JP6663682B2 - Ink jet recording device - Google Patents

Description

  The present invention relates to an inkjet recording device.

  As a background art of this technical field, there is Patent Document 1 (Japanese Patent Application Laid-Open No. H10-264410). In a so-called continuous ink jet recording apparatus described in Patent Document 1, a main body portion has an ink container. , An ink supply pump, and an ink recovery pump, and the print head unit includes a nozzle and a gutter.

  The main body and the print head are connected by a cable. Since the inkjet recording apparatus is used in a production line, the length of the cable is generally set to about 2 to 6 [m].

  The ink in the ink container is sucked by an ink supply pump and supplied under pressure to a nozzle. The ink supplied under pressure to the nozzles is ejected from the nozzles as regular ink particles by the operation of the piezoelectric element in the print head.

  On the other hand, the ink particles that are not charged by the charging electrode travel straight without being deflected by the deflecting electrode, are received by the gutter, pass through the ink recovery path by the suction force of the ink recovery pump, return to the ink container, and reuse. Mechanism.

JP-A-10-264410

  In an ink jet recording apparatus, when the ambient temperature is high, or when the temperature around the pump increases due to an increase in the internal temperature, the capacity of the pump decreases.

  It is an object of the present invention to provide an ink jet recording apparatus using a pump unit that can exchange air around a pump with a simple configuration with a small number of parts.

  In order to solve the above-mentioned problem, for example, the configuration of the claims is adopted.

The ink jet recording apparatus of the present application includes an ink container that stores ink for printing on a printing target, a nozzle that is connected to the ink container, and that discharges ink that is supplied under pressure, and that is discharged from the nozzle. A charging electrode for charging ink used for printing, a deflection electrode for deflecting the ink charged by the charging electrode, a gutter for collecting ink not used for printing, and an ink collected from the gutter. An ink jet recording apparatus comprising: a recovery pump for sucking and recovering the ink in the ink container; and a motor for driving the recovery pump, includes an impeller on a central axis of the motor.
It is.

  According to the present invention, it is possible to provide an ink jet recording apparatus using a pump unit capable of exchanging air around the pump with a simple configuration having a small number of parts.

1 shows an external perspective view of an ink jet recording apparatus. FIG. 3 is a perspective view illustrating a use state of the inkjet recording apparatus. FIG. 3 is a schematic diagram illustrating an operation principle of the inkjet recording apparatus. FIG. 2 shows a path configuration diagram of an inkjet recording apparatus. FIG. 3 is a longitudinal sectional view of the internal structure of the main body of the ink jet recording apparatus. FIG. 2 is a cross-sectional view of the internal structure of the main body showing the configuration of the present invention. It is a figure showing the pump composition of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiments.
<Appearance configuration>
FIG. 1 is an external perspective view of the ink jet recording apparatus of the present invention.

In FIG. 1, 1 is an ink jet recording apparatus main body, 2 is a print head, 3 is an operation display unit, and 4 is a conduit. The ink jet recording apparatus includes an operation display unit 3 in a main body 1 and a print head 2 outside, and the main body 1 and the print head 2 are connected by a conduit 4.
<Usage of device>
Next, a use state of the ink jet recording apparatus will be described with reference to FIG. In FIG. 2, 1 is an ink jet recording apparatus main body, 2 is a print head, 4 is a conduit, 13 is a printed material on which numerals and characters are printed, 15 is a belt conveyor for conveying the printed material, and 16 is a belt conveyor 15. A rotary encoder that measures the transport distance, and 17 is a print sensor.

The ink jet recording apparatus 300 is installed on a production line in a factory where foods and beverages are produced, for example, the main body 1 is installed at a position where a user can operate, and the print head 2 is installed on a production line such as the belt conveyor 15. Is installed at a position where it can be close to the printing target 13 to which the printing object 13 is fed. In order to print on the production line such as the belt conveyor 15 at the same width regardless of the feeding speed, the encoder 16 that outputs a signal corresponding to the feeding speed to the inkjet recording device 400 and the print target 13 are detected. A print sensor 17 for outputting a signal for instructing printing to the ink jet recording apparatus 400 is provided, and each is connected to a control unit (not shown) in the main body 1. The control unit controls the amount and timing of charging the ink particles 7 </ b> C ejected from the nozzles 8 in response to signals from the encoder 16 and the print sensor 17, and controls the charging while the printing target 13 passes near the print head 2. The printing is performed by causing the deflected ink particles 7C to adhere to the printing target 13.
<Operation principle of the device>
Next, the operation principle of the ink jet recording apparatus will be described with reference to FIG.
In FIG. 3, 18 is an ink container, 7A is ink, 24 is a pump that pressurizes and sends out ink, 9 is an electrostrictive element that vibrates at a predetermined frequency when voltage is applied, 8 is a nozzle that discharges ink, and 7B is ink. It is a pillar. Reference numeral 11 denotes a charging electrode for charging ink particles, 7C denotes ink particles, 12 denotes a deflecting electrode, 13 denotes an object to be printed, and 14 denotes a gutter for collecting unprinted ink particles.

  The ink 7A in the ink container 18 is sucked and pressurized by the pump 24, becomes an ink column 7B, and is discharged from the nozzle 8. The nozzle 8 is provided with an electrostrictive element 9, which vibrates the ink at a predetermined frequency to form particles of the ink column 7 </ b> B ejected from the nozzle 8. The number of the generated ink particles 7C is determined by the frequency of the excitation voltage applied to the electrostrictive element 9, and is equal to the frequency. The ink particles 7C can be charged by applying a voltage having a magnitude corresponding to print information to the charging electrode 11.

The ink particles 7 </ b> C charged by the charging electrode 11 fly in an electric field between the deflection electrodes 12. The deflection electric field is formed between the high voltage electrode to which the high voltage of 5 to 6 [kV] is applied and the installed ground electrode, and the charged ink particles 7C receive a force proportional to the charge amount. To fly and land on the print target 13. At this time, the landing position of the ink particle 7C in the deflection direction changes in accordance with the amount of charge, and the production line moves the printing object 13 in a direction perpendicular to the deflection direction, so that the ink particle 7C also moves in the direction perpendicular to the deflection direction. Particles can be landed, and a character is composed of a plurality of landed particles and printed. The ink particles 7C not used for printing fly between the deflection electrodes 12 linearly, are captured by the gutter 14, and are collected in the main ink container 18 via a path.
<Device route configuration>
Next, the path configuration of the inkjet recording apparatus will be described with reference to FIG. FIG. 4 is a diagram illustrating the overall path configuration of the inkjet recording apparatus 400.

  The ink jet recording apparatus 400 includes a main body 1, a print head 2, and a conduit 4 connecting the main body 1 and the print head 2.

  First, an ink supply path of the inkjet recording apparatus 400 according to the present embodiment will be described. The main body 1 is provided with a main ink container 18 for holding the circulating ink 7A. The main ink container 18 has a reference amount that is an appropriate amount of liquid in the main ink container 18 to be held inside. A liquid level sensor 46 for detecting whether or not the liquid level has been reached is provided.

  The main ink container 18 is connected to a viscosity measuring device 43 via a path 201 to grasp the viscosity of the ink 7A in the main ink container 18. The viscosity measuring device 43 is connected to an electromagnetic valve (for supply) 34 that opens and closes the path via a path 202, and the electromagnetic valve (for supply) 34 sucks and pressure-feeds the ink 7A via paths 203 and 204. Connected to a pump (for supply) 24 used for the purpose. The pump (for supply) 24 is connected via a path 205 to a filter (for supply) 28 that removes foreign matter mixed in the ink 7A.

  The filter (for supply) 28 is connected to a pressure reducing valve 33 that adjusts the pressure of the ink 7 </ b> A pressure-fed from the pump (for supply) 24 to an appropriate pressure via a path 206. A pressure gauge 31 for measuring the pressure of the ink 7A supplied to the nozzle via 207 is provided. The pressure gauge 31 is connected to a nozzle 8 provided in the print head 2 via a path 208 passing through the conduit 4.

  The nozzle 8 has a discharge port for discharging the ink 7A. A gutter 14 for catching ink particles 7 </ b> C that fly straight without being charged or deflected because they are not used for printing is arranged in the straight traveling direction of the nozzle 8 discharge port.

  Next, the ink collecting path of the ink jet recording apparatus 400 will be described with reference to FIG. The gutter 14 is connected to a filter (recovery) 30 for removing foreign matter mixed in the ink disposed in the main body 1 via a path 212 passing through the conduit 4, and the filter (recovery) Numeral 30 is connected to a solenoid valve (for collection) 35 that opens and closes the path via a path 213.

  The solenoid valve (for collection) 35 is connected via a path 214 to a pump (for collection) 25 that sucks the ink particles 7C captured by the gutter 14. The pump (for recovery) 25 is connected to the main ink container 18 via the path 215. Further, the main ink container 18 is connected to an exhaust path 217, and the exhaust path 217 is configured to communicate with the outside of the main body 1.

  Next, the ink supply path will be described with reference to FIG. The main body 1 is provided with an auxiliary ink container 20 for holding replenishing ink, and the auxiliary ink container 20 is connected via a path 221 to a solenoid valve 36 that opens and closes the path. The solenoid valve 36 is connected via a path 222 to a merge path 223 connected to the ink supply path 204.

Next, the solvent supply path of the ink jet recording apparatus 400 of FIG. 4 will be described. The main body 1 is provided with a solvent container 19 for holding a solvent for solvent replenishment. The solvent container 19 is connected to a pump (for solvent) 27 used for sucking and pumping the solvent through a path 231. It is connected. The pump (for solvent) 27 is connected to a solenoid valve (for solvent) 38 for opening and closing the flow path via a path 232, and the solenoid valve (for solvent) 38 is connected to the main ink via a path 233. It is connected to the container 18.
<Configuration of main body>
Next, the configuration of the inkjet recording apparatus main body 1 will be described with reference to FIG.
FIG. 5 shows a vertical cross-sectional view of the ink jet recording apparatus. The outside of the main body 1 is constituted by a main body 600 made of a metal plate, and a control circuit 300, a power supply 310 for supplying current to the control circuit, etc. And an operation display unit 3 is provided on the upper front surface. An auxiliary ink container 20 for storing ink to be supplied to the nozzles, a solvent container 19 for storing a solvent to be supplied to the nozzles, and the like are provided on the front side of the lower portion of the main body 1.

  Further, on the rear side of the lower portion of the main body 1, circulating system control parts such as a flow path board 621, solenoid valves 34 to 38, and a pump unit 51 are stored. 2 is connected. The length of the conduit 4 is generally 4 to 6 [m]. In the conduit 4, there are arranged a tube through which ink flows in and out, a high-voltage power supply line for applying each electrode, and a control line.

Further, by opening the door 610 on the lower front surface of the main body 1, the ink container 20 and the solvent container 19 can be taken out from the main body 1, so that maintenance such as replenishment and disposal of ink and solvent can be easily performed. ing.
<Outline of Configuration of Example>
Next, an embodiment of an inkjet recording apparatus 400 according to an embodiment of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view of the main body 1 of FIG.

  The main body 1 is provided with a main body 600 forming an outer wall, a suction port 56 for sucking outside air into a left side surface of the main body 600, and a fan 52. The fan 52 is provided with an intake filter 53 and an intake cover 54 for preventing external dust and the like from entering the inside of the main body 1, and a wire mesh 55 is provided inside the fan 52. ing.

  Further, the main body 1 includes an exhaust port 58 for discharging air to the back of the main body 600, an exhaust filter 59 for preventing external dust and the like from entering, and an exhaust cover 60. An image of the flow of the wind from the intake port 56 to the exhaust port 58 is shown by a wind flow 301.

  The main body 1 includes a flow path board 621 on which the components of the ink circulation system are mounted on the inner rear side, and the pump unit 51.

  Next, the configuration of the pump unit 51 will be described with reference to FIG. FIG. 7 is a partially enlarged view of the pump unit 51 of FIG. The pump unit 51 includes a pump (for supply) 24, a pump (for recovery) 25, a pump (for supply) 27, and three types of pumps, each having an independent flow path configuration. Further, the pump unit 51 includes a pump housing 71 provided on the flow path board 621, a motor 72 on the left side of the pump unit 51, a motor shaft 73, and a motor gear 75 for converting rotation of the motor 72 into pump power. And an impeller A74 that rotates integrally with the motor shaft 73 to generate wind. Further, the pump unit 51 is provided with drive bearings 82 and 83 at both left and right ends of the pump housing 71, and the pump drive shaft 81 is fixed via the drive bearings 82 and 83.

  The pump drive shaft 81 has a drive gear that meshes with the motor gear 75. Therefore, the rotation of the motor 72 can be converted into the rotation torque of the pump drive shaft 81. Further, the pump drive shaft 81 includes eccentric cams 86a to 86c and pump bearings 87a to 87c for each of the pumps 24 to 26. Each of the pumps 24 to 26 is a diaphragm pump, and can generate a flow by reciprocating operation by an eccentric cam. The pump drive shaft 81 is provided with an impeller B89. By rotating the pump drive shaft 81, wind can be generated inside the pump housing 71.

An image of the flow of the wind inside the pump housing 71 caused by the impeller B89 is shown by 302 in FIG.
<Control of Example>
Next, a control method of the motor 72 of the present invention will be described.

The ink jet recording apparatus 400 of the present invention is provided with a temperature sensor (not shown) in the same area where the pump unit 51 is installed. The control unit of the motor 72 can check the temperature of the temperature sensor and control the rotation speed of the motor 72. For example, if the temperature measured by the temperature sensor is lower than 30 ° C., the motor 72 is rotated at 1000 rpm. If the temperature measured by the temperature sensor is 30 ° C. or more and less than 40 ° C., the motor 72 is rotated at 1500 rpm. Further, if the temperature measured by the temperature sensor is 40 ° C. or higher, the motor 72 is rotated at 2000 rpm. At low temperatures, power consumption can be reduced by reducing the number of revolutions of the motor. In addition, by increasing the rotation speed of the motor at high temperatures, the effect of reducing the internal temperature by the impeller 74 and the impeller B89 can be increased. 26 abilities.
<Effect of the present invention>
As described above, according to the present invention, the air around the pump can be exchanged by installing the impeller on the pump driving motor shaft or the pump driving shaft, and the stagnation of the air inside the pump unit 51 is eliminated. It is possible to reduce the possibility that the temperature inside the pump unit 51 becomes high due to the effect of the temperature rise. Therefore, it is possible to provide an ink jet recording apparatus that prevents the ink collecting ability from being reduced and the gutter 14 from overflowing the ink. <Another form>
In the present embodiment, each of the pumps 24 to 26 is a diaphragm pump. However, another pump such as a gear pump (gear pump) may be used.
When a gear pump is used, an impeller is installed on a drive shaft that is driven integrally with a gear used to pump the liquid, or an impeller is installed on a drive unit that moves integrally with the rotation of the motor. (The effect of reducing the rise in internal temperature around the pump) can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Main body part, 2 ... Print head part, 3 ... Operation display part, 4 ... Conduit, 7A ... Ink (in the main ink container 18), 7B ... Ink column, 7C ... Ink particles, 7D ... Ink with a small charge Particles, 7E: ink in the recovery path, 7F: overflowing ink, 8: nozzle, 9: electrostrictive element, 11: charging electrode, 12: deflection electrode, 12A: ground electrode, 12B: plus electrode, 13: printing object , 14 ... gutter, 14B ... gutter, 15 ... belt conveyor, 16 ... encoder, 17 ... print sensor, 18 ... main ink container, 19 ... solvent container, 20 ... auxiliary ink container, 21 ... gas, 24 ... pump (for supply ), 25 ... Pump (for recovery), 26 ... Pump (for solvent), 28 ... Filter (for supply), 29 ... Filter (for recovery), 30 ... Filter (for solvent), 31 ... Pressure gauge, 33 ... Decompression Valve, 34 ... Den Valve (for supply), 35: Solenoid valve (for recovery), 36 ... Solenoid valve (for replenishment), 38 ... Solenoid valve (for solvent), 43 ... Viscometer, 51 ... Pump unit, 52 ... Fan, 53 ... Intake filter, 54 ... intake cover, 55 ... wire mesh, 56 ... intake port, 58 ... exhaust port, 59 ... exhaust filter, 60 ... exhaust cover, 71 ... pump housing, 72 ... motor, 73 ... motor shaft, 74 ... impeller A, 75: motor gear, 81: pump drive shaft, 82: drive bearing, 83: drive bearing, 84: drive gear, 86a to c: eccentric cam, 87a to c: pump bearing, 89: impeller B, 201 208 path (for ink supply), 212 to 215 path (for ink recovery), 217 path (for exhaust), 221 to 222 path (for ink supply), 223 junction path, 231 to 233 path ( Solvent supplement Use), 301 ... wind flow, 302 ... wind flow, 400 ... ink jet recording apparatus, 600 ... main body, 610 ... door 621 ... passage board,

Claims (5)

An ink container that contains ink for printing on a printing target,
A nozzle connected to the ink container, from which ink supplied under pressure is discharged;
A charging electrode that is charged with ink used for printing by being discharged from the nozzle,
A deflection electrode in which the ink charged by the charging electrode is deflected,
A gutter from which ink not used for printing is collected,
A collection pump for sucking and collecting the ink collected from the gutter into the ink container,
A motor for driving the collection pump, and an inkjet recording apparatus comprising:
An impeller is provided on the center axis of the motor ,
An ink jet recording apparatus comprising a temperature sensor in the same area as the recovery pump . The inkjet recording apparatus according to claim 1,
An ink jet recording apparatus, wherein the control unit of the motor controls the number of rotations of the motor based on a temperature. The inkjet recording apparatus according to claim 2, wherein
The ink jet recording apparatus according to claim 1, wherein the control unit of the motor controls the rotation speed of the motor to increase as the temperature increases. The inkjet recording apparatus according to claim 1,
The ink-jet recording apparatus according to claim 1, wherein the recovery pump includes a drive shaft that rotates in conjunction with the motor, and an impeller provided on the drive shaft. The inkjet recording apparatus according to claim 1,
An ink jet recording apparatus further comprising an impeller provided on a pump drive shaft having a drive gear meshing with a gear of the motor.

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