JP7085784B1 - Metal filter element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal filter element such as a disc type, a cylindrical type and a pleated type having improved sealing property. SOLUTION: The metal filter element 10 has a joint portion 31 between a filtration member 11 and an end member 21 arranged at a peripheral end portion 12 of the filtration member 11, and the filtration member 11 is a filter medium 1 and a filter medium 1. It is composed of at least a reinforcing member 2 arranged on one surface or both surfaces (S1 and / or S2) of the filter medium 1, and the end member 21 is a peripheral end portion 12 of the filtration member 11 from both sides S3 and S4. It is a member that is sandwiched and crimped, and the peripheral end portion 12 of the filtration member 11 has a folded end portion 3a in which the filter medium 1 is folded back, and the folded end portion 3a is an end portion while being in contact with the end member 21. The above problem was solved by configuring the member 21 so as to be caulked. [Selection diagram] Fig. 1

Description

The present invention relates to a metal filter element. More specifically, the present invention relates to a metal filter element such as a disc type, a cylindrical type, or a pleated type having improved sealing performance.

There are various types of metal filter elements, such as a disk-shaped filter element consisting of a disk-shaped plate, a cylindrical filter element, and a pleated filter having a filtering portion repeatedly folded in a fold shape to increase the filtering surface area. Elements and the like can be mentioned.

These metal filter elements utilize their durability, heat resistance, corrosion resistance and other characteristics to treat liquids (raw materials and products of the chemical industry, high-viscosity fluids, groundwater, pools, hydroponic cultivation, cultivation, bath water). Widely used in gas treatment (filtration of steam, hydrogen, steam, ammonia, carbon dioxide, volatile organic compounds, oxygen, nitrogen, etc.), solid-liquid separation treatment, gas-liquid separation treatment, etc. For example, Patent Documents 1 to 3).

Among them, the pleated filter element has a filtration part that is repeatedly folded back in a fold shape in order to increase the filtration surface area, and depending on the intended use, it is made of resin, metal, or a combination thereof. Etc. have been proposed in various ways. Of these, the metal pleated filter element has excellent strength, corrosion resistance and heat resistance, and is used for high-pressure filtration applications, special liquid filtration applications, backwashing applications, regeneration processing applications, etc. Has been done.

Japanese Unexamined Patent Publication No. 2-191533 Japanese Unexamined Patent Publication No. 2002-252012 Japanese Unexamined Patent Publication No. 2013-31852

In such a metal filter element, the filtration member is joined to an end member arranged at the peripheral end of the filtration member, but when the sealing property (airtightness) at the joint is insufficient, the filter member is joined. Filtration performance will deteriorate. The joint between the filtration member and the end member is generally connected by welding, brazing, adhesive, press fitting, caulking or the like. Joining by welding requires a high degree of skill to prevent the occurrence of defects, and the sealing performance tends to vary depending on the operator. Further, if welding burn occurs during welding, post-treatment for removing the weld burn must be performed, which increases the number of man-hours. Further, in brazing and joining with an adhesive, the usage environment is limited by the material of the brazing material and the adhesive. Although the process of press-fitting or caulking is simple and efficient, fine gaps may occur at the joint and leakage may occur, and sufficient sealing properties may not be obtained. These problems are the same for disk-type filter elements, cylindrical filter elements, pleated-type filter elements, etc. that join the filtration member and the end member.

In particular, when a filter medium having high filtration accuracy is used, since the filter medium is thin and the strength is low, it is necessary to provide a reinforcing member (also referred to as a reinforcing layer) on one or both sides of the filter medium to reinforce it. When the reinforcing member 2 is provided on one side S2 of the filter medium 1 (see FIGS. 17A and 19A), the filtration direction F is limited and the usage pattern is limited, but the one side S1 of the filter medium 1 is limited. Since the surface S3 of the peripheral edge portion 12 is directly in contact with the end member 21 and crimped, sealing is possible. However, when the reinforcing member 2 is provided on both sides S1 and S2 of the filter medium 1 (see FIGS. 17 (b) and 19 (b)), leakage occurs via the reinforcing member 2 (arrow in the figure). It ends up. Leakage caused by using the reinforcing member 2 for both sides S1 and S2 can occur in each of the disk type, cylindrical type, and pleated type filter elements.

Further, the cylindrical and pleated filter elements are formed into a cylindrical shape by welding. However, since the weld is solid, it may be prone to leaks that pass around it. Further, in the welded portion, the weld bead may be smooth and suitable for sealing, but in reality, the weld bead is rarely flattened. Moreover, since the strength of the filtration member and the welded portion are different, it is difficult to seal by caulking. Further, the density of the filtration member approaches the density of the weld bead (the one in which the filtration member is melted) by caulking, but leakage is likely to occur because the gap created by caulking cannot be filled.

The present invention solves the above-mentioned problems by a new sealing structure that enhances the sealing property of the joint portion between the filtration member and the end member, and the purpose of the present invention is to improve the sealing property of a pleated type, a cylindrical type, or a disk type. To provide metal filter elements such as.

As a result of examining the structure of the joint portion between the filtration member and the end member arranged at the peripheral end portion of the filtration member in order to improve the filtration performance of the filter element, the present inventor has a high sealing property. We have completed the present invention by developing a new sealing structure that can manufacture a metal filter element that achieves the above requirements without the need for advanced welding technology, easy dimensional control, and at a lower cost.

The metal filter element according to the present invention is a metal filter element having a joint portion between a filtration member and an end member arranged at a peripheral end portion of the filtration member, and the filtration member is a filter medium. , At least composed of reinforcing members arranged on one or both surfaces of the filter medium, the end member is a member that sandwiches and crimps the peripheral end portions of the filter member from both sides, and is a peripheral edge of the filter member. The end portion has a folded-back end portion in which the filter medium is folded back, and the folded-back end portion is crimped by the end portion member while being in contact with the end portion member.

According to the present invention, the peripheral end portion of the filtration member has a folded end portion in which the filter medium is folded back, and the folded end portion is caulked by the end member while directly touching the end member. Since the filter medium is made of, the thickened filter medium is crimped to increase the amount of deformation of the filter medium, and the sealing property is likely to be deteriorated. be able to. Further, since the folded end portion is crimped while being in contact with the end portion member, there is no leakage through the reinforcing member. As a result, there are no problems that occur during welding (variation by workers, welding discoloration, deterioration of materials, welding distortion, process increase, etc.) as in the past, and stable sealing performance in the mechanical process by caulking. Can be secured and can be manufactured at low cost. Further, since the peripheral end portion of the filtration member is joined and sealed by mechanical caulking, the usage environment is not limited as in the case of using a brazing material or an adhesive.

In the metal filter element according to the present invention, the folded end portion has the filter medium folded over the end of the reinforcing member, or the filter medium is folded over the filter medium itself.

When a filter medium having a particularly high filtration accuracy is used, the filter medium is thin and the strength is low. According to the present invention, since such a filter medium is folded over the end of the reinforcing member or folded over the filter medium itself, the filter medium is directly in contact with the end member and crimped. As a result, high sealing performance can be exhibited at the joint between the peripheral end portion of the filtration member and the end portion member.

The metal filter element according to the present invention is either a disc type filter element, a cylindrical type filter element, or a pleated type filter element.

According to the present invention, a filter element having a good sealing property can be obtained for any of the disc type, the cylindrical type and the pleated type.

In the cylindrical filter element, the filtration member is a cylindrical member formed by welding the facing sides of the original fabric for the filtration member together, and the welded welded portion is formed over the entire length in the axial direction. ..

According to the present invention, even in the cylindrical filter element, the welded portion formed in the cylindrical member formed by welding the facing sides of the original fabric for the filtration member together is formed over the entire length in the axial direction. However, it has a high sealing property. In addition, "opposite sides" does not include the side that becomes the end of the circle in the case of a cylindrical shape.

In the pleated filter element, the filtration member is a cylindrical member formed by welding the facing sides of the folded original fabrics of the filtration member together, and the welded welded portion is formed over the entire length in the axial direction. Has been done.

According to the present invention, in the pleated filter element, the welded portion formed in the tubular member formed by welding the facing sides of the folded original fabrics for the filtration member together is formed over the entire length in the axial direction. However, it has a high sealing property. It should be noted that "opposite sides" does not include the side where the filter medium is folded back.

In the pleated filter element, the pleated form is formed after folding the filter medium, and the folded end portion is crimped by the end member after being drawn.

According to the present invention, the folded pleated form is formed after the filter medium is folded back, and the folded back end portion is crimped by the end member after being drawn. In the drawing process at this time, the filter media constituting the folded end portion are brought into close contact with each other and overlapped in a state where the surface is flat, so that the structural form of the end portion (dimensions such as thickness, density of filter media, etc.) changes. It becomes constant and the sealing property can be improved more stably.

In the cylindrical type and the pleated type filter element, a sealing material having a size covering the welded end portion of the welded portion to be caulked by the end member is arranged on the welded end and caulked by the end member. There is.

According to the present invention, a sealing material having a size covering the welded end portion to be crimped by the end member of the welded portion is arranged on the welded end portion and crimped by the end portion member, so that the sealing material is on the welded end portion. The sealing material provided in the above acts to further enhance the sealing property. This means is particularly preferable when a filter medium with high filtration accuracy is used, and it is possible to prevent leakage that passes around the solid welded portion that tends to be uneven, and the filter member and the welded portion having different strengths and densities. It is possible to fill the gap generated when crimping and to further improve the sealing property.

In the metal filter element according to the present invention, in the case of the disk type and the cylindrical type filter element, the folded end portion is compressed, and the compressed folded end portion is the end member. In the case of the pleated filter element, the folded end portion is drawn and the drawn folded end portion is crimped by the end member.

The present invention is the case where the folded end (folded end) of the filter medium is processed regardless of whether it is a disc type, a cylindrical type, or a pleated type. According to the present invention, in the case of a disk type or cylindrical filter element, the folded end portion is compressed (for example, compressed by a press), and in the case of a pleated type filter element, the folded end portion is drawn. Therefore, the structural form of the folded end (dimensions such as thickness, density of filter media, etc.) becomes constant, it becomes easy to attach to the end member, and the sealing property after caulking is also stable and improved. Can be done. In particular, in the pleated filter element, the filter medium at the folded end is always in contact with the filter material and the thickness is increased, so that the sealing property after caulking can be further stabilized and improved.

As described above, the new sealing structure proposed in the present invention can be applied to any of the disc type, cylindrical type and pleated type filter elements. A common technical element is that, at the peripheral end of the filtration member, the filter medium has a folded end, and the folded end is crimped by the end member. Of these, the cylindrical and pleated filter elements are welded to form a cylinder, and the pleated filter elements are further folded, so take measures against such welding and folds. Added as a technical element.

In the metal filter element according to the present invention, the filter medium is a metal fiber structure, a metal fine mesh structure, or a combination thereof, and the reinforcing member is a metal net. According to the present invention, high sealing performance can be realized and applied to various applications.

In the metal filter element according to the present invention, the end member is a metal structure for caulking the folded end. According to the present invention, stable sealing property without variation can be realized by mechanical caulking.

According to the present invention, a metal filter element such as a disc type, a cylinder type, a pleated type, etc. having an improved sealing property is provided by a new sealing structure having an improved sealing property at a joint portion between a filtration member and an end member. Can be done. As a result, a metal filter element that achieves high sealing performance can be manufactured at a lower cost with no need for advanced welding technology, easy dimensional control, and higher cost.

It is a schematic block diagram which shows an example of the seal structure constituting the metal filter element which concerns on this invention. It is a schematic block diagram which shows the example of the other form of the folded-back end portion which constitutes a seal structure. It is an overall structure diagram which shows an example of the disk type filter element which provided the seal structure shown in FIG. FIG. 3 is an overall structural diagram showing an example of a cylindrical filter element having a sealing structure shown in FIG. 1. FIG. 3 is an overall structural diagram showing an example of a pleated filter element having a seal structure shown in FIG. 1. It is a detailed explanatory view which shows an example of the seal structure shown in FIG. (C) is a form in which the folded end portion is in contact with the end portion member and is crimped by the end portion member. It is a detailed explanatory view (No. 1) which shows an example which applied the seal structure shown in FIG. 1 to a pleated type filter element, and (a) is the form of the original fabric for a filtration member which made the filter material project from the end of a reinforcing member. Yes, (b) is a form in which the protruding protruding portion is folded back, and (c) is a form in which the folded end portion is folded. It is a detailed explanatory view (No. 2) which shows an example which applied the seal structure shown in FIG. 1 to a pleated type filter element, and (d) is welded together with the facing sides of the original fabric for a fold-folded filter member. (E) is a form in which the peripheral end is drawn and the filter media constituting the folded end are overlapped with each other in close contact with each other, and the peripheral surface of the peripheral end is flattened. In (f), the folded end portion that has been drawn is in contact with the ring-shaped end member and is crimped by the end member. Regarding the pleated filter element, in a cylindrical filtration member formed by welding the facing sides of the folded original fabrics of the filtration member together, the welded welded portion is formed over the entire length in the axial direction. This is just one example. In the form of FIG. 9, it is an example of a form in which a sealing material having a size of covering the welded end portion crimped by the end member of the welded portion is arranged on the welded end portion and crimped by the end member. (A) is a diagram showing an example of a form seen from the side of the weld line of FIG. 8 (e) after drawing the form shown in FIG. 9, and (b) is a diagram showing an example of the form shown in FIG. It is a figure which shows an example of the form which was processed and was seen from the side of the welding line of FIG. 8 (e). It is an example of the form of a filter medium, (a) is an enlarged photograph showing an example of a filter medium made of a metal fiber structure, and (b) and (c) are enlarged photographs showing an example of a filter medium made of a metal fine mesh structure. Is. It is an enlarged photograph which shows an example of the filtration member which arranged the reinforcing member. (A) is a cross-sectional view showing an example of an end member joined to the peripheral end portion of a disc type filter element, (b) is a cross-sectional view showing another example of the end member, and (c) is an end member. It is sectional drawing which shows still another example of. (A) is a diagram showing an example of an end member joined to the peripheral edge of a cylindrical filter element, and (b) shows an example of an end member joined to the peripheral end of a pleated filter element. It is a figure, (c) is a sectional view which shows an example of an end member. It is explanatory drawing for demonstrating the joining form at the peripheral edge of a disk type filter element, (a) is the case where the filter medium is folded back in the same form as FIG. This is the case. It is explanatory drawing for comparatively explaining the joining form at the peripheral end of a disk type filter element when the filter medium is not folded back, and (a) is the reinforcing member arranged only on one side of the filter medium. As an example, (b) is an example in which reinforcing members are arranged on both sides of the filter medium, and (c) is an example in which sealing materials are provided on both sides of the peripheral end portion in (b). It is explanatory drawing for demonstrating the joining form at the peripheral end of a cylindrical filter element, (a) is the case where the filter medium is folded back in the same form as FIG. 1, (b) is the case where the filter medium is folded back together with the reinforcing member. This is the case. It is explanatory drawing for comparatively explaining the joining form at the peripheral end of a cylindrical filter element, when the filter medium is not folded back, and (a) is the reinforcing member arranged only on one side of the filter medium. As an example, (b) is an example in which reinforcing members are arranged on both sides of the filter medium, and (c) is an example in which sealing materials are provided on both sides of the peripheral end portion in (b). It is sectional drawing about the sealing form at the peripheral edge of the welded part of a cylindrical filter element, (a) is an example that the sealing material is not placed on the welded part, and (b) is after caulking (a). (C) is an example in which a sealing material is placed on the welded portion, and (d) is an example after caulking (c).

The metal filter element according to the present invention will be described with reference to the drawings. The present invention includes inventions having the same technical ideas as those described in the embodiments and drawings described below, and the technical scope of the present invention is limited to the description of the embodiments and the drawings. Not.

[Metal filter element]
As shown in FIGS. 1 to 7, the metal filter element 10 according to the present invention has a joint portion 31 between the filtration member 11 and the end member 21 arranged at the peripheral end portion 12 of the filtration member 11. The filter member 11 is composed of at least a filter medium 1 and a reinforcing member 2 arranged on one or both surfaces (S1 and / or S2) of the filter medium 1, and the end member 21 is a filter. It is a member that sandwiches and crimps the peripheral edge portion 12 of the member 11 from both sides S3 and S4, and the peripheral edge end portion 12 of the filtration member 11 has a folded end portion 3a in which the filter medium 1 is folded back, and the folded end portion 3a thereof is provided. The portion 3a is characterized in that it is configured so as to be caulked by the end member 21 while being in contact with the end member 21.

Such a metal filter element 10 has a folded end portion 3a in which the filter medium 1 is folded back at the peripheral end portion 12 of the filtering member 11, and the folded end portion 3a is in contact with the end portion member 21 and has an end portion thereof. Since the filter medium 1 is caulked by the member 21, the thickened filter medium 1 is caulked to increase the amount of deformation of the filter medium 1, and the sealing property is easily deteriorated at the peripheral end portion 12 of the filtration member 11. The sealing property can be further improved. Further, since the folded end portion 3a is crimped while being in contact with the end portion member 21, there is no leakage through the reinforcing member 2. As a result, there are no problems that occur during welding (variation by workers, welding discoloration, deterioration of materials, welding distortion, process increase, etc.) as in the past, and stable sealing performance in the mechanical process by caulking. Can be secured and can be manufactured at low cost. Further, since the peripheral end portion 12 of the filtration member 11 is sealed by mechanical caulking, the usage environment is not limited as in the case of using a brazing material or an adhesive.

(Type form of filter element)
The metal filter element 10 is a disc type (FIG. 3) or a cylindrical type (FIG. 4) having improved sealing property by a new sealing structure having improved sealing property of the joint portion 31 between the filtering member 11 and the end member 21. , A metal filter element such as a pleated type (FIG. 5) can be provided. These various metal filter elements 10 (10A, 10B, 10C) are installed in pipes or filtration housings according to their uses to form a filtration processing unit.

The characteristic sealing structure of these metal filter elements 10 is such that the folded end portion 3a and the filter medium 1 are the ends of the reinforcing member 2 as shown in various forms shown in FIGS. 1 and 2 (a) to 2 (d). It may be folded back on the filter medium, or the filter medium 1 may be folded back on the filter medium itself. When the filter medium 1 having a particularly high filtration accuracy is used, the filter medium 1 is thin and the strength is reduced, but the folded end portion 3a is such that the filter medium 1 is folded over the end of the reinforcing member 2 or the filter medium itself. It can be configured to be folded up. All of these folded end portions 3a are crimped by the end member 21 in a state of being in direct contact with the end member 21, and the filter medium 1 whose thickness is increased by folding is crimped together with the reinforcing member 2 to form the filter medium 1. Since the amount of deformation increases, the sealing property at the joint portion 31 between the peripheral end portion 12 and the end member 21 of the filtration member 1 whose sealing property tends to deteriorate is improved. In the present invention, a high sealing property can be realized at the joint portion 31 by such a characteristic sealing structure.

Such a sealing structure can be applied to any of the disc type (10A), cylindrical type (10B) and pleated type (10C) filter elements. A common technical element is that, in the peripheral end portion 12 of the filtration member 11, the filter medium 1 has a folded end portion 3a, and the folded end portion 3a is caulked by the end member 21. Of these, the cylindrical and pleated filter elements are welded to form a cylinder, and the pleated filter elements are further folded. As will be described later, such welding and folds are performed. Measures for folding are added as a technical element.

As shown in FIG. 3, the disk-type filter element 10A is composed of a disk-type filtration member 11. The disk-shaped filtration member 11 is composed of a disk-shaped main body portion 13 and a ring-shaped peripheral edge end portion 12 located at the peripheral end portion of the main body portion 13. The ring-shaped peripheral edge portion 12 may be joined by a composite type end member 21B in which two members 22 and 23 are combined, as shown in FIG. 14 (a), for example, or FIG. 14 (b). As shown in (c), one member 25 may be joined by an end member 21 formed by bending, and any of the seal structures shown in FIGS. 1 and 2 (a) to 2 (d) may be used. It is composed. The disc-shaped filtration member 11 is reinforced with a filter medium 1 pre-processed into a predetermined shape, unlike the one in which the original fabric 11a for the filtration member is welded into a cylindrical shape as in the cylindrical type and the pleated type described later. The members 2 are overlapped with each other, and at the time of the overlap, the filter media 1 is overlapped so as to protrude from the end of the reinforcing member 2. Then, after that, the protruding portion 3 is processed so as to form a folded end portion 3a, and the folded end portion 3a is processed so as to be caulked by the end member while being in contact with the end member 21. It is desirable, but not limited to these methods.

As shown in FIG. 4, the cylindrical filter element 10B is composed of a filtering member 11 in which a flat original fabric 11a for a filtering member is formed into a cylindrical shape. The filtration member 11 is composed of a cylindrical main body portion 13 and a circular peripheral end portion 12 located at an end portion of the main body portion 13 in the axial direction (longitudinal direction) Y. The circular peripheral end portion 12 is joined by a ring-shaped end member 21 to form any of the seal structures shown in FIGS. 1 and 2 (a) to 2 (d). The cylindrical filter element 10B is also manufactured by rolling the flat original fabric 11a for a filtration member, aligning the facing sides 11b and 11b with each other, and welding the mating portions. The peripheral edge portion 12 is not folded in a fold shape as in the case of the pleated filter element 10C described later. The "opposite sides" of the cylindrical filter element 10B do not include the side that becomes the end of the circle in the case of a cylindrical shape.

As shown in FIGS. 5, 7, and 8, the pleated filter element 10C is composed of a tubular filtration member 11 formed by repeatedly folding back a flat original fabric 11a for a filtration member in a fold shape. The filtration member 11 is composed of a cylindrical main body portion 13 and a circular peripheral end portion 12 located at an end portion of the main body portion 13 in the axial direction (longitudinal direction) Y. The circular peripheral edge portion 12 is also folded back in a fold shape like the main body portion 13, and the circular peripheral edge end portion 12 is joined by a ring-shaped end member 21, and FIGS. 1 and 2 (a). )-(D) constitutes any of the seal structures. In this pleated filter element 10C, the folded end portion 3a in which the filter medium 1 is folded is folded. In the pleated filter element 10C, as shown in FIGS. 7 and 8, the planar filter member 11a is repeatedly folded back in a fold shape to form a tubular filter member 11, but the tubular filter element 11 is formed. The filtration member 11 is manufactured by rolling the original fabric 11a for the filtration member after being folded, aligning the facing sides 11b and 11b, and welding the mating portions. The "opposite sides" of the pleated filter element 10C do not include the side on which the filter medium 1 is folded.

[Each component]
Each component will be described in detail below. In the following, the components of the pleated filter element 10C will be mainly described, but the disk type filter element 10A and the cylindrical filter element 10B will also be described as appropriate.

<Filtration member>
The filtration member 11 is a component for causing the metal filter element 10 to exhibit a desired filtration performance, and a material suitable for the usage environment and purpose of use of the metal filter element 10 is applied, and a structural form according to the purpose is applied. It is processed into. As shown in FIGS. 2 and 13, the filter member 11 in the present invention comprises a filter medium 1 and a reinforcing member 2 arranged on one surface or both surfaces (S1 and / or S2) of the filter medium 1. At least configured. One surface or both surfaces (S1 and / or S2) of the filter medium 1 means that the reinforcing member 2 is arranged on one surface (S1 or S2) of the filter medium 1 as shown in FIGS. 2 (a) and 2 (b). Alternatively, as shown in FIGS. 2 (c) (d) and 13 (b), it means that the reinforcing member 2 may be arranged on both sides (S1 and S2) of the filter medium 1. .. Further, "at least" means that "other members" other than the filter medium 1 and the reinforcing member 2 may be included as long as the function of the filtering member 11 is not impaired.

(Filter material)
The filter medium 1 is an essential configuration of the filtration member 11, and is preferably a metal fiber structure, a metal fine mesh structure, or a combination thereof, which will be described in detail below. The metal material constituting these metal fiber structures and metal fine mesh structures is selected according to the filtration target and the usage environment, but is usually corrosion-resistant stainless steel (for example, SUS304 in the JIS mark). , SUS316, SUS316L, etc.), but the present invention is not limited to these, and various alloy materials may be used. For example, iron, mild steel, nickel alloy, copper alloy, titanium, Hastelloy, Inconel and the like can be used.

As shown in FIG. 12A, the metal fiber structure is a structure made of fine metal fibers, and a non-woven fabric of metal fibers can be preferably mentioned, but is not limited thereto. Further, the diameter and length of the fine fibers are not particularly limited, and those having a diameter and length according to the filtration performance can be adopted. As an example, those composed of metal fibers having an average diameter of about 1 to 200 μm can be mentioned. The metal fiber may have the same or similar fiber diameter and fiber length, or may be a composite of two or more kinds of metal fibers having different fiber diameters and fiber lengths. If necessary, it may be sintered. Such a metal fiber structure is preferably adopted because it can be designed to have a predetermined porosity so that a desired filtration resistance can be obtained. Further, the metal fiber structure may be a single layer or a laminated structure of two or more of the same type, depending on the purpose of filtration and the filtration performance, and the fiber diameter and fiber length may be increased. Two or more of different filtration performances may be laminated.

Such a metal fiber structure can be made like "metal cotton" depending on the fiber diameter and fiber length, and can be easily made dense by compression, and the filtration performance can be arbitrarily controlled. be able to. Further, since it can be preferably applied as the sealing material 42 described later, by using the same metal cotton-like metal fiber structure as the filter medium 1 for the sealing material 42, the sealing performance as a whole can be further improved. It is preferable to apply the metal fiber structure that the applicant has already published in the pamphlet or the like.

As shown in FIGS. 12 (b) and 12 (c), the metal fine mesh structure is a wire mesh structure made of fine metal wires. The fine mesh structure is a woven metal wire, and the diameter of the metal wire is not particularly limited, and a metal wire having a diameter corresponding to the filtering performance after the fine mesh structure can be adopted. As an example, a wire composed of a metal wire having an average diameter of about 10 to 300 μm can be mentioned. The metal wire may be a round wire having the same or the same diameter as long as it is a round wire as shown in FIGS. 12 (b) and 12 (c), or a composite of two or more kinds of wires having different diameters. You may. If necessary, it may be sintered. Such a fine mesh structure is preferably adopted because it can be designed to have a predetermined porosity so that a desired filtration resistance can be obtained. The metal fine mesh structure exemplified in FIG. 12 (b) and the metal fine mesh structure shown in FIG. 12 (c) have different weaving methods, and FIG. 12 (c) has a smaller void ratio. It was done. Further, this fine mesh structure may have various forms as shown in FIGS. 12 (b) and 12 (c) as a single layer, or the same type, depending on the purpose of filtration and the filtration performance. Two or more of them may be laminated, or two or more of them having different diameters and filtration performances may be laminated.

Such a metal fine mesh structure has a larger diameter than the above-mentioned metal fiber structure, and is not like the above-mentioned "metal cotton" which becomes dense easily when compressed, but according to the present invention, it is made of metal. Since the fine mesh structure made of metal is always in contact with the end member 21 and the thickness is increased, the sealing property after caulking and its stability can be improved. It is preferable to apply the mesh filter that the applicant has already published in pamphlets and the like.

(Reinforcing member)
The reinforcing member 2 is an indispensable configuration of the filtration member 11 having high filtration accuracy, and as shown in FIGS. 13A and 13B, the reinforcing member 2 is arranged on one surface or both surfaces of the filter medium 1 to form the filter medium 1. It plays a role of reinforcement. The reinforcing member 2 is preferably a wire mesh having a strength capable of reinforcing the filter medium 1.

As shown in FIGS. 1, 2 (c) and 13 (b), the reinforcing member 2 may be arranged on both sides (S1 and S2) of the filter medium 1 to reinforce the filter medium 1. As shown in FIGS. 2A and 2B, the filter medium 1 may be reinforced by being arranged on only one side (S1 or S2). When it is arranged on only one side, it is desirable that the protrusion 3 is arranged on the surface (S1 or S2) on the folded side as shown in FIGS. 2 (a) and 2 (c), but FIG. 2 (b). ) (D), the protrusion 3 may be arranged on the opposite surface (S1 or S2) on the side to be folded back. As for the folded end portion 3a, as shown in FIGS. 1 and 2 (a) and 2 (c), the projected portion 3 made of the filter medium 1 may be folded back on the end 2a of the reinforcing member 2. 2 (b) As shown in (d), the filter medium 1 may be folded over the filter medium 1 itself. Since the reinforcing member 2 is crimped together with the folded-back end portion 3a in which the filter medium 1 is folded back, when the filter medium 1 whose thickness is increased by the folded-back material 1 is folded back onto the filter medium 1 itself (FIGS. 2B and 2d). The reinforcing member 2 extends to the position of the folded end portion 3a so that the folded end portion 3a and the reinforcing member 2 are crimped together. In any of the folded forms shown in FIG. 2, the end member 21 is in direct contact with the surface of the filter medium at the peripheral end portion 12 of the filtration member 11, so that the sealing property at the joint portion 31 is enhanced.

Wire mesh is a planar structure formed by weaving or knitting metal wires. Specifically, it is preferable that the wire mesh has a woven fabric structure in which a metal wire as a warp and a metal wire as a weft are crossed under certain rules. The diameter of the metal wire constituting the reinforcing member 2 made of the wire mesh is not particularly limited, and a metal wire having a diameter corresponding to the formation of the wire mesh having the strength to reinforce the filter medium 1 can be adopted. As an example, a metal wire having an average diameter of about 20 to 1500 μm can be mentioned, but the metal wire is not limited thereto. The wire mesh may be made of metal wires having the same or similar diameters, or may be made of metal wires having different diameters. If necessary, it may be sintered. Such a reinforcing member 2 is preferably adopted because it can be designed so that the filtering performance of the filter medium 1 is not impaired and the desired strength can be obtained. Further, the reinforcing member 2 may be a single-layer wire mesh, two or more of the same type may be laminated, or two or more different members may be laminated within the range of the purpose thereof. May be. It is preferable to apply the mesh filter that the applicant has already published in pamphlets and the like.

(Original fabric for filtration members)
As shown in FIG. 7A, the original fabric 11a for the filtration member is a flat surface formed by at least the filter medium 1 and the reinforcing member 2 described above. As described in the section of "Mold form of filter element" described above, in the cylindrical filter element 10B and the pleated filter element 10C, the raw fabric 11a for the filtration member is processed to produce the filtration member 11. In the disk type filter element 10A, as described in the above description, the filter medium 1 and the reinforcing member 2 pre-processed into a predetermined shape are superposed, and when the laminating material 1 is superposed, the filter medium 1 is removed from the end of the reinforcing member 2. The original fabric 11a for the filtration member, which is superposed so as to protrude, is used.

(Form of peripheral edge of filtration member)
As shown in FIGS. 6 and 7, the peripheral end portion 12 of the filtration member 11 is formed by processing the original fabric 11a for the filtration member. Then, the folded end portion 3a formed on the peripheral end portion 12 is caulked by the end member 21 described later. Hereinafter, the form of the peripheral end portion 12 of the filtration member 11 will be described for each type of filter element in the order of disk type, cylindrical type, and pleated type.

As shown in FIG. 3, the disk type filter element 10A has a disk shape and is further folded, unlike the pleated type and the cylindrical type in which the original fabric 11a for the filtration member is rolled into a cylindrical shape. do not have. That is, first, the filter medium 1 and the reinforcing member 2 pre-processed into a disk shape are superposed, and the filter medium 1 is prepared to have a size in which a part of the filter medium 1 protrudes from the end of the reinforcing member 2 (FIG. 6). (A)). After that, the protruding portion 3 is folded back onto, for example, the end 2a of the reinforcing member 2 (or above the filter medium 1 itself) to form a folded end portion 3a (FIG. 6 (b)). As in the case of the cylindrical or pleated filter elements 10B and 10C, the folded end portion 3a may be the one in which the protruding portion 3 is folded back as it is, or the folded end portion 3a after the protruding portion 3 is folded back. May be formed to a certain thickness, or may be a folded end portion 3a formed by forming the protruding portion 3 to a certain thickness and then folding back. After that, the peripheral edge portion 12 is drawn and the folded end portion 3a is adjusted to the size of the ring-shaped end member 21 described later, and is sandwiched and crimped from both sides S3 and S4 of the peripheral edge end portion 12 (FIG. 6 (FIG. 6). c)).

As shown in FIG. 4, the cylindrical filter element 10B is not folded, so that it is different from the case of the pleated filter element 10C described with reference to FIGS. 7 and 8. That is, first, a filter member raw fabric 11a having a part of the filter medium 1 protruding from the end 2a of the reinforcing member 2 is prepared (FIG. 6A), and the protruding portion 3 is, for example, the end 2a of the reinforcing member 2. It is folded back onto the top (or above the filter medium 1 itself) to form a folded end portion 3a (FIG. 6 (b)). As in the case of the pleated filter element 10C, the folded end portion 3a may be the one in which the protruding portion 3 is folded back as it is, or the folded end portion 3a after the protruding portion 3 is folded back to a constant thickness. It may be a molded one, or it may be a folded end portion 3a that is folded back after the protruding portion 3 is molded to a certain thickness.

The original fabric 11a for a filtration member having the folded end portion 3a formed thereof is rounded by aligning the facing sides 11b and 11b with each other, and the mating portion is welded into a tubular shape (not shown). As shown in FIG. 4, the peripheral edge portion 12 is formed into a cylindrical main body portion 13 and a peripheral edge end portion 12 by welding the facing sides 11b and 11b to each other. After that, the peripheral edge portion 12 is adjusted as it is or by compression processing to adjust the folded end portion 3a to the size of the ring-shaped end member 21 described later, and the peripheral edge end portion 12 having the folded end portion 3a is double-sided S3, S4. It is sandwiched and crimped from (Fig. 6 (c)).

In the pleated filter element 10C, a raw fabric 11a for a filtration member having a part of the filter medium 1 protruding from the end 2a of the reinforcing member 2 is prepared (FIG. 7A), and the protruding portion 3 is, for example, a reinforcing member. It is folded back onto the end 2a of 2 (or above the filter medium 1 itself as shown in FIGS. 2 (b) and 2 (d)) to form a folded end 3a (FIG. 7 (b)). The folded end portion 3a may be one in which the protruding portion 3 is folded back as it is, or the folded end portion 3a after the protruding portion 3 is folded back may be formed to a certain thickness. It may be a folded end portion 3a that is folded back after the protruding portion 3 is formed to a certain thickness. The thickness of the peripheral edge portion 12 including the folded end portion 3a is preferably a thickness that can be attached to the end member 21 after drawing.

The original fabric for the filtration member 11a on which the folded end portion 3a is formed is then repeatedly folded back in a direction perpendicular to the side including the folded end portion 3a (FIG. 7 (c)), and the original fabric for the filtration member 11a is folded. It forms a pleated form (a fold form in which mountain folds and valley folds are repeated). After the folds are folded, the raw fabric 11a for the filtration member is rounded by aligning the facing sides 11b and 11b with each other, and the mating portions are welded into a tubular shape (FIG. 8 (d)). At this time, the end portion in the axial direction (longitudinal direction) Y in the direction in which the folds extend (the direction in which the ridgeline of the mountain fold extends) is referred to as "peripheral end portion 12". As shown in FIG. 8D, the peripheral edge portion 12 is formed into a cylindrical main body portion 13 and a peripheral edge end portion 12 by welding the facing sides 11b and 11b to each other. After that, the peripheral edge portion 12 is drawn and the outer peripheral edge surface is flat, and the filter media 1 constituting the folded end portion 3a are overlapped with each other in close contact with each other (FIG. 8 (e)). The drawn folded end portion 3a is crimped while being in contact with the ring-shaped end member 21 described later (FIG. 8 (f)).

<End member>
The end member 21 is a member arranged on the peripheral edge portion 12 of the filtration member 11 and caulking the peripheral edge end portion 12 having the folded end portion 3a formed on the peripheral edge end portion 12 by sandwiching the peripheral edge portion 12 from both sides S3 and S4. .. In the disk type filter element 10A, the end member 21 is located on the peripheral edge of the disk-shaped filtration member 11, and the ring-shaped end member 21 is used. As an example of FIG. 14, such an end member 21 may be a composite type end member 21B having a C-shaped groove formed by combining two members 22 and 23 on the entire circumference (as shown in FIG. 14). 14 (a)), one member (24, 25) may be joined by a bending type end member 21 formed by bending (FIGS. 14 (b) and 14 (c)). Reference numerals 22a and 23a are caulking portions constituting the end member 21B. It is preferable that the end member 21 of the composite type is finally caulked after joining the two members 22 and 23 by welding or the like.

In the cylindrical filter element 10B and the pleated filter element 10C, as shown in FIGS. 15A and 15B, the peripheral end portion 12 of the filtration member 11 is one end of the cylindrical filtration member 11 in the axial direction Y or It is located at both ends, and both have a circular peripheral edge. The term "one end or both ends" means that it may be provided at one end or at both ends. As an example of FIG. 15 (c), the end member 21 arranged on the peripheral edge portion 12 having such a shape may be an integrated end member 21A having a U-shaped groove all around. However, it may be a composite type end member (type form in FIG. 14) having a U-shaped groove formed by combining two members all around. Reference numerals 21a, 21b, 21c, 21d are parts constituting the end member 21, and here, the caulking portions 21a, 21b, the abutting portion 21c, and the bottom portion 21d are indicated. The bottom portion 21d may be an open one or a non-open seal form.

The end member 21 used in each of these molds is preferably a metal structure. By forming such a metal structure, it is possible to obtain a stable joint portion 31 without variation by mechanical caulking processing in which the peripheral end portion 12 having the folded end portion 3a is sandwiched from both sides S3 and S4 and caulked. Sealability can be achieved.

<Joining form of filtration member and end member>
The filtration member 11 and the end member 21 are joined by caulking the folded end portion 3a of the filtration member 11 with the end member 21 which is a caulking member. The sealing property at the joint portion 31 greatly affects the filtration performance, and if the sealing property is not sufficient, sufficient filtration performance cannot be obtained. The present invention is characterized in that the sealing property at the joint portion 31 is enhanced by a new sealing structure.

Since the disk type filter element 10A does not have a welded portion, the joining form between the filtration member 11 provided with the welded portion and the end member 21 is not mentioned.

The cylindrical filter element 10B differs in that the filtration member 11 is not a pleated type like the pleated filter element 10C, but is the same as the form of FIG. 9 described later in other respects, and is the same as the above-mentioned contents. The same is true. Therefore, since there is no great difference from the mode shown in FIG. 10 described later, the description thereof will be omitted.

In the pleated filter element 10C, the filtration member 11 is a cylindrical member formed by welding 11b and 11b of the folded original fabrics 11a for the filtration member together. In that case, as shown in FIG. 9, the peripheral end portion 12 has a welded welded portion 41 (referring to a black portion; the same applies hereinafter) formed over the entire length in the axial direction Y. Note that FIG. 11A is a diagram showing an example of the form shown in FIG. 9, and the black portion refers to the welded portion 41.

In this embodiment, the welded portion 41 formed into a cylindrical member formed by rolling the folded raw fabric 11a for the filtration member and welding the facing sides together with the 11b and 11b is formed over the entire length in the axial direction Y. However, in any case, it can have a high sealing property. The welding is preferably performed by seam welding or the like, and the seam welding is preferably performed by TIG or resistance welding.

In FIG. 10, in the form of FIG. 9, a sealing material 42 having a size covering the welded end portion 44 caulked by the end portion member 21 of the welded portion 41 is arranged on the welded end portion 44 and drawn. After that, it is an example of a form crimped by the end member 21. Further, FIG. 11B is a diagram showing an example of the form shown in FIG. 10, and the black portion refers to the welded portion 41. As the sealing material 42 used here, the same metal fiber structure as that applied to the filter medium 1 described above can be processed into a predetermined size and used. By doing this, the same raw materials can be shared and the cost is unlikely to increase. The sealing material 42 may be different from the metal fiber structure applied to the filter medium 1.

In the cylindrical filter element 10B and the pleated filter element 10C, a welded portion 41 extending to the peripheral end portion 12 crimped by the end member 21 is provided. In that case, the end portion of the welded portion 41 is provided. A sealing material 42 having a size covering the welded end 44 crimped by the member 21 is arranged on the welded end 44 and crimped by the end member. By doing so, the sealing material 42 provided on the welded end portion 44 acts to further enhance the sealing property.

In such a metal filter element 10 (10A, 10B, 10C), it is preferable that the folded end portion (folded end portion 3a) of the filter medium 1 is processed. In the case of the disk type filter element 10A and the cylindrical filter element 10B, the folded end portion 3a is compressed (for example, compressed by a press), and the compressed folded end 3a is in contact with the end member 21. However, it is preferable that the end member 21 is caulked. On the other hand, in the case of the pleated filter element 10C, the folded end portion 3a is drawn, and the drawn folded end 3a is crimped by the end member 21 while being in contact with the end member 21. Is preferable. By such processing, the structural form of the folded end (dimensions such as thickness, density of filter media, etc.) becomes constant, it becomes easy to attach to the end member, and the sealing property after caulking is stable and improved. Can be made to. In particular, in the pleated filter element 10C, the filter medium 1 at the folded end 3a is always in contact with the filter medium 1 and the thickness is increased, so that the sealing property after caulking can be further stabilized and improved.

<Comparison of joining morphology at the peripheral edge>
In the metal filter element 10 according to the present invention, the peripheral end portion 12 is caulked and joined by the end member 21, and the joining form thereof will be described in more detail with reference to FIGS. 16 to 20. Note that FIG. 16 is an example of an embodiment of the joining mode at the peripheral end portion 12 of the disk type filter element 10A, and FIG. 17 shows the filter medium 1 not folded back with respect to the joining form at the peripheral edge end portion 12 of the disk type filter element 10A. FIG. 18 is an example of a comparative form of the case, FIG. 18 is an example of a joining form at the peripheral edge portion 12 of the cylindrical filter element 10B, and FIG. 19 is a joining form of the cylindrical filter element 10B at the peripheral edge end portion 12. It is an example of the comparative form in the case where the filter medium 1 is not folded back, and FIG. 20 is an explanatory view of the sealing form at the peripheral end portion 12 of the welded portion 41 of the cylindrical filter element 10B.

(Joining form at the peripheral edge of the disk type filter element)
In the disk type filter element 10A, as shown in FIGS. 16A and 16B, filtration is normally performed in the filtration direction F indicated by the arrow (in the illustrated example, the direction from top to bottom). The folding direction of the protrusion 3 is considered whether the reinforcing member 2 is provided on only one side (S1 or S2) of the filter medium 1 or on both sides (S1 and S2). When the reinforcing member 2 is provided on both sides (S1 and S2) of the filter medium 1, the protruding portion 3 may be folded back onto the reinforcing member 2 on the surface S1 on the side of the filtration direction F, or the reverse of the filtration direction F. It may be folded back on the reinforcing member 2 on the side surface S2, and is not particularly limited, but the protruding portion 3 is folded back on the reinforcing member 2 on the side surface S1 in the filtration direction F to form the folded end portion 3a. Is preferable (FIGS. 16 (a) and 16 (b)).

As shown in FIG. 16B, since the filter medium 1 may be crimped in contact with the end member 21, the filter medium 1 may be folded back together with the reinforcing member 2. This example is preferably applied when the reinforcing member 2 is integrated with the filter medium 1 by, for example, sintering or welding. It is also preferably applied when the "other member" is integrated with the filter medium 1 together with the reinforcing member 2 or by sintering or welding instead of the reinforcing member 2.

FIG. 17 is an example of a comparative form in which the filter medium 1 is not folded back with respect to the joining form at the peripheral end portion 12 of the disk type filter element 10A. FIG. 17A is an example in which the reinforcing member 2 is arranged only on one side S2 of the filter medium 1. When the reinforcing member 2 is provided only on one side S2 of the filter medium 1, the reinforcing member 2 needs to be provided on the opposite surface of the surface on the side of the filtration direction F to reinforce the filter medium 1. Therefore, the example of FIG. 17A. Therefore, it is desirable that the surface S2 (lower surface in the figure) opposite to the surface S1 (upper surface in the figure) on the side of the filtration direction F is provided. However, even in this form, when a flow in the reverse direction of the filtration direction F (backwashing or the like) occurs, the filter medium 1 cannot be protected by the reinforcing member 2 having only one side S2 (lower surface). When the flow in the reverse direction such as backwash does not occur, the reinforcing member 2 may be provided only on one side S2 (lower surface). In the example of FIG. 17A, the folded end portion 3a is not formed, but the filter medium 1 and the end member 21 come into contact with each other by caulking the end member 21, and the sealing property by caulking is improved. Even if the sealing property is not as high as that of the present invention provided with the folded end portion 3a, the sealing property can be ensured. If the folded end portion 3a is formed in the form as shown in FIG. 2B, the thickness of the folded end portion 3a is increased and the sealing property is further improved.

FIG. 17B is an example in which the reinforcing member 2 is arranged on both sides S1 and S2 of the filter medium 1. When the reinforcing members 2 are provided on both sides S1 and S2 of the filter medium 1, the reinforcing members 2 are irrespective of the filtration direction F, and even if there is a flow in the reverse direction of the filtration direction F (backwashing, etc.), the reinforcing members 2 are provided. It is preferable because the filter medium 1 can be protected by 2. However, since the reinforcing member 2 is directly crimped by the end member 21, the reinforcing member 2 is different from the case where the folded end portion 3a of the filter medium 1 is directly crimped by the end member 21 as in the present invention. Leakage as shown by the arrow in the figure occurs via.

FIG. 17C is an example in FIG. 17B in which the sealing material 42 is provided on both sides S3 and S4 of the peripheral edge portion 12. In this form as well, as in FIG. 17B, the reinforcing member 2 can protect the filter medium 1 regardless of the filtration direction F and even if there is a flow in the reverse direction of the filtration direction F (backwashing or the like). preferable. However, although the sealing material 42 is provided on both sides S3 and S4 of the peripheral edge portion 12 and the end member 21 and the sealing material 42 are crimped with good sealing performance, as shown by the arrow in the figure via the reinforcing member 2. Leakage occurs.

(Joining form at the peripheral end of the cylindrical filter element)
In the cylindrical filter element 10B as well, as in the case of the disk type filter element 10A, as shown in FIGS. 18A and 18B, the filtration direction F of the arrow is usually directed from the outside to the inside of the cylinder in the illustrated example. Filtration is performed in the direction). Since the folding direction of the protruding portion 3 is the same as that of the disk type filter element 10A, detailed description thereof will be omitted here, but the protruding portion 3 is folded back onto the reinforcing member 2 on the surface S1 on the side of the filtration direction F. It is preferable to form the folded end portion 3a (FIGS. 18 (a) and 18 (b)).

The form shown in FIG. 18B is the same as the form shown in FIG. 16B, and although detailed description thereof is omitted here, for example, the reinforcing member 2 is integrated with the filter medium 1 by sintering or welding. It is preferably applied when there is. It is also preferably applied when the "other member" is integrated with the filter medium 1 together with the reinforcing member 2 or by sintering or welding instead of the reinforcing member 2.

FIG. 19 is an example of a comparative form in which the filter medium 1 is not folded back with respect to the joining form at the peripheral end portion 12 of the cylindrical filter element 10B. FIG. 19A is an example in which the reinforcing member 2 is arranged only on one side S2 of the filter medium 1 as in FIG. 17A. When the reinforcing member 2 is provided on only one side of the filter medium 1, the reinforcing member 2 needs to be provided on the opposite surface of the surface S1 on the side of the filtration direction F to reinforce the filter medium 1. Therefore, the example of FIG. 19A. Therefore, it is desirable that the surface is provided on the opposite surface S2 (inner side surface) of the surface S1 (outer surface) on the side of the filtration direction F. However, even in this form, when a flow in the reverse direction of the filtration direction F (backwashing or the like) occurs, the filter medium 1 cannot be protected by the reinforcing member 2 having only one side S2 (inner side surface). When the flow in the reverse direction such as backwash does not occur, the reinforcing member 2 may be provided only on one side S2 (inner side surface). In the example of FIG. 19A, the folded end portion 3a is not formed, but by caulking the end member 21, the filter medium 1 and the end member 21 come into contact with each other to improve the sealing property by caulking. Even if the sealing property is not as high as that of the present invention provided with the folded end portion 3a, the sealing property can be ensured. If the folded end portion 3a is formed in the form as shown in FIG. 2B, the thickness of the folded end portion 3a is increased and the sealing property is further improved.

When the reinforcing member 2 is provided on only one side of the filter medium 1, the filter medium 1 is arranged on the outer side surface side and the reinforcing member 2 is arranged on the inner side surface side as shown in FIG. 19A. This may not be the case, but may be the case where the filter medium 1 is arranged on the inner side surface side and the reinforcing member 2 is arranged on the outer side surface side. However, in this case, it is desirable that the filtration direction F is a filtration direction that flows from the inside to the outside, contrary to the case of FIG. 19A.

FIG. 19B is an example in which the reinforcing member 2 is arranged on both sides S1 and S2 of the filter medium 1 as in FIG. 17B. When the reinforcing members 2 are provided on both sides S1 and S2 of the filter medium 1, the reinforcing members 2 are irrespective of the filtration direction F, and even if there is a flow in the reverse direction of the filtration direction F (backwashing, etc.), the reinforcing members 2 are provided. It is preferable because the filter medium 1 can be protected by 2. However, since the reinforcing member 2 is directly crimped by the end member 21, the reinforcing member 2 is different from the case where the folded end portion 3a of the filter medium 1 is directly crimped by the end member 21 as in the present invention. Leakage as shown by the arrow in the figure occurs via.

FIG. 19C is an example in FIG. 19B in which the sealing material 42 is provided on both sides S3 and S4 of the peripheral edge portion 12. In this form as well, as in FIG. 19B, the reinforcing member 2 can protect the filter medium 1 regardless of the filtration direction F and even if there is a flow in the reverse direction of the filtration direction F (backwashing or the like). preferable. However, although the sealing material 42 is provided on both sides S3 and S4 of the peripheral edge portion 12 and the end member 21 and the sealing material 42 are crimped with good sealing performance, as shown by the arrow in the figure via the reinforcing member 2. Leakage occurs.

FIG. 20 is a cross-sectional view of the sealing form of the cylindrical filter element 10B at the peripheral end portion 12 of the welded portion 41. 20 (a) is an example in which the sealing material 42 is not arranged on the welded portion 41, and FIG. 20 (b) is an example after caulking FIG. 20 (a). As shown in FIG. 20A, since the cylindrical filter element 10B is formed by welding the facing sides 11b of the original fabric 11a for the filtration member together, the reinforcing member 2 of the filtration member 11 is welded. Sometimes it melts and tends to become molten metal. At such a location of the molten metal, leakage via the reinforcing member 2 is unlikely to occur, so that a certain degree of sealing property can be ensured as it is. However, due to the "bead" (the swelling of the welding mark generated at the time of welding) that tends to occur at the time of joining by welding, a wavy shape is generated as shown in FIG. Welding may occur. Therefore, it is not preferable when high filtration accuracy is required.

FIG. 20 (c) is an example in which the sealing material 42 is arranged on such a welded portion 41, and FIG. 20 (d) is an example after caulking FIG. 20 (c). By covering the welded portion 41 with the sealing material 42 and caulking it, it is possible to eliminate minute gaps that may occur between the bead and the end member 21, so that leakage can be reliably eliminated. can.

(Joining form at the peripheral edge of the pleated filter element)
The same applies to the pleated filter element 10C as in the case of the cylindrical filter element 10B. Although detailed description is omitted here, as in the case of the cylindrical filter element 10B, the protruding portion 3 of the filter medium 1 is folded back to form a folded end portion 3a having an increased thickness, and then caulked by the end member 21. High sealing performance can be achieved. In particular, in the pleated filter element 10C, as shown in FIG. 8E, the peripheral end portion 12 including the folded end portion 3a is drawn, so that the mountain portion of the folded end portion 3a is tilted. The thickness becomes almost constant as the thickness is further increased by overlapping with each other. After that, by attaching to the end member 21 and caulking, the sealing property after caulking becomes high and stable.

In particular, in the pleated filter element 10C, after folding the folds, the one formed into a tubular shape (see FIG. 8 (d)) is drawn and folded into folds as shown in FIG. 8 (e). The filter media come into contact with each other, and the surfaces of the contacted filter media become flat. Further, since the filter medium 1 is folded back, the thickness is increased and the cushioning property is increased. Due to the effect of drawing and increasing the thickness, the sealing property by caulking is further improved.

The form shown in FIG. 18B can also be applied to the pleated filter element 10C. In particular, it can be applied when the filter medium 1 and the reinforcing member 2 are sintered on one side of the filter medium 1 (the surface on the S1 side in FIG. 18B).

Further, as in the case of FIG. 20 (c), by arranging the sealing material 42 on the welded portion 41 and drawing it as in the form of FIGS. 10 and 11 (b), leakage via the reinforcing member 2 is performed. Leakage caused by beads and beads can be reliably eliminated, and extremely high and stable sealing properties can be realized.

As described above, according to the metal filter element 10 according to the present invention, a pleated type having improved sealing performance by a new sealing structure having improved sealing performance of the joint portion 31 between the filtration member 11 and the end member 21. , Cylindrical type, disc type and the like can be provided. As a result, a metal filter element that achieves high sealing performance can be manufactured at a lower cost with no need for advanced welding technology, easy dimensional control, and higher cost.

1 Filter material 2 Reinforcing member 2a Reinforcing member end 3 Protruding part 3a Folded end part 10 Metal filter element 10A Disc type filter element 10B Cylindrical filter element 10C Pleated type filter element 11 Filtering member 11a Original fabric for filtering member 11b Opposing sides to each other 12 Peripheral end 13 Main body 21 End member 21A Integrated end member 21a, 21b Caulking part 21c Butt part 21d Bottom 21B Composite end member 22,23 Two members to be combined 22a, 23a Caulking part 24 , 25 Bending type end member 31 Joint part 41 Welding part 42 Sealing material 44 Welding end part S1, S2 Filter media surface S3, S4 Peripheral end surface Y Cylindrical axial direction (longitudinal direction)
F Filtration direction

Claims (10)

A metal filter element having a joint between a filtration member and an end member arranged at the peripheral end of the filtration member.
The filter member is composed of at least a filter medium and a reinforcing member arranged on one or both surfaces of the filter medium, and the end member is a member that sandwiches and crimps the peripheral end portions of the filter member from both sides. The peripheral end portion of the filtration member has a folded-back end portion in which the filter medium is folded back, and the folded-back end portion is caulked by the end portion member while being in contact with the end portion member. A metal filter element featuring. The metal filter element according to claim 1, wherein the folded end portion is the filter medium folded over the end of the reinforcing member, or the filter medium folded over the filter medium itself. The metal filter element according to claim 1 or 2, which is either a disc type filter element, a cylindrical filter element, or a pleated type filter element. In the cylindrical filter element, the filtration member is a cylindrical member formed by welding the facing sides of the original fabric for the filtration member together, and the welded welded portion is formed over the entire length in the axial direction. , The metal filter element according to claim 3. In the pleated filter element, the filtration member is a cylindrical member formed by welding the facing sides of the folded original fabrics of the filtration member together, and the welded welded portion is formed over the entire length in the axial direction. The metal filter element according to claim 3. The pleated filter element, wherein the pleated form is formed after folding the filter medium, and the folded end portion is crimped by the end member after being drawn. 5. The metal filter element according to 5. In the cylindrical filter element according to claim 4 or the pleated filter element according to claim 5 or 6, a seal having a size covering the welded end portion of the welded portion to be caulked by the end member. A metal filter element in which a material is placed on the welded end and caulked by the end member. In the case of the disk type and the cylindrical type filter element, the folded end portion is compressed, and the compressed end portion is crimped by the end member, and the pleated end portion is crimped. The metal filter element according to claim 3, wherein in the case of an element, the folded end portion is drawn and the drawn folded end portion is crimped by the end member. The metal filter element according to any one of claims 1 to 8, wherein the filter medium is a metal fiber structure, a metal fine mesh structure, or a combination thereof, and the reinforcing member is a metal net. .. The metal filter element according to any one of claims 1 to 9, wherein the end member is a metal structure for caulking the folded end portion.

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