JP6107072B2 - Inkjet recording device - Google Patents

Description

The present invention also relates to the Lee ink jet recording equipment.

  In an ink jet recording apparatus, there is a liquid application apparatus for applying liquid onto a sheet as a pretreatment. This liquid coating apparatus has a large number of liquid flow paths for the purpose of supplying liquid to a coating unit that applies liquid to paper. This coating liquid is a conductive liquid. When a pump is used in the liquid flow path, means for detecting a current supplied to the pump in order to detect a failure of the pump is already known.

  For the purpose of diagnosing the failure of the electric oil pump, a configuration for reporting the rotational speed information of the brushless motor that gives rotational driving force to the electric oil pump and the failure information of the brushless motor driver to the host controller is disclosed (for example, (See Patent Document 1).

However, the technique described in Patent Document 1 cannot detect a mechanical failure of the pump.
An object of the present invention is a child detecting a failure of the mechanical failure was also included pump.

In order to solve the above-mentioned problem, the invention according to claim 1 has a suction-side flow path and a discharge-side flow path at both ends, and a valve that opens to the output side is disposed in both flow paths. Detecting the impedance between the electrodes, the pump for moving the liquid in the flow path by changing the electrode, the electrodes respectively provided in the flow path on the suction side and the flow path on the discharge side, Based on the conversion circuit that converts the impedance into a DC voltage, and the output of the conversion circuit, the impedance between the electrodes varies periodically during the driving of the pump, and the first normal voltage range is obtained. After detecting, when a second normal voltage range lower than the first normal voltage range is detected after a predetermined time, it is determined that the pump is operating normally, and the second normal voltage range is detected. If not, the pump is Provided with a determination circuit for determining that a, characterized in that as coating the paper with the liquid supplied by the pump as a pretreatment.

  According to the present invention, it is possible to detect pump failures including mechanical failures.

It is explanatory drawing about an example of the apparatus which apply | coats the coating liquid as a liquid to a paper. (A), (b), (c) is a figure explaining an example of the structure of the diaphragm type | mold supply pump 52 in FIG. It is explanatory drawing for demonstrating the failure detection means of the diaphragm type | mold supply pump 52 using the liquid detection sensor by this embodiment. (A)-(d) is explanatory drawing for demonstrating in detail the circuit shown in FIG. FIG. 4 is an explanatory diagram for explaining voltage amplitude generated in the configuration shown in FIG. 3. It is an example of the flowchart for demonstrating the operation | movement of a pump failure check.

<Overview>
An embodiment of the present invention will be described.
The present invention relates to pump failure detection including mechanical failure, and an outline is given below.
Prepare two electrodes as a means to detect the leakage of the coating liquid and the presence or absence of liquid in the tube, apply an AC voltage to one, ground the other, detect the impedance between the electrodes, Is converted to a DC voltage and the difference from the reference voltage is compared. Two electrodes of a liquid detection sensor for detecting the presence or absence of a coating liquid as a liquid are provided in the flow paths connected to both ends of the pump, respectively, and are in contact with the coating liquid inside the tube. When the diaphragm pump is driven, the valve inside the pump repeatedly opens and closes at regular intervals. Along with this opening and closing, the impedance between the electrodes fluctuates at a constant period. That is, the voltage fluctuation obtained by converting the impedance fluctuation into the voltage can be detected, and if the voltage fluctuation is constant and the fluctuation is periodic, it can be confirmed that the pump is operating normally. Further, when a constant voltage fluctuation or a periodic voltage fluctuation cannot be detected even though the pump is driven, it can be determined as a failure.

<Configuration>
This embodiment will be described in detail below with reference to the drawings.
FIG. 1 is an explanatory diagram of an example of an apparatus for applying a coating liquid as a liquid to a sheet.
The apparatus for applying the coating liquid to the paper 60 includes a coating liquid tank 51, a diaphragm-type supply pump 52, a coating liquid tank 53, a coating roller 54, a pressing roller 55, a solenoid valve 56 using a solenoid, a waste liquid tank 57, and each It has the flow path 58 which connects a member.
Diaphragm type supply pump 52 may be a pump of another driving system in which impedance varies periodically and constantly during driving.

An unused coating solution is held in the coating solution tank 51, and the unused coating solution in the coating solution tank 51 is supplied to the coating solution tank 53 by a supply pump 52 through a channel 58 using a tube. The coating solution tank 53 holds the supplied coating solution 59. The application roller 54 applies the application liquid 59 held in the application liquid tank 53 to the paper 60. The sheet 60 is pressed against the application roller 54 by the pressing roller 55.
When the coating liquid 59 in the coating liquid tank 53 deteriorates due to a change over time or the like, it is necessary to drain the liquid. Normally, the electromagnetic valve 56 is closed so that no waste liquid is discharged. However, when the liquid is discharged, the electromagnetic valve 56 is opened, and the coating liquid 59 is discharged into the waste liquid tank 57 by using a water head difference.

2A, 2 </ b> B, and 2 </ b> C are diagrams illustrating an example of the structure of the diaphragm supply pump 52 in FIG. 1.
The diaphragm supply pump 52 includes a drive unit 71, a diaphragm 72, a suction side check valve 73, a discharge side check valve 74, a liquid chamber 75, and a flow path 76.
The drive unit 71 is, for example, a known drive unit that moves the diaphragm 72 in the direction of the arrow by combining a solenoid actuator (not shown) or a link mechanism (not shown) and a geared motor. The drive unit 71 is driven and controlled by the pump drive circuit 110.
The suction side check valve 73 and the discharge side check valve 74 are valves made of a flexible material such as silicone rubber or butadiene rubber.

In the diaphragm 72, when the coating liquid is sucked, the driving unit 71 moves upward, and pulls the diaphragm 72 upward. By being pulled upward of the diaphragm 72, the pressure inside the liquid chamber 75 is lowered, the suction side check valve 73 is opened, and the coating liquid flows into the liquid chamber 75. At that time, the discharge-side check valve 74 is closed (FIG. 2A).
When discharging the coating liquid, the drive unit 71 is driven downward to push the diaphragm 72 downward. As a result, the pressure inside the liquid chamber 75 increases, the discharge-side check valve 74 opens, and the coating liquid is discharged from the liquid chamber 75. At that time, the suction-side check valve 73 is closed (FIG. 2C).
The liquid chamber 75 functions as a pump by repeatedly performing the suction operation and the discharge operation of the diaphragm 72.
Further, the liquid chamber 75 has a state where both the suction side check valve 73 and the discharge side check valve 74 are open as an intermediate state between the suction operation and the discharge operation (FIG. 2B).

FIG. 3 is an explanatory diagram for explaining the failure detection means of the diaphragm supply pump 52 using the liquid detection sensor according to the present embodiment.
4A to 4D are explanatory diagrams for explaining the circuit shown in FIG. 3 in detail. 4A is a circuit diagram of the conversion circuit and the AC power supply shown in FIG. 3, FIG. 4B is an input voltage waveform, FIG. 4C is a voltage waveform at the connection point P1, and FIG. 4 (d) is a diagram showing an output voltage waveform.

First, the liquid detection sensor will be described.
The liquid detection sensor shown in FIG. 3 includes electrodes 104 and 105, an AD (Analog to Digital) converter 107, a determination circuit 108, a control circuit 109, and a pump drive circuit 110. The distance between the electrodes 104 and 105 from the pump is arbitrary. The electrodes 104 and 105 have any surface area in contact with the coating solution. The AC voltage applied to the electrodes 104 and 105 has an arbitrary voltage value or frequency.
The electrode 104 is connected via the AC power source 101 and the first cable 102. The electrode 105 is grounded via the second cable 103. The conversion circuit 106 converts the impedance between the electrode 104 and the electrode 105 into a DC voltage.

The conversion circuit 106 illustrated in FIG. 4 includes a differentiation circuit, a voltage dividing circuit, and a rectifier circuit.
The differentiation circuit has an input terminal to which an AC voltage (pulse voltage) from the AC power supply 101 is input, one end of the capacitor Cd connected to the input terminal, one end grounded, and the other end connected to the other end of the capacitor Cd. It is a circuit having a resistor Rd.
The voltage dividing circuit has a resistor R1 having one end connected to the other end of the capacitor Cd and the other end connected to the electrode 104, and an impedance R2 of the coating liquid between the electrodes 104 and 105.
The rectifier circuit includes a diode (for example, silicon diode) Dr having an anode connected to the other end of the resistor R1, a resistor Rr having one end connected to the cathode of the diode Dr, and the other end grounded, and a capacitor Cr.

The determination circuit 108 detects a failure of the diaphragm supply pump 52 based on the digital data converted by the AD converter 107. The control circuit 109 receives the signal from the determination circuit 108 and reflects it in the drive control of the pump.
Here, the change in impedance is detected as a voltage by a voltage division ratio with the resistors connected in series.

  When the impedance between the electrode 104 and the electrode 105 is larger than a predetermined value, the DC voltage converted by the conversion circuit 106 becomes high. Conversely, when the impedance between the electrode 104 and the electrode 105 is smaller than a predetermined value, the DC voltage converted by the conversion circuit 106 becomes low.

Used in the apparatus (FIG. 1) for applying the coating liquid onto the paper 60. In the apparatus shown in FIG. 3, the conductive coating liquid is filled in the flow path, and the electrode 104 is connected to one tube 111 of the diaphragm supply pump 52. The electrode 105 is installed in the other tube 112. Thus, the electrode 104 is in contact with the coating liquid in the tube 111, and the electrode 105 is in contact with the liquid in the tube 112.
When the diaphragm supply pump 52 is driven by the pump drive circuit 110, the diaphragm supply pump 52 repeats the suction operation and the discharge operation as described with reference to FIG. When either the suction side check valve 73 or the discharge side check valve 74 is closed, the coating liquid between the electrode 104 and the electrode 105 is transferred between the suction side check valve 73 and the discharge side check valve 74. As a result, the impedance between the electrodes 104 and 105 increases.
However, in the intermediate state between the suction operation and the discharge operation, both the suction side check valve 73 and the discharge side check valve 74 are open. For this reason, the coating liquid between the electrode 104 and the electrode 105 is conducted, and the impedance between the two electrodes 104 and 105 is reduced.

As a result, when the diaphragm supply pump 52 is driven, a state in which the impedance between the two electrodes 104 and 105 is large and a state in which the impedance is small are repeated, and a voltage amplitude having a constant period is generated.
At this time, when the conductivity of the conductive coating liquid is 1.5 S / m, the distance from the diaphragm supply pump 52 to the electrode is, for example, about 10 cm, and the AC power supply is 5 V and 60 Hz, the voltage amplitude is 1.0 V. Will occur. The period depends on the rotation speed of the diaphragm type supply pump 52.

FIG. 5 is an explanatory diagram for explaining the voltage amplitude generated in the configuration shown in FIG.
In the configuration shown in FIG. 3, when the diaphragm supply pump 52 is driven, a voltage amplitude having a constant period as shown in FIG. 5 is generated at the output of the conversion circuit 106 due to the impedance variation between the electrodes 104 and 105. . The waveform of this voltage amplitude is a sine wave, because the suction side check valve 73 and the discharge side check valve 74 have flexibility.
When the diaphragm type supply pump 52 is stopped, a constant voltage is output. However, the voltage depends on the state of the suction-side check valve 73 or the discharge-side check valve 74 when stopped.
The voltage increases when either the suction side check valve 73 or the discharge side check valve 74 is closed, and the voltage increases when both the suction side check valve 73 and the discharge side check valve 74 are open. Becomes lower.
The output voltage difference is 1.0 [V] and the cycle is 2n [ms]. At this time, when normal voltage range 1 is set on the high voltage side and normal voltage range 2 is set on the low voltage side, and normal voltage range 2 cannot be detected within n [ms] after detection of normal voltage range 1 Is determined to be a failure of the diaphragm supply pump 52.

FIG. 6 is an example of a flowchart for explaining the operation of the pump failure check.
After the pump failure check is started, it is determined whether or not the output voltage of the normal voltage range 1 is detected within 2n [ms] (step S1). When the output voltage of the normal voltage range 1 is detected (step S1 / Y), the process proceeds to step S2, and when the output voltage of the normal voltage range 1 is not detected (step S1 / N), the diaphragm supply pump 52 is abnormal. Is determined (step S4).
It is determined whether or not the output voltage in the normal voltage range 2 has been detected n [ms] after the output voltage in the normal voltage range 1 has been detected (step S2). When the output voltage in the normal voltage range 2 is detected (step S2 / Y), it is determined that the diaphragm supply pump 52 is normal (step S3). When the output voltage in the normal voltage range 2 is not detected (step S2 / N), it is determined that the diaphragm supply pump 52 is abnormal (step S4).
When it is determined whether the diaphragm supply pump 52 is normal or abnormal (steps S3 and S4), the pump failure check operation is terminated (step S5).

<Effect>
As described above, according to the present embodiment, two electrodes are prepared as means for detecting leakage and detecting the presence or absence of the coating liquid in the tube, applying an AC voltage to one and grounding the other. The impedance between the electrodes is detected. There is a liquid detection sensor that detects the presence or absence of a coating liquid by converting the impedance into a DC voltage after detection and comparing the difference with a reference voltage. The two electrodes of the liquid detection sensor are provided in flow paths connected to both ends of the pump, respectively, and are in contact with the coating liquid inside the tube. At this time, when the diaphragm pump is driven, the valve inside the pump repeatedly opens and closes at a constant cycle. Accordingly, the impedance between the two electrodes fluctuates at a constant period.
That is, according to the present embodiment, the voltage fluctuation obtained by converting the impedance fluctuation into the voltage is detected using the AD converter, and the pump is operating normally if the voltage fluctuation is constant and the fluctuation is periodic. Can be confirmed. If a constant voltage fluctuation or periodic voltage fluctuation cannot be detected even though the pump is driven, it can be determined as a failure.
That is, according to the present embodiment, it is possible to detect a pump failure including a mechanical failure.

<Program>
The apparatus according to the present invention described above is realized by a program that causes a computer to execute processing. Examples of the computer include general-purpose computers such as personal computers and workstations, but the present invention is not limited to this. Therefore, as an example, a case where the present invention is realized by a program will be described below.

For example,
A pump that has a suction-side flow path and a discharge-side flow path at both ends, a valve that opens to the output side in each flow path, and moves the liquid in the flow path by changing the volume. In the computer of the device that detects the failure,
A procedure in which the conversion circuit detects the impedance between the electrodes provided in the suction-side flow path and the discharge-side flow path, and converts the impedance into a DC voltage;
Based on the output of the conversion circuit, the determination circuit utilizes the fact that the impedance between the electrodes periodically varies during the driving of the pump, detects the first voltage range, and then the first voltage after a predetermined time. A procedure for determining that the pump is operating normally when a second voltage range lower than the range is detected, and determining that the pump has failed if the second voltage range is not detected;
A program that executes

  Accordingly, the pump failure detection apparatus and the ink jet recording apparatus according to the present invention can be realized anywhere as long as there is a computer environment capable of executing the program.

<Storage medium>
Such a program may be stored in a computer-readable storage medium.
Examples of storage media include computer-readable storage media such as CD-ROM (Compact Disc Read Only Memory), flexible disc (FD), and CD-R (CD Recordable), flash memory, RAM (Random Access Memory), Examples thereof include semiconductor memories such as ROM (Read Only Memory) and FeRAM (ferroelectric memory) and HDDs (Hard Disc Drives).

  The above-described embodiment shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto, and various modifications can be made without departing from the scope of the invention. is there.

DESCRIPTION OF SYMBOLS 51 Coating liquid tank 52 Diaphragm type supply pump 53 Coating liquid tank 54 Coating roller 55 Press roller 56 Solenoid valve 57 Waste liquid tank 58, 76 Flow path 59 Coating liquid 60 Paper 71 Drive part 72 Diaphragm 73 Suction side check valve 74 Discharge side reverse Stop valve 75 Liquid chamber 101 AC power supply 102 First cable 103 Second cable 104, 105 Electrode 106 Conversion circuit 107 ADC
108 Discrimination circuit 109 Control circuit 110 Pump drive circuit 111, 112 Tube

JP 2010-183787 A

Claims (7)

A pump that has a suction-side flow path and a discharge-side flow path at both ends, disposes valves that open to the output side in both flow paths, and moves the liquid in the flow path by changing the volume. When,
Electrodes provided respectively in the suction-side flow path and the discharge-side flow path;
A conversion circuit that detects impedance between the electrodes and converts the impedance into a DC voltage;
Based on the output of the conversion circuit, using the fact that the impedance between the electrodes periodically fluctuates during driving of the pump, the first normal voltage range is detected, and then the first normal voltage range is detected after a predetermined time. Judgment that the pump is operating normally when a second normal voltage range lower than the normal voltage range is detected, and that the pump is determined to have failed when the second normal voltage range is not detected Circuit,
Equipped with a,
An ink jet recording apparatus, wherein the liquid supplied by the pump is applied to paper as a pretreatment. The inkjet recording apparatus according to claim 1, wherein the electrode has an arbitrary distance from the pump. The inkjet recording apparatus according to claim 1, wherein the electrode has an arbitrary surface area in contact with the liquid . 2. The ink jet recording apparatus according to claim 1, wherein the AC voltage applied to the electrode has any voltage value or frequency . The pump jet recording apparatus according to claim 1, the impedance during driving characterized in that it is a pump that varies periodically and constant. 2. The ink jet recording apparatus according to claim 1, wherein a predetermined normal voltage range in which the determination circuit determines normal is arbitrary. The inkjet recording apparatus according to claim 1, further comprising an application roller that applies the liquid supplied to the application liquid tank by the pump to the paper.

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