JP2010075881A - Filter apparatus and method of manufacturing filter body used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter apparatus which can suppress a decrease in filtration area and a density change in a bond part of filter media, and a method of manufacturing a filter body used for the same. <P>SOLUTION: Adhesion of nonwoven fabrics 21 and 22 by pressing a vibratory horn 104 of an ultrasonic welding apparatus to nonwoven fabric outer peripheral surfaces 21a and 22a of the nonwoven fabrics 21 and 22 can reduce pressing power of the vibratory horn 104 remarkably less than the ultrasonic vibratory horn-pressing power in manufacturing the conventional filter apparatus, and at the same time can also minify the size of a welded zone, by which the area percentage of the welded zone 23 to the filtration area of a filter element 20 and the density change in the vicinity of the welded zone of the filter media can be made smaller than those by the conventional filter apparatus. Accordingly, it is possible to provide the filter apparatus which can suppress the decrease in filtration area and the density change in the bond part of the filter media, and the method of manufacturing the filter body used for the same. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a filter device for purifying a fluid by collecting solid foreign matters mixed in the fluid by allowing the fluid to pass through the inside, and a method of manufacturing a filter body used therefor.

  As a conventional filter device, a plurality of types of filter media having different densities, for example, non-woven fabrics, are arranged in series along the fluid flow direction, and a non-woven fabric having a coarse mesh, that is, a low density, is arranged upstream. However, a fine non-woven fabric having a high density is arranged on the downstream side so that the entire filter device has a density gradient. By using a filter device having a density gradient, relatively small foreign matter is collected in a low-density nonwoven fabric, and small fine foreign matter is collected in a high-density nonwoven fabric. It aims to make the filter life longer by making it uniform.

In this case, the laminated nonwoven fabrics that are a plurality of filter media are joined together and integrated. As a bonding method, a method in which a nonwoven fabric is sandwiched between a pair of hot rolls of an embossing roll and a smooth roll and pressed in the laminating direction for welding, or a method in which a hot melt resin is applied to the surface of the nonwoven fabric and heated in the laminating direction. In addition, a method of welding by pressing a vibration horn of an ultrasonic welding apparatus in the stacking direction is applied.
JP 2003-236321 A

  In order to achieve the density gradient required for the filter device, the number of filter media to be stacked may be increased, or the thickness of a single filter media may be increased. When the number of filter media to be stacked increases or the thickness of one filter media increases, the joining method of a plurality of filter media in the conventional filter device, that is, the method of pressing the filter media in the stacking method, ensures reliable joining. This causes a problem that it becomes difficult to realize a density gradient accurately. That is, it is necessary to increase the force for pressing the filter medium to the laminating method in the joining step. For this reason, the density increases in the vicinity of the joined portion, and the density gradient as the filter device becomes uneven. In addition, the pressing member becomes larger with a larger pressing force, so that the area for joining increases and the area contributing to filtration decreases.

  The present invention has been made in view of the above-described problems, and a filter device capable of laminating and joining filter media while suppressing density changes and filter area reductions of the respective filter media to a necessary minimum, and manufacture of a filter body used therefor It aims to provide a method.

  In order to achieve the above object, the present invention employs the following technical means.

  A filter device according to a first aspect of the present invention includes a casing including a fluid inlet and outlet, and a filter housed between the inlet and outlet in the casing. Is formed by laminating a plurality of filter media and fusing together adjacent filter media, and the filter media is a filter device formed from a nonwoven fabric, a fiber assembly, a resin having a continuous cell structure, etc. The welded portion formed by welding the filter media is formed on the outer peripheral surface of the filter media, which is the outer peripheral surface of the filter media.

  When welding a plurality of filter media, in the conventional filter device, the filter media are welded by pressing a heat roll or an ultrasonic vibration horn from the stacking direction of the filter media. For this reason, it is necessary to press with a larger force, so that the number of the filter media laminated | stacked and the thickness of the filter media laminated | stacked are thick. For this reason, a portion around the welded portion, which is a portion where the filter media are melted and welded to each other, is dragged to the welded portion and compressively deformed, and the density may change. Furthermore, the ratio of the area of the welded portion to the area of the filtration surface, which is a surface orthogonal to the fluid passage direction in the filter medium, may increase, and the filtration area, which is the area used for filtration, may decrease.

  On the other hand, in the filter device according to claim 1 of the present invention, a plurality of filter media constituting the filter body are joined to each other on the outer peripheral surface thereof. In other words, an ultrasonic vibration horn or a heating head is brought into contact with the outer peripheral surface of the filter medium to melt the filter medium, and a plurality of filter media are welded and joined together. That is, unlike the conventional filter device, the pressing direction of the ultrasonic vibration horn or the heating head to the filter medium is not pressing in the thickness direction of the filter medium but pressing in the direction along the filtration surface. Since the filter medium is easily welded when pressed against the ultrasonic vibration horn or heating head, it can be reliably used even with a force much smaller than the pressing force of the ultrasonic vibration horn or heating head in the case of the conventional filter device. Can be welded. Therefore, the density change accompanying the ultrasonic vibration horn or heating head pressing in the vicinity of the welded portion of the filter medium can be reduced as compared with the case of the conventional filter device.

  As described above, it is possible to realize a filter device capable of laminating and joining the filter media while suppressing the density change and reduction of the filtration area of each filter media to the minimum necessary.

  The filter device according to claim 2 of the present invention is characterized in that the welded portions are continuously integrated to form the outer peripheral surface of the filter body.

  The welded portion is formed by curing after the filter medium is partially melted and integrated. Therefore, according to the above-described configuration, the outer peripheral portion of the filter body is covered with the welded portion that is fused and integrated. That is, the fused and integrated welded part forms a cylinder, and has a structure equivalent to a plurality of stacked filter media held and fixed therein. Thereby, the rigidity of a filter body improves. Therefore, it is possible to realize a filter device capable of laminating and joining the filter media while suppressing the density change of each filter medium and the reduction of the filtration area to the minimum necessary, and the deformation of the filter body in the filter device assembly process and the filter device use process. Can be prevented.

  The method for producing a filter body according to claim 3 of the present invention is a method for producing a filter body used in the filter device according to claim 1 or 2, wherein a plurality of filter media are stacked and held by pressing. And a welding step of welding the outer peripheral surfaces of the two filter media adjacent to each other.

  According to the above-described filter body manufacturing method, the welded portion formed by welding the filter media in the completed filter body is formed on the outer periphery of the filter body, so that the density change of each filter medium and the reduction of the filtration area are minimized. It is possible to provide a production method capable of reliably producing a filter body in which filter media are laminated and bonded while being suppressed.

  In the filter body manufacturing method according to claim 4 of the present invention, the welding apparatus used in the welding step is an ultrasonic welding apparatus, and the ultrasonic welding apparatus is used to vibrate the filter medium by pressing and contacting the outer peripheral surface of the filter medium. A vibration horn as a member is provided, and in the welding process, the vibration horn moves from the outer peripheral side of the filter medium toward the outer peripheral surface of the filter medium and contacts the outer peripheral surface of the filter medium.

  In the manufacturing process of the filter body described above, the force for holding the plurality of filter media in the stacking direction when welding the plurality of filter media may be a force large enough to hold the filter media so as not to move in the welding step. That is, a strong force is not required as in pressing the vibrating horn in the filter material stacking direction in the filter body manufacturing process of the conventional filter device. Therefore, it is possible to provide a production method capable of reliably producing a filter body in which filter media are laminated and joined while suppressing changes in the density of the filter media and reduction of the filtration area to the minimum necessary.

  In this case, as in the filter body manufacturing method according to claim 5 of the present invention, the filter medium side end of the cross-sectional shape in the laminating direction of the filter medium of the vibration horn is formed at both ends in the laminating direction of the filter medium, and the filter medium outer peripheral surface If it is set as the structure provided with the recessed part which is concave with respect to the filter material outer peripheral surface formed between the convex part which protrudes toward both sides and both convex parts, in the welding process, the recessed part of a vibration horn is adjacent 2 sheets which are welding object The two filter media can be surely welded by facing the boundary of the filter media and pressing both convex portions against the two filter media.

  In the method for producing a filter body according to claim 6 of the present invention, the welding apparatus used in the welding step is to weld a heating head that is heated to a temperature higher than the melting temperature of the filter medium to contact the outer peripheral surface of the filter medium. In the process, the heating head moves from the outer peripheral side of the filter medium toward the outer peripheral surface of the filter medium, and contacts the outer peripheral surface of the filter medium.

  In the manufacturing process of the filter body described above, the force for holding the plurality of filter media in the stacking direction when welding the plurality of filter media may be a force large enough to hold the filter media so as not to move in the welding step. That is, a strong force is not required as in the case of pressing the heating head in the filter material stacking direction in the filter body manufacturing process of the conventional filter device. Therefore, it is possible to provide a production method capable of reliably producing a filter body in which filter media are laminated and joined while suppressing changes in the density of the filter media and reduction of the filtration area to the minimum necessary.

  In this case, as in the filter body manufacturing method according to claim 7 of the present invention, the heating and welding apparatus is an electric resistance heating apparatus that heats the heating head to the melting temperature or higher by an electric resistance heating method, or As in the method for producing a filter body according to claim 8 of the present invention, if the heat welding apparatus is a high frequency induction heating apparatus that heats the heating head to the melting temperature or higher by a high frequency induction heating technique, the heating head It is possible to easily and reliably reach the desired temperature.

  Hereinafter, an embodiment of a filter device according to the present invention will be described with reference to the drawings, taking as an example a case where the filter device is applied to a fuel filter 10 mounted on an automobile and used to filter fuel supplied from a fuel tank to an engine.

(First embodiment)
As shown in FIG. 1, the fuel filter 10 according to the first embodiment of the present invention includes a casing 30 provided with an inlet 31 a and a discharge port 32 a for fuel as a fluid, and a filter body accommodated in the casing 30. It is composed of a certain filter element 20.

  The casing 30 is formed by joining an upper case 31 formed in a substantially bottomed cylindrical shape and a substantially lid-shaped lower case 32 as shown in FIG. The upper case 31 and the lower case 32 are made by molding a resin material, for example. An inlet 31a for introducing fuel into the casing 30 is provided at the bottom of the upper case 31, that is, at the upper end in FIG. The upper case 31 includes a cylindrical accommodating portion 31c, and a filter element 20 that is a filter body to be described later is accommodated in the accommodating portion 31c. The diameter of the upper case 31 is narrower than that of the accommodating portion 31c in the portion from the vicinity of the bottom portion to the bottom portion thereof, so that the abutting portion 31b is formed at the boundary between the accommodating portion 31c and the small diameter portion due to the difference in diameter between the two. Is formed. The abutting portion 31b restricts the filter element 20 from moving in the direction toward the introduction port 31a. At the bottom of the lower case 32, that is, at the lower end in FIG. 1, a discharge port 32 a for discharging the fuel from the casing 30 is provided. A fuel filter 10 is attached in the middle of a fuel pipe (not shown) for supplying fuel from a fuel tank (not shown) to an engine (not shown). That is, the inlet 31a is located upstream of the fuel pipe (on the fuel tank side). ) Are connected to the downstream side (engine side) of the fuel pipe, the fuel flows in the direction indicated by the arrow in FIG. That is, it flows into the fuel filter 10 from the introduction port 31a, passes through the filter element 20, and flows out from the discharge port 32a.

  The filter element 20 that is a filter body is formed by laminating and joining two nonwoven fabrics 21 and 22 that are a plurality of filter media. That is, in the fuel filter 10 according to the first embodiment of the present invention, a nonwoven fabric is used as the filter medium constituting the filter element 20. The filter element 20 is formed in a substantially cylindrical shape so as to be accommodated in the accommodation chamber 31 c of the casing 30. After the filter element 20 is assembled into the accommodation chamber 31 c of the upper case 31 from the opening end of the upper case 31, when the lower case 32 is fitted and fixed to the upper case 31, the filter element 20 is brought into contact with the upper case 31. It is sandwiched between the abutting portion 32 b of the portion 31 b and the lower case 32 and is accommodated and held in the casing 30. The length in the stacking direction of the nonwoven fabrics 21 and 22 in the filter element 20 unit state, in other words, the length in the fuel flow direction is set to be longer than the length between the abutting portion 31 b and the abutting portion 32 b in the casing 30. Therefore, when the filter element 20 is assembled in the upper case 31 and the lower case 32 is fitted and fixed to the upper case 31, the filter element 20 is compressed in the axial fuel flow direction, that is, in the vertical direction in FIG. It becomes.

  Here, the two nonwoven fabrics 21 and 22 constituting the filter element 20 will be described.

  The two nonwoven fabrics 21 and 22 are different in density, that is, the size of the mesh formed by overlapping a large number of fibers, or the gaps between the fibers. The density is lower than 22. That is, the density as the filter element 20 is not uniform as a whole, and is low in the nonwoven fabric 21 and high in the nonwoven fabric 22 and has a so-called density gradient. In the usage state of the fuel filter 10, the filter element 20 is laminated in the order of the nonwoven fabric 21 and the nonwoven fabric 22 from the upstream side of the fuel flow, so that the density as the filter element 20 is low on the upstream side and high on the downstream side. ing. The fuel flowing into the fuel filter 10 first passes through the nonwoven fabric 21 and then passes through the nonwoven fabric 22. Thereby, relatively large foreign matter is collected in the nonwoven fabric 21 on the upstream side of the filter element 20, and smaller and finer foreign matter is collected in the nonwoven fabric 22 on the downstream side. Therefore, since the collected foreign matter is distributed almost uniformly in the filter element 20, the degree of increase in the pressure loss of the fuel filter 10 accompanying the increase in the amount of foreign matter collected can be reduced, and the life of the fuel filter 10 is extended. it can. As shown in FIG. 2, the nonwoven fabric 21 and the nonwoven fabric 22 are integrally welded and joined by ultrasonic welding. That is, the non-woven fabric 21 and the non-woven fabric 22 are melted and fused to each other at a boundary portion between the non-woven fabric outer peripheral surface 21a that is a surface parallel to the lamination direction of the non-woven fabric 21 and the non-woven fabric outer peripheral surface 22a that is a surface parallel to the lamination direction of the non-woven fabric 22. A weld portion 23 formed by integrating and welding is formed, whereby the nonwoven fabric 21 and the nonwoven fabric 22 are joined to form the filter element 20.

  Next, a method for manufacturing the filter element 20 of the fuel filter 10 according to the first embodiment of the present invention described above will be described with reference to FIGS. In the manufacturing process of the filter element 20, the process of welding and integrating the nonwoven fabric 21 and the nonwoven fabric 22 is the most important process. Below, the process of welding the nonwoven fabric 21 and the nonwoven fabric 22 is demonstrated.

  First, an apparatus used for welding the nonwoven fabric 21 and the nonwoven fabric 22 during the manufacturing process of the filter element 20 will be described. The rotating jig 101 and the clamp 102 hold the laminated nonwoven fabric 21 and nonwoven fabric 22. A shaft 101 a provided on the rotating jig 101 is rotatably fitted to a bearing of the bed 103, so that the rotating jig 101 can rotate about the shaft 101 a with respect to the bed 103. As a welding apparatus for welding the nonwoven fabric 21 and the nonwoven fabric 22, an ultrasonic welding apparatus is used. In this method, a vibrating horn 104 that vibrates at an ultrasonic frequency is pressed against the nonwoven fabric 21 and the nonwoven fabric 22 that are objects to be welded, and both are melted and bonded by ultrasonic vibration and pressure. The vibrating horn 104 is held by a holder 105, and the holder 105 can move on the bed 103 in the left-right direction in FIG. The vibrating horn 104 is vibrated by an oscillator (not shown), and the holder 105 is moved by a driving device (not shown). As shown in FIG. 3, the vibrating horn 104 is a nonwoven fabric outer peripheral surface 21 a, 22 a that is a filter medium outer peripheral surface of the nonwoven fabric 21, 22 in the cross-sectional shape of the upper body in which the nonwoven fabrics 21, 22 are set in an ultrasonic welding apparatus. Two convex portions 104a projecting toward the surface, and a concave surface 104b that is concave with respect to the non-woven fabric outer peripheral surfaces 21a and 22a formed between the two convex portions 104a. In the ultrasonic welding apparatus according to the first embodiment of the present invention, the concave portion 104b is formed in a substantially V shape as shown in FIG. In the vibration horn 104, the portions where the above-described convex portions 104a and concave portions 104b are formed are formed in an arc shape having substantially the same shape as the outer peripheral arc shape of the nonwoven fabrics 21 and 22, as shown in FIG.

  Next, a specific process for manufacturing the filter element 20 by welding the nonwoven fabric 21 and the nonwoven fabric 22 will be described.

  First, as a holding process, the nonwoven fabric 21 and the nonwoven fabric 22 are placed on the rotating jig 101 and the nonwoven fabric 21 is pressed and held by the clamp 102. At this time, the cylindrical nonwoven fabric 21 and the nonwoven fabric 22 are arranged coaxially with respect to the shaft 101 a of the rotating jig 101.

  Next, the vibration horn 104 is moved forward on the bed 103 toward the nonwoven fabric outer peripheral surface 21a and the nonwoven fabric outer peripheral surface 22a which are parallel to the lamination direction of the nonwoven fabric 21 and the nonwoven fabric 22, and the nonwoven fabric 21 and the nonwoven fabric are moved. 22 At this time, the both convex portions 104a of the vibration horn 104 are biting into the nonwoven fabric 21 or the nonwoven fabric 22 as shown in FIG. When the vibration horn 104 stops at a predetermined position with respect to the nonwoven fabric 21 and the nonwoven fabric 22, the vibration horn 104 is ultrasonically vibrated. When the nonwoven fabric 21 and the nonwoven fabric 22 are vibrated by the vibration horn 104, frictional heat is generated at the interface between the nonwoven fabrics 21 and 22, the nonwoven fabric 21 and the nonwoven fabric 22 instantaneously reach the melting temperature, and both are fused and welded.

  Incidentally, at the end of the holding step, there may be a gap as shown in FIG. 3 at the boundary between the nonwoven fabric 21 and the nonwoven fabric 22. In the manufacturing method of the filter element 20 of the fuel filter 10 according to the first embodiment of the present invention, the vibration horn 104 is set so that the concave portion 104b is provided between the two convex portions 104a as described above. As the horn 104 bites into the non-woven fabrics 21 and 22, the gap is closed. Thereby, even if the clearance gap has arisen between the nonwoven fabrics 21 and 22 at the time of completion | finish of a holding process, it can be crushed reliably and the nonwoven fabric 21 and the nonwoven fabric 22 can be joined.

  When the welding is completed, the ultrasonic vibration of the vibration horn 104 is stopped, and then the vibration horn 104 is moved on the bed 103 in a direction away from the nonwoven fabrics 21 and 22, as shown in FIG. As shown in FIG. 7, a welded portion 23 in which both are fused is formed at the boundary between the nonwoven fabrics 21 and 22. The welded portion 23 is formed only in a portion that is in contact with the vibration horn 104 and is not formed in a portion where the vibration horn 104 is not in contact. Therefore, the rotating jig 101 is rotated, and the above-described welding process is performed again on the portion that has not been welded in the first welding process.

  In FIGS. 3 to 8 for explaining the welding process of the filter element 20 of the fuel filter 10 according to the first embodiment of the present invention, only one vibrating horn 104 is shown for the sake of clarity, but in the actual welding process, FIG. 8A, a pair of vibration horns 104 are arranged to face each other by 180 degrees with the rotating jig 101 interposed therebetween, and these two vibration horns 104 are simultaneously placed on the nonwoven fabrics 21 and 22. The welding operation is performed by moving forward and backward. The two vibrating horns 104 have the same shape, and the central angle of the arc is set to 100 degrees. When the first welding operation is completed, the rotating jig 101 is rotated 90 degrees, and the second welding operation is performed. When the second welding operation is completed, as shown in FIG. 8B, an annular weld 23 is formed over the entire circumference of the boundary between the nonwoven fabrics 21 and 22, and the joining of the nonwoven fabric 21 and the nonwoven fabric 22 is completed. Thus, the filter element 20 is completed. In the first embodiment of the present invention, the central angle of the arc of the vibration horn 104 is set to 100 degrees, and the nonwoven fabrics 21 and 22 are rotated 90 degrees from the first welding operation to perform the second welding operation. That is, since the central angle of the arc of the vibration horn 104 is larger than the angle at which the nonwoven fabric is rotated before the next welding operation, the nonwoven fabric has a portion to be welded in both the first welding operation and the second welding operation. . That is, the welded portion 23 of the filter element 20 is formed by arranging the first welded portion X, the second welded portion Y, and the overlapping welded portion Z welded twice as shown in FIG. 8B. Has been. Thereby, since the welding part 23 is formed in an annular shape with certainty, the fuel passing through the filter element 20 can be prevented from flowing out to the outer periphery of the filter element 20.

  According to the method for manufacturing the filter element 20 in the fuel filter 10 according to the first embodiment of the present invention described above, the vibration horn 104 of the ultrasonic welding device is arranged so that the nonwoven fabric 21 and the nonwoven fabric 22 are parallel to their laminating direction. Are pressed against the nonwoven fabric outer peripheral surface 21a and the nonwoven fabric outer peripheral surface 22a, thereby forming a welded portion 23 on the nonwoven fabric outer peripheral surface 21a and the nonwoven fabric outer peripheral surface 22a that is fused and fused, and this welded portion 23 The two nonwoven fabrics 21 and 22 are joined together.

  When welding a plurality of nonwoven fabrics laminated in the manufacturing process of a conventional filter device, a hot roll or an ultrasonic vibration horn is pressed from the lamination direction of the nonwoven fabrics. For this reason, it is necessary to press with a larger force, so that the number of the nonwoven fabrics laminated | stacked increases, and the thickness of the nonwoven fabric laminated | stacked is thick. For this reason, the peripheral part of the welding part which is the part where the nonwoven fabrics are melted and welded to each other may be dragged to the welding part to compress and deform, and the density may change. Furthermore, the ratio of the area of the welded portion to the area of the filtration surface, which is the surface orthogonal to the fluid passage direction in the nonwoven fabric, may increase, and the filtration area, which is the area used for filtration, may decrease.

  On the other hand, according to the manufacturing method of the filter element 20 in the fuel filter 10 according to the first embodiment of the present invention, the vibration horn 104 of the ultrasonic welding apparatus is parallel to the stacking direction of the nonwoven fabric 21 and the nonwoven fabric 22. The non-woven fabric outer peripheral surface 21a and the non-woven fabric outer peripheral surface 22a are pressed against each other to weld and bond the non-woven fabrics 21 and 22 together. For this reason, since the welding can be reliably performed even with a force much smaller than the pressing force of the ultrasonic vibration horn in the manufacturing process of the conventional filter device, the size of the welded portion itself can be reduced. Thereby, the area ratio of the welding part 23 with respect to the filtration area which contributes to fuel filtration, and the density change in the welding part vicinity of a nonwoven fabric can be made small compared with the case of the conventional filter apparatus. Therefore, the fuel filter 10 capable of laminating and joining the nonwoven fabrics 21 and 22 while suppressing the density change of each nonwoven fabric 21 and 22 and the degree of reduction of the filtration area to the necessary minimum are realized, and the manufacturing method of the filter element 20 used therefor is realized. be able to.

  In addition, in the manufacturing method of the fuel filter 10 and the filter element 20 used therefor according to the first embodiment of the present invention described above, two nonwoven fabrics are laminated, but may be three or more. . In that case, although the nonwoven fabric boundary part which is a joining location becomes two or more, a plurality of nonwoven fabric boundary parts are sequentially welded using a pair (one on one side) of the vibration horn 104 as in this embodiment. Alternatively, the vibration horn 104 may be provided in the same number as the number of the nonwoven fabric boundary portions that are the joint portions (a plurality of one side), and all the nonwoven fabric boundary portions may be welded simultaneously. Further, with the horn 104 pressed against the non-woven fabrics 21 and 22, the rotating jig 101 is rotated to rotate the non-woven fabrics 21 and 22 as workpieces with respect to the horn 104, thereby continuously connecting the non-woven fabric outer peripheral surfaces 21a and 22a. May be welded.

(Second Embodiment)
The fuel filter 10 according to the second embodiment of the present invention is different from the fuel filter 10 according to the first embodiment of the present invention in the method of manufacturing the filter element 20 that is a filter body. That is, in the manufacturing method of the filter element 20 in the first embodiment of the present invention, an ultrasonic welding apparatus is used for joining the nonwoven fabrics 21 and 22, but in the manufacturing method of the filter element 20 in the second embodiment of the present invention. For the joining of the nonwoven fabrics 21 and 22, a heating welding apparatus having a configuration in which a heating head heated to a temperature equal to or higher than the melting temperature of the nonwoven fabrics 21 and 22 is brought into contact with the nonwoven fabric outer peripheral surface 21a and the nonwoven fabric outer peripheral surface 22a for welding. In the method for manufacturing the filter element 20 according to the second embodiment of the present invention, an electric resistance heating device is used as the heating welding device. In this method, an electric current is passed through the heating head 106 made of a conductive material, and the temperature of the heating head 106 is raised to the melting temperature of the nonwoven fabrics 21 and 22 by Joule heat generation due to the electric resistance of the heating head 106 itself. Below, the manufacturing method of the filter element 20 of the fuel filter 10 by 2nd Embodiment of this invention is demonstrated.

  As shown in FIG. 9, the heating welding apparatus used for welding the filter element 20 of the fuel filter 10 according to the second embodiment of the present invention has the same configuration as that of the first embodiment of the present invention except for the heating head 106. Same as the case. That is, the holding step of pressing and holding the nonwoven fabrics 21 and 22 to the rotating jig 101 by the clamp 102, the heating head 106 is moved forward to weld the nonwoven fabrics 21 and 22, and the heating head is moved backward to move the rotating jig 101. After rotating 90 degree | times, the heating head 106 is moved forward again again, and the point which welds the nonwoven fabrics 21 and 22 is the same. The heating head 106 is formed in a cylindrical surface shape having the same curvature as the nonwoven fabric outer peripheral surface 21a and the nonwoven fabric outer peripheral surface 22a, and its central angle is 100 degrees as in the case of the first embodiment of the present invention. However, the length in the axial direction (vertical direction in FIG. 9) of the filter element 20 of the heating head 106 is longer than the stacked height of the nonwoven fabrics 21 and 22 held in the rotating jig 101 as shown in FIG. Is set. For this reason, as shown in FIG. 9, when the heating head 106 is energized with the heating head 106 in contact with the nonwoven fabrics 21 and 22, the temperature of the heating head 106 rises above the melting temperature of the nonwoven fabrics 21 and 22, The non-woven fabric outer peripheral surface 21a and the non-woven fabric outer peripheral surface 22a are melted in the entire axial direction, and both are fused and welded at the boundary between them. The heating head 106 is moved away from the nonwoven fabrics 21 and 22 after the energization is stopped immediately after the nonwoven fabric outer circumferential surface 21a and the nonwoven fabric outer circumferential surface 22a are melted and the welded portion 23 is solidified. Actually, when the energization of the heating head 106 is stopped, air is blown from a nozzle (not shown) to the heating head 106 to cool the heating head 106 and promote solidification of the welded portion 23. As shown in FIG. 10, the weld portion 23 is formed in the entire axial direction of the outer peripheral portion of the filter element 20. When the welding process is completed, the welding portion 23 is formed in a thin cylindrical shape on the outer peripheral portion of the filter element 20.

  Also in the method of manufacturing the filter element 20 of the fuel filter 10 according to the second embodiment of the present invention, the heating head 106 of the electric resistance heating device is used to connect the outer circumferential surface of the nonwoven fabric 21 and the nonwoven fabric 22 to the nonwoven fabric outer peripheral surface which is parallel to the stacking direction. 21a and the nonwoven fabric outer peripheral surface 22a are pressed and both the nonwoven fabrics 21 and 22 are welded and joined. For this reason, since the welding can be reliably performed even with a force much smaller than the pressing force of the heating head in the manufacturing process of the conventional filter device, the size of the welded portion itself can be reduced. Thereby, the area ratio of the welding part 23 with respect to the filtration area which contributes to fuel filtration, and the density change in the welding part vicinity of a nonwoven fabric can be made small compared with the case of the conventional filter apparatus. Therefore, the fuel filter 10 capable of laminating and joining the nonwoven fabrics 21 and 22 while suppressing the density change of each nonwoven fabric 21 and 22 and the degree of reduction of the filtration area to the necessary minimum are realized, and the manufacturing method of the filter element 20 used therefor is realized. be able to.

  Moreover, in the method for manufacturing the filter element 20 of the fuel filter 10 according to the second embodiment of the present invention, the axial length of the filter element 20 of the heating head 106 is the nonwoven fabric 21 held by the rotating jig 101, 22 is set to be longer than the stacking height. Thereby, the welding part 23 is formed in a thin cylindrical shape in the whole axial direction area of the outer peripheral part of the filter element 20, as shown in FIG. That is, a thin cylinder with high rigidity is integrally formed on the outer peripheral portion of the soft nonwoven fabric. Thereby, since the rigidity of the completed filter element 20 can be improved, it can prevent that the filter element 20 is damaged during the manufacturing process of the fuel filter 10.

  In addition, the welded portion 23 prevents fuel outflow / inflow on the side surface that is the outer peripheral surface of the filter element 20, so that the fuel that has flowed into the fuel filter 10 always passes through the filter element 20 and is filtered. Therefore, the filtration efficiency and the filter life of the filter element 20 can be stabilized.

(Third embodiment)
The fuel filter 10 according to the third embodiment of the present invention is different from the fuel filter 10 according to the second embodiment of the present invention in the heat welding apparatus used for manufacturing the filter element 20 that is a filter body. That is, in the manufacturing method of the filter element 20 in the third embodiment of the present invention, a high frequency induction heating device is used instead of the electric resistance heating device. As shown in FIGS. 11 and 12, a coil 108 is integrally mounted behind the heating head 107 used for manufacturing the filter element 20 in the third embodiment of the present invention. When a high-frequency current is passed through the coil, an eddy current is generated by electromagnetic induction in the heating head 107 formed of a conductive material, and the temperature of the heating head 107 is equal to or higher than the melting temperature of the nonwoven fabrics 21 and 22 by Joule heat generation due to this eddy current. It is to raise to. The configuration other than the portion related to the temperature raising principle of the heating head 107 is the same as that of the method of manufacturing the filter element 20 of the fuel filter 10 according to the second embodiment of the present invention described above, and detailed description thereof is omitted.

  Also in the method for manufacturing the filter element 20 of the fuel filter 10 according to the third embodiment of the present invention, the heating head 107 of the high-frequency induction heating device is used as the nonwoven fabric outer peripheral surface which is a surface parallel to the lamination direction of the nonwoven fabric 21 and the nonwoven fabric 22. 21a and the nonwoven fabric outer peripheral surface 22a are pressed and both the nonwoven fabrics 21 and 22 are welded and joined. For this reason, since the welding can be reliably performed even with a force much smaller than the pressing force of the heating head in the manufacturing process of the conventional filter device, the size of the welded portion itself can be reduced. Thereby, the area ratio of the welding part 23 with respect to the filtration area which contributes to fuel filtration, and the density change in the welding part vicinity of a nonwoven fabric can be made small compared with the case of the conventional filter apparatus. Therefore, the fuel filter 10 capable of laminating and joining the nonwoven fabrics 21 and 22 while suppressing the density change of each nonwoven fabric 21 and 22 and the degree of reduction of the filtration area to the necessary minimum are realized, and the manufacturing method of the filter element 20 used therefor is realized. be able to.

  Further, in the method for manufacturing the filter element 20 of the fuel filter 10 according to the third embodiment of the present invention, the lengths in the axial direction of the filter element 20 of the heating head 107 are the nonwoven fabrics 21 and 22 held in the rotating jig 101. It is set longer than the stacking height. Thereby, the welding part 23 is formed in a thin cylindrical shape in the whole axial direction area of the outer peripheral part of the filter element 20, as shown in FIG. That is, a thin cylinder with high rigidity is integrally formed on the outer peripheral portion of the soft nonwoven fabric. Thereby, since the rigidity of the completed filter element 20 can be improved, it can prevent that the filter element 20 is damaged during the manufacturing process of the fuel filter 10.

  In addition, the welded portion 23 prevents fuel outflow / inflow on the side surface that is the outer peripheral surface of the filter element 20, so that the fuel that has flowed into the fuel filter 10 always passes through the filter element 20 and is filtered. Therefore, the filtration efficiency and the filter life of the filter element 20 can be stabilized.

(Fourth embodiment)
In the method for manufacturing the filter element 20 of the fuel filter 10 according to the fourth embodiment of the present invention, the lower case 33 is integrally laminated and joined in addition to the nonwoven fabrics 21 and 22. That is, the nonwoven fabric 21, the nonwoven fabric 22, and the lower case 33 are laminated in this order and integrally joined. The lower case 33 forms a fuel outlet in the filter 10 and connects the filter 10 to a member that forms a fuel path. The lower case 33 is made by molding a resin material. Moreover, the electric resistance heating apparatus which is a heating welding apparatus used for the welding operation | work of the filter element 20 of the fuel filter 10 by 4th Embodiment of this invention is a structure as shown in FIG. 13, and is 2nd of this invention. It is the same as that of the electrical resistance heating apparatus in the manufacturing method of the filter element 20 of the fuel filter 10 by embodiment. Hereinafter, the description of the method of manufacturing the filter element 20 of the fuel filter 10 according to the fourth embodiment of the present invention is omitted for the method similar to the method of manufacturing the filter element 20 of the fuel filter 10 according to the second embodiment of the present invention. The difference will be mainly described. In addition, although the electrical resistance heating apparatus is used as a heating welding apparatus, it may replace with this and may use a high frequency induction heating apparatus.

  The heating head 106 of the electric resistance heating device is formed in a cylindrical surface shape having the same curvature as the outer circumferential surface of the nonwoven fabric outer circumferential surface 21a, the nonwoven fabric outer circumferential surface 22a, and the lower case 33, and the central angle thereof is the case of the first embodiment of the present invention. Like 100 degrees. However, the length in the axial direction (vertical direction in FIG. 13) of the filter element 20 of the heating head 106 is determined by the nonwoven fabrics 21 and 22 and the lower case 33, which are welded objects held by the rotating jig 101, as shown in FIG. It is set longer than the stacking height. For this reason, as shown in FIG. 13, when the heating head 106 is energized with the heating head 106 in contact with the nonwoven fabrics 21 and 22 and the lower case 33, the temperature of the heating head 106 melts the nonwoven fabrics 21 and 22 and the lower case 33. The temperature rises above the temperature, and the outer circumferential surface 21a of the nonwoven fabric, the outer circumferential surface 22a of the nonwoven fabric, and the outer circumferential surface of the lower case 33 are melted in the entire axial direction, and both are fused and welded at the boundary between the three.

  As described above, according to the method for manufacturing the filter element 20 of the fuel filter 10 according to the fourth embodiment of the present invention, a force that is far smaller than the pressing force of the heating head in the manufacturing process of the conventional filter device is ensured. Since the size of the welded portion itself can be reduced, the ratio of the area of the welded portion 23 to the filtration area contributing to fuel filtration and the density change in the vicinity of the welded portion of the nonwoven fabric are compared with those of the conventional filter device. At the same time, in addition to the nonwoven fabrics 21 and 22 that are filter media, a resin component that can be melted by the heating head 106 can be integrally welded.

  In addition, in the filter 10 by 2nd Embodiment-4th Embodiment of this invention demonstrated above, although the number of the nonwoven fabrics as the filter medium which forms the filter element 20 is two, it is good also as three or more.

  Moreover, in the filter 10 by 2nd Embodiment-4th Embodiment of this invention demonstrated above, the axial direction length of the filter element 20 of the heating head 106 and the heating head 107 is in the state hold | maintained at the rotation jig | tool 101. FIG. Although it is set longer than the stacking height of the nonwoven fabrics 21 and 22, it is not always necessary to do so, and may be a length that covers a limited range including the boundary portion of the nonwoven fabrics 21 and 22. Even in this case, a fuel filter 10 capable of laminating and joining the nonwoven fabrics 21 and 22 while suppressing the density change of each nonwoven fabric 21 and 22 and the degree of filtration area reduction to the necessary minimum, and a method of manufacturing the filter element 20 used therefor. Can be realized.

  In the filter 10 according to the first to fourth embodiments described above, the arcuate central angle of the vibrating horn 104, the heating head 106, and the heating head 107 formed in an arc is set to 100 degrees, and the first After the second welding operation, the rotation jig 101 is rotated 90 degrees to perform the second welding operation. The arcuate central angle of the vibration horn 104, the heating head 106, and the heating head 107, and the rotation jig 101 The rotation angle and the number of welding operations may be appropriately changed as long as the welded portion 23 is continuously formed on the entire outer periphery of the filter element 20.

  Moreover, in the filter 10 by 1st Embodiment-4th Embodiment demonstrated above, the vibration horn 104, the heating head 106, and the heating head 107 are made into the direction orthogonal to the lamination direction of the nonwoven fabrics 21 and 22 etc. which are to-be-welded materials. Although it is moved and pressed against the object to be welded, it is not necessary to limit the moving direction of the vibration horn 104, the heating head 106, and the heating head 107 to the above-mentioned direction, and other than 90 degrees with respect to the stacking direction of the object to be welded. You may move to the direction which makes the angle of.

  Moreover, in the filter 10 by 1st Embodiment-4th Embodiment demonstrated above, although the shape of the filter element 20 is cylindrical, ie, the cross-sectional shape orthogonal to a fuel passage direction is circular, it is another shape. Also good. For example, the shape of the filter element 20 may be a rectangular parallelepiped, that is, the cross-sectional shape orthogonal to the fuel passage direction may be a rectangle. In this case, the shape of the vibration horn 104, the heating head 106, and the heating head 107 is a planar shape or a substantially angle shape having an L-shaped cross section.

  In each of the embodiments described above, the case where the present invention is applied to a fuel filter is described as an example. However, it is not necessary to limit the liquid to be filtered to fuel, and other types of fluids are used. You may apply to the filter which filters. For example, the fluid may be applied to drinking water, industrial water, various edible beverages, liquids such as various chemicals, or gas.

1 is a cross-sectional view of a fuel filter 10 according to a first embodiment of the present invention. 1 is an external view of a single filter element 20 of a fuel filter 10 according to a first embodiment of the present invention. It is a schematic cross section explaining the holding process in the filter element 20 manufacturing process. It is IV arrow line view in FIG. It is a schematic cross section explaining the welding process in the filter element 20 manufacturing process. FIG. 6 is a view taken along arrow VI in FIG. 5. It is a schematic cross section explaining the welding process in the filter element 20 manufacturing process. It is a schematic diagram explaining the welding process in the filter element 20 manufacturing process, (a) is the positional relationship of the vibration horn of ultrasonic welding, (b) is the welding part 23 in the filter element 20 which the welding process was complete | finished. Is shown. It is a schematic cross section explaining the welding process in the filter element 20 manufacturing process of the fuel filter 10 by 2nd Embodiment of this invention. It is a schematic cross section explaining the welding process in the filter element 20 manufacturing process of the fuel filter 10 by 2nd Embodiment of this invention. It is a schematic cross section explaining the welding process in the filter element 20 manufacturing process of the fuel filter 10 by 3rd Embodiment of this invention. It is a XII arrow line view in FIG. It is a schematic cross section explaining the welding process in the filter element 20 manufacturing process of the fuel filter 10 by 4th Embodiment of this invention. It is a schematic cross section explaining the welding process in the filter element 20 manufacturing process of the fuel filter 10 by 4th Embodiment of this invention.

Explanation of symbols

10 Fuel filter (filter device)
20 Filter element (filter body)
21 Non-woven fabric 21a Non-woven fabric outer peripheral surface 22 Non-woven fabric 22a Non-woven fabric outer peripheral surface 23 Welded portion 30 Casing 31 Upper case 31a Inlet 31b Guide portion 31c Storage portion 32 Lower case 32a Discharge port 32b Guide portion 33 Lower case 101 Rotating jig 101a Shaft 102 Clamp 103 Bed 103a Bearing 104 Vibrating horn (ultrasonic welding equipment)
104a convex part 104b concave part 105 holder 106 heating head (heating welding apparatus, electric resistance heating apparatus)
107 Heating head (heating welding device, high frequency induction heating device)
108 Coils (heating welding equipment, high frequency induction heating equipment)
X 1st welding part Y 2nd welding part Z Duplicate welding part C Rotating jig rotation center

Claims (8)

A casing having a fluid inlet and outlet;
A filter body accommodated between the inlet and the outlet in the casing,
The filter body is formed by laminating a plurality of filter media and welding and integrating adjacent filter media,
The filter medium is a filter device formed from a nonwoven fabric, a fiber assembly or a resin having an open cell structure,
The filter device, wherein a welded portion formed by welding adjacent filter media is formed on a filter media outer peripheral surface which is an outer peripheral surface of the filter media.   The filter device according to claim 1, wherein the welded portion is continuously integrated to form an outer peripheral surface of the filter body. A method for producing a filter body used in the filter device according to claim 1 or 2,
A holding step of pressing and holding a plurality of the filter media; and
And a welding step of welding the outer peripheral surfaces of the two filter media adjacent to each other. The welding device used in the welding process is an ultrasonic welding device,
The ultrasonic welding apparatus includes a vibrating horn that is a member for vibrating the filter medium by pressing and contacting the filter medium outer peripheral surface,
4. The filter body manufacturing method according to claim 3, wherein in the welding step, the vibrating horn moves from the outer peripheral side of the filter medium toward the outer peripheral surface of the filter medium and contacts the outer peripheral surface of the filter medium.   At the filter medium side end of the cross section of the vibrating horn in the filter medium stacking direction, formed at both ends of the filter medium in the stacking direction and projecting toward the filter medium outer peripheral surface and between the two protrusions The filter body manufacturing method according to claim 4, further comprising a concave portion that is concave with respect to the outer peripheral surface of the filter medium. The welding apparatus used in the welding step is to weld a heating head that is heated above the melting temperature of the filter medium in contact with the outer peripheral surface of the filter medium,
4. The method for manufacturing a filter body according to claim 3, wherein in the welding step, the heating head moves from the outer peripheral side of the filter medium toward the outer peripheral surface of the filter medium and contacts the outer peripheral surface of the filter medium.   The method for producing a filter body according to claim 6, wherein the heat welding apparatus is an electric resistance heating apparatus that heats a heating head to the melting temperature or higher by an electric resistance heating method.   The method for manufacturing a filter body according to claim 6, wherein the heat welding apparatus is a high frequency induction heating apparatus that heats a heating head to the melting temperature or higher by a high frequency induction heating method.

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