JP2016007750A - Ink cartridge and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink cartridge to which a lid member is welded in a relatively short time with sufficient strength without causing breakage of a recording element substrate and a method of manufacturing the same.SOLUTION: In an ink tank 4 to which a lid member 7 is welded with ultrasonic wave, two facing lateral walls 4a and 4b are made to be asymmetric, and phases in which the lateral walls 4a and 4b are deformed at the time of ultrasonic welding are made to be different from each other to suppress strong stress from acting on a recording element substrate 2.

Description

  The present invention relates to an ink cartridge and a method for manufacturing the same.

  In an ink cartridge in which a recording element substrate for ejecting ink and an ink tank for supplying ink to the recording element substrate are integrally configured, the ink is accommodated in a hollow ink cartridge body, and then a lid member is joined to the opening. Manufactured by. At this time, while pressing the lid member from the upper side against the opening, the lid member is vibrated in the pressing direction, the mutual heat is generated by the frictional heat generated on the contact surface between the resins, and further cooling is performed. So-called vibration welding that couples the two may be employed. Among vibration welding, ultrasonic welding is particularly excellent and useful in terms of short time, high accuracy, high reproducibility, high airtightness, and strong welding power. However, in a configuration that applies so-called longitudinal vibration in which the pressing direction and the vibration direction coincide with each other, wave deformation occurs in the side wall of the ink tank during vibration welding, and the recording element substrate bonded to the side facing the lid member There is a risk of cracking.

  For this reason, for example, in Patent Document 1, as shown in FIG. 9, the vibration of the booster 61 is transmitted to the workpiece 64 through the horn 62, so that the direction perpendicular to the pressing direction (that is, the lateral direction) is transmitted. A method of welding an object by ultrasonic vibration is disclosed. Further, in Patent Document 2, as shown in FIG. 10, in a state where the cartridge main body is installed in the receiving jig 13a and the lid member is installed in the upper jig 13b, the two are pressed laterally and are vibrated with the same amplitude. A method for avoiding welding unevenness is disclosed.

Japanese Patent Laid-Open No. 10-16244 JP 2006-44230 A

  However, according to the method of Patent Document 1, a certain amplitude difference occurs in the lateral vibration depending on the distance from the booster 61 (for example, 65 and 66). Therefore, when the ultrasonic welding is applied to the large workpiece 64, the welding strength is uneven between regions having different amplitudes, and sufficient strength cannot be obtained. The technique disclosed in Patent Document 1 is an effective technique when assembling a micro component having a welding area of about 10 mm, such as manufacturing a recording element substrate by bonding an orifice plate to a heater board. That is, the method of Patent Document 1 is effective for a workpiece of such an order. However, when the ink cartridge and the lid member are welded as the problem of the present invention, the welding strength is high. There are concerns that it will be insufficient.

  On the other hand, the method of Patent Document 2 is vibration welding using a jig, and there is a problem that it takes longer time and cost than conventional ultrasonic vibration of longitudinal vibration, and sufficient productivity cannot be obtained.

  The present invention has been made to solve the above problems. Accordingly, an object of the present invention is to provide an ink cartridge in which a lid member is welded in a relatively short time and with a sufficient strength without causing damage to the recording element substrate, and a method for manufacturing the ink cartridge.

  To this end, the present invention provides a recording element substrate on the bottom surface, and two ink tanks facing each other that connect the bottom surface and the opening to an ink tank that is an opening having a surface opposite to the bottom surface. An ink cartridge manufactured by closing the opening by ultrasonically welding a lid member to the side wall, wherein the two side walls are asymmetric.

  According to the present invention, it is possible to suppress the damage of the recording element substrate when performing ultrasonic welding of the lid member, and to improve the yield when manufacturing the ink cartridge.

(A) And (b) is a block diagram of an ink cartridge. FIG. 3 is an enlarged configuration diagram of a recording element substrate. It is a figure which shows a mode that an ink absorber is inserted in an ink tank. It is a block diagram of a cover member. (A)-(d) is a figure which shows the manufacturing process of an ink cartridge. (A)-(c) is the figure which showed the deformation | transformation state of the ink tank wall surface of this invention. (A)-(c) is the figure which showed the deformation | transformation state of the conventional ink tank wall surface. It is a figure which shows another shape of the ink tank employable for this invention. It is a figure which shows a conventional structure. It is a figure which shows a conventional structure.

  1A and 1B are configuration diagrams of an ink cartridge 1 that can be employed in the present invention. FIG. 1A is an external perspective view of the ink cartridge 1, and FIG. 1B is a cross-sectional view taken along line AA ′. The ink cartridge 1 mainly includes a hollow ink tank 4, an ink absorber 3 contained in the ink tank 4 and containing ink, a recording element substrate 2 on which recording elements for ejecting ink are arranged, and an upper surface of the ink tank 4. It is comprised from the cover member 7 for covering an opening part. The ink tank 4 is formed of a resin material having a high barrier property containing glass fibers so as to suppress evaporation of ink components. A plurality of recording elements are arranged in the Y direction on the recording element substrate 2, and the ejection direction of the individual recording elements and the direction in which the lid member 7 is pressed against the ink tank 4 are substantially the same in the Z direction. In the present embodiment, the two opposing side walls 4a and 4b connected in the direction from the bottom surface side to the opening side of the ink tank 4 have different thicknesses. Specifically, the left side wall 4a in the figure has a thickness of 2.3 mm, and the right side wall 4b has a thickness of 1.8 mm. The effect of such a feature will be described in detail later.

  FIG. 2 is an enlarged configuration diagram of the recording element substrate 2. The recording element substrate 2 is configured by adhering an orifice plate 23 having discharge ports to a silicon substrate 21 on which a heater is disposed. An ink supply port 21A extending in the Y direction is formed in a groove shape in the silicon substrate 21, and a plurality of heaters 22 are arranged in the Y direction at a predetermined pitch on both sides thereof. The ink supplied from the ink tank 4 is guided to individual heaters via the ink supply port 21A. In the orifice plate 23, discharge ports 23A are formed at positions corresponding to the individual heaters. On both sides of the silicon substrate 21 in the Y direction, electrode portions 24 for receiving recording signals for applying individual heaters are provided. Under such a configuration, when a voltage pulse is applied to the heater in accordance with the recording signal, film boiling occurs in the ink as the heater generates heat, and ink is ejected as droplets from the ejection port 23A by the foaming energy.

  FIG. 3 is a diagram showing how the ink absorber 3 is inserted into the ink tank 4. The ink absorber 3 is configured by laminating a plurality of absorption layers having fibers extending in the Z direction in the X direction, and is inserted in the Z direction from the opening of the ink tank 4 in a compressed state. After the ink absorber 3 is inserted, the ink absorber 3 is filled with a predetermined amount of ink, and then the lid member 7 is ultrasonically welded to close the ink tank 4.

  FIG. 4 is a configuration diagram of the lid member 7. The lid member 7 has substantially the same dimensions as the opening of the ink tank 4, and a welding rib 9 protruding in the Z direction for joining to the opening is provided on the outer periphery thereof. In the present embodiment, the welding rib 9 has a width of 0.8 mm and a length of 0.7 mm in the Z direction. An air communication port 8 for communicating the inside of the ink tank 4 after the lid member 7 is welded with the air is provided at the center, and a press-contact rib 12 for pressing the ink absorber 3 in the Z direction is provided in the periphery thereof. Is deployed.

  5A to 5D are cross-sectional views for explaining the manufacturing process of the ink cartridge 1. FIG. 5A shows a state where the ink absorber 3 is inserted into the ink tank 4 and filled with ink. FIG. 5B shows a state in which the lid member 7 is mounted in the opening located on the side opposite to the recording element substrate 2 after FIG. 5A. The welding rib 9 of the lid member 7 is aligned so as to contact the peripheral upper end 11 of the ink tank 4.

  When the alignment is completed, as shown in FIG. 5C, the ultrasonic horn 10 is moved to the upper surface of the lid member 7, and the lid member 7 is pressed toward the ink tank 4 in the Z direction. In the present embodiment, the ultrasonic horn is pressed to such an extent that a pressure of about 200 N is applied between the welding rib 9 and the peripheral upper end 11.

  When it is confirmed that a pressure of about 200 N is applied almost uniformly to the peripheral upper end 11, the ultrasonic horn vibrates longitudinally at a frequency of about 20 HHz while maintaining the pressure (FIG. 5D). By this longitudinal vibration, frictional heat is generated at the contact surface between the welding rib 9 and the peripheral upper end 11, and the resin component including the glass material of the welding rib 9 and the peripheral upper end 11 is compatibilized. After the two are sufficiently compatible, when the longitudinal vibration is stopped and cooled, the welding rib 9 and the peripheral upper end 11 are fixed, and the ink cartridge in which the lid member 7 and the ink tank 4 are coupled is completed.

  FIGS. 6A to 6C are views showing a deformed state of the wall surface of the ink tank 4 that occurs during the longitudinal vibration as shown in FIG. 7A to 7C show the deformation of the wall surface when using a conventional ink tank, that is, an ink tank having the same thickness of two opposite side walls when longitudinal vibration is generated under the same conditions. FIG.

  When the longitudinal vibration is applied to the end of the wall surface, the wall surface is deformed so as to wave (transverse vibration) accordingly. At this time, if longitudinal vibrations having the same amplitude and frequency are added to the same shape (thickness) side wall of the same material, that is, a symmetrical side wall, these side walls have the same phase as shown in FIGS. 7 (a) and (b). And is transmitted to the bottom surface of the ink tank 4. As a result, the recording element substrate 2 disposed on the bottom surface via the adhesive 6 is repeatedly subjected to stress that is pulled from both sides or pushed from both sides as shown in FIG. As a result, cracks are likely to occur in the structure formed in units of several microns, and the possibility of damage to the recording element substrate increases.

  On the other hand, when the thicknesses of two side walls facing each other are different as in the present embodiment, even if longitudinal vibrations having the same amplitude and frequency are applied, these side walls have different phases as shown in FIGS. 6 (a) and (b). Deform. For this reason, it becomes difficult to repeatedly apply stress to the recording element substrate that is pulled from both sides or pushed from both sides (FIG. 6C). As a result, it is possible to reduce the risk of cracking compared to FIG. That is, according to the present embodiment, the thickness of the two side walls 4a and 4b facing each other of the ink tank 4 is made different, so that the recording element substrate is prevented from being damaged when the lid member is ultrasonically welded. The yield of time can be improved.

  In the above description, an example in which the thicknesses of the two side walls 4a and 4b facing the ink tank 4 are different from each other has been described. However, the present invention is not limited to such a form. The effect of the present invention can be obtained if the two side walls 4a and 4b facing each other are in an asymmetric relationship.

  FIG. 8 is a diagram showing another shape of the ink tank that can be used in the present invention. Of the two side walls 5a and 5b facing the X direction of the ink tank 5, the thickness of the side wall 5a changes in two stages. Even in such a form, when the same longitudinal vibration is applied to the side walls 5a and 5b, these two side walls are deformed in different phases. That is, the stress that is pulled from both sides or pushed from both sides does not act repeatedly on the recording element substrate 2. As a result, the risk of occurrence of cracks can be kept low, and the yield at the time of manufacturing the ink cartridge can be improved.

1 Ink cartridge
2 Recording element substrate
4 Ink tank 4a, 4b Side wall
7 Lid member

Claims (5)

A recording element substrate is disposed on the bottom surface, and an ink tank that is an opening having an opening on the opposite side to the bottom surface is provided with a lid member on two opposite side walls of the ink tank that connects the bottom surface and the opening. An ink cartridge manufactured by closing the opening by sonic welding,
The ink cartridge is characterized in that the two side walls are asymmetric.   2. The ink cartridge according to claim 1, wherein the ultrasonic welding is performed by applying ultrasonic longitudinal vibration in a pressing direction in a state in which the lid member is pressed against the two side walls.   The ink cartridge according to claim 1, wherein the two side walls have different thicknesses.   3. The ink cartridge according to claim 1, wherein the thickness of one of the two side walls changes in a direction from the bottom surface toward the opening. An ink cartridge manufacturing method comprising:
A recording element substrate is provided on the bottom surface, and a lid member is pressed to a plurality of side walls connecting the bottom surface and the opening portion with a predetermined pressure against an ink tank that is an opening portion having a surface opposite to the bottom surface. Capping the opening;
While maintaining the predetermined pressure, by applying longitudinal vibration to the lid member at a predetermined frequency in a direction toward the bottom surface, frictional heat is generated on the contact surface of the lid member and the opening to generate the heat. Welding the lid member to the ink tank;
Have
A method for manufacturing an ink cartridge, wherein two of the plurality of side walls are asymmetric.