JP2011240543A - Inkjet head unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet head unit highly reliable in joining, in which there is a difference of a coefficient of linear thermal expansion between a base plate and a channel forming member.SOLUTION: The inkjet head unit includes: the base plate 2 on which ink jetting members 4 are arranged in rows; and a channel forming member 3 which is connected to a side of the base plate 2 opposite to a side where the ink jetting members 4 are arranged, and forms a channel 8 to supply ink to the base plate 2 externally. The base plate 2 is provided with: a common liquid chamber 6 formed corresponding to the width in the row direction of the row consisting of two or more ink jetting members 4; and a communication opening 9 that communicates the common liquid chamber 6 and the channel 8 of the channel forming member 3. A connected part of the channel forming member 3 to the base plate 2 is provided corresponding to only the region of an opening edge of the communication opening 9.

Description

  The present invention relates to an inkjet head unit that performs recording by discharging a liquid. In particular, the present invention relates to a long-type inkjet head unit.

  In an ink jet recording apparatus, recording is performed by ejecting fine droplets of ink from a plurality of ejection openings arranged on an ink ejection member. As the discharge port array is longer, a wider area can be recorded, so that high-speed recording is possible. In recent years, a long type inkjet head unit having a long discharge port array has been proposed.

  In forming the ejection port in the ink ejection member, if any one of the numerous ejection ports is different from the others, the ink ejection member cannot be used in a product. When a long type inkjet head unit is configured with one ink ejection member without reducing the density of ejection ports, the number of ejection ports per ink ejection member increases, so the yield of ink ejection members is increased. It was falling.

  Therefore, Patent Document 1 discloses an inkjet head unit in which the number of ejection ports per ink ejection member is reduced and a plurality of ink ejection members are arranged to lengthen the ejection port array. Since this method can reduce the number of ejection openings per ink ejection member, it is possible to suppress a decrease in yield of the ink ejection member.

  An inkjet head unit disclosed in Patent Document 1 includes a base plate in which a plurality of ink discharge members are arranged in a row, and a flow path forming member that is bonded to the side of the base plate opposite to the ink discharge member side. have. The flow path forming member forms a flow path for supplying ink to the base plate from the outside. A slit is formed in the base plate at a position where the ink discharge member is disposed, and a common liquid chamber is formed in the flow path forming member so as to communicate with the slit. By sending ink to the common liquid chamber, the ink is uniformly supplied to the ink ejection member through the slit.

JP 2007-296638 A

  However, in the inkjet head unit disclosed in Patent Document 1, the flow path forming member must be fixed to the base plate so as to cover a plurality of slits formed in the base plate. Accordingly, the joint between the base plate and the flow path forming member extends over substantially the entire surface of the base plate adjacent to the flow path forming member, and the width of the joint becomes longer as the ink jet head unit becomes longer.

  When the width of the joint portion is long, when the base plate and the flow path forming member are inflated at different linear expansion rates during use of the ink jet head unit, there is a difference in the amount of expansion of both at the joint portion. Therefore, a large force is applied to the joint, and there is a possibility that peeling occurs at the joint.

  In particular, in order to eject ink, when heat is applied to the ink and pressure is used when bubbles in the ink grow, heat is generated each time the ink is ejected. That is, the heat of the ink discharge member is transmitted to the base plate and the flow path forming member, and the thermal expansion is repeated, so that the joint portion is easily peeled off and the reliability of the joint portion is reduced.

  A ceramic such as alumina or silicon carbide having a linear expansion coefficient substantially equal to that of the ink discharge member is used for the base plate, and a resin material capable of forming a complicated shape is used for the flow path forming member. Generally, a resin material has a larger linear expansion coefficient than a ceramic, and there is a difference in linear expansion coefficient between the base plate and the flow path forming member. If the flow path forming member is formed of a material having a linear expansion coefficient substantially equal to that of the base plate, there is a risk of an increase in cost and a decrease in moldability.

  Therefore, the present invention provides an ink jet head unit having a high reliability of the joint between the base plate and the flow path forming member in the ink jet head unit having a difference in linear expansion coefficient between the base plate and the flow path forming member. With the goal.

  In order to achieve the above object, according to the present invention, a base plate in which ink discharge members are arranged in a row is joined to a side of the base plate opposite to the side on which the ink discharge member is arranged, and ink is supplied from the outside to the base plate. A flow path forming member that forms a flow path for supplying to the liquid crystal. The base plate includes a common liquid chamber formed corresponding to the width in the column direction of the plurality of ink discharge members, and a communication port that communicates the common liquid chamber and the flow path of the flow path forming member. The part joined to the base plate of the flow path forming member is provided corresponding to only the region of the opening edge of the communication port.

  According to the present invention, in an inkjet head unit having a difference in linear expansion coefficient between the base plate and the flow path forming member, the reliability of the joint portion between the base plate and the flow path forming member is enhanced.

1 is a schematic cross-sectional view of an inkjet head unit in an embodiment of the present invention. 1 is a perspective view of an inkjet head unit in an embodiment of the present invention. 1 is an exploded perspective view of an inkjet head unit in an embodiment of the present invention. The disassembled perspective view of a flow-path formation member. The exploded perspective view of a base plate. The exploded plan view which shifted each layer of the baseplate planarly.

  Next, specific embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a sectional view schematically showing an ink jet head unit 1 according to the present invention.

  The ink jet head unit 1 is provided with a base plate 2, and a plurality of ink ejection members 4 for ejecting liquid droplets of ink are arranged on one surface of the base plate 2. A slit 5 is formed corresponding to the position of the base plate 2 where the ink discharge member 4 is disposed.

  A common liquid chamber 6 is formed in the base plate 2 corresponding to the width in the row direction of the row of the ink discharge members 4. Therefore, the common liquid chamber 6 is provided so as to communicate with the slit 5.

  A plurality of flow path forming members 3 are fixed to the surface of the base plate 2 that is located on the opposite side of the surface on which the ink discharge member 4 is disposed. A connection port 7 for transmitting and receiving ink to and from the outside is formed at a position where each channel forming member 3 is not in contact with the base plate 2. In addition, a flow path 8 is formed from the connection port 7 to the base plate 2 inside each flow path forming member, and a communication port 9 for communicating the flow path 8 and the common liquid chamber 6 is formed in the base plate 2. Is provided.

  The flow path 8 is provided with a filter 10 for removing dust and bubbles in the ink from the connection port 7 toward the base plate 2.

  In the present embodiment, a plurality of flow path forming members 3 are provided, a communication port 9 for communicating one flow path forming member 3 and the common liquid chamber 6, and another flow path forming member 3 and a common liquid chamber. Another communication port 9 that communicates with 6 is formed at a position farthest from each other in the common liquid chamber 6. That is, as shown in FIG. 1, one communication port 9 is formed in the vicinity of one end of the common liquid chamber 6, and the other communication port 9 is formed in the vicinity of the other end of the common liquid chamber 6. Is formed.

  In this embodiment, when ink is supplied from one communication port 9, the ink is discharged from the other communication ports 9 after all the ink ejection members 4 are filled with ink. Therefore, by disposing the communication port 9 apart, a sufficient amount of ink is uniformly fed to the ink ejection member 4, and an insufficient amount of ink in the ink ejection member 4 is suppressed.

  The flow path forming member 3 is joined to the base plate 2 at the joint portion 11 at the opening edge of the communication port 9. Examples of the bonding method include a method in which an adhesive is applied and bonded to the bonding portion 11.

  In the present embodiment, the joint portion 11 between the flow path forming member 3 and the base plate 2 is provided in a limited region corresponding only to the opening edge of the communication port 9. Therefore, even if the base plate 2 and the flow path forming member 3 expand with heat, the dimensional change of the joint portion 11 due to the expansion is small. Therefore, the joining part 11 does not receive a large force, and peeling at the joining part 11 is suppressed.

  Moreover, even if the area | region which applies an adhesive agent is narrow and the quantity of an adhesive agent is small, since expansion / contraction of the junction part 11 is small, peeling in the junction part 11 can be suppressed. Therefore, the cost of the adhesive can be reduced.

  Furthermore, a seal member and a screw can be used for joining the base plate 2 and the flow path forming member 3. In fixing using screws, a plurality of screws are evenly arranged in the joint portion 11 in order to increase the fixing force.

  In the structure in which the common liquid chamber 6 is formed in the flow path forming member 3 and the joint portion 11 is provided long along the base plate 2 as in the prior art, the range in which the screw is arranged is widened. Therefore, the amount of expansion due to heat increases, and the screw is easily damaged or loosened.

  In this embodiment, since the opening edge of the communication port 9 is fixed with a screw, the distance between the screws is small, and damage or loosening of the screw can be suppressed by thermal expansion.

  When the base plate 2 and the flow path forming member 3 are bonded with an adhesive, since the bonding portion 11 comes into contact with the ink, an adhesive that does not elute into the ink and whose adhesive strength is not weakened by the ink is required. In the fixing method using the seal member and the screw, since the base plate 2 and the flow path forming member 3 are held by the screw, a material that does not elute into the ink may be used for the seal member, and the selection of the material can be expanded.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these. In the following description, the same portions as those shown in the above-described embodiment will be described using the same reference numerals.

Example 1
2A and 2B are perspective views of the inkjet head unit 1 in the first embodiment of the present invention, and FIGS. 3A and 3B are exploded perspective views of the inkjet head unit 1. FIG.

  As shown in FIG. 2, the inkjet head unit 1 is provided with a base plate 2, and a plurality of ink ejection members 4 are arranged on one surface of the base plate 2 in a staggered manner. By arranging the ink discharge members 4 in a staggered manner, an overlapping region is formed between the ink discharge members 4 and the ink discharge members 4, and ink can be discharged without a gap.

  A flow path forming member 3 is fixed to the surface of the base plate 2 that is located on the opposite side of the surface on which the ink ejection member 4 is disposed.

  FIG. 4 is an exploded perspective view of the flow path forming member 3. As shown in FIG. 4, the flow path forming member 3 includes a main forming member 18 that forms the connection port 7 and the flow path, and a lid member 19 that serves as a lid for the main forming member 18. A joint rubber 17 is press-fitted into the connection port 7.

  Ink is supplied to the flow path forming member 3 by connecting a tube or the like provided in an ink tank (not shown) to the connection port 7. By providing the joint rubber 17 at the connection port 7, it is possible to prevent ink from evaporating from the connection port 7 and ink leakage during ink supply.

  The main forming member 18 is formed with a flow path (not shown) from the connection port 7 to the base plate 2. In the present embodiment, a first flow path (not shown) for supplying ink to the main forming member 18 and a second flow path (not shown) for discharging are provided. The first and second flow paths merge inside the main forming member 18 so that the ink that has passed through the second flow path can pass through the first flow path again.

  A first filter 37 and a second filter 38 are provided in the first and second flow paths, respectively.

  After the joint rubber 17, the first filter 37 and the second filter 38 are fixed to the main forming member 18, the lid member 19 is joined to the main forming member 18 by US welding (ultrasonic welding) or the like. The forming member 3 is formed.

  As shown in FIGS. 2 and 3, the electrical signal connection member 12 having the connector 13 is fixed so as to cover one surface of the base plate 2.

  As shown in FIG. 3B, a slit 5 is formed at a position where the ink discharge member 4 of the base plate 2 is disposed, and a window is provided at a position corresponding to the ink discharge member 4 of the electric signal connection member 12. 14 is provided. Accordingly, the ink is sent to the ink discharge member 4 through the slit 5.

  The ink discharge member 4 is provided with a pad portion (not shown) for receiving an electric signal, and the pad portion and the electric signal connection member 12 are electrically connected using a welding technique such as wire bonding. . Therefore, the electrical signal received from the connector 13 is transmitted to the ink ejection member 4 via the electrical signal connection member 12.

  Further, as shown in FIGS. 2 and 3, a reference member 16 serving as a reference for the position of the inkjet head unit 1 is fixed to the base plate 2. When the ink jet head unit 1 is mounted on the ink jet recording apparatus, the reference member 16 improves the positional accuracy between the ink discharge member 4 and the recording member, and high recording quality is obtained.

  FIG. 5 is an exploded perspective view of the base plate 2. As shown in FIG. 5, the base plate 2 is formed by laminating the first to third slit layers 20, 21 and 22, the common liquid chamber layer 23, the partition layer 24, the flow path layer 25 and the communication port layer 26 in this order. Is formed by.

  FIG. 6 is an exploded plan view when the layers of the base plate 2 are shifted in a plane. A slit 5 is formed in the first to third slit layers 20, 21 and 22, and a common liquid chamber 6 is formed in the common liquid chamber layer 23 so as to communicate with the slit 5.

  A supply port 33 is formed at a position corresponding to one end of the common liquid chamber 6 in the partition layer 24, and a discharge port 34 is formed at a position corresponding to the other end of the common liquid chamber 6. Has been.

  In the flow path layer 25, a supply flow path 31 that communicates with the common liquid chamber 6 through the supply port 33 and a discharge flow path 32 that communicates with the common liquid chamber 6 through the discharge port 34 are formed. .

  In the partition layer 24, which corresponds to the common liquid chamber 6, a hole penetrating the partition layer 24 is not formed except at a position where the supply port 33 and the discharge port 34 are formed. The supply port 33 is formed at one end of the common liquid chamber 6, and the discharge port 34 is formed at the other end. Therefore, the ink sent from the supply flow path 31 to the common liquid chamber 6 is sent to the discharge flow path 32 after filling the ink discharge member 4.

  The flow path forming member 3 is joined to the side of the communication port layer 26 opposite to the side where the flow path layer 25 is adjacent. The first communication port 35 and the second communication port 36 communicate with each other so that the first flow channel and the second flow channel of the flow channel forming member 3 communicate with the supply flow channel 31 and the discharge flow channel 32. It is formed in the mouth layer 26. Therefore, the first communication port 35 and the second communication port 36 can be formed close to each other by arbitrarily determining the shapes of the supply channel 31 and the discharge channel 32.

  Further, a channel forming member fixing hole 27 for fixing the channel forming member 3 and a reference member screwing hole 30 for screwing the reference member 16 are formed in each layer. The first communication port 35 and the second communication port 36 are formed so as to be sandwiched between the flow path forming member fixing holes 27. Accordingly, the bonding force between the first communication port 35 and the second communication port 36 and the flow path forming member 3 is increased.

  In this embodiment, as shown in FIG. 6, a reference member positioning hole 29 for positioning the reference member 16 is formed in the second slit layer 21, and the positioning portion of the reference member 16 is provided in the other layer. A hole for guiding to the reference member positioning hole 29 is provided. By forming the reference member positioning hole 29 in the second slit layer 21, that is, a layer close to the ink discharge member 4, the positional accuracy between the ink discharge member 4 and the reference member 16 can be improved.

  According to this embodiment, by providing the slit 5, the common liquid chamber 6, the supply flow path 31, and the discharge flow path 32 inside the base plate 2, even if a plurality of ink discharge members 4 are combined, at least two communication ports are provided. Can be summarized. Therefore, the joint portion between the flow path forming member 3 and the base plate 2 can be minimized.

  The base plate 2 and the flow path forming member 3 are fixed by joints formed at the opening edges of the first communication port 35 and the second communication port 36. For the joining portion, any one of an adhesive or a sealing member and screwing is used. Since the joint between the base plate 2 and the flow path forming member is a limited region, even if there is a difference in the linear expansion coefficient between the base plate 2 and the flow path forming member 3, a highly reliable joint can be obtained. . Moreover, since the amount of the adhesive can be suppressed, there is an effect of cost reduction.

  In particular, the joining for fixing the base plate 2 and the flow path forming member 3 using a sealing member and screwing is easy to assemble, and in the case of a defective part, it can be removed once and reassembled. Productivity can be improved.

DESCRIPTION OF SYMBOLS 1 Inkjet head unit 2 Base plate 3 Flow path forming member 4 Ink ejection member 5 Slit 6 Common liquid chamber 8 Flow path 9 Communication port 11 Joint 16 Reference member 20 First slit layer 21 Second slit layer 22 Third slit Layer 23 Common liquid chamber layer 24 Partition layer 25 Channel layer 26 Communication port layer

Claims (8)

A base plate in which ink discharge members are arranged in a row and a flow path for supplying ink to the base plate from the outside are formed by joining the base plate to the side opposite to the side on which the ink discharge member is arranged. An ink jet head unit comprising:
The base plate includes a common liquid chamber formed corresponding to the width in the column direction of the plurality of ink discharge members, and a communication port that communicates the common liquid chamber and the flow path of the flow path forming member. ,
The ink jet head unit according to claim 1, wherein a joint portion to be joined to the base plate of the flow path forming member is provided corresponding only to a region of an opening edge of the communication port.   A common liquid chamber in which the base plate includes a slit layer having a plurality of slits corresponding to a plurality of positions where the ink discharge members are disposed, and the common liquid chamber provided so as to communicate with some of the slits. The inkjet head unit according to claim 1, further comprising: a layer, and a communication port layer provided between the common liquid chamber layer and the flow path forming member and having the communication port.   The inkjet head according to claim 2, further comprising: a flow path layer that forms a flow path connecting the common liquid chamber and the communication port between the common liquid chamber layer and the communication port layer. unit.   4. The ink jet head unit according to claim 1, wherein the joint is an adhesive applied to a region of an opening edge of the communication port. 5.   The said joint part has a sealing member corresponding to the area | region of the opening edge of the said communicating port, The said flow path formation member is being fixed with the screw with respect to the said base plate. The inkjet head unit of any one of Claims.   The inkjet head unit according to claim 5, wherein the screw is disposed so as to sandwich the communication port. A reference member adjacent to the base plate and serving as a reference for the position of the ink discharge member is further provided,
The base plate has a reference member positioning hole for positioning the reference member;
The inkjet according to any one of claims 1 to 6, wherein the reference member positioning hole is formed in a layer adjacent to a layer of the base plate on which the ink ejection member is disposed. Head unit.   The inkjet head unit according to claim 1, wherein the flow path forming member and the base plate have different linear expansion coefficients.

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