JPH0783738A - Hopper closure monitoring device for weighing instrument - Google Patents

Abstract

PURPOSE:To instantaneously detect the occurrence of interposition of an object to be measured in a hopper and to always automatically adjust the checking timing for outputting a check signal following a delay in the closing operations of the hopper to the optimum value. CONSTITUTION:Checking means 20 and 21 detect whether or not a sensor 24 detects the normal closing state of a hopper and outputs a closure detecting signal (j) at the timing the hopper returns to a closing state. A detecting means 19 always detects the outputting timing of the closure detecting signal (j) from the sensor 16 and sets the outputting timing of check signals (i) from the means 20 and 21 which detect the output of the signal (j) based on the detected time TS of the detecting means 19 so that the outputting timing of the signals (i) can be delayed from the outputting timing of the signal (j).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly used in an automatic or semi-automatic weighing device to monitor whether a pool hopper or a weighing hopper performs an opening operation for dropping an object to be weighed and then returns to a normal closed state. By doing so, the present invention relates to a hopper closing monitoring device in a weighing device that detects a closing failure due to the object to be weighed being caught.

[0002]

2. Description of the Related Art Conventionally, a semi-automatic combination weighing device as shown in FIG. 7 is known as this type of weighing device. The figure is a side view, partly in section, showing the overall schematic configuration of the combination weighing device with the number N of heads. In the figure, a load cell (not shown) as a weight detector for measuring the weight of the loaded object is attached to the weighing hoppers 1A, 1B, ..., 1N arranged in rows. . Each of the weighing hoppers 1A, 1B, ..., 1N has a form in which a container having an open upper surface is vertically divided into two parts, one of which is a fixed part and the other of which is a rotatable movable part. Then, the movable part is rotated by the movement of the piston rod of an air cylinder (not shown) as a drive source, so that the movable part of each of the weighing hoppers 1A, 1B, ..., 1N is joined to the fixed part. Fully closed state to form a container by
The movable portion is separated from the fixed portion and can be changed into two states, that is, a fully opened state in which the object to be weighed is stored and opened so as to be discharged downward.

Each of the weighing hoppers 1A, 1B, ..., 1
Above each N, each of these weighing hoppers 1A, 1
A pool hopper 2A, 2B, ..., 2N in which the objects to be weighed to be supplied to B, ..., 1N are stored in advance is provided below each of the weighing hoppers 1A, 1B, ..., 1N. Is provided with a conveyer conveyor 3 for carrying out the objects to be weighed discharged from them, and below both ends of the conveyer conveyor 3 are respectively through a positive quantity discharge port 8 and a non-quantity goods discharge port 9. A regular quantity storage box 6 and an unquantified quantity collection box 7 are arranged. This pool hopper 2A, 2
B, ..., 2N are also weighing hoppers 1A, 1B ,.
It has the same form as N and is operated by a similar drive mechanism. Further, the top plate portion of the box-shaped casing 4 is provided with insertion ports 5A, 5B, ..., 5N for inserting the objects to be weighed into the pool hoppers 2A, 2B ,. .

The combination weighing device described above operates as follows. That is, each pool hopper 2A, 2B, ..., 2N
After the objects to be weighed such as broilers, livestock products, fruits and vegetables are put in by the operator, the pool hoppers 2A, 2
B, ..., 2N are opened and the objects to be weighed are dropped into the respective weighing hoppers 1A, 1B, ..., 1N directly below, and the respective weighing hoppers 1A, 1B ,.
The object to be weighed is individually weighed. Subsequently, for example, the microcomputer performs a combined calculation of the measured values respectively input from the load cells described above, and compares the calculated results with a preset target value to calculate the maximum value of the target value within a certain allowable range. Select a close combination.

Next, when a combination calculation value is selected within the above-mentioned certain allowable range, only the selected weighing hoppers 1A, 1B, ..., 1N are opened by the suction operation of the air cylinder. At the same time, the transport conveyor 3 is driven in the forward rotation direction N to open the weighing hoppers 1A, 1B, ...
The 1N object to be weighed falls on the conveyor 3 and is stored in the correct quantity storage box 6 through the correct quantity discharge port 8. on the other hand,
When there is no combination calculation value within the above-mentioned fixed permissible range, the conveyor 3 is driven in the reverse direction R, and all or part of the weighing hoppers 1A, 1B, ..., 1N.
Is released, the object to be weighed falls on the conveyor 3,
The non-quantity goods are collected in the non-quantity goods collection box 7 through the non-quantity goods discharge port 9.

[0006]

By the way, an object to be weighed is sandwiched between the movable part and the fixed part of the weighing hoppers 1A, 1B, ..., 1N or the pool hoppers 2A, 2B ,. May be When this trapping occurs in the pool hoppers 2A, 2B, ..., 2N, the lower part of the suspended weighing object hits the weighing hoppers 1A, 1B ,. ..., a measurement error occurs in 1N. On the other hand, when the object to be weighed is sandwiched between the weighing hoppers 1A, 1B, ..., 1N, the fixed portion 8 and the movable portion 9 which are not completely closed.
There is a problem that a part of the object to be weighed falls on the conveyor 3 from the gap between the and.

Therefore, the present invention can immediately detect the occurrence of pinching of the object to be weighed in the hopper and quickly cancel this abnormal state, and can further accurately detect the occurrence of object being pinched in the hopper for a long period of time. It is a technical object to provide a hopper closure monitoring device in a weighing device that can be automatically adjusted as described above.

[0008]

In order to achieve the above-mentioned object, the present invention comprises a hopper closure monitoring device in a weighing device as follows. That is, a hopper that stores the object to be weighed in the closed state, opens it and discharges the object to be weighed,
The opening / closing control means of the hopper, the sensor for detecting a normal closed state of the hopper, and the presence or absence of the output of the closing detection signal from the sensor at a predetermined timing based on the opening / closing command signal output from the opening / closing control means. It is configured to include a check unit for detecting.

Further, in the hopper closing monitoring device in the above-mentioned weighing device, the detecting means for detecting the output timing of the closing detection signal from the sensor and the checking timing by the checking means are based on the detection time of the detecting means. It is also possible to add a timing adjusting means for adjusting.

[0010]

According to the present invention, the opening and closing control signal of the hopper outputs an opening and closing command signal to the hopper, which causes the sensor to detect the normal closed state of the hopper at a constant timing when the hopper returns to the fully closed state. Then, the checking means detects whether or not the closing detection signal is output. Therefore, the abnormal closed state of the hopper can be detected from the check result of the checking means, and when the abnormal closed state occurs, it can be quickly released.

Further, when a detection means for detecting the output timing of the closing detection signal from the sensor and a timing adjustment means for adjusting the check timing of the check means based on the detection time of the detection means are additionally provided, for example, By setting the check timing by the check means by adding a certain delay time to the detection time by the detection means by the timing adjustment means, the check timing can be adjusted so as to always be delayed from the output timing of the closing detection signal. That is, even if the time until the hopper is completely closed is changed by the change in the operating speed of the drive source controlled by the opening / closing control means, the opening / closing of the hopper is detected by the detection means, and the detection time is Accordingly, the timing of checking by the checking means is automatically adjusted. Therefore, it is possible to automatically adjust the timing of checking the presence or absence of the closing detection signal output by automatically following the change in the operating speed of the hopper drive source, and to ensure the abnormal closed state of the hopper for a long period of time. Can be detected.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a block diagram of an embodiment of the present invention, and FIG. 2 shows a schematic side view of a hopper drive mechanism thereof. The present invention is applied to, for example, a combination weighing device as shown in FIG. 7, and each of the weighing hoppers 1A, 1B, ..., 1N and the pool hoppers 2A, 2B ,. As shown in, the container has an open top and is divided in two vertically.
One is a fixed portion 10 and the other is a movable portion 11 which is rotatable around a support shaft 12 as a fulcrum. And the movable part 11
Is connected to a piston rod 14 of an air cylinder 13 as a drive source via a connecting portion 15,
Rotation of the movable part 11 by moving in and out 4 causes each of the weighing hoppers 1A, 1B, ..., 1N or each of the pool hoppers 2 to be moved.
A, 2B, ..., 2N are stored in a fully closed state in which the movable part 11 is mated and joined to the fixed part 10 to form a container, and the movable part 11 is separated from the fixed part 10. It is set in two states, that is, a state in which the object to be weighed inside is opened so as to be discharged downward, and a fully opened state indicated by a dashed line in the figure.

A magnetic sensor 16 is provided at a predetermined position corresponding to the moving position of the piston rod 14 when the air cylinder 13 is in the fully closed state. When the magnetic sensor 16 detects a predetermined magnetic amount due to the proximity of the piston 13P of the air cylinder 13, the piston rod 14 of the air cylinder 13 causes the weighing hoppers 1A, 1
B, ..., 1N or pool hopper 2A, 2B, ...
.., 2N is judged to have reached a normal closed state, and a closing detection signal j is output.

In FIG. 1, a control unit 17 including a microcomputer controls the entire weighing device.
An opening / closing command signal f for opening or closing is output to the opening / closing control means 18, and the air cylinder 13 shown in FIG. 2 is driven via the opening / closing control means 18 to measure the weighing hoppers 1A, 1B, ... Shown in FIG. …, 1N and pool hopper 2
2N are controlled to open and close, and the sensor output monitoring timer 19 and the fully closed position detection check timer 20 are output at the output timing of the opening and closing command signal f of the closing command.
Command each to start the clocking operation. The sensor output monitoring timer 19 times up when the closing detection signal j is output from the magnetic sensor 16.

On the other hand, the fully closed position detection check timer 20
Outputs a time measurement end signal h to the signal generator 21 at the time when the elapsed time of the set check timing time A is completed. The signal generator 21 outputs a check signal i to the control unit 17 when the aging end signal h is input, so that the control unit 17 detects whether or not the closing detection signal j is output from the magnetic sensor 16. The fully closed position detection checking timer 20 and the signal generator 21 constitute the checking means of the present invention.

The memory 22 includes a sensor output monitoring timer 1
The detection time TS measured by the time of time 9 and the detection result k of whether or not the closing detection signal j is output from the magnetic sensor 16 by the check signal i are stored. The timing adjusting unit 23 adds a constant delay time D to the detection time TS stored in the memory 22 to check the check timing time A.
And the check timing time A is updated and set in the fully closed position detection check timer 20.

Next, the operation of the above embodiment will be described with reference to the timing chart of FIG. 3 and the flowchart of FIG. From the control unit 17, the opening / closing control means 1
8 is low level (OFF) as shown in FIG.
The opening / closing command signal f including the closing command signal or the high level (ON) opening command signal is output. Weighing hoppers 1A, 1B, ..., 1N or pool hoppers 2A, 2
In the open state of B, ..., 2N, the control unit 17 waits for the low-level closing command signal f to be output (step S1), and the control is performed at the timing P at which the low-level closing command signal f is output. The section 17 instructs the sensor output monitoring timer 19 to start the time counting operation (step S2), and at the same time, also instructs the fully closed position detection check timer 20 to start the time counting operation (step S3).

The low-level closing command signal f causes the opening / closing control means 18 to operate so as to cause the piston rod 14 of the air cylinder 13 to project, and the weighing hoppers 1A, 1B, ..., 1N or the pool hoppers 2A, 2.
In B, ..., 2N, these movable parts 11 are rotated toward the fixed part 10 and start to shift from the fully open state to the fully closed state as shown in FIG. 3B. Then, whether or not the closing detection signal j is output from the magnetic sensor 16, that is,
It is determined whether or not it is in the fully closed state (step S
4) If the closing detection signal j is not output, whether or not the elapse of the check timing time A set in the fully closed position detection check timer 20 from the time when the low level closing command signal f is output is determined. It is determined (step S6) and the determination as to whether or not the closing detection signal j is output is continued until it is determined that the check timing time A has elapsed.

Then, the movable part 11 is completely fitted and joined to the fixed part 10, and the weighing hoppers 1A, 1B, ..., 1N or the pool hoppers 2A, 2B, ..., 2N are in a normally closed state (fully closed state). Then, the output of the magnetic sensor 16 becomes high level as shown in FIG. 3C, that is, the closing detection signal j is output from the magnetic sensor 16, and it is determined that the closing detection signal j is output (step S4). ), The control unit 17 causes the sensor output monitoring timer 19 to time up as shown in FIG. 3 (d), and the detection time TS measured by the output monitoring timer 19 until then.
Are stored in the memory 22. Then, after waiting for the fully closed position detection check timer 20 to finish measuring the check timing time A (step S6), the fully closed position detection check timer 20 is set at the time when the check timing time A is finished. By outputting the timing end signal h, the check signal i is output from the signal generator 21 as shown in FIG. 3 (e), and the check signal i causes the control unit 17 to output the closing detection signal j from the magnetic sensor 16. It is determined whether or not it is output (step S7).

When the output of the closing detection signal j is confirmed, as shown in FIG.
As shown in (e), a constant delay time D is added to the detection time TS stored in the memory 22 to calculate a new check timing time A, and the calculated check timing time A is used for the fully closed position detection check. The timer 20 is updated and set, and then the process returns to step 1 to repeat the same signal processing as described above. Regarding the update of the check timing time A, it is determined whether or not the value obtained by subtracting the detection time TS measured by the sensor output monitoring timer 19 from the preset check timing time A is different from the constant delay time D. The check timing time A calculated only when discriminated and different may be updated and set in the fully closed position detection check timer 20.

As described above, the timing delayed by the time A from the falling timing of the opening / closing command signal f output from the opening / closing control means 18, that is, the weighing hopper 1A,
1B, ..., 1N or pool hopper 2A, 2B, ...
The check signal i is output from the signal generator 21 constituting the check means at the timing when it is estimated that the 2N has returned to the fully closed state, and the check signal i is output from the magnetic sensor 16 as the closing detection signal j. It is detected whether it was done. Therefore, depending on the check result, the weighing hopper 1
A, 1B, ..., 1N or pool hopper 2A, 2
B, ..., 2N abnormal closed state can be detected,
If an abnormal closed state occurs, it can be quickly released.

Further, in the above embodiment, the output of the closing detection signal j is constantly detected by the sensor output monitoring timer 19, and a constant delay time D is added to the detection time TS to calculate the check timing time A. , The calculated check timing time A is the timer 20 for the fully closed position detection check
Since it is updated and stored in, the following effects can be obtained.

That is, the operating speed of the air cylinder 13 is
When it is used for a long period of time, it generally changes due to a decrease in air pressure with time, wear of the link mechanism, etc., so the time from when the hopper closing drive signal is output until the fully closed state also changes with time. Becomes longer. Therefore, if the output timing of the above-mentioned check signal i is kept constant for a long period of time, the check signal i will be output before the completely closed state, and the closing failure will occur even if the object to be weighed is not sandwiched. Will be falsely detected as. Therefore, if the above-mentioned delay time is set to be long with a sufficient margin in anticipation that the operating speed of the air cylinder 13 as described above becomes slow due to long-term use, the efficiency of the weighing work in the weighing device is reduced and the operating rate is reduced. Markedly reduced.

Therefore, in this embodiment, the magnetic sensor 1
The check timing time A for checking whether or not the closing detection signal j is output from 6 does not require any complicated work and automatically follows the change in the operating speed of the air cylinder 13 and always has an optimum value. It can be automatically adjusted so that . For example, when the operating speed of the air cylinder 13 becomes slow as shown by the two-dot chain line in FIG. 3B, the check timing time A is changed as shown by the one-dot chain line in FIG. 3E.

Further, as shown by the alternate long and short dash line in FIG. 3B, when the object to be weighed is caught, it is determined that the check timing time A has elapsed (step S).
6) After that, since it is determined that the closing detection signal j is not output (step S7), it is determined that the object to be weighed is pinched, the alarm generator 25 is activated, and an alarm is issued by a display or buzzer. (Step S9),
Instruct the operator to remove the object to be weighed.
When the operator eliminates the pinching of the object to be weighed, the process returns to step 1 and the same signal processing as described above is repeated.

FIG. 5 is a block diagram of another embodiment, and FIG. 4 is a schematic side view of the hopper drive mechanism section thereof. In FIG. 6, the same or equivalent parts as those in FIG. 2 are designated by the same reference numerals, and the structure different from that of FIG. 2 has a fixed part 10 and a movable part 11 instead of the magnetic sensor (16).
The fixed electrode portion 24a and the movable electrode portion 24b are fixed to the respective lower end portions of the
a and the movable electrode portion 24b, each weighing hopper 1
A, 1B, ..., 1N or each pool hopper 2A, 2
The only difference is that the sensor 24 is configured to detect the normal closed state of B, ..., 2N. In this sensor 16, the movable electrode portion 16b is electrically connected to the fixed electrode portion 16a only when the weighing hoppers 1A, 1B, ..., 1N or the pool hoppers 2A, 2B ,. The magnetic sensor 16 is functionally similar to the magnetic sensor 16, and the magnetic sensor 16 may be used as it is.

5 is different from FIG. 1 in that, in addition to the sensor 24 being provided in place of the magnetic sensor 16, a check including a sensor output monitoring timer 19, a memory 22 and a timing adjusting section 23 is provided. It is only the configuration in which the timing time adjusting means is deleted. However, the fully closed position detection check timer 20 is not one in which the set time to be elapsed is automatically variable as in the above-described embodiment,
The average time required for the air cylinder 13 to be in the fully closed state of the hopper from the time when the closing command of the opening / closing command signal f is output is experimentally obtained in advance, and the check time obtained by adding a predetermined delay time to this average time is fixed. Is set to
At the time when the counting of the elapse of the check time is completed, the timing end signal h is output.

When the occurrence of the abnormal closed state is detected because the closing detection signal j is not output, for example, the opening / closing control means 18 is driven again to perform the opening / closing operation of the hopper, so that the object to be sandwiched is weighed. The abnormal closed state can be quickly released by shaking off. Alternatively, as shown by the alternate long and short dash line in FIG. 5, an alarm generator 25 composed of a buzzer or an indicator lamp is driven to notify the occurrence of the abnormal closed state, and the operator is prompted to remove the object to be weighed. It should be noted that the check time set in the fully closed position detection check timer 20 is the air cylinder 1 at regular intervals.
The operation speed of No. 3 is measured, and only when it is changed, the operation speed is changed to correspond to the operation speed.

In addition, the above-mentioned configuration has the weighing hopper 1A,
1B, ..., 1N and pool hoppers 2A, 2B, ...
, 2N, or both are used for monitoring the closed state. Further, the case where the closed state of the hopper is detected by the position of the piston rod 12 of the air cylinder 13 or the fixed portion of the variable portion 11 of the hopper has been described, but not limited to this, for example,
The closed state may be detected by the rotation angle of the support shaft 12 of the movable portion 11. Further, a sensor for detecting the open state of the hopper may be added so that it is possible to detect that the object to be weighed cannot be fully opened due to the bite.

If the opening / closing mechanism of the hopper is broken, the piston rod of the air cylinder will have an excessive stroke, and will overshoot the hopper closing position or opening position. At this time, a sensor for detecting the stroke position (piston position) of the driving machine (air cylinder 13), such as the sensor 16 shown in FIG. 2, detects the closed state of the hopper or the open state. When it is used as a sensor, a detection signal is not generated even when the piston 13P goes too far from a predetermined fully closed position or fully open position, so that the stroke of the air cylinder can be detected too much, and thereby the breakage of the opening / closing mechanism can be detected.

[0031]

As described above, according to the hopper closing monitoring device in the weighing apparatus of the present invention, the sensor detects the normal closed state of the hopper at the timing when the hopper returns to the closed state, and outputs the closing detection signal. Since it is configured to detect whether or not it is output by the checking means, it is possible to detect the abnormal closed state of the hopper based on the check result of the checking means, and if the abnormal closed state occurs, promptly cancel it. You can

Further, if a detecting means for detecting the output timing of the closing detection signal from the sensor and a timing adjusting means for adjusting the check timing of the checking means based on the detection time of the detecting means are additionally provided, the hopper drive source Even if the operating speed changes over time, it can automatically follow this and automatically adjust the check timing by the check means to the optimum value, and the abnormal closed state of the hopper can be eliminated without any complicated work. It can be reliably detected for a long period of time.

[Brief description of drawings]

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

FIG. 2 is a schematic side view of a drive mechanism of the hopper of the embodiment. Is.

FIG. 3 is a timing chart showing a signal waveform of each part of the embodiment.

FIG. 4 is a flowchart for explaining the operation of the embodiment.

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

FIG. 6 is a schematic side view of a drive mechanism of the hopper of the embodiment.

FIG. 7 is a schematic side view with a partial cross section showing the overall configuration of a combination weighing device to which the present invention can be applied.

[Explanation of symbols]

1A to 1N ... Weighing hopper (hopper), 2A to 2N ...
Pool hopper (hopper), 16 ... Magnetic sensor (sensor), 18 ... Opening / closing control means, 19 ... Detecting means (sensor output monitoring timer), 20, 21 ... Checking means (fully closed position detection checking timer, signal generator) ), 23 ... Timing adjusting means (timing adjusting unit), 24 ... Sensor, j
… Closure detection signal.

Claims (2)

[Claims] 1. A hopper for storing an object to be weighed in a closed state and opening it for discharging the object to be weighed, an opening / closing control means for the hopper, a sensor for detecting a normally closed state of the hopper, and a sensor for this. A hopper closure monitoring device in a weighing device, comprising check means for detecting whether or not a closure detection signal is output from the opening / closing control signal at a predetermined timing based on an opening / closing command signal output from the opening / closing control means. 2. A detecting means for detecting the output timing of a closing detection signal from the sensor, and a timing adjusting means for adjusting the check timing of the checking means based on the detection time of the detecting means. The hopper closing monitoring device in the equipped weighing device.