JP2990463B2 - 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 as shown in FIG. 4 has been used.

In this combination weighing apparatus, an article carry-in conveyor 1 carries articles in an article receiver 1a into a top 2a of a dispersion feeder 2, and a circular umbrella-shaped dispersion feeder 2 has a top 2a.
Feeder 3 arranged on the outer periphery of the article received by
₁ vibration dispersed to to 3 _n direction, the radiating feeders 3 ₁ to 3
_n means that each intermediate hopper 4
Articles are supplied to each of ₁ to 4 _n almost every predetermined amount.

[0004] supplied to the intermediate hopper 4 ₁ to 4 _n articles are supplied to the weighing hopper 5 ₁ to 5 _n, is metered by the respective meter 6 ₁ to 6 _n.

[0005] When receiving the 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 6 _{1 to} 6 _n performs the combination calculation 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
Simultaneously open and close the weighing hoppers selected for the combination, discharge the articles to the collecting chute 7, and collectively discharge 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 2 to vibrate except when all the radiation feeders are continuously stopped for a predetermined time.

When the amount of articles on the dispersion feeder 2 is reduced to a predetermined amount or less while the combination discharging operation is repeatedly performed, the articles are replenished from the article carry-in conveyor 1.

As shown in FIG. 5, this decrease in the amount of articles
Floodlight 1 for projecting light that traverses over the top of the dispersion feeder 2
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 determination circuit 17 is provided to block light incident on the light receiver 16 by a disturbing object, light shielding by an article being carried in, falling, or light reception by a gap or the like generated between articles at the top of the dispersion feeder 2. 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 time of continuation, an activation signal for activating the article loading by the article loading conveyor 1 is output. Conversely, when the state changes from the light receiving state to the non-light receiving state, the non-light receiving state changes for a predetermined time (T
_OFF ) Stops the output of the start signal when continued.

Therefore, as shown in FIG. 6A, the article amount (height) on the dispersion feeder 2 is reduced from the time t ₁ at which the light emitting / receiving level R is reduced to the time t ₂ at which the T _ON time elapses. the article carrying-by input conveyor 1 is started, the article weight from time t ₃ when increased to R, at t ₄ has passed more T _OFF time, the article conveyed is stopped, the article of the dispersion feeder 2 is substantially projecting The light reception level R is regulated.

However, since the work of replenishing articles to the article receiver 1a of the article carry-in conveyor 1 often depends on manual operation or direct connection with the production line, the discharge amount per unit time greatly fluctuates.

When articles are carried into the distributed feeder 2 in a state where the amount of discharge per unit time is large, a large quantity of articles is carried during the T _OFF time as shown in FIG. 6B. Will be.

When a large amount of articles is carried in such a short time, a large variation in the quantity of the articles appears as a variation 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 the articles are carried into the dispersion feeder 2 in a state where the amount of discharge per unit time is small, as shown in FIG. 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.

Further, in this shortage state, if the discharge amount from the article carry-in conveyor 1 is further reduced, the carry-in amount cannot be sufficient for the amount of articles consumed by the weighing and discharging operation, and the operation of the weighing device is stopped. There is also a situation that must be done.

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

[0019]

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. An article carry-in device for carrying in, a duty detecting means for detecting a ratio of a time during which the article carry-in device continues to carry in the article to the distributed supply device and a time when the article carry-in is stopped, and the duty detection. And carrying-in control means for variably controlling the article carrying force of the article carrying-in device so that the ratio detected by the means approaches a predetermined value.

[0020]

Since the combination weighing device of the present invention is configured as described above, while the combination discharge of the articles from the weighing section is continued, if the quantity of the articles on the dispersion feeder becomes less than a predetermined quantity, The article is carried in by the article carrying device. Then, the ratio between the time during which the article carrying-in device carries in the article and the time during which the carrying-in of the article is stopped is detected, and the conveying force is controlled such that the ratio approaches a predetermined value.

[0021]

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.

This combination weighing apparatus is similar to the above-mentioned conventional apparatus, in that an article carrying conveyor 1, which is an article carrying apparatus,
Articles to the top of the dispersion feeder 2 to form a radiation feeders 3 ₁ to 3 _n and the intermediate hopper 4 ₁ dispersion feeder with to 4 _n is supplied. Articles distributed on the dispersion feeder 2, the radiating feeders 3 ₁ to 3 _n and the intermediate hoppers 4 ₁ to
Through 4 _n is supplied to the weighing hoppers 5 ₁ to 5 _n.

Collecting chute 7 from weighing hoppers 5 _{1 to} 5 _n
Are discharged to the discharge hopper 8.

Upon receiving a discharge request signal from a packaging line or the like, the discharge hopper opening / closing circuit 9 drives the discharge hopper 8 to open and close, discharges the articles in the discharge hopper 8 to a packaging machine or the like, and sets a combination selection circuit 10. To output a combination request signal.

[0026] Combination selection circuit 10 receives the combined request signal, based on the weight signals from the measuring instrument 6 ₁ to 6 _n, selects a combination that falls within a predetermined target range, the weighing hopper close circuit 11 Then, the weighing hopper selected for the combination is opened and closed to discharge the combined article from the weighing hopper.

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 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 feeders 3 ₁ to 3 _n is in while being driven with no intervals or the predetermined time T _B, continuously drives the dispersion feeder 2,
All radiation feeders stops and the state is stopped subsequent T _B time driving the dispersion feeder 2.

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 supplied to the duty detection circuit 20 and the conveyor speed control circuit 30.
Has been entered.

The duty detection circuit 20 inputs a start signal from the level determination circuit 17 to the carry-in time integration circuit 22 and the stop time integration circuit 23.

The carry-in time integration circuit 22 integrates the time during which the start signal is output from the level determination circuit 17 until a reset signal described later is received, and the stop time integration circuit 23
Accumulates the time during which the output of the activation signal is stopped until a reset signal is received. Note that this stop time integrating circuit 2
Reference numeral 3 denotes that while the driving of the distributed feeder 2 is stopped, the stop time is not integrated, and the integrated value immediately before the stop is held.

The carry-in number detection circuit 24 counts the number of start signals output from the level determination circuit 17 and outputs a calculation command signal to the duty ratio calculation circuit 25 every time the counted value reaches a predetermined value M. The reset signal is supplied to the carry-in time integrating circuit 22 at a timing slightly delayed from the output of the operation command signal.
And to the stop time integrating circuit 23.

When the duty ratio calculation circuit 25 receives the calculation command signal, it latches the integrated values of the carry-in time integration circuit 22 and the stop time integration circuit 23, and stops the integrated value _Td of the latched carry-in time, for example. The result obtained by subtracting “1” from the value obtained by dividing by the integrated value Ts of the time is output to the conveyor speed control circuit 30.

The conveyor speed control circuit 30 controls the conveyor speed of the article carry-in conveyor 1 to a speed corresponding to the operation result of the duty ratio operation circuit 25 while receiving the start signal.

That is, when a positive operation result is received, the conveyor speed is set faster by an amount corresponding to the absolute value, and conversely, when a negative operation result is received, only the amount corresponding to the absolute value is set. Control the conveyor speed slowly.

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 2.
The articles are supplied in a state higher than 5 and 16, the weighed hoppers 4 ₁ to 4 _n store the weighed articles, and the discharge hopper 8 stores the articles already combined and discharged from the weighing hoppers. Shall be

Here, when a discharge request signal is input from the packaging machine, the discharge hopper opening / closing circuit 9 causes the discharge hopper 8 to open.
The combination in the weighing hoppers 4 ₁ to 4 _n is selected by the combination selection circuit 10.

The weighing hoppers containing the articles selected for the combination are opened and closed by a weighing hopper opening / closing circuit 11, and the combined articles are accommodated in the discharge hopper via the collecting chute 7.

The empty weighing hopper is supplied with new articles 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 drive circuit 13 for a predetermined time, and a new article is supplied to the intermediate hopper.

The dispersion feeder 2, 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.

If the articles on the dispersion feeder 2 become lower than the light emitting / receiving level R during such a series of weighing and discharging operations, a start signal is output from the level determination circuit 17.

FIG. 2 shows the operation state of the radiation feeder and the dispersion feeder 2 during operation, the change in the amount of articles on the dispersion feeder 2, and the operation state of the article carry-in conveyor 1.

[0046] That is, is started metered discharge operation described above, as shown in (a) of FIG. 2, when any of the radiation feeders 3 ₁ to 3 _n are driven at t _0, in FIG. (B) As shown in (2), the driving of the dispersion feeder 2 is started.

While the weighing and discharging operation is repeated, as shown in FIG. 2C, when the amount of articles on the dispersion feeder 2 becomes lower than the light emitting / receiving level R, the T _ON time has elapsed ( At t ₁ ), an activation signal is output from the level determination circuit 17, and the article carry-in conveyor 1 is driven to carry in the article at a predetermined initial speed V ₀ , as shown in FIG.

The stop time T _S1 from the operation start time t ₀ to the time t ₁ at which the first article loading is started is stored in the stop time integrating circuit 23 as an initial value of the integration.

When the first article carry-in is started and the T _OFF time has elapsed since the quantity of articles on the distributed feeder 2 has reached the light emitting / receiving level R (at t ₂ ), the output of the start signal from the level determination circuit 17 is performed. Stops, and the drive of the article carrying-in conveyor 1 is stopped. The carry-in time T _{d1 at} this time is stored in the carry-in time integrating circuit 22 as an initial value of the integration.

Similarly, every time the amount of articles on the dispersion feeder 2 decreases below the light emitting / receiving level 12, the article carrying conveyor 1 is driven to replenish the articles, and the carrying-in time and the stopping time are integrated. .

When the M-th carry-in is completed at t ₃ , an operation command signal from the carry-in number detecting circuit 24 is output to the duty ratio computing circuit 25 and the carry-in time integrating circuit 22
, _Td = _Td1 + _Td2 +... + _Tdm, and the integrated value output from the stop time integrating circuit 23,
That is, a value obtained by subtracting 1 from the ratio T _d / T _S to T _S = T _S1 + T _S2 +... + T _Sm is calculated, and the calculation result is output to the conveyor speed control circuit 30.

As shown from t ₀ to t _{3 in} FIG. 2, when each stop time is longer than each carry-in time (when the carry-in amount per unit time is large), T _d / T _S becomes “ Since the value is smaller than “1”, a calculation result of a negative value is output to the conveyor speed control circuit 30.

For this reason, after the next article is loaded (at t ₄ ), the articles are loaded at a speed V ₁ lower than the initial speed V ₀ .

Due to this variable speed, the fluctuation of the article amount of the dispersion feeder 2 is reduced.

Although not shown, when the carry-in amount per unit time from the article carry-in conveyor 1 is small, each stop time is shorter than each carry-in time, and T _d / T _S
Is larger than "1", a positive calculation result is output to the conveyor speed control circuit 30, and the conveying speed of the article carrying conveyor 1 is changed to a state faster than the previous speed.

In this way, every time the article is carried in M times, the speed of the article carry-in conveyor 1 is variably controlled so that the ratio of the carry-in time and the stop time always approaches 1: 1. Variations in the amount of articles on the dispersion feeder 2 due to the state of article supply to the conveyor 1 can be reduced, and operation can be continued while maintaining highly accurate combination weighing.

If the state where the combination request signal is not input for the time T _B or more continues due to the convenience of the packaging machine or the like, the time during which all the radiation feeders are stopped is reduced to T as shown in FIG. The driving of the dispersion feeder 2 is stopped because the time _B continues.

When one of the radiation feeders is driven after the lapse of the T _P time, the dispersion feeder 2 is again activated.
Is driven.

[0059] In addition, in T _P time, stop time integrating circuit 23
Is in the hold state, the _TP time is excluded from the duty calculation, and the _fourth stop time T
_S4 is the sum of T _S4 (a) and T _S4 (b), and an accurate duty can be detected only during operation.

In this embodiment, a conveyor-type apparatus is used as the article carrying-in apparatus. However, when the conveying force of the vibrating feeder-type article carrying-in apparatus is varied, the vibration intensity may be varied. When a bucket-type carry-in device is used, the input amount to each bucket may be changed.

In the above-described embodiment, the decrease in the number of articles on the dispersion feeder 2 is detected by the light emitting and receiving device. However, this is not a limitation of the present invention. For example, the dispersion feeder 2 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 2
Although radiation feeders 3 ₁ to 3 _n and the intermediate hopper 4 ₁ dispersion feeder by to 4 _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 drive stop time of the dispersion feeder 2 is not included in the calculation of the duty ratio. However, for example, when the opening and closing of the discharge hopper 8 is stopped for a predetermined time or more, the stop time integrating circuit is used. 23 may be in a hold state. This stop detection can be realized by using a retrigger-type timer started by a signal from the discharge hopper opening / closing circuit 9.

In the above-described embodiment, the carrying force of the article carry-in device is changed every time M articles are carried in.
It may be performed every time, or may be performed every fixed time or every time the combination discharge is performed a predetermined number of times. Furthermore, in the above-described embodiment, the duty ratio is controlled so as to approach 1: 1. However, the target duty ratio may be changed according to the type of the article or the like.

[0065] In the above embodiment, the integrated value T _d and the integrated value T _S downtime (T _d / T _S) of the carry-in time -
1 was calculated, but this calculation is performed, for example, by T _d / T _S =
The variable amount of the conveyor speed differs between the case of 2 and the case of T _d / T _S = 速度.

That is, when T _d / T _S = 2,
Since the amount of discharge per unit time is small and there is a risk of shortage of articles, the speed of the conveyor is greatly increased (according to the operation result 1). Conversely, when T _d / T _S = _S , the operation result 1 / 2 prevents rapid speed change.

This is not a limitation of the present invention. For example, the conveying force is simply proportionally controlled by the calculation result of T _d −T _S , or the calculation result of 1− (T _S / T _d ) Control reverse to that of the embodiment may be performed.

Further, in the above-described embodiment, each weighing section is constituted by the weighing hopper and the weighing device. However, the weighing hopper is provided with a plurality of article storing sections, and the weighing of the articles stored in each of the storing sections 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.

[0069]

As described above, in the combination weighing device of the present invention, the variation in the carry-in amount per unit time of the article carry-in device is determined by the time during which the articles are carried from the article carry-in device onto the dispersion feeder. And the time during which the carry-in is stopped, and the article carrying force of the article carry-in device is controlled such that the ratio approaches a predetermined value.

For this reason, a change in the amount of articles on the dispersion feeder can be suppressed in a stable state that does not cause a shortage of articles, the quantity of articles supplied to each measuring section is stabilized, and highly accurate weighing can be performed. 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]

REFERENCE SIGNS LIST 1 article carrying conveyor 2 dispersion feeder 3 _{1 to} 3 _n radiation feeder 4 ₁ to 4 _n intermediate hopper 5 _{1 to} 5 _n weighing hopper 6 _{1 to} 6 _n weighing device 7 collective chute 8 discharge hopper 10 combination selection circuit 11 weighing hopper open / close circuit REFERENCE SIGNS LIST 12 Intermediate hopper opening / closing circuit 13 Radiation feeder driving circuit 14 Distributed feeder driving circuit 15 Emitter 16 Receiver 17 Level determination circuit 20 Duty detection circuit 22 Loading time integration circuit 23 Stop time integration circuit 24 Loading frequency detection circuit 25 Duty ratio calculation circuit 30 Conveyor Speed control circuit

──────────────────────────────────────────────────続 き 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) 34432 (JP, U) Actually open 63-200129 (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 dispersion supply device, and the time and the article carry-in time during which the article carry-in to the dispersion supply device by the article carry-in device is continued. With the time A duty detecting means for detecting, said combination weighing apparatus ratio detected by the duty detecting means and a carry-control means for variably controlling the article transporting force of the article carrying apparatus to approach a predetermined value.