JP4437409B2 - Filter unit - Google Patents

Description

  The present invention relates to a filter unit that is disposed in a flow path through which liquid flows, for example, is disposed in a flow path through which ink (liquid) in an ink jet recording apparatus flows, and removes foreign matters contained in the liquid (ink).

  An ink jet recording apparatus forms an image by ejecting ink droplets from a plurality of nozzles provided in an ink jet head in accordance with image data and attaching the ejected ink droplets to a recording medium. Ink flows from the ink reservoir through the flow path and is supplied to the inkjet head.

  In such an ink jet recording apparatus, if foreign matter exists in the ink, the foreign matter is clogged in the nozzle, ink droplet ejection performance from the nozzle is lowered, and the quality of the formed image is lowered.

  For this reason, a filter unit containing a filter in a housing is installed in the flow path to remove foreign substances contained in the ink. As a structure of the filter unit, there is known a structure in which a housing is formed by two members and a filter is sandwiched between these two members and ultrasonic welding is performed (for example, Patent Documents 1, 2, and 3). In these filter units, two spaces partitioned by a filter are formed in the housing, one space is connected to the ink reservoir, and the other space is connected to the inkjet head.

Japanese Patent Laid-Open No. 2001-239677 JP 2002-67342 A JP-A-8-197736

  It is known that when ultrasonically welding a resin or the like, burrs are generated when the ultrasonically welded portion is melted and crushed, and dust is generated by dropping the burrs or a part of the burrs. Yes.

  In the invention disclosed in Patent Document 1, when two members forming the housing are ultrasonically welded with a filter interposed therebetween, dust generated from the two members along with the ultrasonic welding is connected to an ink reservoir in the housing. And the space connected to the inkjet head. It is not a problem that dust enters the space connected to the ink reservoir in the housing, but if dust enters the space connected to the ink jet head, the dust causes clogging of the nozzles.

  In the invention disclosed in Patent Document 2, the filter is thermally welded to one member forming the housing, and then the member to which the filter is thermally welded and the other member are ultrasonically welded. Occurrence of dust entering the space connected to the inkjet head in the housing is sometimes reduced. However, as a process for forming the filter unit, a heat welding process for the filter and an ultrasonic welding process for forming the housing are required, which increases the number of processes and increases the cost.

  In the invention disclosed in Patent Document 3, the generation of dust that enters the space connected to the ink jet head in the housing is prevented during ultrasonic welding for forming the housing, and the filter is removed after ultrasonic welding. A seal member for sealing the peripheral edge is provided. However, the seal member may be deteriorated by the ink component to generate a gap, and foreign matter contained in the ink passes through the gap portion, and the filter function is impaired. In order to prevent the deterioration of the seal member, the seal member may be formed of a material that is durable against various inks. However, such a material may include some fluorine that is an expensive material. It is rubber, and the cost is increased by forming the sealing member with such fluororubber.

  An object of the present invention is to provide a liquid chamber formed in a filter unit at the time of ultrasonic welding when forming a fill unit containing a filter by ultrasonic welding of a primary housing and a secondary housing. In other words, it is possible to prevent the generation of dust in which the liquid that has passed through the filter enters the secondary liquid chamber supplied to the liquid supply portion.

The filter unit of the present invention is disposed in a flow path connecting a liquid supply section and a liquid supply section to which liquid is supplied from the liquid supply section, and ultrasonically welds the primary side housing and the secondary side housing. One of the filters at a position inside the ultrasonic welding portion between the primary side housing and the secondary side housing provided in the primary side housing, the filter housed in the housing, and the filter housed in the housing. A primary side contact portion that is in contact with an outer peripheral portion of one side of the filter, and a filter that is provided on the secondary side housing and is located at a position inside the ultrasonic welding portion between the primary side housing and the secondary side housing. Formed in the housing surrounded by the secondary side contact portion that is in contact with the outer peripheral portion of the other side, the primary side housing, the primary side contact portion, and the filter. And formed in the housing surrounded by the primary liquid chamber connected to the liquid supply section, the secondary housing, the secondary contact section, and the filter. A secondary side liquid chamber connected thereto, wherein the melting point of the secondary side contact portion is higher than the melting point of the primary side housing, the melting point of the secondary side housing, and the melting point of the primary side contact portion. It is set.
At the time of ultrasonic welding, the primary side housing and the secondary side housing are brought into contact with each other, the primary side contact portion is brought into contact with the outer peripheral portion of one side of the filter, and the secondary side contact portion is filtered. Then, ultrasonic vibration is applied while pressing the primary side housing and the secondary side housing in the contact direction. Then, the abutting portions are heated and melted by the applied pressure and ultrasonic vibration, and the abutting portions are welded.
The melting phenomenon at the time of ultrasonic welding starts from a portion with a low melting point.For example, if the primary side housing and the secondary side housing are formed of the same material and have the same melting point, the primary side housing and the secondary side housing Starts melting at the same timing and is well welded. In addition, the primary housing and the secondary housing are made of a low melting point material such as resin, whereas the filter is made of a high melting point material such as metal. Welding can be performed.
Since the melting point of the secondary side contact portion is set higher than the melting point of the primary side housing, the melting point of the secondary side housing, and the melting point of the primary side contact portion, ultrasonic welding is performed on the primary side housing and the secondary side housing. And the primary contact portion are melted and the secondary contact portion is not melted.

  In the filter unit of the present invention, ultrasonic welding is performed in a condition where the primary side housing and the secondary side housing are melted but the secondary side contact portion is not melted. Therefore, it is possible to prevent generation of dust that enters the secondary side liquid chamber with ultrasonic welding. Accordingly, it is possible to prevent the dust generated during the ultrasonic welding and entering the secondary side liquid chamber from entering the liquid supply portion and causing problems such as clogging.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal front view showing a filter unit formed by ultrasonic welding, FIG. 2 is a longitudinal front view showing a filter unit before ultrasonic welding, and FIG. 3 is an exploded perspective view showing the filter unit before ultrasonic welding. is there.

  The filter unit 1 is disposed in a flow path 4 that connects an ink storage unit 2 that is a liquid supply unit and an inkjet head 3 that is a liquid supply unit to which ink is supplied, and includes a primary housing 5, The secondary side housing 6, the filter 7, the primary side contact portion 8, the secondary side contact portion 9 and the like are formed.

  The primary housing 5 is a bowl-shaped member having a conical inclined surface portion 10 formed on the inner peripheral surface, and an inflow port 11 connected to the flow path 4 is formed at the center of the inclined surface portion 10. . On the outer periphery of the primary housing 5, a ring-shaped flange 12, a ring-shaped ultrasonic welding convex portion 13 formed on the flange 12, and a ring-shaped ring formed on the inside of the flange 12 A primary side contact portion 8 is provided. The flange portion 12, the ultrasonic welding convex portion 13, and the primary side contact portion 8 are integrally formed as a part of the primary side housing 5.

  The secondary housing 6 is a bowl-shaped member having a conical inclined surface portion 14 formed on the inner peripheral surface, and an outlet 15 connected to the flow path 4 is formed at the center of the inclined surface portion 14. Yes. A ring-shaped boss portion 16 and a ring-shaped secondary-side contact portion 9 positioned inside the boss portion 16 are provided on the outer peripheral portion of the secondary housing 6. The boss part 16 is formed as a part of the secondary housing 6, and the outer diameter dimension of the boss part 16 and the outer diameter dimension of the flange part 12 are formed to the same dimension. The secondary side housing 6 and the secondary side contact part 9 are formed by two-color molding. The secondary side housing 6 and the primary side housing 5 are formed of the same resin material (for example, PBT: polybutylene terephthalate), and the secondary side abutting portion 9 includes the secondary side housing 6 and the primary side housing 5 and the primary side housing. It is made of a resin material (for example, PPS: polyphenylene sulfide) having a higher melting point than the side contact portion 8.

  The filter 7 is formed of a metal mesh, and its melting point is set higher than that of PBT or PPS.

  The primary housing 5 and the secondary housing 6 become a housing 17 by ultrasonic welding performed by applying pressure and ultrasonic vibration, and the filter 7 is accommodated in the housing 17. Formation of the housing 17 by ultrasonic welding is performed by bringing the ultrasonic welding convex portion 13 into contact with the tip surface of the boss portion 16 and applying pressure and ultrasonic vibration. By applying pressure and ultrasonic vibration, the temperature of the abutting portion gradually rises and eventually melts, and adhesion (welding) is performed as the melting proceeds.

  When the housing 17 is formed by ultrasonic welding of the primary housing 5 and the secondary housing 6, a filter 7 is interposed between the primary housing 5 and the secondary housing 6, and the primary housing 5 and the secondary housing 6 are primarily welded to the outer peripheral portion of one side of the filter 7 at a position inside the ultrasonic welding portion (the portion where the ultrasonic welding convex portion 13 and the tip surface of the boss portion 16 abut). The side contact portion 8 is in contact. Further, the secondary contact portion 9 is in contact with the outer peripheral portion of the other one surface of the filter 7 at a position inside the ultrasonic welding portion between the primary housing 5 and the secondary housing 6. Therefore, at the time of ultrasonic welding, pressure and ultrasonic vibration are also applied to the contact portion between the filter 7 and the primary contact portion 8 and the contact portion between the filter 7 and the secondary contact portion 9. The temperature rises.

  A housing 17 is formed by ultrasonic welding, and the filter 7 in contact with the primary side contact portion 8 and the secondary side contact portion 9 is accommodated in the housing 17, so that the primary side housing 5 and the primary side contact are accommodated. A primary side liquid chamber 18 surrounded by the contact portion 8 and the filter 7 is formed in the housing 17, and a secondary side liquid chamber surrounded by the secondary side housing 6, the secondary side contact portion 9, and the filter 7. 19 is formed in the housing 17. By installing the filter unit 1 in the middle of the flow path 4, the primary side liquid chamber 18 is connected to the ink reservoir 2 via the flow path 4, and the secondary side liquid chamber 19 is connected to the ink jet head via the flow path 4. 3 is connected.

  In such a configuration, a process of forming the filter unit 1 by ultrasonic welding will be described with reference to FIG.

  FIG. 4A shows a state before the pressure and the ultrasonic vibration are applied. The primary housing 5 and the secondary housing 6 are in contact with each other with the filter 7 interposed therebetween. A primary side contact portion 8 is in contact with the outer peripheral portion of one side of the filter 7, and a secondary side contact portion 9 is in contact with the outer peripheral portion of the other side of the filter 7. Further, the ultrasonic welding convex portion 13 formed on the flange portion 12 of the primary side housing 5 is brought into contact with the distal end surface of the boss portion 16 of the secondary side housing 6.

  When the primary side housing 5 and the secondary side housing 6 shown in FIG. 4A are ultrasonically welded, pressure is applied in a direction in which the primary side housing 5 and the secondary side housing 6 are brought into contact with each other, In addition, ultrasonic vibration is applied to the primary housing 5 and the secondary housing 6. This ultrasonic vibration is applied so as to act at the maximum at the contact portion between the ultrasonic welding convex portion 13 formed on the collar portion 12 and the tip surface of the boss portion 16.

  When the ultrasonic welding is started, each contact portion (the contact portion between the ultrasonic welding convex portion 13 and the tip surface of the boss portion 16, the primary side contact portion 8 and the filter is generated by the applied pressure and ultrasonic vibration. 7, the temperature of the contact portion between the secondary contact portion 9 and the filter 7) rises.

  For this reason, as shown in FIG.4 (b), the ultrasonic welding convex part 13 is fuse | melted and crushed, and the space | interval of the primary side housing 5 and the secondary side housing 6 becomes narrow gradually.

  As the distance between the primary side housing 5 and the secondary side housing 6 is gradually narrowed, deformation occurs in the primary side contact portion 8 where the pressure and ultrasonic vibration accompanying ultrasonic welding are applied and the temperature rises. . The contact surface of the primary contact portion 8 with the filter 7 has undulations such as fine shrinkage and warpage, and a gap 20 caused by the undulations exists between the filter 7 and ultrasonic welding. As a result of the deformation of the primary contact portion 8, the gap 20 between the primary contact portion 8 and the filter 7 is reduced, and the contact area between the primary contact portion 8 and the filter 7 is increased. In addition, since ultrasonic vibration is applied so that it may act to the contact part of the ultrasonic welding convex part 13 and the front end surface of the boss | hub part 16 to the maximum, the ultrasonic welding convex part 13 and the boss | hub part 16 of FIG. Compared to the temperature rise at the contact portion with the tip surface, the temperature rise at the contact portion between the primary contact portion 8 and the filter 7 and the temperature rise at the contact portion between the secondary contact portion 9 and the filter 7 are as follows: Get smaller.

  Since the melting point of the secondary contact part 9 is higher than the melting point of the primary contact part 8, the temperature of the secondary contact part 9 rises in the same manner as the temperature of the primary contact part 8. However, the deformation amount accompanying the temperature rise of the secondary side contact part 9 is smaller than the deformation amount accompanying the temperature rise of the primary side contact part 8. Alternatively, even if the primary contact portion 8 is softened and deformed due to a temperature rise, the secondary contact portion 9 is not deformed.

  FIG. 4C shows a state in which ultrasonic welding has been completed. The melted ultrasonic welding convex portion 13 is largely crushed, and the distance between the primary side housing 5 and the secondary side housing 6 is further narrowed. The filter 7 is firmly sandwiched between the primary side contact portion 8 and the secondary side contact portion 9, and the primary side liquid chamber 18 surrounded by the primary side housing 5, the primary side contact portion 8, and the filter 7. A secondary side liquid chamber 19 surrounded by the secondary side housing 6, the secondary side contact portion 9 and the filter 7 is formed in the housing 17.

  When the ultrasonic welding is completed, the deformation amount of the primary side contact portion 8 is also increased, and the gap 20 between the filter 7 is further reduced. Moreover, the burr | flash 21 generate | occur | produces when the ultrasonic welding convex part 13 collapses largely, and the dust 22 accompanying ultrasonic welding has generate | occur | produced when a part of the burr | flash 21 falls off.

  Further, at the end of the ultrasonic welding, burrs may be generated in a part of the primary side contact portion 8 deformed due to the temperature rise, and a part of the burrs is dropped to generate dust accompanying the ultrasonic welding. There are things to do. The dust generated from the primary contact portion 8 enters the primary liquid chamber 18.

  On the other hand, even if the temperature of the secondary contact part 9 rises due to ultrasonic welding, the melting point of the secondary contact part 9 is higher than the melting point of the primary contact part 8, so that the ultrasonic welding is performed. By appropriately managing the temperature rise of the secondary side contact portion 9 at that time, burrs accompanying ultrasonic welding occur at the primary side contact portion 8 and a part of the burrs drop off to generate dust. Even if it becomes like this, generation | occurrence | production of the dust by the generation | occurrence | production of the burr | flash in the secondary side contact part 9, or a part of the burr | flash falling can be prevented. Accordingly, it is possible to prevent generation of dust that enters the secondary side liquid chamber 19 at the time of ultrasonic welding, and dust that has entered the secondary side liquid chamber 19 at the time of ultrasonic welding flows through the flow path 4 to perform ink jetting. It is possible to prevent the dust flowing into the head 3 and the dust flowing into the inkjet head 3 from clogging the nozzles provided in the inkjet head 3.

  In the filter unit 1 according to the present embodiment, the case where the secondary housing 6 and the secondary contact portion 9 are molded in two colors has been described as an example. It may be insert-molded or bonded to the side housing.

  In insert molding, first, a ring-shaped secondary contact portion is formed, and this secondary contact portion is positioned at a predetermined position in a mold for molding the secondary housing, and resin is placed in the mold. Fill.

  In the case of bonding, a secondary side housing in which a bonding region of the secondary side contact portion is formed is formed, and the secondary side contact portion is bonded to the bonding region in the secondary side housing.

It is a vertical front view which shows the filter unit of one embodiment of this invention formed by ultrasonic welding. It is a vertical front view which shows the filter unit before ultrasonic welding. It is a disassembled perspective view which shows the filter unit before ultrasonic welding. It is a vertical front view which shows the process of forming a filter unit by ultrasonic welding.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Liquid supply part 3 Liquid to-be-supplied part 4 Flow path 5 Primary side housing 6 Secondary side housing 7 Filter 8 Primary side contact part 9 Secondary side contact part 17 Housing 18 Primary side liquid chamber 19 Secondary side liquid chamber

Claims (3)

A housing formed by ultrasonic welding of the primary side housing and the secondary side housing, disposed in a flow path connecting the liquid supply unit and the liquid supply unit to which liquid is supplied from the liquid supply unit;
A filter housed in the housing;
A primary side contact portion provided in the primary side housing and in contact with an outer peripheral portion of one side of the filter at a position inside an ultrasonic welding portion between the primary side housing and the secondary side housing;
A secondary contact portion provided on the secondary housing and in contact with the outer peripheral portion of the other side of the filter at a position inside the ultrasonic welded portion between the primary housing and the secondary housing. When,
A primary-side liquid chamber formed in the housing surrounded by the primary-side housing, the primary-side contact portion, and the filter, and connected to the liquid supply portion;
A secondary side liquid chamber formed in the housing surrounded by the secondary side housing, the secondary side contact part and the filter, and connected to the liquid supply part;
Have
The filter unit in which the melting point of the secondary contact portion is set higher than the melting point of the primary housing, the melting point of the secondary housing, and the melting point of the primary contact portion.   The filter unit according to claim 1, wherein the secondary housing and the secondary contact portion are formed by two-color molding. The filter unit according to claim 1, wherein the secondary contact portion is insert-molded in the secondary housing.

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