2. Therefore, the outputs of the FFs 32 and 33 remain at the L level as shown in (g) and (h) of FIG. 3, the abnormality detection signal (i) does not become the H level, and Ts starts at t _0.
At t ₄ after a lapse of time, the weight signal is input to the determination circuit 16 by the measurement signal (c), and the selection determination is performed by the weight signal.

However, when the carry-in sensor 12 fails and the output thereof continuously becomes the H level from, for example, t ₅ and the carrying-in of the article W is started at t _{6 in} the meantime,
The output (e) of the AND circuit 31 is the output (d) of the comparator 23.
And becomes the same time width (t ₁₀ -t _7), the output of the timing t ₉ o'clock FF32 output of the timer circuit 34 falls (g) is set to H level, the output of the OR circuit 36 in synchronism with ( i) becomes H level, and an abnormality detection signal is output.

Therefore, an alarm sound is generated and the article is rejected as a defective article on the sorting conveyor 2.

Similarly, while the output of the carry-in sensor 12 continues to be in the H-level abnormal state, the abnormality detection signal continues to be output, but the worker notices the alarm and repairs the carry-in sensor 12, and the FF 32, Normal operation can be resumed by resetting and setting 33.

As shown in FIG. 4, the weight signal (b)
Sensor 1 even though the number started to increase at t _11.
In the abnormal state in which the L level state of 2 continues, the AND circuit 31 at t ₁₂ when the output (f) of the timer circuit 34 rises.
Since the output (e) of is in the L level state, the output (h) of the FF 33 is set to the H level. Therefore, the output (i) of the OR circuit 36 becomes the H level, and the alarm sound is generated and the article is forcibly removed as described above.

In this way, even if the carry-in sensor 12 is in any abnormal state, the abnormality is immediately detected, so that the uninspected product is not sent to the subsequent line. In addition, in this embodiment, when the abnormality is detected, all the articles are excluded from the sorting conveyor 2, but the processing at the time of detecting the abnormality may be performed according to the line form, for example, all lines are stopped. You may do it.

In the above-described embodiment, when the weight signal of the weighing machine 11a exceeds the reference value R, it is determined that the article is carried in. The reference value R becomes smaller, and the weight signal exceeds the reference value due to external shock or vibration, and there is a possibility that the sensor is erroneously detected as an abnormality. In this case, the waveform of the weight signal at the time of loading the article may be stored in advance as a reference waveform, and it may be determined that the article has been loaded only when the weight signal having a waveform close to the reference waveform is input.

FIG. 5 shows the construction of a weight sorting device 20 'which determines whether or not an article is carried in based on the weight signal waveform.

In FIG. 5, the weight change determination unit 21 'is
In addition to the comparator 23 and the reference value setting device 22 described above, a basic waveform memory 24 and a waveform comparison circuit 25 are provided. In the reference waveform memory 24, an average waveform of the weight signal at the time of carrying in a lightweight product as shown in FIG. 6A is stored in advance in the order of addresses as a basic waveform. The waveform comparison circuit 25 includes the comparator 2
When the output of 3 rises, the reference waveforms are read in the order of addresses, the respective waveform data are compared with the weight signal from the weighing instrument 11a, and only when the weight signal is within the range of ± α of the reference waveform A in FIG. An H level signal indicating that an article has been carried in is output Th time after the rising of the comparator 23.

The output of the waveform comparison circuit 25 is input to the clock terminal of the FF 37 of the abnormality detection circuit 30 '. F
The output signal of the OR circuit 36 is input to the D terminal of F37. Therefore, the output of FF37 is FF32, 3
In the state where any one of the outputs 3 is set to the H level, it becomes the H level only when the carry-in of the article is confirmed by the waveform comparison circuit 25, and this H level output is output as the abnormality detection signal.

7 to 9 are timing charts showing the operation of the weight selecting device 20 ', and FIG.
2 indicates the operation at the normal time.

In FIG. 7, when the weight signal (b) from the weighing instrument 11a exceeds the reference value R'at t _{15 due} to an external shock or the like, the output (d) of the comparator 23 is output as described above.
Rises, the timer circuit 34 is activated in synchronization with this, and its output (f) rises. Therefore, the output (h) of the FF 33 is set to the H level.

During this period, the waveform comparison circuit 25 compares the weight signal waveform with the reference waveform. However, since the weight waveform due to disturbance is significantly different from the reference waveform, the waveform comparison circuit 2
The output (d ') of 5 remains L level, and the output (j) of FF 37 is not set to H level.

Next, when the article is carried in, the output (a) of the carry-in sensor 12 rises at t _{16 and the} weight signal increases, and when the reference value R'is exceeded at t ₁₇ , the output of the comparator 23 (d). And the output (e) of the AND circuit 31 becomes H level, the timer circuit 34 is activated, and the output of the FF 33 returns to L level.

The output of the timer circuit 34 returns to the L level t
_{At 18:00} , the output of the AND circuit 31 is already at the L level, so the outputs of the two FFs 32 and 33 remain at the L level. Then, the measurement signal (c) is output at t ₁₉ when Ts has elapsed from t ₁₆ o'clock, and the sorting determination based on the weight of the article is performed.

At Th ₂₀ after Th has elapsed from t ₁₇ o'clock, an H level signal (d ') indicating that the waveform of the weight signal is substantially equal to the reference waveform is output, so that the output (j) of the FF 37 is L. When set to level, no abnormality detection signal is output. As described above, when the carry-in sensor 12 is normal, even if there is a change in the weight signal due to disturbance, the abnormality detection signal is not output.

In FIG. 8, an abnormality occurs in the carry-in sensor 12,
The operation when the output (a) is fixed to the H level state is shown. When the weight signal (b) exceeds the reference value R'at t ₂₁ after the goods are loaded from this state, the outputs of the comparator 23 and the AND circuit 31 rise, the waveform comparison is started, and the timer circuit 34 is started. .

The output (f) of the timer circuit 34 falls t
_Since the output (e) of the AND circuit 31 at _22:00 is H level,
The output (g) of the FF 32 is set to the H level, and the output (i) of the OR circuit 36 becomes the H level. When the H-level signal indicating the at article loading waveform comparison is completed t ₂₃ (d ') is output, the output of the FF 37 (j) is set to H level, the abnormality of the carrying sensor 12 is detected, the same Is processed.

FIG. 9 shows the operation in an abnormal state in which the output of the carry-in sensor 12 is fixed at the L level. From this state, the weight signal increases due to the carry-in of an article, and when the reference value R'is exceeded at t _24. , The timer circuit 34 starts up, and in synchronization with this, the output (h) of the FF 33 is set to the H level,
The output (i) of the OR circuit 36 becomes H level. After the output of the timer circuit 34 falls at t ₂₅ , when the signal (d ′) indicating the article carry-in is output at t ₂₆ from the waveform comparison circuit 25, the output (j) of the FF 37 is set to the H level, An abnormality of the carry-in sensor 12 is detected.

In this way, if an abnormality of the carry-in sensor 12 is once detected, even if there is a disturbance or a carry-in of the next article,
As long as the output state of the carry-in sensor 12 does not change, the FF 37
Output is held at H level.

In this embodiment, the case where the article is a lightweight article has been described. However, even when the article is not a lightweight article, the article carry-in may be detected by the waveform change of the weight signal.

[0047]

As described above, the weight sorting apparatus of the present invention has a weight change judging means for judging that the weight signal from the weighing conveyor indicates a change due to the carry-in of goods, the judgment result and the carry-in sensor. Since an abnormality detection means for detecting an abnormality of the carry-in sensor based on the signal from the device is provided, another carry-in sensor should be provided even if the output of the carry-in sensor is in an abnormal state indicating non-passage of articles. It is possible to reliably detect the abnormality and prevent uninspected products from passing through to the subsequent line.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a circuit of a main part of one embodiment.

FIG. 3 is a timing chart for explaining the operation of one embodiment when there is no abnormality in the sensor and when an abnormality occurs.

FIG. 4 is a timing chart for explaining the operation of one embodiment when another abnormality occurs in the sensor.

FIG. 5 is a diagram showing the configuration of another embodiment of the present invention.

FIG. 6 is a diagram for explaining the operation of the main part of another embodiment.

FIG. 7 is a timing chart for explaining the operation of another embodiment when there is no abnormality in the sensor.

FIG. 8 is a timing chart for explaining the operation of another embodiment when the sensor has an abnormality.

FIG. 9 is a timing chart for explaining the operation of another embodiment when another abnormality occurs in the sensor.

FIG. 10 is a diagram showing a configuration of a conventional device.

FIG. 11 is a timing chart for explaining the operation of the conventional device.

[Explanation of symbols]

 1 Carry-in Conveyor 2 Sorting Conveyor 20 Weight Sorting Device 11 Weighing Conveyor 11a Weighing Machine 12 Carry-in Sensor 13 Sorting Judgment Unit 14 Timer Circuit 15 Switch 16 Judgment Circuit 20 Weight Sorting Device 21 Weight Change Judgment Unit 22 Reference Value Setter 23 Comparator 30 Abnormal Detection circuit 31 AND circuit 32, 33 Flip-flop 34 Timer circuit 35 Reference time setter 40 Alarm circuit

Claims (1)

[Claims] 1. A weighing conveyor that outputs a weight signal corresponding to a load of the loaded article while it is being transported, a loading sensor that optically detects loading of the article into the weighing conveyor, and an article from the loading sensor. In a weight sorting apparatus having a sorting determination means for performing sorting determination of the carried-in articles based on the weight signal of the weighing conveyor when a predetermined timing has elapsed after receiving a signal indicating loading, the weighing signal of the weighing conveyor is An abnormality of the carry-in sensor is detected by a weight change judging means for judging whether or not a change due to the carry-in of the article to the weighing conveyor is shown, and a signal from the carry-in sensor and a judgment result by the weight change judging means. A weight sorting device comprising an abnormality detecting means.