JP2020001037A - Metallic porous body, metallic filter and manufacturing method of metallic porous body - Google Patents

Abstract

To provide a metallic porous body which returns to an original shape after deformation due to an external force in the metallic porous body manufactured by winding a metal wire spirally and in a multilayer shape, and to spread usage and application of the metallic porous body.SOLUTION: A hollow cylindrical body made by winding stainless metal wiring spirally and in a multi-layer shape such that inclination angles of respective metallic wires 20A, 20B which constitute wire layers L1, L2 adjacent to each other are differentiated from each other is manufactured and heat treatment for four hours in the range of 600 to 700°C is executed for the manufactured hollow cylindrical body. An obtained metallic porous body can be extended and contracted in the axial direction and can be curved and deformed by receiving an external force and is returned to the original shape by removing the external force.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a metal porous body produced by spirally winding a metal wire in a multilayer shape, and in particular, can be freely deformed from an initial shape by applying an external force, and by removing the external force The present invention relates to a self-restoring metal porous body which returns to its original shape.

BACKGROUND ART Conventionally, a tubular metal porous body produced by spirally winding a metal wire in a multilayered manner has been known.
Patent Literature 1 discloses an inflator filter used for an airbag of an automobile. In this filter, one metal wire is wound around a mandrel, formed into a cylindrical shape, and then subjected to a sintering process to join adjacent metal wires. For this reason, this filter has a high rigidity, and has a feature that the entire shape and the aperture can be maintained even by the impact of the high-temperature gas generated by the explosive combustion of the gas generating agent.
Patent Literature 2 describes a metal porous body that does not kink even when deformed by a human hand. Note that "kink" refers to a phenomenon in which when an external force is applied to a metal porous body, the metal porous body is crushed, and the metal porous body is not restored to its original shape even when the external force is removed. This metal porous body can also be obtained by winding a single metal wire around a mandrel and forming it into a cylindrical shape, followed by sintering.

JP 2001-171472 A JP 2014-140892 A

The metal porous bodies described in Patent Literatures 1 and 2 are subjected to a sintering process, and adjacent metal wires are joined to each other. Particularly, in Patent Literature 1, since a sintering process is performed to obtain a highly rigid filter, it is not planned to deform and use the filter.
Further, in the metal porous body described in Patent Document 2, it is possible to bend and deform freely by hand, but since the metal wires are joined together, the metal porous body remains deformed even after removing the external force. It is assumed that the device is used while maintaining the shape described above. Therefore, it does not return to its original shape by itself after removing external force.
A metal porous body formed by spirally winding a metal wire in a helical and multilayer form, which can return to its original shape by itself after deformation, has not been proposed so far. Such a metal porous body has been developed. If so, there is a possibility that the usage and use of the metal porous body will be expanded.
The present invention has been made in view of the above-described circumstances, and in a metal porous body produced by spirally winding a metal wire in a multilayered manner, a metal porous body returns (restores) to its original shape by itself after deformation. It is an object of the present invention to provide a metallic porous body.

In order to solve the above-mentioned problem, the invention according to claim 1 is configured such that the metal wires are spirally and multilayerly wound such that the inclination angles of the metal wires constituting the adjacent wire layers are different. A hollow cylindrical metal porous body, wherein the metal porous body deforms when an external force is applied, and returns to its original shape when the external force is removed.
The invention according to claim 2 is characterized in that the metal porous body is expanded and contracted in the axial direction by the application of the external force in the axial direction, and returns to the original shape by removing the external force. .
The invention described in claim 3 is characterized in that the metal porous body is bent and deformed when the external force is applied, and returns to its original shape when the external force is removed.

The invention described in claim 4 is characterized in that the metal porous body has a cylindrical shape whose axis extends straight.
The invention according to claim 5 is at least a part of a hollow cylindrical body in which the metal wires are spirally and multilayerly wound so that the inclination angles of the respective metal wires constituting the adjacent wire layers are different. Characterized by being subjected to a stress relief annealing treatment.
According to a sixth aspect of the present invention, there is provided a metal filter including the metal porous body according to any one of the first to fifth aspects.

The invention according to claim 7 is a method for manufacturing a metal porous body, wherein the metal wires are spirally and multilayerly wound so that the inclination angles of the metal wires constituting adjacent wire layers are different. And a heat treatment step of performing stress relief annealing on at least a part of the hollow cylindrical body.
The invention according to claim 8 is a method for manufacturing a metal porous body, wherein the metal wire is stainless steel, and a processing temperature in the heat treatment step is 600 ° C to 700 ° C.

  ADVANTAGE OF THE INVENTION According to this invention, although it deform | transforms when an external force is applied, the novel metal porous body which returns to an original shape by removing an external force can be provided, and the usage and use of a metal porous body expand. .

FIG. 2 is a plan view of the porous metal body according to the first embodiment of the present invention. 1 is a partially enlarged perspective view of a metal porous body according to a first embodiment of the present invention. It is a perspective view showing the state where the metal porous body was curved. It is the flowchart which showed the manufacturing process of the metal porous body. It is a schematic diagram which shows an example of the manufacturing apparatus of a metal porous body. (A)-(c) is a top view of a metal porous object concerning a second embodiment of the present invention. It is a figure which shows the material of a test body, a shape, heat treatment conditions, and the result of an expansion evaluation test in a table. (A), (b) is a figure shown by the enlarged photograph of the surface of a test body, (a) is a figure which shows an initial state, (b) is a figure which shows the state at the time of expansion | extension. It is a figure showing the principle of a bubble point test.

  Hereinafter, the present invention will be described in detail using embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are not merely intended to limit the scope of the present invention but are merely illustrative examples unless otherwise specified. .

Hereinafter, embodiments of the present invention will be described in detail.
[First embodiment]
The metal porous body according to the first embodiment of the present invention will be described. FIG. 1 is a plan view of a porous metal body according to the first embodiment of the present invention. FIG. 2 is a partially enlarged perspective view of the metal porous body according to the first embodiment of the present invention. FIG. 3 is a perspective view showing a state in which a metal porous body is curved. FIG. 1 shows a state in which the metal porous body is in an original shape (initial shape).
The metal porous body according to the present embodiment has elasticity and flexibility, deforms when an external force is applied, and returns to the original shape (or original posture) by removing the external force (restores to the original shape). It has a characteristic that it has elasticity.

As shown in FIG. 2, the metal porous body 10 is formed by spirally winding one metal wire 20 so that the inclination angles of the metal wires 20A and 20B constituting the adjacent wire layers Ln and Ln-1 are different from each other. It is a hollow cylindrical shape formed by winding in a multilayer shape.
As shown in FIG. 1, when in the initial shape, the metal porous body 10 is in a state where its axis X extends linearly and contracts in the axial direction.
The metal porous body 10 can expand and contract in the axial direction. When an external force is applied to the metal porous body 10 in the initial shape in the direction along the axial direction, the metal porous body 10 expands and contracts in the axial direction. . Further, the metal porous body 10 has a property of self-restoring to the initial shape by removing the external force.
The metal porous body 10 has flexibility (or flexibility), and when an external force for bending the axis X is applied to the metal porous body 10 in the initial shape shown in FIG. The body 10 curves without kinking as shown in FIG. Further, the metal porous body 10 has a property of self-restoring to the initial shape by removing the external force. Here, “kink” means that when an external force for bending the metal porous body 10 is applied to the metal porous body 10, the metal porous body 10 is crushed and the external force is removed from the metal porous body. Even if it does not return to its original shape.

Hereinafter, the detailed configuration of the metal porous body will be described.
<Shape of porous metal body>
As shown in FIG. 2, the hollow cylindrical metal porous body 10 according to the embodiment of the present invention sets at least one metal wire 20 at a certain inclination angle with respect to the axial direction (vertical direction in the figure). It is formed by being spirally wound and multilayered. Here, the individual layers wound in the same direction are referred to as wire rod layers L1, L2, L3,. The metal wires constituting the wire layers L1, L2, L3,... Extend in the same direction that is inclined with respect to the axial direction of the metal porous body 10 when viewed from the front, and form adjacent wire layers. The metal wires extend in directions crossing each other (not parallel).

The direction in which the wire 20A (the thickness is not shown) of the outermost wire layer Ln in FIG. 1 extends is the direction indicated by the solid arrow, and the wire 20B of the wire layer Ln-1 immediately inside extends. The direction is the direction indicated by the dashed arrow.
That is, the metal porous body 10 includes one wire layer (for example, a wire layer L1) formed by spirally winding the metal wire 20 at a certain inclination angle with respect to the axial direction, and one wire layer L1. Another wire layer (for example, wire layer L2) formed by spirally winding a metal wire at an inclination angle different from that of the metal wire forming the one wire layer L1 so as to overlap the outer peripheral side of the wire rod. And The metal wires constituting one wire layer L1 and another wire layer L2 adjacent thereto are non-parallel to the axial direction and are configured to cross each other.
In addition, you may comprise so that the inclination angle with respect to the axial direction of the metal wire which comprises a wire rod layer may change in one wire rod layer.

When used as a filter, the metal porous body 10 removes unnecessary substances and the like from various fluids such as liquids and gases, and also cools the fluid passing through the metal porous body at the same time depending on the application. The size (axial dimension, diameter, thickness, etc.) of the metal porous body is appropriately determined according to the structure and size of the device equipped with the metal porous body.
Examples of the type of metal used as the material of the metal porous body include iron, mild steel, stainless steel, nickel alloy, and copper alloy, and among them, austenitic stainless steel (SUS304, SUS316, SUS316L, etc.) is preferable. is there.
The thickness and cross-sectional shape of the metal wire used for the metal porous body are appropriately determined according to the size of the metal porous body, the substance to be removed by the metal porous body, pressure loss, and the like.
As the metal porous body, for example, a metal wire having a cross section of a perfect circle, a flat rolled wire obtained by rolling a metal wire, or the like which has been rolled to have a predetermined cross-sectional shape is used.

<Manufacturing process>
The manufacturing process of the metal porous body will be described. FIG. 4 is a flowchart showing a process for manufacturing a metal porous body.
The metal porous body 10 has a winding step (Step S1), a die-cutting step (Step S2), a heat treatment step (Step S3), a fitting attaching step (Step S4), a cleaning step (Step S5), and an inspection step (Step S6). ).
Steps S1 and S2 are steps for forming a hollow cylindrical body that is a base of a metal porous body.
Further, the die cutting step of step S2 and the heat treatment step of step S3 can be performed interchangeably. Further, after the die removing step in step S2, the metal fitting mounting step shown in step S4 may be performed, and then the heat treatment step in step S3 may be performed.

<< Wind process, die cutting process >>
FIG. 5 is a schematic diagram illustrating an example of a manufacturing apparatus for a metal porous body. This device is for producing a hollow cylindrical body which is a base of a metal porous body from a metal strand. Further, the shape of the manufactured hollow cylindrical body becomes the initial shape of the metal porous body.
The manufacturing apparatus 100A includes a rolling device 110 that rolls a metal wire 21 supplied from a bobbin (not shown) and a metal wire (hereinafter, referred to as a “metal wire 20”) whose cross-sectional shape has been deformed by rolling. A tension unit 120 that applies a predetermined tension in the direction and a winding device 130 that winds the metal wire 20 around the mandrel 131 to form a hollow cylindrical body are roughly provided. A plurality of transport rollers 140 that transport the metal wire while guiding the metal wire are arranged on the transport path of the metal wire 20.
The rolling device 110 includes two columnar rolling rollers 111a and 111b which are arranged opposite to each other and rotate. The portion where the surfaces (opposing surfaces) of the rolling rollers 111a and 111b are in contact with each other constitutes a pressing unit 112 for deforming the metal wires 21 into a desired shape with the metal wires 21 interposed therebetween. The rolling device 110 plastically deforms the metal element wire 21 at a predetermined temperature and pressure at the pressing portion 112 to obtain the metal wire 20 having a predetermined cross-sectional shape. Rolling may be cold rolling or hot rolling.

The tension unit 120 includes a fixed roller 121 that is rotatably fixed at a predetermined position, and a movable roller 122 that moves toward or away from the fixed roller 121 and is rotatable. By moving the movable roller 122 toward or away from the fixed roller 121, a predetermined tension is applied to the metal wire 20 wound around and transported around the fixed roller 121 and the movable roller 122.
The winding device 130 includes a mandrel 131 that rotates in a predetermined direction at a predetermined speed, and a guide member that guides the metal wire 20 by reciprocating at a predetermined speed in the axial direction of the mandrel 131 (a direction orthogonal to the paper surface in the drawing). 132. The mandrel 131 is substantially cylindrical or cylindrical, and is generally formed from a metal such as stainless steel, a copper alloy, or an aluminum alloy.

In order to manufacture the hollow cylindrical body, one end of the metal wire 20 is locked in place on the mandrel 131, and the mandrel 131 is held in a state where a predetermined tension is applied to the metal wire 20 by the tension unit 120. The metal wire 20 is reciprocated in the axial direction of the mandrel 131 by the guide member 132. By this operation, the metal wire 20 is spirally wound around the outer periphery of the mandrel 131 in a multilayered manner. Further, the metal wires constituting the adjacent wire layers cross each other to form a mesh.
For example, in the first metal wire layer wound directly around the outer periphery of the mandrel 131, assuming that each wire is inclined clockwise by a predetermined angle θ with respect to the axial direction of the mandrel in FIG. The wire constituting the second metal wire layer wound around the outer periphery of the wire layer is inclined counterclockwise by a predetermined angle θ with respect to the axial direction of the mandrel.

After the metal wire 20 is wound a predetermined number of times (a predetermined number of layers), the metal wire 20 is cut, and the cut end is joined to a proper position of the wound wire by spot welding or the like and removed from the mandrel 131. Thereby, a hollow cylindrical body is obtained (Step S2: die-cutting step).
The angle (winding angle) of the metal wire 20 with respect to the axial direction of the mandrel 131 and the interval (pitch) between the metal wires 20 adjacent in the axial direction are determined by the ratio between the rotation speed of the mandrel 131 and the moving speed of the guide member 132. It can be changed by appropriately adjusting. When the metal porous material is used as a filter, the pressure loss of the fluid passing through the metal porous material is controlled to an appropriate value by appropriately changing the thickness, winding angle, pitch, and number of windings of the metal wire. can do.

<< heat treatment process >>
In the heat treatment step, a stress relief annealing (low-temperature annealing) for reducing or removing the residual stress of the metal wire generated at the time of rolling or winding is performed. The metal porous body obtained through this heat treatment step has elasticity, and can be freely expanded, contracted or deformed by applying an external force. However, when the external force is removed, the porous body exhibits a self-restoring ability to return to an initial shape.
In the heat treatment step, the hollow cylindrical body is placed in a heating furnace, maintained at a predetermined temperature for a certain time, and then cooled. The heat treatment is performed for about several hours (for example, about 4 hours) in a furnace set at a processing temperature of 600 ° C. to 700 ° C., preferably 600 ° C.
Although the heat treatment can be performed in the air, it is preferably performed in a vacuum or an inert gas that does not cause a chemical reaction to occur due to a reducing gas that reduces oxides on the surface or a metal wire. . Examples of the reducing gas include hydrogen gas, a mixed gas of hydrogen and nitrogen, and an ammonia decomposition gas. Examples of the inert gas include nitrogen gas, argon, and the like.

<< Mounting, cleaning and inspection processes >>
A metal fitting is attached to the metal porous body 10 to facilitate handling of the metal porous body obtained through the heat treatment step. In this example, the end fitting 13 is attached to the end in the axial direction by welding. The end fitting 13 may be a cylindrical member having a hole communicating with the inside of the hollow portion of the metal porous body 10. The end fitting 13 shown in FIG. 1 has a flange portion that protrudes from the surface of the metal porous body 10 in a stepwise manner in the outer diameter direction.
The metal porous body 10 manufactured as described above is cleaned and completed through a predetermined inspection.

<Effect>
The metal porous body is a porous body having a plurality of fine pores. The porous metal body has a larger pore size (aperture) when expanded in the axial direction, and a smaller pore size when contracted, so that it can be used as a metal filter whose filtration accuracy can be adjusted as necessary. (See FIGS. 8A and 8B).
Further, as shown in FIG. 3, the metal porous body can remove foreign matters in a state where it is appropriately curved and deformed at a desired curvature, so that it can be used as a flexible metal filter. When the metal porous body is used as a flexible metal filter, it can be used as a static filter for removing foreign matter while keeping the curved shape fixed. In addition, by connecting two rotating members whose axial directions are not on a straight line with a metal porous body, the metal porous body can be used as a dynamic filter that performs filtration while rotating.
Since the metal porous body freely bends and deforms, it is used as a power transmission member for transmitting the rotational force output from one of the two rotating members whose axial directions are not linear to the other rotating member at a constant speed. It is also possible.

Since the metal wires constituting the metal porous body are not joined to each other, when the metal porous body is deformed, the metal wires displace each other. Since the metal porous body has elasticity and self-restoring force, when the metal porous body is deformed, the positional relationship between the metal wires is substantially uniformly displaced (see FIG. 8B). Therefore, in the case of expanding and contracting in the axial direction, the apertures expand and contract almost uniformly. Further, when the metal wires are bent and deformed, the positions of the metal wires are substantially uniformly displaced in accordance with the curvature of each portion of the metal porous body. Therefore, the opening itself does not greatly differ only at a specific portion due to the deformation.
From the above, in a state where the metal porous body obtained by the present invention is deformed into a desired amount of elongation and a desired curved shape, by performing the sintering process while maintaining the shape, any arbitrary It is possible to produce a hollow cylindrical metal filter deformed into a shape.

The initial shape of the metal porous body is determined by the shape of the hollow cylindrical body obtained in the winding process. In this example, a metal porous body is produced from a cylindrical hollow cylindrical body produced by winding a metal wire around a cylindrical or cylindrical mandrel whose axis extends linearly. Therefore, a metal porous body having a cylindrical initial shape having an axis X extending linearly can be manufactured by a relatively simple manufacturing method.
As described above, the present invention has been described with reference to the example of the cylindrical metal porous body having both ends opened in the axial direction. However, the metal porous body may be a cylindrical shape having one end closed in the axial direction. Further, depending on the shape of the mandrel around which the metal wire is wound, it is also possible to produce a porous metal body having a rectangular tube shape, a conical shape, a pyramid shape, or another shape.
In addition, as the deformed shape, expansion and contraction and bending are exemplified, but the deformed shape includes various deformations such as bending and twisting.

[Second embodiment]
A second embodiment of the present invention will be described. The second embodiment is characterized in that the metal porous body partially has a non-recoverable portion having no self-restoring property.
FIGS. 6A to 6C are plan views of a metal porous body according to the second embodiment of the present invention.
The metal porous body 30 has a restorable portion 31 and a non-restorable portion 33.
The restorable portion 31 is a portion having the property of the metal porous body shown in the first embodiment, and is capable of expanding and contracting in the axial direction and freely bending the axis X. It is a part that can be restored.
The non-restorable portion 33 is a portion that can be expanded, contracted, or deformed in a curved manner, but cannot be restored by its own power after the deformation, or cannot be deformed even when an external force is applied.

6A is an example having a restorable portion 31 and a non-restorable portion 33 alternately arranged in the axial direction.
The metal porous body 30B shown in FIG. 6B is an example in which a non-restorable portion 33 extending in the axial direction is arranged in a part of the circumferential direction, and the rest of the circumferential direction is made a restorable portion 31.
FIG. 6C shows an example in which the non-restorable portion 33 is spirally arranged with respect to the metal porous body 30C, and the other portion is set as the restorable portion 31.

The non-restorable portion 33 can be manufactured by partially applying a heat treatment under a condition that the original shape cannot be restored after deformation by an external force, or a heat treatment under a condition that the deformation cannot be performed by an external force. It is. For example, the restorable portion 31 and the non-restorable portion 33 are mixed by performing a partial heat treatment (including a sintering process) using a high frequency, a light beam, or an electron beam, or a partial welding process. The metal porous body 30 can be manufactured.
By mixing the restorable portion 31 and the non-restorable portion 33, the metal porous body 30 is deformed while displacing the positions of the metal wires constituting the metal porous body 30 substantially uniformly, and the shape after the deformation is obtained. Can be held.

〔Evaluation test〕
A plurality of metal porous bodies were prepared by changing only the temperature conditions during the heat treatment, and an evaluation test was performed. FIG. 7 is a table showing the material, shape, heat treatment conditions, and results of the expansion / contraction evaluation test of the test specimen. 8 (a) and 8 (b) are diagrams showing enlarged photographs of the surface of the test specimen, (a) showing an initial state, and (b) showing a state at the time of extension.

<Preparation of test specimen>
A metal porous body as a test body was produced as follows.
First, a round wire of austenitic stainless steel SUS316L having a wire diameter of 0.13 mm was formed into a flat rolled wire having a thickness of 0.065 mm by cold rolling. Next, the flat rolled wire is spirally wound into a multilayer mandrel having an outer diameter of 3.7 mm so that adjacent wires intersect with each other in a spiral manner, and then the mandrel is removed to obtain a cylindrical hollow cylindrical body. Was prepared.
The dimensions of this hollow cylindrical body are 3.7 mm in inner diameter, 6.2 mm in outer diameter, and 100 mm in total length. The interval between adjacent metal wires is approximately 630 μm, and the angle between intersecting metal wires is approximately 46 degrees (see FIG. 8A). Although this hollow cylindrical body can be expanded and contracted in the axial direction by applying an external force, it does not have a self-restoring property, and once deformed, remains in the shape after the deformation.

The heat treatment was performed on this hollow cylindrical body in the range of 400 to 1250 degrees with only the temperature conditions changed. Regarding heat treatment conditions, common items other than the temperature are as follows. The heat treatment was performed in a non-oxidizing H2 atmosphere. The inside of the heat treatment furnace was heated from normal temperature (range of 15 ° C. to 25 ° C.) to a target temperature at a rate of 13 ° C./min, and maintained at the target temperature for 4 hours. Thereafter, the specimen was taken out of the heat treatment furnace and quenched (taken out in a normal temperature atmosphere and naturally cooled).
For the test pieces 1 to 6, the heat treatment at a temperature of 400 to 900 ° C. was performed at 100 ° C. intervals. The test piece 7 was heat-treated at a temperature of 1250 ° C.
After the heat treatment, the test pieces were completed by attaching and cleaning an end fitting having a flange portion having a larger diameter than the test pieces at both ends in the axial direction of each test piece. The end fitting was attached so that the axial edge of the porous metal body was exposed.

<Expansion evaluation test>
A change when the test pieces 1 to 7 are extended will be described. The elongation evaluation test was performed from the viewpoint of whether the test specimen was stretched (with or without mobility), stretched to a certain extent, or returned to its pre-stretched shape (with or without self-restoring property) when pulled in the axial direction. .
Specimen 1-2 was mobile and stretched up to 24.5 mm and 37.0 mm, respectively, but remained stretched even when the tensile force was removed, and did not have self-restoring properties.
Specimen 3 was extended up to 23.8 mm. After the stretching, the tensile force was removed, and the state returned to the state before the stretching.
Specimen 4 was extended up to 12.5 mm. After the stretching, the tensile force was removed, and the state returned to the state before the stretching. However, as compared with the test piece 3, the extension amount was about half, which resulted in a narrow movable range.
In the test body 5-7, the metal wires were sintered and did not have mobility.
From the above, it has been found that the heat treatment conditions are preferably 600 ° C. to 700 ° C., and more preferably 600 ° C.

<Bubble point test>
For the test piece 3, a bubble point test based on ASTM-E-128-61 was performed to measure the filtration accuracy when a metal porous body was used as a filter.
FIG. 9 is a diagram illustrating the principle of the bubble point test.
In the bubble point test, a test filter is immersed in isopropyl alcohol, and the internal pressure of the filter is gradually increased from zero. Then, air bubbles are generated from the largest hole first (initial point). The maximum pore diameter can be determined from the internal pressure at this time. The pore diameter D [μm] is obtained by the following equation (1).

D = 4S · cos θ / (P−γh) Equation (1)
However,
D: pore diameter S: interfacial tension of isopropyl alcohol θ: paint angle P: internal pressure γ: density of isopropyl alcohol h: liquid depth

However, in actuality, the pore diameter D [μm] is compared with the glass bead method.
D [μm] = 3700 / P [mmH ₂ O] Equation (2)
Is required. Note that the numerical value 3700 is a constant.

  As the internal pressure is further increased, the flow rate of the air changes. When the relationship between the internal pressure and the flow rate is shown in a graph, the internal pressure at the time when a state called a burst point where the entire surface of the test filter foams uniformly is obtained. From this internal pressure, the average pore size of the filter can be determined.

The average pore diameter before and after the expansion and contraction of the test piece 3 was determined by the bubble point test. In this test, an air supply tube was connected to the end fitting 13 shown in FIG. 1, and the portion of the metal porous body 10 located between the end fittings 13, 13 (in FIG. (Shown portion), the extension amount and the average pore diameter were measured.
Here, FIG. 8A is an enlarged photograph of the surface of the specimen before extension (in an initial state), and FIG. 8B is an enlarged photograph of the surface of the specimen during extension.
The length between the end fittings of the test piece before extension (initial state) was 88 mm, and the average pore diameter at this time was 28 [μm]. Further, as shown in FIG. 8A, the interval between adjacent metal wires is approximately 630 μm, and the angle between the intersecting metal wires is approximately 46 degrees.
The test piece was fixed by a jig in a stretched state so that the length between the end fittings became 98 [mm] (elongation ratio 111.4%), and a bubble point test was performed. [Μm]. At this time, as shown in FIG. 8B, the interval between the adjacent metal wires was approximately 792 μm, and the angle between the intersecting metal wires was approximately 59 degrees.

As described above, the metal porous body obtained by the present invention is extended in the axial direction to change the angle between the intersecting metal wires, thereby increasing the hole diameter. The extension amount and the hole diameter have a monotonically increasing relationship within the extendable range.
When the metal porous body according to the present invention is used as a filter, it can be used as a filter having a desired filtration accuracy (pore diameter) by appropriately extending the metal porous body in the axial direction. Further, by performing the backwash by extending the metal porous body more than at the time of filtration, more effective backwash can be performed.
Similarly, for a rectangular cylindrical metal porous body, a metal porous body closed at one end in the axial direction, and a conical metal porous body, the pore diameter is expanded and reduced by changing the angle between the metal wires. Can be.

[Summary of Embodiments, Functions, and Effects of the Present Invention]
<First embodiment>
This embodiment is a hollow cylindrical metal porous material in which the metal wires 20 are spirally wound and multilayered so that the metal wires 20A and 20B constituting the adjacent wire layers L1 and L2 have different inclination angles. The body 10, which is characterized in that the metal porous body deforms when an external force is applied, and returns to its original shape when the external force is removed.
The metal porous body according to the present embodiment is deformed when an external force is applied, but returns to its original shape when the external force is removed. Therefore, the metal porous body can be used in a new usage and application different from the conventional one.
Note that the deformation referred to here includes various deformations such as expansion, contraction, bending, bending, and twisting.

<Second embodiment>
The porous metal body according to the present aspect is characterized in that it expands and contracts in the axial direction when an external force is applied in the axial direction, and returns to its original shape when the external force is removed.
The porous metal body according to this aspect is expanded and contracted by the application of an external force in the axial direction, but returns to its original shape by removing the external force. Can be used for any purpose.

<Third embodiment>
The metal porous body according to this aspect is characterized in that it is bent and deformed when an external force is applied, and returns to its original shape when the external force is removed.
The porous metal body according to the present embodiment bends and deforms when an external force for bending the axis X is applied, but returns to its original shape when the external force is removed. And use.

<Fourth embodiment>
In this embodiment, the metal porous body is characterized by having a cylindrical shape whose axis X extends linearly as the original shape.
The original shape of the metal porous body is determined by the shape of the hollow cylindrical body that is the base of the metal porous body. In this embodiment, a metal porous body is produced from a cylindrical hollow tubular body produced by winding a metal wire around a cylindrical or cylindrical mandrel whose axis extends linearly. Therefore, the metal porous body according to this embodiment can be manufactured by a relatively simple method.

<Fifth embodiment>
The metal porous body according to this aspect is a hollow cylinder in which the metal wires are spirally wound and multilayered so that the inclination angles of the metal wires 20A and 20B constituting the adjacent wire layers L1 and L2 are different. A stress relief annealing treatment is performed on at least a part of the shape.
According to this aspect, the metal porous body obtained by performing the stress relief annealing treatment has elasticity, and can freely expand, contract, or bend by applying an external force. Expresses the ability to return to its original form.

<Sixth embodiment>
This embodiment is a metal filter including the metal porous body according to any one of the first to fifth aspects.
According to this aspect, the use and use of the metal filter can be expanded by including the metal porous body having a novel property.

<Seventh embodiment>
In the method for manufacturing the metal porous body 10 according to the present embodiment, the metal wires are spirally and multilayerly wound so that the inclination angles of the metal wires 20A and 20B constituting the adjacent wire layers L1 and L2 are different. (Steps S1 and S2) to produce a porous hollow cylindrical body by heat treatment and a heat treatment step (step S3) of performing stress relief annealing on at least a part of the hollow cylindrical body. Features.
According to this aspect, it is possible to manufacture a novel metal porous body which is deformed by applying an external force but returns to its original shape when the external force is removed.

<Eighth embodiment>
In the method for manufacturing the metal porous body 10 according to the present embodiment, the metal wire is made of stainless steel, and the treatment temperature in the heat treatment step is from 600 ° C to 700 ° C.
According to this aspect, it is possible to manufacture a novel metal porous body which is deformed by applying an external force but returns to its original shape when the external force is removed.

  L1, L2: wire layer, 10: metal porous body, 13: end fitting, 20: metal wire, 21: metal element wire, 30: metal porous body, 31: restorable portion, 33: non-restorable portion, 100A: Manufacturing device, 110: Rolling device, 111a: Rolling roller, 111b: Rolling roller, 112: Pressure unit, 120: Tension unit, 121: Fixed roller, 122: Movable roller, 130: Winding device, 131: Mandrel , 132: guide member, 140: transport roller

請 Motomeko invention described in 1, as the inclination angle of each metal wire material constituting the adjacent wire layers are different, the metal wire is spiral, and at least one hollow cylindrical body wound on a multi-layered wherein the heat treatment to reduce or eliminate residual stress of the metal wire in the relative parts are subjected.
The invention according to claim 2, characterized by metal filter including a metallic porous body according to claim 1.

The invention according to claim 3 is a method for manufacturing a metal porous body, wherein the metal wires are spirally and multilayerly wound so that the inclination angles of the metal wires constituting the adjacent wire layers are different. And forming a porous hollow cylindrical body by attaching, and a heat treatment step of reducing or removing residual stress in the metal wire for at least a part of the hollow cylindrical body. .
The invention according to claim 4 is a method for producing a metal porous body, wherein the metal wire is stainless steel, and a processing temperature in the heat treatment step is 600 ° C to 700 ° C.

Claims (8)

The metal wire rod is a spiral, and a hollow cylindrical metal porous body wound in a multilayer shape so that the inclination angle of each metal wire rod constituting the adjacent wire layer is different,
The metal porous body is characterized in that the metal porous body is deformed when an external force is applied, and returns to its original shape when the external force is removed.   The metal porous body according to claim 1, wherein the metal porous body expands and contracts in the axial direction when the external force is applied in the axial direction, and returns to its original shape when the external force is removed. body.   The metal porous body according to claim 1, wherein the metal porous body bends and deforms when the external force is applied, and returns to its original shape when the external force is removed.   The metal porous body according to any one of claims 1 to 3, wherein the metal porous body has a cylindrical shape whose axis extends linearly.   Stress relief annealing treatment for at least a part of a hollow cylindrical body in which the metal wires are spirally and multilayerly wound such that the inclination angles of the metal wires constituting the adjacent wire layers are different. A porous metal body, characterized in that a porous body is provided.   A metal filter comprising the metal porous body according to claim 1. Forming a porous hollow cylindrical body by winding the metal wire spirally and in a multilayer shape so that the inclination angles of the metal wires constituting the adjacent wire layers are different,
A heat treatment step of performing stress relief annealing on at least a part of the hollow cylindrical body.   The method for producing a metal porous body according to claim 7, wherein the metal wire is stainless steel, and a treatment temperature in the heat treatment step is 600C to 700C.

Images