JP5114229B2 - Damper and inkjet printer - Google Patents

Description

  The present invention relates to a damper and an ink jet printer.

2. Description of the Related Art Conventionally, a configuration using a damper that absorbs ink pressure fluctuation is known in an inkjet printer. In such a damper, the pressure is adjusted by, for example, a leaf spring (see, for example, Patent Document 1).
JP-A-6-115092

  In recent years, the functions of inkjet printers have been diversified, and various inks and inkjet heads have been used. And the preferable supply pressure in the case of supplying ink to an inkjet head changes variously according to the difference in the viscosity by the kind of ink, and the capability of an inkjet head. Therefore, conventionally, it is necessary to change the configuration of the ink supply mechanism including the damper according to the type of ink and the capability of the ink jet head. However, if a damper or the like is individually designed for each type of ink or ink-jet head, the number of man-hours required for development increases, resulting in an increase in cost.

  To cope with this, for example, by making the ink supply pressure set by the damper variable, it is conceivable that the ink supply mechanism can be used in common even when the type of ink and the performance of the inkjet head are different. . Therefore, conventionally, for example, it has been demanded to provide a damper capable of setting the ink supply pressure freely and simply. Accordingly, an object of the present invention is to provide a damper and an ink jet printer that can solve the above-described problems.

In order to solve the above problems, the present invention has the following configuration.
(Configuration 1) A damper for adjusting a supply pressure of ink supplied to an ink jet head of an ink jet printer, a tank side liquid chamber storing ink supplied from an ink tank, and a head storing ink supplied to the ink jet head A side liquid chamber, an ink path through which ink flows from the tank side liquid chamber to the head side liquid chamber, and a pressure variable chamber capable of changing the setting of the supply pressure of ink supplied to the inkjet head by changing the pressure in the chamber A pressure transmission unit that transmits the pressure in the pressure variable chamber to the head side liquid chamber, and a valve that closes the ink path when the pressure in the tank side liquid chamber is higher than the pressure difference in the pressure variable chamber by a preset value. Prepare.

  When configured in this way, for example, the setting of the supply pressure of ink to be supplied to the inkjet head can be changed by changing the pressure in the pressure variable chamber. Therefore, if constituted in this way, a damper which can set ink supply pressure freely and simply can be provided, for example. This also makes it possible to stably supply ink to the inkjet head by an ink supply mechanism that uses the same damper, even when the type of ink and the capability of the inkjet head are different.

In this configuration, a valve is provided in the ink path between the head side liquid chamber and the tank side liquid chamber. Thereby, for example, it is possible to prevent the supply pressure of the ink supplied from the ink tank from greatly affecting the pressure in the head side liquid chamber. For example, when the supply pressure of the ink supplied from the ink tank temporarily increases, the ink path is closed by the valve, and the supply pressure of the ink supplied to the inkjet head can be prevented from excessively rising. Therefore, if comprised in this way, the supply pressure of the ink supplied to an inkjet head can be stabilized more appropriately, for example. This also makes it possible to change the supply pressure of the ink supplied to the inkjet head more appropriately.

  (Configuration 2) The valve closes the ink path according to the force in the direction from the tank side liquid chamber to the head side liquid chamber, and the ink path according to the force in the direction from the head side liquid chamber to the tank side liquid chamber. The damper opens a valve opening member that opens the valve according to the pressure in the pressure variable chamber by applying a force in the direction from the head side liquid chamber to the tank side liquid chamber to the valve according to the pressure in the pressure variable chamber. In addition. When the pressure in the pressure variable chamber becomes larger than a preset pressure, the valve opening member forcibly opens the valve according to the pressure in the pressure variable chamber, for example, regardless of the pressure in the head side liquid chamber.

  If comprised in this way, a valve can be forcedly opened as needed, for example. Accordingly, for example, when ink is forcibly filled into the head side liquid chamber, the ink supply pressure from the ink tank is intentionally increased, and the ink can be reliably filled in a short time.

  The forcible ink filling into the head side liquid chamber is performed, for example, at the time of cleaning the nozzles of the ink jet head or at the time of ink filling for filling the empty head side liquid chamber. In such a case, if ink is to be filled without forcibly opening the valve, for example, it may be necessary to suck out ink from the inkjet head. However, when such a method is used, there is a possibility that the time required for ink filling becomes very long. Further, for example, at the time of cleaning, there is a possibility that some of the nozzles may not be filled with sufficient ink.

  On the other hand, with the configuration 2, the ink can be reliably filled in the head side liquid chamber and the ink jet head in a short time. In addition, for example, sufficient ink can be appropriately filled in all the nozzles in the inkjet head.

  (Configuration 3) The ink path linearly connects the tank side liquid chamber and the head side liquid chamber, and the valve is provided in the tank side liquid chamber, and the ink path moves forward and backward in a direction parallel to the direction in which ink flows. The head side liquid chamber has an opening connected to the pressure variable chamber on the side opposite to the ink path in the valve advance / retreat direction, and the pressure transmission portion is an opening of the head side liquid chamber. The valve opening member is provided in the head side liquid chamber, and contacts the flexible membrane and the valve at one end and the other end, respectively, according to the pressure in the pressure variable chamber. Tell the valve the power. If comprised in this way, a valve can be appropriately opened by a valve opening member, for example.

  (Configuration 4) An opening member biasing spring that biases the valve opening member in a direction toward the flexible membrane is further provided. If comprised in this way, the pressure in the pressure variable chamber which will open a valve compulsorily can be set appropriately, for example.

  (Configuration 5) A valve biasing spring that biases the valve toward the head side liquid chamber in the tank side liquid chamber is further provided. If comprised in this way, the pressure difference of the pressure in the tank side liquid chamber which will close a valve, and the pressure in a pressure variable chamber can be set appropriately, for example.

  (Structure 6) An ink jet printer that performs printing by an ink jet system, and includes an ink tank that stores ink, the damper according to any one of structures 1 to 5, and a nozzle that discharges ink to a medium. With. If comprised in this way, the effect similar to the structures 1-5 can be acquired, for example.

  (Structure 7) A pressure setting unit for changing the pressure in the pressure variable chamber is further provided, and ink filling is performed so that the nozzle of the ink jet head is cleaned, or an empty head side liquid chamber is filled with ink from the tank side liquid chamber. At least one of the times, the pressure setting unit makes the pressure in the pressure variable chamber higher than when printing is performed in the inkjet printer. At least one of cleaning and ink filling, the ink tank supplies ink to the tank-side liquid chamber of the damper at a higher supply pressure than when printing is performed, for example. With such a configuration, for example, at the time of cleaning or ink filling, for example, the ink can be reliably filled in the head side liquid chamber and the ink jet head in a short time.

  According to the present invention, for example, it is possible to provide a damper capable of setting an ink supply pressure freely and simply.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. FIG. 1 shows an example of the configuration of an inkjet printer 10 according to an embodiment of the present invention. The ink jet printer 10 is a printing apparatus that performs ink jet printing, and includes a carriage 22, an ink jet head 12, a platen 14, a plurality of rollers 16, an ink tank 18, a damper 20, and a pressure setting unit 24.

  The carriage 22 holds the inkjet head 12 and the damper 20 and moves the inkjet head 12 in the main scanning direction by reciprocating in a predetermined main scanning direction on the medium 50. The inkjet head 12 is a print head having nozzles that eject ink onto the medium 50. In this example, the inkjet head 12 is held by the carriage 22 together with the damper 20 and reciprocates in the main scanning direction as the carriage 22 moves. Thereby, the inkjet head 12 discharges ink to each position on the medium 50 in the main scanning direction. The platen 14 is a table that holds the medium 50 onto which the ink is ejected by the inkjet head 12 on the upper surface. The plurality of rollers 16 convey the medium 50 in the conveyance direction orthogonal to the main scanning direction. Accordingly, the plurality of rollers 16 move the inkjet head 12 relative to the medium 50 in the sub-scanning direction orthogonal to the main scanning direction.

  The ink tank 18 is a tank that stores ink supplied to the inkjet head 12. In this example, the ink tank 18 supplies ink to the inkjet head 12 via the damper 20.

  The damper 20 constitutes a part of the ink supply mechanism of the ink jet printer 10 and is provided in the middle of the ink supply path connecting the ink tank 18 and the ink jet head 12 to supply ink to the ink jet head 12. Adjust pressure. In this example, the damper 20 can change the supply pressure to be set, and changes the ink supply pressure in accordance with the operation of the pressure setting unit 24. The pressure setting unit 24 changes the setting of the supply pressure of ink from the damper 20 to the inkjet head 12 according to the setting by the user of the inkjet printer 10, for example.

  According to this example, the setting of the supply pressure of the ink supplied to the inkjet head 12 can be changed appropriately. Therefore, the ink supply pressure can be set according to the difference in viscosity depending on the type of ink used and the performance of the inkjet head 12. This also makes it possible to perform printing with high accuracy.

  FIG. 2 is a cross-sectional view of the damper 20 showing an example of a detailed configuration of the damper 20. In this example, the damper 20 includes a tank side liquid chamber 102, an ink path 106, a head side liquid chamber 104, a flexible film 110, a pressure variable chamber 108, a valve 112, a valve opening member 114, and a plurality of springs 116, 118. Have

  The tank side liquid chamber 102 is a liquid chamber connected to the ink tank 18 via an ink path such as a tube, and stores ink supplied from the ink tank 18. The ink path 106 is a straight through hole that connects the tank side liquid chamber 102 and the head side liquid chamber 104, and allows ink to flow from the tank side liquid chamber 102 to the head side liquid chamber 104.

  The head-side liquid chamber 104 is a liquid chamber that is connected to the inkjet head 12 via an ink path such as a tube, and stores ink to be supplied to the inkjet head 12. In this example, the head-side liquid chamber 104 has an opening 202 connected to the pressure variable chamber 108 on the surface opposite to the surface connected to the ink path 106. The opening 202 is covered with a flexible film 110 that is an example of a flexible member.

  The flexible membrane 110 is also an example of a pressure transmission unit, and is provided between the pressure variable chamber 108 and the head side liquid chamber 104 to transmit the pressure in the pressure variable chamber 108 to the head side liquid chamber 104. The pressure variable chamber 108 is a liquid chamber or an air chamber that can change the pressure in the room, and changes the pressure in the room in accordance with the operation of the pressure setting unit 24.

  Here, the pressure setting unit 24 changes the pressure in the pressure variable chamber 108 by, for example, a pump or the like. Further, the pressure variable chamber 108 transmits the pressure in the chamber to the head side liquid chamber 104 via the flexible film 110. Further, the pressure in the head side liquid chamber 104 becomes the supply pressure of the ink supplied to the inkjet head 12.

  The valve 112 is provided in the tank-side liquid chamber 102 and opens and closes the ink path 106 by performing an advance / retreat operation in a forward / backward direction parallel to the direction in which the ink path 106 flows ink. In this example, the valve 112 closes the ink path 106 according to the force in the direction from the tank side liquid chamber 102 toward the head side liquid chamber 104. Further, the ink path 106 is opened according to the force in the direction from the head side liquid chamber 104 toward the tank side liquid chamber 102.

  The valve opening member 114 is a member that applies a force corresponding to the pressure in the pressure variable chamber 108 to the valve 112. In this example, the valve opening member 114 is provided in the head-side liquid chamber 104 and is in contact with the flexible membrane 110 and the valve 112 at one end and the other end, respectively. Therefore, when the pressure in the pressure variable chamber 108 increases, the valve opening member 114 applies a force in a direction from the head side liquid chamber 104 to the tank side liquid chamber 102 according to the pressure in the pressure variable chamber 108. Add to 112. Thereby, the valve opening member 114 forcibly opens the valve 112 according to the pressure in the pressure variable chamber 108.

  In this example, the contact area between the valve opening member 114 and the flexible membrane 110 is larger than the contact area between the valve opening member 114 and the valve 112. Therefore, according to this example, the force according to the pressure in the pressure variable chamber 108 can be transmitted to the valve 112 more appropriately. Also. Thereby, the valve 112 can be opened more appropriately.

  The plurality of springs 116 and 118 adjust the force applied to the valve 112 from the front and rear in the forward / backward direction. The spring 116 is an example of an opening member biasing spring, and biases the valve opening member 114 in a direction toward the flexible membrane 110. Accordingly, the spring 116 sets a pressure at which the valve 112 is forcibly opened by the pressure in the pressure variable chamber 108, for example. The spring 118 is an example of a valve biasing spring, and biases the valve 112 in a direction toward the head side liquid chamber 104 in the tank side liquid chamber 102. Thereby, for example, the spring 118 sets a pressure difference between the pressure in the tank-side liquid chamber 102 and the pressure in the pressure variable chamber 108 at which the valve 112 is closed.

  Hereinafter, the operation of the damper 20 will be described in more detail. In the following description, the pressure in the pressure variable chamber 108 is P1, the pressure in the head side liquid chamber 104 that is the supply pressure of the ink to be supplied to the inkjet head 12 is P2, and the pressure from the ink tank 18 to the tank side liquid chamber 102. P3 is the pressure in the tank-side liquid chamber 102 that is the supply pressure of the ink supplied to the tank. The spring pressure of the spring 116 is F1, and the elastic force of the spring 118 is F2.

In this example, for example, when the pressure P1 in the pressure variable chamber 108 is atmospheric pressure, the ink supply pressure P2 to the inkjet head 12 is determined by the balance of the spring pressures F1 and F2 of the springs 116 and 118. . From this state, for example, when the pressure P1 in the variable pressure chamber 108 is changed by the pressure setting unit 24, the ink supply pressure P2 also changes in accordance with the change in P1. For example, if the pressure setting unit 24 has a pressure P1 of the pressure-variable chamber 108 greater than atmospheric pressure, also supply pressure P2 of the ink is greater than P1 is atmospheric pressure. Further, for example, if the pressure setting section 24 is less than atmospheric pressure P1 in the pressure variable chamber 108, also the supply pressure P2 of the ink is smaller than P1 is atmospheric pressure.

  Therefore, according to this example, the setting of the supply pressure P2 of the ink supplied to the inkjet head 12 can be appropriately changed by changing the pressure P1 in the pressure variable chamber 108, for example. Therefore, for example, the ink supply pressure P2 can be set freely and simply. This also makes it possible to stably supply ink to the inkjet head 12 using the same damper 20 even when the type of ink and the performance of the inkjet head 12 are different.

  In this example, the valve 112 opens and closes based on the spring pressures F1 and F2 of the springs 116 and 118, the pressure P1 in the pressure variable chamber 108 transmitted by the valve opening member 114, and the pressure P3 in the tank side liquid chamber 102. When the pressure P3 in the tank side liquid chamber 102 is higher than the pressure P1 in the pressure variable chamber 108 by a preset pressure difference or more, the ink path 106 is closed. This pressure difference is determined according to the spring constant of the springs 116 and 118, for example.

  Therefore, in this example, for example, when the supply pressure P3 of the ink supplied from the ink tank 18 temporarily increases, the valve 112 is closed. Thereby, for example, the supply pressure P2 of the ink supplied to the inkjet head 12 can be prevented from excessively rising, and the supply pressure P1 of the ink can be stabilized more appropriately.

  Further, in this example, the valve opening member 114 presses the valve 112 in the direction in which the valve 112 opens in accordance with the pressure in the pressure variable chamber 108. As a result, for example, when the pressure in the pressure variable chamber 108 becomes larger than a preset pressure, the valve opening member 114 does not depend on the pressure in the head-side liquid chamber 104, for example, in the pressure variable chamber 108. Depending on the pressure, the valve 112 is forcibly opened.

  Therefore, according to this example, the valve 112 can be forcibly opened as necessary. Thereby, for example, when ink is forcibly filled into the head-side liquid chamber 104, the ink supply pressure P3 from the ink tank 18 can be intentionally increased to reliably fill the ink in a short time. . In addition, since the damper 20 is opened by opening the valve 112, the ink can be filled into the inkjet head 12 reliably in a short time.

  In addition, under such a configuration, the pressure setting unit 24 performs, for example, printing in which the pressure P1 in the pressure variable chamber 108 is printed in the inkjet printer at the time of cleaning in which the nozzles of the inkjet head 12 are cleaned. Make it higher than time. Further, even when ink is filled in the empty head side liquid chamber 104 from the tank side liquid chamber, the pressure P1 in the pressure variable chamber 108 is made higher than when printing is performed.

  Thereby, at the time of cleaning and ink filling, the valve opening member 114 forcibly opens the valve 112 and opens the damper 20. For example, the ink tank 18 supplies ink to the tank-side liquid chamber 102 at a supply pressure P3 that is higher than when printing is performed. According to this example, at the time of cleaning or ink filling, for example, ink can be reliably filled in the head-side liquid chamber 104 and the inkjet head 12 in a short time. This also makes it possible to appropriately increase the success rate of cleaning and ink filling.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

  The present invention can be suitably used for an inkjet printer, for example.

1 is a diagram illustrating an example of a configuration of an inkjet printer 10 according to an embodiment of the present invention. 3 is a cross-sectional view of the damper 20 showing an example of a detailed configuration of the damper 20. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Inkjet printer, 12 ... Inkjet head, 14 ... Platen, 16 ... Roller, 18 ... Ink tank, 20 ... Damper, 22 ... Carriage, 24 ... Pressure Setting unit, 50 ... medium, 102 ... tank side liquid chamber, 104 ... head side liquid chamber, 106 ... ink path, 108 ... pressure variable chamber, 110 ... flexible membrane (Pressure transmission part), 112... Valve, 114... Valve opening member, 116... Spring (opening member biasing spring), 118... Spring (valve biasing spring), 202. Part

Claims (7)

A damper for adjusting a supply pressure of ink to be supplied to an inkjet head of an inkjet printer,
A tank side liquid chamber for storing ink supplied from the ink tank;
A head side liquid chamber for storing ink to be supplied to the inkjet head;
An ink path for flowing ink from the tank side liquid chamber to the head side liquid chamber;
A pressure variable chamber capable of changing the setting of the supply pressure of the ink supplied to the inkjet head by changing the pressure in the chamber;
A pressure transmission unit for transmitting the pressure in the pressure variable chamber to the head side liquid chamber;
And a valve for closing the ink path when the pressure in the tank-side liquid chamber is higher than a pressure difference set in advance by a pressure higher than the pressure in the pressure variable chamber. The valve closes the ink path according to a force in a direction from the tank side liquid chamber to the head side liquid chamber, and according to a force in a direction from the head side liquid chamber to the tank side liquid chamber. Open the ink path,
The damper opens the valve according to the pressure in the pressure variable chamber by applying a force in a direction from the head side liquid chamber to the tank side liquid chamber to the valve according to the pressure in the pressure variable chamber. The damper according to claim 1, further comprising a valve opening member. The ink path linearly connects the tank side liquid chamber and the head side liquid chamber,
The valve is provided in the tank-side liquid chamber, and opens and closes the ink path by performing an advance / retreat operation in a forward / backward direction parallel to the direction in which the ink path flows.
The head side liquid chamber has an opening connected to the pressure variable chamber on the opposite side of the ink path in the advance / retreat direction of the valve,
The pressure transmission unit is a flexible film that covers the opening of the head-side liquid chamber,
The valve opening member is provided in the head-side liquid chamber, and contacts the flexible membrane and the valve at one end and the other end, respectively, thereby applying a force according to the pressure in the pressure variable chamber. The damper according to claim 2, wherein the damper is transmitted.   The damper according to claim 3, further comprising an opening member biasing spring that biases the valve opening member in a direction toward the flexible membrane.   The damper according to any one of claims 1 to 4, further comprising a valve biasing spring that biases the valve in a direction toward the head side liquid chamber in the tank side liquid chamber. An inkjet printer that performs printing by an inkjet method,
An ink tank for storing ink;
A damper according to any one of claims 1 to 5;
An ink jet printer comprising: an ink jet head having a nozzle for ejecting ink to a medium. A pressure setting unit for changing the pressure in the pressure variable chamber;
In at least one of cleaning when the nozzles of the inkjet head are cleaned or filling ink into the empty head side liquid chamber from the tank side liquid chamber, the pressure setting unit is configured to change the pressure. The inkjet printer according to claim 6, wherein the pressure in the room is set higher than when printing is performed in the inkjet printer.

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