JP3011608B2 - Failure detection 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 failure detecting device for detecting a failure of a transport mechanism for transporting goods in a vending machine.

[0002]

2. Description of the Related Art For example, as a failure detecting device of a transport mechanism such as a vending machine, a device using a carrier switch for detecting the presence or absence of rotation of a transport belt for transporting goods is known. This conventional failure detection device includes a carrier switch mounted on a chassis beside a conveyor belt rotated by a motor, an engagement member mounted on the conveyor belt and engageable with the carrier switch, and a switch for the carrier switch. A failure detection unit that monitors a signal to detect a failure of the transport mechanism. When a product is transported, the motor rotates, and accordingly, the transport belt rotates. When the transport mechanism is operating normally, the transport belt rotates and the carrier switch is turned on by the engagement member engaging the carrier switch. When this ON signal is output to the failure detection unit, the failure detection unit determines that the transport mechanism is operating normally. On the other hand, when there is no input of the ON signal, the failure detection unit determines that a failure has occurred in the transport mechanism.

[0003]

However, in the conventional failure detecting device, if the carrier switch does not operate, it is possible to detect that the transport mechanism has failed, but whether the carrier switch has failed. It is not possible to identify the location of the failure, whether a failure has occurred in the motor, or a failure in the transport belt or other components of the transport mechanism. For this reason, there is a problem that it takes much time to find a faulty portion and it is not possible to repair the device quickly.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a failure detection device that can quickly identify a failure portion of a transport mechanism.

[0005]

In order to achieve the above object,
A failure detection device according to claim 1, wherein the failure detection device detects a failure of a transport mechanism including a transport motor, wherein the failure detection device detects a motor current value of the motor, and a detected motor current value. A comparison unit that compares a reference current value larger than a steady-state current value when the motor is in a steady state and smaller than a lock current value when the motor is locked with a preset current value . Comparison of comparison section
And a determination unit for determining whether there is a motor failure based on the result.

[0006] The failure detection device according to claim 2 is the first invention.
In the failure detection device described in the above, the determination unit is configured to start the motor
Later, based on the comparison result of the comparison unit after a predetermined time has elapsed
To determine whether the motor is locked .

[0007]

According to the first aspect of the present invention, when the transport motor operates, the motor current detecting section detects the value of the motor current flowing through the motor. The comparison unit sets the detected motor current value to a value larger than a steady current value flowing when the motor is in a steady state, and smaller than a lock current value flowing when the motor is locked due to a failure of the transport belt or the like. Compare with a preset reference current value. On the other hand, the judgment unit
Is the motor current value that flows when the motor is started.
Determines whether the motor has failed based on the results of comparison with
I do. Specifically, the starting current value of the motor is the lock current value
It is almost equal to
Using the characteristics, the starting current value is larger than the reference current value
It is determined that the motor has started when the comparison result is
If the result of the comparison is reversed, the motor
judge. As a result, if the transport mechanism fails,
When it is determined that the motor has started, the motor
Normal operation, failure of transport mechanism components other than motor
Motor is taking into account
It is not necessary to perform
It should be fixed. On the other hand, if it is determined that the motor has failed,
First, repair the motor. Repair of this motor
If the transfer mechanism operates normally,
There is no need to consider any structural components, and
It can operate normally quickly. Also, repair the motor.
Only when the transport mechanism does not operate normally
If the transport mechanism other than the data
No. Therefore, when starting the motor,
By performing a failure determination, if the transport mechanism breaks down,
The fault location is the motor, or
Immediately identify whether it is a component of the transport mechanism other than
As a result, the transport mechanism can be repaired more quickly.
Can be planned.

According to failure detection device according to claim 2, Mo
After the motor has been started, the motor
After the time for normal rotation has elapsed, the comparison
Based on the result, the determination unit determines whether the motor is locked or not.
judge. Specifically, when the motor locks,
Characteristics that the motor current value becomes larger than the steady-state current value.
When the motor current value is larger than the reference current value
Determines that the motor is locked,
For example, a conveyor belt that may lock the motor
Can be estimated to have failed. Conversely, the motor
If the current value is smaller than the reference current value, the motor
It is determined that there is no
For parts other than the feed belt, such as a carrier switch
It can be estimated that a failure has occurred. Therefore,
To determine whether the motor is locked.
The failure detection device according to claim 1 of the present application determines
Operation of the transport mechanism from the start of the motor.
During rotation, in addition to the motor,
Failure of components (transport belt, carrier switch, etc.)
The location can be identified immediately, and repair of the transport mechanism is
Speeding up can be further achieved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a failure detecting device according to one embodiment of the present invention is applied to a product discharging mechanism (transport mechanism) of a vending machine will be described in detail with reference to the drawings.

FIG. 1 shows a part of the commodity discharging mechanism and a failure detecting circuit 1 for detecting a failure of the commodity discharging mechanism.

The product discharging mechanism includes a transport belt (not shown) for transporting the product, and a motor M for rotating the transport belt.
And a power supply 2 for supplying DC power to the motor M, and a motor driver 3 for operating the motor M. In this product discharging mechanism, when money is inserted in a vending machine main body (not shown) and a product is selected, a control unit (not shown) that performs all controls such as vending machine sales.
Outputs a motor drive signal to the motor driver 3. Then, based on the motor drive signal, the motor driver 3 operates the motor M, and the conveyance belt rotates with the operation of the motor M, so that the product is discharged to a product discharge port (not shown).

The failure detecting device 1 compares a voltage corresponding to the motor current value of the motor M with a reference voltage, which will be described later, and determines whether or not a failure has occurred in the product discharging mechanism. And a carrier switch S1 attached to the chassis on the side of the transport belt.

One of the two input terminals of the motor M is connected to a power supply 2 via a resistor (motor current detector) R1.
The other is connected to the motor driver 3. The control input terminal of the motor driver 3 is connected to the control unit, and the above-described motor drive signal is input from the control unit.

One end of the resistor R1 on the power supply 2 side is connected to a resistor R2.
The other end on the motor M side is connected to ground via R3 and the volume RV1, and the other end on the motor M side is connected to ground via resistors R4 and R5. The connection between the resistors R2 and R3 is connected to the plus input of the comparator 4, and the connection between the resistors R4 and R5 is connected to the minus input of the comparator 4. Further, a stabilizing capacitor C1 is connected in parallel to both input terminals of the comparator 4.

The output of the comparator 4 is connected to one of the inputs of the determination unit 5 and to a power supply (not shown) for the failure detection device 1 via a resistor R6 which is a pull-up resistor. .

The other two input units of the determination unit 5 are connected to the control unit and the carrier switch S1, respectively, and the control unit outputs a motor drive signal. The output unit of the determination unit 5 is connected to the control unit, and outputs a failure signal described later to the control unit. The carrier switch S1 is turned on by engaging with the engaging member on the conveyor belt when the conveyor belt is rotated at the time of discharging the product, and outputs a switch signal that is turned on to the determination unit 5.

When a motor drive signal is output from the control unit, the determination unit 5 monitors both the comparison signal (comparison result) from the comparator 4 and the switch signal from the carrier switch S1, thereby determining the motor M and the carrier. Switch S
It is determined whether a failure has occurred in 1 and other components of the transport mechanism. When any one of them is determined to be faulty, the fault detecting device 1 outputs a fault signal to the control unit, and the control unit causes the printing device to print the fault details as described later.

Next, the operation of the failure detecting device 1 will be described with reference to FIG.

In the failure detection device 1, a reference voltage (voltage at point A shown in FIG. 1) is set according to the following procedure. When the control unit outputs a motor drive signal to the motor driver 5, the motor M is started.
The starting current shown in FIG. The reference voltage is set by the volume RV1 such that the output voltage of the comparator 4 changes from the L voltage (low voltage) to the H voltage (high voltage) when the starting current flows. Specifically, a voltage smaller than the voltage of the minus input portion (point B in FIG. 1) of the comparator 4 when a current (reference current) having a value slightly smaller than the maximum value of the starting current of the motor M flows through the motor M Is set as the reference voltage. That is, this reference voltage is a voltage equal to a voltage obtained by dividing the voltage of the terminal of the resistor R1 on the motor M side (point C in the figure) when the reference current flows by the resistance values of the resistors R4 and R5. When the maximum value of the starting current is known in advance, the reference voltage may be set using a tester or the like so that a voltage slightly smaller than the maximum value is applied to the point A.

After setting such a reference voltage, a motor drive signal is output from the control unit, and when the motor M is started,
The motor current value changes as follows. That is, the resistance R
1, a motor current flows, and a voltage drop occurs in the resistor R1.
In this case, when the motor current becomes larger than the reference current value shown in FIG.
The voltage at the point becomes lower than the reference voltage at the point A. That is, the resistance R1 is proportional to the magnitude of the motor current flowing through the motor M.
, The voltage at point B becomes lower than when the reference current flows. As a result, the voltage at the point B becomes lower than the reference voltage at the point A, so that the output voltage of the comparator 4 changes from the L voltage to the H voltage.

When the operation of the motor M starts to stabilize and the motor current becomes smaller than the reference current value, the output voltage of the comparator 4 changes from the H voltage to the L voltage. As a result,
The comparator 4 outputs a pulse signal S1 as shown in FIG. Further, when the operation of the motor M is stabilized (steady state), the motor current becomes a steady current as shown in FIG. 2A, and the output voltage of the comparator 4 maintains the L voltage.

On the other hand, when a failure occurs in the transport belt or the like and the transport belt does not rotate, the motor M is overloaded, and a lock current as shown in FIG. 2A flows. This lock current is a current having a value substantially equal to the maximum value of the start-up current.
Outputs the H voltage S2 shown in FIG. 2A to the determination unit 5 in the same manner as when the starting current flows.

The determination unit 5 makes a failure determination based on the above-described characteristics of the change in the motor current value. That is, when a motor drive signal is output from the control unit, a change in the voltage output from the comparator 4 is detected, and it is determined whether or not a failure has occurred in the motor M. Specifically, since the time during which the starting current flows immediately after the motor drive signal is output is about 0.1 second, the time from when the motor drive signal is output, for example, when 0.3 seconds elapses Then, when the comparator 4 outputs the H voltage, the determination unit 5 reads this voltage change and determines that the motor M has started normally. on the other hand,
When the H voltage is not output from the comparator 4 during this 0.3 second, the determination unit 5 determines that the motor M has failed.

The determination unit 5 continuously monitors the output voltage of the comparator 4 after that, and after 0.3 seconds has elapsed from the time when the motor drive signal is output, the H voltage is output from the comparator 4. And the carrier switch S1
When the ON signal is not output from the controller, it is determined that the motor M is locked and the transport belt has failed. That is, in this case, the determination unit 5 determines that the transport belt does not rotate and the motor M is overloaded. When it is determined that a failure has occurred in the motor M and that a failure has occurred in the transport belt, the determination unit 5 outputs a motor failure signal and a transport belt failure signal to the control unit.

The determination unit 5 determines that the motor M operates normally, is not locked, and the carrier switch S1
When the ON signal is not output from the switch, it is determined that the carrier switch S1 has failed. That is, in this case, both the motor M and the conveyor belt are operating normally, a failure occurs in the carrier switch S1, and no ON signal is output even when the carrier switch S1 is engaged with the engaging member of the conveyor belt. Is determined. Then, a carrier switch failure signal is output to the control unit.

Next, an example of printing when a failure is detected will be described with reference to FIG. The figure shows an example in which the control unit causes a printing device (not shown) to print when a motor failure signal is output from the determination unit 5 to the control unit.
In the figure, reference numeral 11 denotes the date and time when printing was performed, reference numeral 12 denotes the date and time when the motor M operated, and reference numeral 13 denotes a failure code ( In this case, it indicates a motor failure).
Is the number of the motor M that has operated, and reference numeral 15 is the motor M
16 indicates the time (seconds) from when the motor M operates until the motor M is locked, and 17 indicates the motor M
Indicates the lock time (seconds). By this printing, it is possible to know which component of the commodity discharging mechanism has failed and when, and it is possible to facilitate failure analysis.

As described above, according to the present embodiment, by monitoring the ON signal of the carrier switch and the comparison signal of the comparison section 4, a failure has occurred in any of the motor M, the conveyor belt and the carrier switch S1. Can be easily determined.

In the above embodiment, the determination unit 5
It is determined that the lock state has occurred when the H voltage is output from the comparator 4 after the lapse of a predetermined time. However, the present invention is not limited to this.
However, when the H voltage is continuously output for a time longer than 0.3 second, it may be determined that the locked state has occurred immediately. This is because the time during which the start-up current flows is known empirically, and when the comparator 4 outputs the H voltage for a longer time, it is considered that the lock state has occurred. is there.

Further, in this embodiment, an example in which a DC motor is used as the motor M has been described, but the present invention is not limited to this, and an AC motor may be used. In this case, the resistor R1
By picking up the voltage applied to both ends of the rectifier, rectifying it after full-wave rectification or half-wave rectification,
If the converted DC voltage is input to the minus input of the comparator 4 and a reference voltage is applied to the plus input of the comparator 4, the circuit shown in this embodiment can be applied.

In this embodiment, an example in which the present invention is applied to a product discharging mechanism of a vending machine has been described. However, the present invention is not limited to this, and can be applied to failure detection of all other transport mechanisms.

[0031]

As described above, according to the failure detection device of the present invention, when the motor is started and a predetermined time elapses after the start of the motor.
After passing, compare the motor current value with the reference current value
Motor failure and whether the motor is locked or not.
If the transport mechanism breaks down,
Failure location can be quickly identified and the transport mechanism repaired.
Process can be speeded up.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of a failure detection device according to the present embodiment.

FIG. 2A is a current waveform diagram of a motor whose failure is to be detected by the failure detection device according to the embodiment;
FIG. 6B is an output waveform diagram of the comparator of the failure detection device according to the present embodiment.

FIG. 3 is a diagram illustrating a print example of failure detection.

[Explanation of symbols]

 1 Failure detection device 4 Comparator 5 Judgment unit M Motor R1 Resistance

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G07F 9/00 107 H02H 7/085 H02P 3/06 H02P 7/06

Claims (2)

(57) [Claims] 1. A failure detection device for detecting a failure of a transport mechanism including a transport motor, comprising: a motor current detector that detects a motor current value of the motor; A comparing unit for comparing a reference current value larger than a steady current value when the motor is in a steady state and smaller than a lock current value when the motor is locked with a preset current value ; Based on the comparison result of the comparison unit
A determination unit for determining whether or not the motor has a failure . 2. The method according to claim 1, wherein the determining unit is configured to determine a location after starting the motor.
Based on the comparison result of the comparison unit after the fixed time has passed
The failure detection device according to claim 1, wherein it is determined whether the motor is locked .