JP2807948B2 - Weight sorter - Google Patents

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 for detecting a weight value of an article while transporting the article on a weighing conveyor, and for judging an article based on the detected weight value.

[0002]

2. Description of the Related Art In order to efficiently sort goods by weight,
Conventionally, a weight sorting device 10 shown in FIG. 10 has been used.

[0003] The weighing conveyor 11 of the weight sorting apparatus 10 includes:
A weight signal corresponding to the load of the article W carried in from the carry-in conveyor 1 is output from the weighing device 11a to the sorting determination unit 13.

On the loading side of the weighing conveyor 11, a loading sensor 12 for optically detecting the loading of the article W is provided. The carry-in sensor 12 is composed of a pair of light-emitters and light-receivers (not shown) arranged to face each other with the article carry-in path interposed therebetween. Is, for example, a high level (hereinafter, referred to as an H level). When the article is not between the light emitting and receiving devices, the light receiving device is in a light receiving state, and the sensor output is at a low level (hereinafter, referred to as an L level).

Therefore, when an article W of a predetermined length is carried into the weighing conveyor 11 from the carry-in conveyor 1, the output of the carry-in sensor 12 is changed to a predetermined time H as shown in FIG.
Level, during which the weight signal from the weighing device 11a increases as shown in FIG. 7B, and is stabilized after the article W is completely transferred to the weighing conveyor 11.

The sorting determining unit 13 starts the timer circuit 14 when the output of the carry-in sensor 12 rises, and outputs a signal shown in FIG. 15 is closed, and a stable weight signal corresponding to the weight of the article W is input to the determination circuit 16. The judging circuit 16 sorts and determines the input weight signal based on a predetermined sorting criterion, sends the judgment result to a sorting machine (not shown) of the sorting conveyor 2, and sends the determined article to a route according to the judgment result. Let it be sorted.

[0007] In this manner, the articles W carried into the weight sorting apparatus 10 are sequentially subjected to sorting judgment, sent to the sorting conveyor 12, and sorted according to their weight.

[0008]

However, as described above, in the weight sorting apparatus in which the carry-in sensor 12 detects the carry-in of an article, if the carry-in sensor itself fails,
Workers must be constantly monitored because the carried-in articles are successively carried out without inspection.

In particular, the carry-in sensor 12 often variably adjusts its height position and orientation in accordance with the size and shape of the article, etc., and may be damaged due to the handling thereof, and its fixing is insufficient. In some cases, the light emitting and receiving axes may change.

For this reason, the abnormality of the carry-in sensor is detected,
It is necessary to perform alarm generation, line stop processing, and the like.

The abnormality of the carry-in sensor 12 includes a case where a signal indicating a light blocking state is continuously output regardless of the passage of an article, and a case where a signal indicating a light receiving state is continuously output. As shown by the dotted line in FIG. 11A, when the light blocking state continues, the sensor abnormality can be detected by determining whether the H level of the sensor output has continued for a predetermined time or more.

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

[0013]

In order to solve the above-mentioned problems, a weight sorting apparatus according to the present invention comprises: a weighing conveyor for outputting a weight signal corresponding to a load of a conveyed article while conveying the article; A carry-in sensor that optically detects the carry-in of the article, and a sorting judgment of the carry-in article based on a weight signal of the weighing conveyor when a predetermined timing has elapsed after receiving a signal indicating the carry-in of the article from the carry-in sensor. Weight sorting device having a sorting determination unit for performing, the weight signal of the weighing conveyor, weight change determination unit to determine whether the change due to the loading of articles to the weighing conveyor, and a signal from the loading sensor and Abnormality detecting means for detecting an abnormality of the carry-in sensor based on a result of the determination by the weight change determining means.

[0014]

With such a configuration, in the weight selection device of the present invention, if the determination result indicating the article loading is output from the weight change determining unit while the carry-in sensor is not outputting the signal indicating the article loading, An abnormality is detected in the carry-in sensor.

[0015]

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 according to one embodiment. In FIG. 1, the weighing conveyor 11, the carry-in sensor 12, and the sorting 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 numeral is given and the description is omitted.

The weight signal from the weighing device 11a of the weight selection device 20 is supplied to a selection determination unit 13 and a weight change determination unit 2
1 has been entered.

The weight change determining unit 21 includes a reference value setting unit 22
The reference value R set in advance and the weight signal are compared with the comparator 2.
The comparison is made at 3, and an 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 1/3 of the average weight is set in advance, and the output of the comparator 23 is that the article W is carried out of the carry-in conveyor 1 and about half thereof is on the weighing conveyor 11. To H level during a period from transfer to the sorting 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 or not 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 to two flip-flops (hereinafter, referred to as “flip-flops”).
FF) are 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, while the other FF33 latches the D level at the rising edge of the input clock.
Latch the pin level.

The timer circuit 34 is activated at the rise of the output of the comparator 23, and outputs an H level signal of the time width Tr to the FF.
32 and 33 are input to clock terminals. Timer circuit 34
Is set in the reference time setting unit 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.
2L / V) is set in advance.

Accordingly, the inverted output of the FF 33 is set to the H level only when the output of the carry-in sensor 12 is at 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 at the H level at the falling timing of the output of the timer circuit 34. These two states are states indicating an abnormality of the carry-in sensor 12, and the H level output of the OR circuit 36 that calculates the logical sum of the output of the output FF32 of the OR circuit 36 and the inverted output of the FF 33 is an alarm as a sensor abnormality signal. The signal is output to the circuit 40 and the determination circuit 16.

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

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

[0024] t ₀ at the article W starts carried onto the weighing conveyor 11 from input conveyor 1, the weight signals from the weighing device 11a together with the output of the carry-sensor 12 as shown in FIG. 3 (a) rises 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 are shown in FIG.
Stand up as shown in (f).

[0026] If there is no abnormality in the carrying sensor 12, the sensor output falls at the timing t ₂ article W is possess entirely on the weighing conveyor 11, the output of the AND circuit 31 (e) to sync with this Fall. As described above, the timer time Tr of the timer circuit 34 is such that the article W
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, (g) the output of FF32,33 3, remains at the L level as shown in (h), the abnormality detection signal (i) does not become H level, Ts from time t ₀
Weight signal by the measurement signal (c) to t ₄ of time later is inputted to the determining circuit 16, the selection determination by the weight signal is made.

However, if the carry-in sensor 12 breaks down and its output continuously becomes H level from, for example, t ₅ , and the carry-in of the article W is started at t ₆ during this time,
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.

For this reason, an alarm sound is generated, and the article is rejected on the sorting conveyor 2 as a defective product.

In the same manner, while the output of the carry-in sensor 12 continues to be in the abnormal state of the H level, the abnormality detection signal continues to be output. However, the operator notices the alarm, repairs the carry-in sensor 12, and resets the FF 32, By resetting and setting 33, normal operation can be resumed.

As shown in FIG. 4, the weight signal (b)
Sensor 1 started to increase at t ₁₁
When the abnormal state where two L-level condition persists, the AND circuit 31 o'clock t ₁₂ output the (f) rises in the timer circuit 34
Is in the L level state, the output (h) of the FF 33 is set to the H level. For this reason, the output (i) of the OR circuit 36 becomes H level, and the alarm sound is generated and the article is forcibly eliminated as described above.

In this way, no matter which abnormal state of the carry-in sensor 12 occurs, the abnormality is immediately detected, so that the uninspected product is not sent to the subsequent line. In this embodiment, when the abnormality is detected, all the articles are removed from the sorting conveyor 2. However, the processing at the time of detecting the abnormality may be performed according to the line form, for example, stopping all the lines. You may do so.

In the above-described embodiment, when the weight signal of the weighing device 11a exceeds the reference value R, it is determined that the article is carried in. The reference value R becomes small, and the weight signal may exceed the reference value due to an external shock or vibration, and the sensor may be erroneously detected as abnormal. 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 only when a weight signal having a waveform close to the reference waveform is input, it may be determined that the article has been loaded.

FIG. 5 shows the configuration of a weight selection device 20 'for determining whether to carry in an article based on a weight signal waveform.

In FIG. 5, the weight change determining unit 21 '
In addition to the comparator 23 and the reference value setting unit 22, a basic waveform memory 24 and a waveform comparison circuit 25 are provided. In the reference waveform memory 24, an average waveform of a weight signal when a lightweight product is carried in 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 No. 3 rises, the reference waveform is read out in the order of addresses, and each waveform data is compared with the weight signal from the weighing device 11a. 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 loaded is output after a time Th from the rise 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, the output becomes the H level only when the waveform comparison circuit 25 confirms that the article has been carried in, and this H level output is output as an abnormality detection signal.

FIGS. 7 to 9 are timing charts showing the operation of the weight sorting device 20 '. FIG.
Numeral 2 indicates the normal operation.

[0037] In FIG. 7, the weight signal from t ₁₅ at meter 11a by shock or the like from the outside (b) exceeds the reference value R ', the output of the similarly comparator 23 (d)
Rises, and in synchronization with this, the timer circuit 34 is activated and its output (f) rises. Therefore, the output (h) of the FF 33 is set to the H level.

During this time, the weight signal waveform and the reference waveform are compared by the waveform comparison circuit 25. However, since the weight waveform due to disturbance is significantly different from the reference waveform, the waveform comparison circuit 2
The output (d ') of No. 5 remains at the L level, and the output (j) of the FF 37 is not set to the H level.

Next, the weight signal is increased with the output of the t ₁₆ at loading sensor 12 (a) rises by the carrying of the article, exceeds the reference value R 'at t _17, the output of comparator 23 (d) Then, 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.

When the output of the timer circuit 34 returns to the L level, t
_{At 18:00} , the outputs of the AND circuit 31 are already at the L level, so that the outputs of the two FFs 32 and 33 remain at the L level. Then, sometimes the measurement signal t ₁₉ that Ts has elapsed from the time t ₁₆ (c) is outputted, is made more selective determination by weight of the article.

[0041] Sometimes t ₂₀ Th has elapsed from time t _17, since the H-level signal indicating that the waveform of the weight signal is substantially equal to the reference waveform (d ') is output, the output of the FF 37 (j) is L Set to the level, no abnormality detection signal is output. As described above, even when the weight signal changes due to disturbance when the carry-in sensor 12 is normal, the abnormality detection signal is not output.

FIG. 8 shows that when an abnormality occurs in the carry-in sensor 12,
The operation when the output (a) is fixed to the H level state is shown. If t ₂₁ at weight signal from this state to carry articles (b) exceeds the reference value R ', the comparator 23, the rising output of the AND circuit 31, a timer circuit 34 with the waveform comparison is started is activated .

T at which the output (f) of the timer circuit 34 falls
_Since the output (e) of the AND circuit 31 at _{22:00 is} at the H level,
The output (g) of the FF 32 is set to the H level, and the output (i) of the OR circuit 36 is set to 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 performed.

[0044] Figure 9, the output of the carry-in sensor 12 indicates the operation of the abnormal state of being fixed to the L level, the weight signal is increased by an article carried in from this state, exceeds t ₂₄ at the reference value R ' , The timer circuit 34 rises, 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 has fallen at t ₂₅ , when a signal (d ′) indicating the carry-in of goods is output from the waveform comparison circuit 25 at t ₂₆ , the output (j) of the FF 37 is set to the H level, An abnormality of the carry-in sensor 12 is detected.

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

In this embodiment, the description has been given of the case where the article is a lightweight article. However, even when the article is not a lightweight article, the article may be detected by a change in the waveform 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 loading of an article, the determination result and the loading sensor. And an abnormality detection means for detecting an abnormality of the carry-in sensor based on the signal from the controller. Therefore, even if the output of the carry-in sensor is in an abnormal state indicating that the article is not passing, another carry-in sensor is provided. Therefore, it is possible to reliably detect the abnormality and prevent an uninspected product from passing through the subsequent line.

[Brief description of the drawings]

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

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

FIG. 3 is a timing chart for explaining an operation of the 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 the embodiment when another abnormality occurs in the sensor.

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

FIG. 6 is a diagram for explaining an operation of a 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 an operation of another embodiment when a 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]

 REFERENCE SIGNS LIST 1 carry-in conveyor 2 sorting conveyor 20 weight sorting device 11 weighing conveyor 11a weighing device 12 carry-in sensor 13 sorting determination unit 14 timer circuit 15 switch 16 determination circuit 20 weight sorting device 21 weight change determination unit 22 reference value setting unit 23 comparator 30 abnormality Detection circuit 31 AND circuit 32, 33 flip-flop 34 timer circuit 35 reference time setting device 40 alarm circuit

Claims (1)

(57) [Claims] 1. A weighing conveyor for outputting a weight signal corresponding to a load of a conveyed article while conveying the conveyed article, a carry-in sensor for optically detecting the introduction of an article to the weighing conveyor, and an article from the carry-in sensor. A weight determination device having a sorting determination unit that performs sorting determination of a carried-in article based on a weight signal of the weighing conveyor when a predetermined timing has elapsed after receiving a signal indicating the loading, wherein the weight signal of the weighing conveyor is Detecting a change in the carry-in sensor based on a signal from the carry-in sensor and a result of the determination by the weight change determiner; A weight sorting device comprising an abnormality detecting means.