JP2990466B2 - Combination weighing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for distributing articles supplied to a dispersing device by an article carry-in device to a plurality of weighing sections, and for weighing the articles weighed in each weighing section based on the measured values. The present invention relates to a combination weighing device for performing combination discharge.

[0002]

2. Description of the Related Art In order to combine articles having variations in individual weight by a target amount,
Conventionally, a combination weighing device shown in FIG. 4 has been used.

The article carrying device of this combination weighing device comprises a bucket conveyor 1 and a vibrating feeder 2. Articles are supplied from the vibrating feeder 2 to each bucket 1a, and the buckets are conveyed and carried into the top 3a of the dispersion feeder 3. . Circular umbrella-like dispersion feeder 3, an article receiving at the top 3a, is vibrated dispersed into place radiation feeder 4 ₁ to 4 _n direction on the outer periphery thereof, each radiating feeder 4 ₁ to 4 _n is the vibration of a predetermined time to supply the article by nearly a predetermined amount to each of the intermediate hopper 5 ₁ to 5 _n by.

[0004] supplied to the intermediate hopper 5 ₁ to 5 _n articles are supplied to the weighing hoppers 6 ₁ to 6 _n, is metered by each metering device 7 ₁ to _7-n.

[0005] Upon receiving a combination request signal from a packaging machine (not shown) or the like, the combination selection circuit 10 receiving the measurement value signals from the respective weighing devices 7 _{1 to} 7 _n performs a combination operation of the measurement values. A combination within a predetermined target weight range is selected, and a selection signal is output to the weighing hopper opening / closing circuit 11.

A weighing hopper opening / closing circuit 11 receiving a selection signal
Opens and closes the weighing hoppers selected for the combination at the same time, discharges the articles to the collecting chute 8 and collectively discharges them to the packaging machine or the like.

On the other hand, the intermediate hopper opening / closing circuit 12 causes articles to be supplied from the intermediate hopper corresponding to the empty weighing hopper, and the radiation feeder driving circuit 13 supplies new articles from the radiation feeder corresponding to the empty intermediate hopper. Supply the goods.

The dispersion feeder driving circuit 14 always drives the dispersion feeder 3 to vibrate except when all the radiation feeders are continuously stopped for a predetermined time.

When the amount of articles on the dispersion feeder 3 decreases to a predetermined amount or less while the combination discharging operation is repeatedly performed, the articles are replenished from the bucket conveyor 1.

As shown in FIG. 5, this decrease in the amount of articles
Floodlight 1 that emits light that traverses over the top of dispersion feeder 3
5 and a light receiver 16 that receives light from the light emitter 15, and the light reception signal is input to a level determination circuit 17.

The level judging circuit 17 shields the light incident on the light receiver 16 from light by a disturbance, the light from an article being dropped in, or the light from a gap formed between the articles at the top of the dispersion feeder 3. to eliminate the influence of light, such as by the disturbance light, it is composed of a retrigger type timer circuit or the like, since the light receiver 16 is changed to the light receiving state from the non-light-receiving state, the receiving state a predetermined time (T _oN) At the point of continuation, an activation signal for activating the loading of articles by the bucket conveyor 1 is output. Conversely, the state changes from the light receiving state to the non-light receiving state, and the non-light receiving state changes for a predetermined time (T
_OFF ) Stops the output of the start signal when continued.

The synchronization circuit 18 sets the timing between the feeding of the bucket 1a of the bucket conveyor 1 and the vibration of the vibration feeder 2 while receiving the start signal, and drives the vibration feeder 2 for a predetermined time each time one bucket is fed. Let it.

Therefore, as shown at A in FIG. 6A, the t _ON time elapses further from the time t ₁ when the article amount (height) on the dispersion feeder 3 decreases to the light emitting / receiving level R. _2:00, as shown in FIG. (b), the bucket feeding by the bucket conveyor 1 is started, t ₄ the article quantity has elapsed from time t ₃ when increased to R, further T _OFF time
Occasionally, the bucket feed is stopped, and the amount of articles on the dispersion feeder 3 is substantially regulated to the light emitting / receiving level R.

However, since the work of replenishing articles to the vibration feeder 2 often depends on manual operation or direct connection with a production line, the quantity of articles per bucket of the bucket conveyor 1 fluctuates greatly.

In a state where the quantity of articles per bucket is large, when articles are loaded onto the dispersion feeder 3,
As shown in B of FIG. 6A, a large amount of articles are carried in during the T _OFF time.

When a large number of articles are carried in such a short time, a large change in the quantity of the articles appears as a change in the quantity of the articles discharged from each radiation feeder. A high-precision combination cannot be obtained with a weighing device for which an article supply is desired.

Conversely, when articles are loaded onto the dispersion feeder 3 in a state where the quantity of articles per bucket is small, as shown in FIG. The time to reach becomes extremely long. In this state, the shortage state of the articles continues for a long time, so that a highly accurate combination cannot be obtained.

Furthermore, if the amount of articles in the bucket further decreases in this shortage state, the carry-in amount will not be enough for the amount of articles consumed by weighing and discharging, and the operation of the weighing device must be stopped. There is also a situation in which it does not.

This problem is the same even when a belt conveyor type article carrying device is used.

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

[0021]

In order to solve the above-mentioned problems, a combination weighing device according to the present invention comprises a plurality of weighing sections for weighing articles received by an article receiver with a weighing device, and weighing the articles by the weighing sections. Among the articles, a combination in which the combination of the weighing values is within a predetermined range is selected, and a combination discharging means for discharging the selected articles from the weighing section, and the articles received at a predetermined receiving location are sent to the plurality of weighing sections. Dispersed into a plurality of corresponding paths, to the weighing unit from which the articles are discharged by the combination discharge means, a distributed supply device that supplies the articles from the corresponding paths,
An article amount detecting means for detecting that the amount of the article on the dispersion supply device has decreased to a predetermined amount or less, and an article in a receiving place of the dispersion supply apparatus while receiving a detection signal from the article amount detection means. A carry-in frequency detecting means for detecting, as a carry-in frequency, the number of carry-in times or the cumulative carry-in time of articles carried from the article carry-in device onto the distributed supply device within a predetermined period, and the carry-in frequency detection. A carry-in control means for variably controlling an article carry-in input of the article carry-in device in a direction in which the carry-in frequency detected by the means approaches a predetermined value.

[0022]

Since the combination weighing device of the present invention is configured as described above, when articles are combined and discharged from the weighing section,
New articles are supplied from the dispenser to the empty metering section.
When the amount of articles on the disperser becomes equal to or less than a predetermined amount, new articles are carried in from the article transport device.

The carry-in frequency of the article carry-in device during a predetermined period is detected, and the carry-in input of the article carry-in device is controlled such that the carry-in frequency approaches a predetermined value.

[0024]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a combination weighing device according to one embodiment.

The article carrying-in device of this combination weighing device comprises a bucket conveyor 1 and a vibrating feeder 2 as in the above-mentioned conventional device. Articles from the bucket conveyor 1 are supplied with radiation feeders 4 ₁ to 4 _n and an intermediate hopper 5. It is supplied to the top 3a of the dispersion feeder 3 to form a dispersion feeder with ₁ to 5 _n. Articles distributed on the dispersion feeder 3 is supplied to the weighing hoppers 6 ₁ to 6 _n via the respective radiation feeders 4 ₁ to 4 _n and the intermediate hopper 5 ₁ to 5 _n.

The articles stored in the weighing hoppers 6 _{1 to} 6 _n are weighed by the respective weighing devices 7 _{1 to} 7 _n . The weighing signal of each weighing device is output to the combination selection circuit 10.

When the combination selection circuit 10 receives the combination request signal, the combination selection circuit 10 sequentially performs the calculation of the combination of the weighing values from the weighing devices 7 _{1 to} 7 _{n in} accordance with the different combination patterns, and selects the combinations falling within the preset target weight range. And outputs the combination pattern to the weighing hopper opening / closing circuit 11 as a selection signal.

The weighing hopper opening / closing circuit 11 opens and closes the weighing hoppers selected for the combination, and discharges the combined articles through the collecting chute 8 at a time.

The intermediate hopper opening / closing circuit 12 opens and closes the intermediate hopper corresponding to the empty weighing hopper to supply new articles to the weighing hopper, and the radiation feeder drive circuit 13 controls the radiation hopper corresponding to the empty intermediate hopper. The feeder is driven to supply new articles to the intermediate hopper.

The dispersion feeder drive circuit 14, the radiation feeder 4 ₁ to 4 _n is in while being driven with no intervals or the predetermined time T _B, continuously drives the dispersion feeder 3,
All radiation feeders stops and the state is stopped subsequent T _B Time driving the dispersion feeder 3.

On the other hand, the light receiver 1 for receiving the light from the light emitter 15
The light receiving signal from 6 is input to the level determination circuit 17.

The start signal from the level determination circuit 17 is input to the synchronization circuit 18. The synchronization circuit 18 outputs a bucket feed signal to the bucket conveyor 1 at predetermined intervals while receiving the start signal, and outputs a vibration drive signal synchronized with the bucket feed signal.

The carry-in frequency detection circuit 20 counts the number of times the bucket feed signal has been output from the synchronization circuit 18 until a reset pulse described later is received.

The number-of-discharges detecting circuit 21 counts the number of times a combination is selected by the combination selecting circuit 10 and outputs a latch pulse to the vibration intensity control circuit 25 when the counted value reaches a predetermined value M. At the same time, the reset pulse is output to the carry-in frequency detection circuit 20.

The vibration intensity control circuit 25 receives the latch pulse from the number-of-discharges detecting circuit 21 and latches the integrated value of the carry-in frequency detecting circuit 20. When the integrated value is larger than the preset target value K, Outputs a vibration drive signal for increasing the vibration intensity of the vibration feeder 2 to increase the amount of articles carried into the bucket.

Conversely, when the latched value is smaller than the target value K, a vibration drive signal for weakening the vibration of the vibration feeder 2 is output to reduce the amount of articles carried into the bucket.

As the target value K, for example, a value obtained by dividing the time until the combination request signal is input M times by twice the period of the bucket feed is set in advance.

Next, the operation of the combination weighing device will be described.

Now, the light emitting and receiving device 1 is placed on the dispersion feeder 3.
The operation is started in a state where the articles are supplied in a state higher than 5 and 16 and the weighing hoppers 6 _{1 to} 6 _n contain the weighed articles, and the discharge number detecting circuit 21 is reset with the start of the operation. Shall be performed. Therefore, at the start of operation, the output value of the carry-in frequency detection circuit 20 is reset to zero.

Here, when a combination request signal is input from the packaging machine, the combination selection circuit 10 causes each of the weighing devices 7 ₁ to 7 ₁ to.
The calculation of the combination of the measured values from 7 _n is started according to a different combination pattern, and a combination that falls within the set weight range is selected.

This combination selection signal is output to the weighing hopper opening / closing circuit 11, and the articles selected as the combination are discharged from the weighing hopper all at once and stored in the packaging machine or the like via the collecting chute 8.

The count value of the number-of-discharges detecting circuit 21 becomes "1" due to this discharge.

A new article is supplied to the empty weighing hopper from the intermediate hopper opened and closed by the intermediate hopper opening and closing circuit 12. The radiation feeder corresponding to the empty intermediate hopper is driven by the radiation feeder driving circuit 13 for a predetermined time, and a new article is supplied to the intermediate hopper.

The dispersion feeder 3, a state where all of the radiation feeders is stopped, unless it continues for a predetermined time T _B above, to distribute the continuous article to each radiation feeder direction.

Thereafter, similarly, each time a combination request signal is input, a combination within the set weight range is selected, and the combined article is discharged.

[0047] reduced as shown in the combination discharge is as shown in (a) of FIG. 2, while being continuously performed from time t _0, the article of the dispersion feeder 3 is FIG (b) Then, when the T _ON time elapses after the light emission level falls below the light emission / reception level R (at t ₁ ), the activation signal is output from the level determination circuit 17 as shown in FIG.

For this reason, bucket feed of the bucket conveyor 1 is performed at a predetermined time interval, and in synchronism with this, the vibration feeder 2 transfers the articles to each bucket with a predetermined initial vibration intensity P as shown in FIG. Housed inside.

When the first article loading is started and the quantity of articles on the dispersion feeder 3 reaches the light emitting / receiving level R, T _OFF
When the time has elapsed (at t ₂ ), the output of the activation signal from the level determination circuit 17 is stopped, and the bucket feed of the bucket conveyor 1 is stopped. The number of times S ₁ (three times in the figure) of bucket feeding from t ₁ to t ₂ is counted by the carry-in frequency detection circuit 20.

Similarly, every time the quantity of articles on the dispersion feeder 3 decreases below the light emitting / receiving level R, the bucket conveyor 1 and the vibrating feeder 2 are driven to replenish articles, and the number of times of bucket feeding is counted. .

[0051] Then, at t ₃ M times combination discharge is performed by counting from time t _0, the output value of the carry-frequency detecting circuit 20 by the latch pulse from the carry-out count detection circuit _{21 S T = S 1 + S} 2 + .. + _Sm are latched by the vibration intensity control circuit 25.

The vibration intensity control circuit 25 calculates the latched value S
_T is compared with the target value K, and the vibration intensity of the vibration feeder 2 from the next time is varied by an amount corresponding to the difference.

[0053] As shown in the time t ₀ in FIG. 2 until t _3, the bucket feed count is small, i.e., when the article quantity per bucket is large, S _T is smaller than the target value K.

For this reason, after the next article is carried in (at time t ₄ ), articles are carried into each bucket with a vibration intensity P ₁ that is weaker than the initial vibration intensity P ₀ .

[0055] This variable intensity, variation of the articles of the dispersion feeder 3 is reduced as shown in t ₄ o'clock after.

Conversely, when the amount of articles per bucket is small, the vibration intensity of the vibration feeder 2 is varied so as to be higher than the previous intensity.

In this way, the number of times of bucket feed is detected every M combined discharges, and the vibration intensity of the vibration feeder 2 is variably controlled so that the value approaches the target value.
Dispersion feeder 3 depending on the state of supply of goods to the vibration feeder 2
It is possible to reduce the above-mentioned fluctuation in the amount of articles, and to continue driving while maintaining high-accuracy combination weighing.

[0058] Incidentally, the convenience of the packaging machine or the like, T _B Time from time t ₅ to time t _6, as shown in FIG. 2 (a),
If the combined articles are not discharged, the driving of the dispersion feeder 3 is stopped. The article of the dispersion feeder 3 in this state is not reduced, when again the radiation feeders discharge is either started at t ₇ combinations article is driven, is again dispersed feeder 3 is driven.

In this embodiment, the article carrying device using the bucket conveyor 1 and the vibration feeder 2 is used. However, when a belt conveyor type material carrying device is used, the driving time of the conveyor within a predetermined period and The drive frequency may be set as the carry-in frequency, and the carry-in input may be varied in a direction in which the carry-in frequency approaches the target value.

In the above-described embodiment, the decrease in the number of articles on the dispersion feeder 3 is detected by the light emitter / receiver. However, this is not a limitation of the present invention. For example, the dispersion feeder 3 is placed on a scale. When the weight detection value of the weigher becomes equal to or less than a predetermined value, a new article may be supplied.
In this case, if a natural dispersion type, that is, a dispersion feeder that does not vibrate is used, the weight of the scale can be easily detected.

In the above embodiment, the dispersion feeder 3
Although radiation feeder 4 ₁ to 4 _n and the intermediate hopper 5 ₁ to 5 dispersed feeder by _n has been formed, the form was omitted intermediate hopper or, as shown in FIG. 3, the article receiving part 4
A plurality of feeders 42, 4 arranged in parallel
The same can be applied to a weighing device having a dispersion feeder that carries out the dispersion in 2, 42,.

In the above embodiment, the conveying force of the article carry-in device is changed every time the combination discharge number is performed a predetermined number of times (M), but may be changed every fixed time.

In the above-described embodiment, each weighing section is composed of the weighing hopper and the weighing device. However, the weighing hopper is provided with a plurality of article storage sections, and the weighing of the articles stored in each storage section is performed. The present invention can be similarly applied to a combination weighing apparatus having a weighing unit of a type calculated from the output of a container or a type in which articles weighed by one weighing hopper are transferred to another hopper.

[0064]

As described above, according to the combination weighing device of the present invention, the carry-in amount of the article carry-in device in the direction in which the frequency (number of times or time) of articles carry-in from the article carry-in device during the predetermined period approaches the target value is obtained. Variable control.

For this reason, it is possible to suppress a change in the amount of articles on the dispersion feeder in a stable state without causing an article shortage, to stabilize the quantity of articles supplied to each measuring section, and to perform highly accurate weighing. Become.

[Brief description of the drawings]

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

FIG. 2 is a timing chart showing the operation of one embodiment.

FIG. 3 is a perspective view showing a main part of another embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a conventional device.

FIG. 5 is a schematic diagram for explaining the operation of the conventional device.

FIG. 6 is a diagram showing a change in the amount of articles on a dispersion feeder of a conventional apparatus.

[EXPLANATION OF SYMBOLS] 1 bucket conveyor 1a bucket 2 vibrating feeder 3 dispersion feeder 4 ₁ to 4 _n radiation feeders 5 ₁ to 5 _n intermediate hopper 6 ₁ to 6 _n weighing hoppers 7 ₁ to _7-n meter 8 collecting chute 10 combinations selected Circuit 11 Weighing hopper opening / closing circuit 12 Intermediate hopper opening / closing circuit 13 Radiation feeder driving circuit 14 Distributed feeder driving circuit 15 Projector 16 Receiver 17 Level judgment circuit 18 Synchronization circuit 20 Loading frequency detection circuit 21 Ejection frequency detection circuit 25 Vibration intensity control circuit

Continuation of the front page (56) References JP-A-63-30725 (JP, A) JP-A-60-10125 (JP, A) JP-A-60-179616 (JP, A) Jpn. , U) Fully open sho 63-200129 (JP, U) Fully open sho 58-60238 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01G 19/387

Claims (1)

(57) [Claims] 1. A plurality of weighing units for weighing articles received by an article receiver with a weighing device, and a combination of weighed values within each of the weighing units, the combination of which is within a predetermined range. A combination discharging means for discharging the selected article from the weighing unit, and dispersing the articles received at a predetermined receiving location to a plurality of paths corresponding to the plurality of weighing units, and discharging the article by the combination discharging means. A dispense feeder that supplies the articles from the corresponding path to the weighing unit; an article quantity detection unit that detects that the quantity of the articles on the dispense feeder has decreased to a predetermined amount or less; and While receiving the detection signal, an article carry-in device that carries in the article to the receiving place of the dispersed supply device; and a carry-in count or carry-in cumulative number of articles carried from the article carry-in device onto the distributed supply device within a predetermined period. Bring in time A carry-frequency detection means for detecting a number of carry-power detected by the carry-frequency detection means,
A combination weighing device comprising: a carry-in control unit that variably controls an article carry-in input of the article carry-in device in a direction approaching a predetermined value.