WO2022079883A1 - Hollow cylindrical body and method for manufacturing hollow cylindrical body - Google Patents

Abstract

To provide a hollow cylindrical body in which strength thereof is improved in the axial direction. A hollow cylindrical body 10 according to the present embodiment is obtained by deforming a precursor having a hollow cylinder shape, the precursor having: crossing portions 22, in which metallic wires 20 are spirally wound forming multiple layers and the metallic wires constituting adjacent wire layers are fixed to be in contact with each other in a radial direction; and non-crossing portions 23, each of which is located between the two crossing portions spaced next to each other along the longitudinal direction of the metallic wire. At least some of the non-crossing portions in the hollow cylindrical body are placed in the wire layers different from those of the crossing portions disposed on both sides of the longitudinal direction of the non-crossing portions, and the non-crossing portions are deformed to form axial contact portions 24 that are in contact, in the axial direction, with the metallic wires belonging to the wire layers different from the wire layers to which the non-crossing portions belong. The formation of the axial contact portions can improve strength in the axial direction.

Description

Hollow cylinder and method for manufacturing hollow cylinder

The present invention relates to a hollow cylindrical body formed by winding a metal wire in a spiral and multi-layered manner.

Hollow cylinders in which metal wires are wound in a spiral and multi-layered shape are used in various fields. As an example of utilization of such a hollow cylinder, for example, a filter incorporated in an inflator for an airbag mounted on an automobile can be mentioned.
An airbag mounted on an automobile includes a sensor for detecting an automobile collision, an inflator that burns a gas generating agent to generate gas at the time of an automobile collision, and a bag that is deployed by the generated gas. The inflator incorporates a filter that cools the gas while removing the solid residue generated by the combustion of the gas generating agent.
The filter for an airbag inflator described in Patent Document 1 is made by rolling a metal wire having a perfect circular cross section and processing the metal wire into a rectangular cross section in a spiral shape at a predetermined angle and a predetermined pitch. It is formed by winding in layers and optionally sintering. Patent Document 1 describes that the airbag inflator filter has rigidity to withstand the impact of an explosively generated combustion gas.

Japanese Unexamined Patent Publication No. 2001-171472

In the inflator described in Patent Document 1, since the gas generating agent is arranged in the hollow portion of the filter, the combustion gas mainly applies pressure in the outer diameter direction of the filter. However, in an inflator (see FIG. 1) in which the gas generating agent and the filter are arranged in the axial direction, the filter receives a larger pressure in the axial direction than in the outer radial direction. As described above, there is a demand for a hollow cylindrical body having a strength capable of withstanding a load applied in the axial direction.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hollow cylindrical body having improved axial strength.

In order to solve the above problems, in the invention according to claim 1, the metal wires are spirally and multilayerly wound, and the metal wires constituting the adjacent wire layers are fixed in the radial direction. It is obtained by deforming a hollow cylindrical member in which an intersection in contact with the metal wire and a non-intersection located between two intersections arranged adjacently and spaced apart along the longitudinal direction of the metal wire are formed. It is a hollow cylindrical body, and at least a part of the non-intersections has entered a wire layer different from the intersections located on both sides in the longitudinal direction of the non-intersections, and the wire layer to which the non-intersections belong. It is characterized in that it is deformed so as to be in axial contact with the metal wire rod belonging to a wire rod layer different from that of the above.

According to the present invention, it is possible to provide a hollow cylindrical body having improved strength in the axial direction.

It is a vertical sectional view which shows the schematic structural example of the inflator on which the hollow cylindrical body which concerns on one Embodiment of this invention is mounted. It is a figure which shows the hollow tubular body which concerns on one Embodiment of this invention by the X-ray CT photograph, (a) is a front view, (b) is a partially enlarged view, (c) is a partially enlarged vertical cross section. It is a figure. It is a schematic perspective view which shows the precursor of the hollow cylindrical body which concerns on one Embodiment of this invention. It is a schematic diagram which enlarged and showed the part where the metal wire material intersects in the precursor body. (A) to (c) are flowcharts showing the manufacturing process of the hollow cylindrical body which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of the precursor manufacturing apparatus. It is a schematic diagram which shows the other example of the precursor manufacturing apparatus. It is a perspective view which shows an example of a compression molding type. (A) and (b) are schematic vertical cross-sectional views showing how the precursor is compressed by using the compression molding mold shown in FIG. It is a figure which shows the hollow cylindrical member which concerns on a reference example by an X-ray CT photograph, (a) is a front view, (b) is a partially enlarged view, (c) is a partially enlarged vertical sectional view. It is a figure which shows the result of the axial compression test. It is a figure which shows the result of the pressure loss measurement.

Hereinafter, the present invention will be described in detail using the embodiments shown in the figure. However, unless there is a specific description, the components, types, combinations, shapes, relative arrangements, etc. described in this embodiment are merely explanatory examples, not the purpose of limiting the scope of the present invention to that alone. ..

The hollow cylindrical body according to the embodiment of the present invention is used in various fields. For example, a hollow cylinder is used as a filter to remove foreign matter from various fluids. Alternatively, the hollow cylinder is used as a sound deadening material or as a heat exchange member. The use case of the hollow cylindrical body is an example. The hollow cylindrical body may be used for a purpose different from the above cases in fields other than the above.

In the following description, the auxiliary codes n and m indicating the layer numbers are positive integers.
[Outline configuration of cylinder type inflator]
The hollow cylindrical body according to the embodiment of the present invention is used, for example, as a filter constituting an inflator of an automobile airbag device.
FIG. 1 is a vertical sectional view showing a schematic configuration example of an inflator in which a hollow cylindrical body according to an embodiment of the present invention is mounted as a filter.

The inflator 200 includes a cylindrical housing 201, an igniter 203 attached to one end of the housing 201 in the axial direction, and a diffuser 215 attached to the other end of the housing 201 in the axial direction.
A combustion chamber 205 is formed in the hollow portion of the housing 201, and the combustion chamber 205 is filled with the gas generating agent 207. In the combustion chamber 205 near the other end in the axial direction of the housing 201, a bottomed cylindrical cup member 209 having one end surface in the axial direction closed is arranged. A large number of gas passage holes 211 through which the combustion gas generated by the gas generator 207 passes are formed on the circumferential side surface of the cup member 209. The gas passage hole 211 is set to a size that prohibits the passage of the gas generating agent 207. An opening 213 that communicates with the hollow inside of the diffuser 215 is formed on the other end surface of the cup member 209 in the axial direction.
The diffuser 215 includes a case 217 in which one end surface in the axial direction is open and the other end surface (bottom surface 217a) is closed, and a hollow cylindrical body 10 housed in the case 217. A gas discharge hole 219 that discharges combustion gas to the outside is formed on the circumferential side surface of the case 217. The hollow tubular body 10 functions as a means for cooling the high-heat combustion gas generated by the combustion of the gas generating agent 207, and also functions as a filter means for capturing the combustion residue generated by the generation of the combustion gas.

The operation outline of the inflator 200 is as follows.
The igniter 203 is activated to ignite the gas generating agent 207 in the combustion chamber 205. The gas generator 207 burns to generate combustion gas. The combustion gas enters the diffuser 215 side through the gas passage hole 211 and the opening 213 of the cup member 209 (in the directions of arrows A1 and A2 in the figure). The combustion gas that has entered the hollow portion 11 of the hollow tubular body 10 from the opening 213 collides with the bottom surface 217a of the case 217, and then moves inside the hollow tubular body 10 in the outer radial direction from the gas discharge hole 219. It is discharged to the outside (in the direction of arrow A3 in the figure). The combustion gas discharged to the outside finally inflates the bag.
Both ends in the axial direction and the outer peripheral surface of the hollow tubular body 10 are closely supported by the case 217, and movement in the axial direction is prohibited. However, since the hollow tubular body 10 receives a large amount of pressure in the axial direction and the outer diameter direction due to the combustion of the gas generating agent 207, the hollow tubular body 10 needs to have a strength capable of withstanding this pressure. .. In the cylinder type inflator 200 shown in FIG. 1, the combustion gas applies a particularly strong pressure in the axial direction of the hollow cylindrical body 10 in the process of moving from the housing 201 toward the diffuser 215. In the hollow cylindrical body 10 mounted as a filter on the cylinder type inflator, it is particularly necessary to increase the strength in the axial direction.

[Rough configuration of hollow cylinder]
2A and 2B are views showing a hollow tubular body according to an embodiment of the present invention by an X-ray CT photograph, FIG. 2A is a front view, FIG. 2B is a partially enlarged view, and FIG. 2C is a partially enlarged view. It is a BB sectional view of (b). In the figure, the part circled is the corresponding part in each figure. Further, this figure is an example of using a metal wire 20 having a thickness of 0.42 mm by rolling a metal wire (round wire) having a wire diameter of φ0.6 mm by 30%. Further, a precursor having an axial length of 50 mm is compressed in the axial direction to form a hollow cylindrical body 10 having an axial length of 25 mm.
In the hollow cylindrical body 10 according to the embodiment of the present invention, the metal wire rod 20 is wound spirally and in a multilayer shape, and the metal wire rods 20 and 20 constituting the adjacent wire rod layers are fixed in the radial direction. A precursor in which an intersecting portion 22 in contact with the above and a non-intersecting portion 23 located between the two intersecting portions 22 and 22 arranged adjacent to each other along the longitudinal direction of the metal wire 20 constituting each layer are formed. It is obtained by compressing and deforming 30 (see FIGS. 3 and 4) in the axial direction. In the hollow tubular body 10, at least a part of the non-intersection portion 23 (metal wire rod 20n-2m) has a wire rod layer whose radial position is different from that of the intersection portions 22 and 22 located on both sides of the non-intersection portion 23 in the longitudinal direction. The metal wire 20n belonging to a wire layer (wire layer Ln) different from the wire layer (wire layer Ln-2m) to which the non-intersection portion 23 belongs is deformed so as to be in axial contact with the metal wire 20n. It is characterized by being. The auxiliary codes n and n-2m attached to the reference numerals 20 and the reference numerals L indicate the numbers or positions of the wire rod layer L. The metal wire 20n indicates that the metal wire 20 belongs to the wire layer Ln.

The hollow cylindrical body 10 is porous and can be used as a filter for removing unnecessary substances exceeding a specific size from various fluids such as liquids and gases. The hollow cylindrical body 10 can be used as a cooling means for cooling the passing fluid in the process of passing various fluids through the holes formed in the hollow tubular body 10. Further, the hollow cylindrical body 10 can be used as a sound deadening material, a heat exchange member, or the like.
The hollow cylindrical body 10 forms a flow path through which the fluid passes in the direction in which the wire rod layers overlap, that is, in the radial direction of the hollow tubular body. The fluid may be passed from the inner diameter side to the outer diameter side of the hollow cylinder, or may be passed from the outer diameter side to the inner diameter side. Here, the radial direction does not mean the diametrical direction (radial direction) in the strict sense, but generally means the radial direction with respect to the axial direction and the circumferential direction.
The size (axial dimension, diameter, thickness, etc.) of the hollow tubular body 10 is appropriately determined according to the structure, size, and the like of the device on which the hollow tubular body 10 is mounted.

Hereinafter, the method and apparatus for manufacturing the hollow cylindrical body 10 will be described first, and various features of the hollow tubular body will be described later.
[Appearance composition of precursor]
FIG. 3 is a schematic perspective view showing a precursor of a hollow cylindrical body according to an embodiment of the present invention.
The precursor (hollow tubular member) 30 processed into the hollow tubular body 10 according to the embodiment of the present invention has at least one metal wire 20 constant in the axial direction (vertical direction in the figure). It is formed by winding in a spiral and multi-layered manner with an inclination angle θ. Here, the individual layers (layers having different radial positions) wound in the same direction are referred to as wire rod layers L1, L2, and so on. The metal wires constituting the respective wire layers L1, L2 ... Extend in the same direction inclined with respect to the axial direction of the precursor 30 in the front view, and the metal wires constituting the adjacent wire layers are mutually. It extends in the direction of intersection (not parallel).

The extending direction of the metal wire 20n (thickness not shown) constituting the outermost wire layer Ln in FIG. 3 is the direction indicated by the solid arrow, and the metal wire 20n forming the wire layer Ln-1 immediately inside the metal wire 20n. The extending direction of -1 is the direction indicated by the broken line arrow. Further, the extending direction of the metal wire 20n-2 constituting the wire layer Ln-2 immediately inside the wire layer Ln-1 is the direction indicated by the solid arrow like the metal wire 20n.
The precursor 30 has one wire layer (for example, wire layer L1) formed by spirally winding the metal wire 20 at a constant inclination angle with respect to the axial direction, and the outer peripheral side of one wire layer L1. Another wire material layer (for example, wire material layer L2) formed by spirally winding the metal wire material at an inclination angle different from that of the metal wire material constituting the one wire material layer L1. Have. The metal wires constituting one wire layer L1 and the other wire layers L2 adjacent thereto are not parallel to each other in the axial direction and are configured to intersect each other.
It should be noted that the metal wire rod constituting one wire rod layer may be configured so that the inclination angle with respect to the axial direction changes in one wire rod layer.

Examples of the type of metal used as the material of the precursor 30 include iron, mild steel, stainless steel, nickel alloy, and copper alloy, and austenitic stainless steel (SUS304) is particularly preferable. When the above metal is used, a sintering step may be included in the manufacturing process of the hollow cylindrical body 10.
When the manufacturing process of the hollow tubular body 10 does not include the sintering process, a metal material that is difficult to sinter can be used as the material of the precursor 30 in addition to the above metal material. For example, titanium, aluminum, magnesium and the like can also be used as the material of the precursor 30.

The thickness and cross-sectional shape of the metal wire used for the precursor 30 depend on the size of the final product, the hollow cylindrical body 10, the substance removed by the hollow tubular body by its filter function, the pressure loss, and the like. Will be decided as appropriate.
As the precursor 30, for example, a metal wire rod obtained by rolling a metal wire having a substantially perfect circular cross section and processing it into a predetermined cross section shape is used. For example, as the metal wire, a flat rolled wire obtained by crushing the metal wire in the radial direction so as to have a predetermined rolling ratio may be used, or the metal wire may be rolled so that the cross section has an irregular shape (hereinafter, "" A deformed wire (referred to as "deformed rolling") may be used.
In addition, the irregular shape is generally defined as "having a suspicious shape / appearance different from the usual one", but here, the irregular shape means that the cross-sectional shape is circular, elliptical, polygonal, etc. over the entire length. The cross-sectional shape of the metal wire is irregular over the entire length in the longitudinal direction with respect to the metal wire having a regular shape, for example, W-shaped, U-shaped, J-shaped, L-shaped, X. It broadly includes those having a character shape, a shape, and the like. Further, the cross-sectional shape and outer shape of the metal wire rod are not constant over the entire length in the longitudinal direction of the metal wire rod, and the configuration having different cross-sectional shapes and outer shapes depending on the position in the longitudinal direction is also included in the irregular shape.

FIG. 4 is an enlarged schematic view showing a portion where the metal wires intersect in the precursor body. In this figure, the case where the metal wire is a flat rolled wire is shown.
In the precursor 30, the metal wires 20n and 20n-1, 20n-1 and 20n-2, 20n-2, which respectively constitute the adjacent wire layers Ln and Ln-1, Ln-1 and Ln-2, ... By extending in the direction in which ... At the intersection 22, the overlapping metal wires 20 are in contact with each other.
Hereinafter, the metal wire portion between the intersection 22 adjacent to the metal wire 20 in the longitudinal direction and the intersection 22 is referred to as a non-intersection portion 23 (non-overlap portion). That is, the intersecting portion 22 and the non-intersecting portion 23 appear alternately along the longitudinal direction of the metal wire rod 20. The non-intersecting portion 23 is not in contact with the metal wire 20 constituting another adjacent wire layer, and when the precursor 30 is compressively deformed in the axial direction, it can be twisted and deformed in various directions. Is.
In the precursor 30, the intersecting portion 22 and the non-intersecting portion 23 formed on the metal wire rod 20n constituting the wire rod layer Ln belong to the wire rod layer Ln.

In the precursor 30, the metal wire rods 20 constituting one wire rod layer L are arranged apart in the axial direction. As a result, a spiral spiral space S (Sn, Sn-1, Sn-2 ...) Extending along the metal wire 20 is formed in each wire layer L. The spiral space S is formed between the metal wires 20 adjacent to each other in the axial direction.
At least one of the metal wires 20n-2, 20n-4 ... Extending in the same direction as the spiral space Sn along the longitudinal direction of the spiral space Sn overlaps the spiral space Sn in the radial direction. The conditions that at least a part of the metal wires 20n-2, 20n-4, etc. overlapping in the spiral space Sn in the radial direction satisfy the metal wire 20n will be described by the example of the metal wire 20n-2 as follows. be.
That is, the separation t between the metal wire 20n-2 and the metal wire 20n in the lateral direction is such that when the non-intersection portion 23 of the metal wire 20n-2 is deformed and enters the spiral space Sn, the non-intersection portion 23 It is set so as to come into contact with the metal wire 20n in the axial direction with a predetermined pressing force capable of improving the axial strength. The separation t is the projected metal wire 20n-2 and the metal wire 20n when the metal wire 20n-2 is projected onto the wire layer Ln from the normal direction of the wire layer Ln (the radial direction of the precursor 30). Shown as a distance from and in the short direction.

[Manufacturing method of hollow cylinder]
5 (a) to 5 (c) are flowcharts showing a manufacturing process of a hollow cylindrical body according to an embodiment of the present invention.
The manufacturing process of the hollow cylindrical body 10 according to the embodiment of the present invention includes a rolling step (step S1) of rolling a metal wire to form a metal wire, and a hollow by winding the metal wire in a spiral and multilayer shape. It includes a wire rod winding step (step S2) for forming a tubular precursor 30 and a compression step (step S3) for axially compressing the precursor 30 to form a hollow tubular body 10. The hollow cylindrical body 10 is completed through the compression step. In the compression step, the precursor 30 (see FIG. 3) in which the metal wires 20 and 20 constituting the intersection 22 are in fixed contact with each other is compressed in the axial direction.
The manufacturing process of the hollow tubular body 10 may optionally include a sintering step (step S4) in which the metal wires 20 and 20 in contact with each other are diffusion-bonded to each other. The sintering step may be performed before the compression step, as shown in FIG. 5 (b). In this case, the precursor 30 to which the intersection 22 is joined is obtained. Alternatively, the sintering step may be performed after the compression step, as shown in FIG. 5 (c). After the compression step of FIG. 5B, a sintering step may be further performed.

<Rolling / wire winding process-Manufacturing equipment 1>
The rolling step (step S1) and the wire rod winding step (step S2) will be described together with the precursor 30 manufacturing apparatus used in these steps.
FIG. 6 is a schematic diagram showing an example of a precursor manufacturing apparatus. This device manufactures a hollow cylindrical precursor 30 from a metal wire 21.
The manufacturing apparatus 100A is longitudinal with respect to a rolling apparatus 110 that rolls a metal wire 21 supplied from a bobbin (not shown) and a metal wire (hereinafter referred to as “metal wire 20”) whose cross-sectional shape is deformed by rolling. A tension unit 120 that applies a predetermined tension in a direction and a winding device 130 that winds a metal wire rod 20 around a mandrel 131 to form a precursor are substantially provided. Further, on the transport path of the metal wire rod 20, a plurality of transport rollers 140 for transporting while guiding the metal wire rod are arranged.
The rolling apparatus 110 is an apparatus for carrying out the rolling step of step S1. The winding device 130 is an device that carries out the wire rod winding step of step S2.

The rolling apparatus 110 includes two columnar rolling rollers 111a and 111b that are arranged so as to face each other and rotate. The portion where the surfaces (opposing surfaces) of the rolling roller 111a and the rolling roller 111b come into contact with each other constitutes a pressurizing portion 112 that sandwiches the metal wire 21 and deforms it into a desired shape. The rolling apparatus 110 plastically deforms the metal wire 21 at the pressurizing section 112 under a predetermined temperature and pressure to obtain a metal wire 20 having a predetermined cross-sectional shape. The rolling may be cold rolling or hot rolling. The cross-sectional shape of the metal wire 21 supplied from the bobbin is usually circular.
The rolling rollers 111a and 111b are means for processing a metal wire 21 (round wire) having a circular cross-sectional shape into a so-called "flat rolled wire" having a metal wire rod 20 having a substantially elliptical cross section or a substantially rectangular cross section. But it may be. Alternatively, convex portions and / or concave portions for rolling the metal wire into a desired cross-sectional shape may be formed on the surface of either one or both of the rolling rollers 111a and 111b. In this case, when the metal wire passes through the pressure portion 112, it is rolled by these convex portions and concave portions and plastically deformed to be processed into a metal wire having an irregular cross-sectional shape.

The tension unit 120 has a fixed roller 121 fixedly arranged at a predetermined position in a rotatable state, and a movable roller 122 that moves closer to or away from the fixed roller 121 and is rotatable. By moving the movable roller 122 closer to or further away from the fixed roller 121, a predetermined tension is applied to the metal wire 20 wound around the fixed roller 121 and the movable roller 122 and conveyed.
The winding device 130 is a guide member that guides the metal wire rod 20 by reciprocating at a predetermined speed in the axial direction of the mandrel 131 (direction orthogonal to the paper surface in the drawing) and the mandrel 131 that rotates in a fixed direction at a predetermined speed. 132 and. The mandrel 131 is generally columnar or cylindrical and is generally made of a metal such as stainless steel, copper alloy or aluminum alloy.

In order to produce the precursor 30, one end of the metal wire 20 is locked at an appropriate position on the mandrel 131, and the mandrel 131 is attached to the axis of the mandrel 131 in a state where a predetermined tension is applied to the metal wire 20 by the tension unit 120. The metal wire rod 20 is reciprocated in the axial direction of the mandrel 131 by the guide member 132 while rotating at a constant speed in a constant direction around the center. By this operation, the metal wire 20 is spirally and multi-layered around the outer circumference of the mandrel 131. Further, the metal wires constituting the adjacent wire rod layers intersect with each other to form a mesh.
For example, in the first wire rod layer directly wound around the outer circumference of the mandrel 131, it is assumed that each metal wire rod is wound in the clockwise direction in a state of being inclined by a predetermined angle θ with respect to the axial direction of the mandrel in FIG. The metal wire constituting the second wire layer to be wound around the outer periphery of the first wire layer is wound in the counterclockwise direction in a state of being inclined by a predetermined angle θ with respect to the axial direction of the mandrel. The metal wire constituting the third wire layer to be wound around the outer periphery of the second wire layer is wound in the clockwise direction in a state of being inclined by a predetermined angle θ with respect to the axial direction of the mandrel. Hereafter, it is repeated sequentially.

After winding the metal wire 20 a predetermined number of times (a predetermined number of layers), the rotation of the mandrel 131 is stopped. Then, the metal wire 20 is cut, and the cut end portion is joined to an appropriate position of the metal wire that has been wound by spot welding or the like and removed from the mandrel 131 to obtain a hollow tubular precursor 30.
The angle (winding angle) of the metal wire 20 with respect to the axial direction of the mandrel 131 and the distance (pitch) between the metal wires 20 adjacent to each other in the axial direction are the ratio of the rotation speed of the mandrel 131 to the moving speed of the guide member 132. It can be changed by adjusting it as appropriate. By appropriately changing the diameter of the metal wire 21 and its rolling shape, the winding angle of the metal wire 20, the pitch, and the number of windings, the pressure loss of the fluid passing through the hollow cylindrical body 10 is controlled to an appropriate value. be able to.

<Rolling / wire winding process-Manufacturing equipment 2>
FIG. 7 is a schematic diagram showing another configuration example of the precursor manufacturing apparatus 100B. The manufacturing apparatus 100B is provided with a plurality of rolling devices 110 (110A, 110B) on the transport path of the metal wire 21, and can perform rolling on the metal wire 21 a plurality of times.
When a plurality of rolling apparatus are arranged in the manufacturing apparatus 100B, the buffer unit 150 may be optionally inserted between the rolling apparatus 110A and 110B. The buffer unit 150 has a fixed roller 151 whose axis is fixed in a position rotatably at a predetermined position, and a rotatable movable roller 152 that moves closer to or further from the fixed roller 151. A metal wire after being rolled by the rolling apparatus 110A in the previous stage is wound around the fixed roller 151 and the movable roller 152. By moving the movable roller 152 closer to or further away from the fixed roller 151, the buffer unit 150 synchronizes between the rolling apparatus 110A and the winding apparatus 130, or causes a machining speed difference between the rolling apparatus 110A and 110B. Absorb.
When rolling a plurality of times, the rolling directions of the metal strands 21 by the rolling devices 110A and 110B may be the same direction or different directions.
When the metal wire is rolled a plurality of times, a metal wire having a more complicated outer surface shape can be obtained than in the case of one rolling. Further, by performing rolling a plurality of times, the effect that the shape of the metal wire can be stabilized can be obtained.

<Compression process-Compression molding mold>
The compression step (step S3) will be described together with the configuration of the compression molding die used in this step.
FIG. 8 is a perspective view showing an example of a compression molding mold.
The compression molding die 300 includes a cavity 310 (female mold) having a compression space 311 for accommodating the precursor 30 to be molded, and a stamp 320 (core, male mold) for pressing the precursor 30.
The cavity 310 closes a cylindrical outer cylinder 313, a cylindrical columnar body 315 protruding into the hollow portion of the outer cylinder 313 along the axial direction of the outer cylinder 313, and one end surface of the outer cylinder 313 in the axial direction. A bottom plate 317 is provided. The outer cylinder 313 is a hollow body having both ends in the axial direction open, and the columnar body 315 and the bottom plate 317 are integrated. The cylindrical space formed by the outer cylinder 313, the columnar body 315, and the bottom plate 317 is the compression space 311 that receives the precursor 30 and the stamp 320.
The stamp 320 is a cylinder provided with a hollow insertion portion 321 penetrating in the axial direction. When the axial one end of the stamp 320 is inserted into the compression space 311 from the axial other end opening of the cavity 310, the axial other end opening thereof is inside the hollow portion 31 (see FIG. 3) of the precursor 30. The columnar body 315 is inserted from.

9 (a) and 9 (b) are schematic vertical cross-sectional views showing how the precursor is compressed using the compression molding mold shown in FIG.
As shown in FIG. 9A, the cylindrical precursor 30 is first housed in the compression space 311 of the compression molding die 300 (in the direction of arrow C1 in the figure). The inner shape of the outer cylinder 313 is set to be substantially the same as or slightly larger than the outer shape of the precursor 30. The outer shape of the columnar body 315 is made to be substantially the same as or slightly smaller than the inner shape of the precursor 30. At least one of the inner surface of the outer cylinder 313 and the outer surface of the columnar body 315 serves to position the precursor 30 in the compression space 311.
As shown in FIG. 9B, the hollow cylindrical body 10 is produced by compressing the precursor 30 in the axial direction (direction of arrow C2 in the figure) by the stamping die 320. The inner and outer shapes of the precursor 30 are deformed according to the shape of the compression space 311 in the process of being compressed.

<Sintering process>
The hollow tubular body after being compressed by the precursor 30 produced by the manufacturing apparatus 100A and 100B shown in FIGS. 6 and 7 or the compression molding die 300 shown in FIGS. 8 and 9 is baked at a high temperature. It may be tied (step S4 shown in FIGS. 5 (b) and 5 (c)). The temperature at the time of sintering varies depending on the type, thickness, number of windings, pitch, winding angle, etc. of the metal wire, but it shall be in the range of 500 to 1500 degrees (° C.). Of these, the range of 1100 to 1201 degrees is preferable.
Sintering is performed for the purpose of alleviating the internal strain of the metal wire rod generated during rolling and joining the overlapping portions of the metal wire rod. Sintering is preferably performed in an electric furnace set to a predetermined temperature, and the sintering time varies depending on the type, thickness, number of windings, winding density, pitch, and sintering temperature of the metal wire, but is 30 to 80. It is preferable to select within the range of minutes. Sintering can be performed in air, but it is preferably performed in vacuum or in an inert gas that does not embrittle the metal wire or cause a chemical reaction. Examples of the inert gas include nitrogen gas and argon, but nitrogen gas is particularly preferable.
As shown in FIG. 5 (b), in the sintering step performed before the compression step, the intersection 22 (see FIG. 4) in the precursor 30 is bonded (fixed) at the atomic level, and the non-intersection 23 is joined (fixed). Promotes deformation.
As shown in FIG. 5 (c), in the sintering step performed after the compression step, the metal wires 20 that have come into contact with each other after the compression deformation are joined at the atomic level, so that the strength of the hollow tubular body 10 as a final product is increased. Further improvement.

[Characteristics of hollow cylinder]
The characteristics of the hollow cylindrical body produced as described above will be described in detail with reference to FIG. 2 while comparing with reference examples.
<Reference example>
10A and 10B are views showing a hollow tubular member according to a reference example by an X-ray CT photograph, FIG. 10A is a front view, FIG. 10B is a partially enlarged view, and FIG. 10C is a partial enlarged view. It is a DD cross-sectional view. In the figure, the part circled is the corresponding part in each figure.
In the reference example 40 shown in this figure, a metal wire having a wire diameter of φ0.4 mm and rolled so as to have a rolling ratio of 50% (thickness 0.2 mm) is wound spirally and in a multilayer shape to form a hollow cylinder. It is formed in a shape. Since Reference Example 40 has not undergone the compression step (step S3), the metal wire rod 20 is aligned in any of the axial direction, the radial direction, and the circumferential direction. The non-intersecting portion 23 is not curved or twisted, and the non-intersecting portion does not enter another wire layer.
The metal wires in the precursor 30 are also in an aligned state in the same manner as in Reference Example 40 shown in FIG.

<Maintaining contact at intersections>
The hollow tubular body 10 shown in FIG. 2 and the precursor 30 shown in FIG. 3 have an intersection 22 in which the metal wires constituting the adjacent wire layers are in fixed contact with each other in the radial direction. The state in which the metal wires 20 and 20 are in contact with each other at the intersection 22 is maintained before and after the compression step. In other words, the longitudinal position of the intersection 22 with respect to the metal wire 20 is maintained before and after the compression step. Further, in the method of manufacturing the hollow cylindrical body 10, the contact state between the metal wires at the intersection 22 is controlled so as to be maintained before and after the compression step.

In the case of a manufacturing method in which the sintering step is not performed before the compression step of step S3, the tension applied to the metal wire 20 from the tension unit 120 in the wire winding step (step S2) of the metal wire 20 is before and after the compression step. The size is set so that the position of the intersection 22 with respect to the longitudinal direction of the metal wire 20 can be maintained, that is, a frictional force can be exerted to the extent that the metal wires 20 do not slip (or shift) at the intersection 22. The metal wire rod 20 has a longitudinal strength capable of maintaining its own shape against the above tension. At the intersection 22, the metal wires 20 and 20 are in surface contact with each other and exert the above frictional force.

In the case of the manufacturing method in which the sintering step is carried out before the compression step of step S3, since the intersection 22 is joined by sintering, the tension applied to the metal wire 20 in the wire winding step of the metal wire 20 is increased. It may be smaller than the manufacturing method in which the sintering step is not carried out. However, in order to reliably join the intersection 22, it is desirable that the metal wires 20 and 20 are in surface contact with each other at the intersection 22. Since the intersection 22 is joined by sintering, the position of the intersection 22 with respect to the longitudinal direction of the metal wire 20 is maintained before and after the axial compression of the precursor 30.

At the intersection 22, the state of contact between the metal wires 20 is maintained before and after the compression step. Therefore, in the compression step, deformation of the non-intersecting portion 23, specifically, bending deformation, torsional deformation, and the like are promoted.
In the non-intersecting portion 23 in the precursor 30, since the metal wires 20 are not in contact with each other, the amount of deformation of the non-intersecting portion 23 from the precursor 30 in the compression step is larger than the amount of deformation of the intersecting portion 22. The amount of deformation can be shown as an index that comprehensively considers the amount of movement of the metal wire 20 in the radial and axial directions, the amount of twist, and the like.
The relative positional relationship between the number of intersections and the intersections 22 is maintained before and after the compression process. Therefore, at the intersection 22, the radial layer structure (layer structure) of the hollow cylindrical body 10 is maintained before and after the compression step. Further, the number of holes (mesh) formed in the precursor 30 and the relative positional relationship between the holes (mesh) are maintained before and after the compression step.

<Changes in inner and outer diameters>
By compressing the precursor 30 in the axial direction, the distance between the adjacent intersecting portions 22 is shortened, so that the non-intersecting portion 23 is deformed so as to project in the outer diameter direction or the inner diameter direction. Due to the deformation of the non-intersecting portion 23 as shown in FIG. 2, at least one of the outer diameter and the inner diameter of the precursor 30 changes.
However, since the deformation at the intersection 22 is limited, the outer diameter of the hollow cylindrical body 10 does not expand beyond a certain range, or the inner diameter does not shrink beyond a certain range.

Deformation at the intersection 22 is limited because the intersection 22 is fixed.
Deformation at the intersection 22 is limited because the precursor 30 has a large resistance to torsional deformation about its axis. That is, the precursor 30 includes S- wound metal wires 20n, 20n-2 ... (Metal wires spirally wound in the first direction) and Z-wound metal wires 20n-1, 20n-3 ... (First). The metal wire rod spirally wound in the second direction opposite to the direction of the above) is sequentially laminated in the radial direction. The S-wound metal wire and the Z-wound metal wire mutually suppress torsional deformation centered on the axis of the precursor 30. Therefore, the circumferential movement and the radial movement of the intersection 22 in the compression step are suppressed.
Further, since the compression molding die 300 is used in the compression step, the expansion of the outer diameter and the reduction of the inner diameter of the hollow tubular body 10 are also limited by the size of the compression space 311 of the compression molding die 300. ..

<Improved strength by forming axial contact parts>
The hollow cylindrical body 10 has an axial contact portion 24 in which the metal wires 20 and 20 are in axial contact with each other.
The axial contact portion 24 is a metal wire rod 20 in which at least a part of the non-intersection portion 23 deformed by the compression process belongs to a wire rod layer different from the intersection portions 22 and 22 located on both sides of the non-intersection portion 23 in the longitudinal direction. It is formed by making axial contact with the intersecting portion 22 or the non-intersecting portion 23). The axial contact portion 24 is formed by the non-intersecting portions 23 deformed in the compression step, or by the non-intersecting portions 23 and the intersecting portions 22 deformed in the compression step. Before and after the compression step, it is permissible that the angles of the metal wires 20 constituting the intersection 22 change within a range in which the axial contact portion 24 can be formed.
In the axial contact portion 24, the metal wires 20 and 20 come into contact with each other at a predetermined pressing force capable of improving the axial strength of the hollow cylindrical body 10. By forming such an axial contact portion 24, the axial strength of the hollow tubular body 10 is improved.

The radial position of the non-intersection portion 23 (or the distance from the central axis Ax of the hollow cylindrical body 10 shown in FIG. 3) is different from the radial position of the intersection 22 located on both sides of the non-intersection portion 23 in the longitudinal direction. In this case, it is determined that the non-intersecting portion 23 has entered a wire rod layer different from the wire rod layer to which it belongs. The "wire layer to which it belongs" is a wire layer to which the intersections 22 and 22 located on both sides of the non-intersection portion 23 in the longitudinal direction belong.

For example, the axial contact portion 24 is formed as follows. In the compression step, first, the outer diameter side or the inner diameter side or the inner diameter side so that at least a part of the non-intersection portion 23 enters the wire rod layer L different from the intersection portions 22 and 22 located on both sides in the longitudinal direction of the non-intersection portion 23. Transform to the side. Then, at least a part of the deformed non-intersecting portion 23 is deformed so as to come into contact with the metal wire rod 20 belonging to the wire rod layer different from the wire rod layer to which it belongs so as to be in contact with the metal wire rod 20 in the axial direction with a predetermined pressing force.

In the hollow cylindrical body 10, the metal wires 20 and 20 come into contact with each other at the intersection 22 and the axial contact portion 24. The total area of the portions of the hollow cylindrical body 10 where the metal wires come into contact with each other includes the contact area at the intersection 22 and the contact area at the axial contact portion 24. In the present embodiment, since the axial contact portion 24 is formed, the total area of the portions where the metal wires come into contact with each other in the hollow cylindrical body 10 is increased, so that the strength of the hollow tubular body 10 is particularly high. Improve in direction.

<Relationship between metal wires that come into contact with each other in the axial direction>
The axial contact portion 24 is formed by metal wires 20 having the same winding direction. That is, when the outermost wire rod layer is Ln, the metal wire rods constituting the wire rod layer Ln-2, the wire rod layer Ln-4, and the like are in axial contact with the metal wire rod constituting the wire rod layer Ln. , The axial contact portion 24 is formed with the metal wire rod constituting the wire rod layer Ln.
In the hollow cylindrical body 10, the number of axial contact portions 24 increases from the inner diameter side to the outer diameter side. The distance between the intersections 22 adjacent to each other in the longitudinal direction of the metal wire 20 is larger on the outer diameter side than on the inner diameter side. The non-intersecting portion 23 located on the outer diameter side is more likely to enter the other wire rod layer L due to deformation than the non-intersecting portion 23 located on the inner diameter side, and the axial contact portion 24 is more likely to be formed.

<Homogeneity of porosity>
As shown in FIG. 3, the precursor 30 is formed by spirally winding a continuous metal wire 20 at an angle θ with respect to the axis of the mandrel 131 (see FIGS. 6 and 7). Has been done. A plurality of holes (mesh) are uniformly formed in the radial direction (within the wall thickness) of the precursor 30. In other words, the precursor 30 has a uniform porous shape (or uniform network structure) in the radial direction (direction in which the wire rod layers overlap) (see FIG. 4).
As described above, the quantity of the intersection 22 formed on the precursor 30 does not change before and after the compression step. Further, the relative positional relationship between the intersections 22 formed on the precursor 30 is maintained before and after the compression step. The number and relative positional relationship of the holes (mesh) formed in the precursor 30 are also maintained before and after the compression step. Therefore, the hollow cylindrical body 10 has a uniform porous shape in the radial direction (within the wall thickness).

<Precursor and compression molding mold size>
The gap between the precursor 30 and the compression molding die 300 is set so that the non-intersecting portion 23 can be deformed into a desired shape. The compression molding die 300 is set to have a shape having a gap between the precursor 30 and the precursor 30 so that at least one of the expansion of the outer diameter and the reduction of the inner diameter of the precursor 30 can be performed.
For example, in the compression molding die 300 shown in FIG. 9, the outer diameter of the columnar body 315 is set to be substantially the same as the inner diameter of the precursor 30. The term "substantially the same" here allows the existence of a gap sufficient to allow the precursor 30 to be inserted into the compression space 311 of the compression molding die 300, but positively changes the diameter size of the precursor 30. It means that it is not intended to be made.
On the other hand, the inner diameter of the outer cylinder 313 is set to be larger than the outer diameter of the precursor 30, so that the outer diameter of the precursor 30 is increased to some extent according to the inner shape of the outer cylinder 313 in the compression step. Intended. The outer cylinder 313 has a gap between the precursor 30 and the precursor 30 so that the outer diameter of the precursor 30 can be increased.
The relationship between the inner and outer diameters of the compression molding die 300 and the precursor 30 may be reversed from the above, and the inner diameter of the precursor 30 may be reduced and deformed.

<Rolling rate or rolling shape of metal wire>
The rolling ratio (or rolling shape) of the metal wire 21 is set so that the metal wires 20 can come into contact with each other at a predetermined pressure in the axial direction by compressing the precursor 30.
When a flat rolled wire is used as the metal wire rod 20, the rolling ratio is preferably 20 to 80%, particularly preferably 20 to 50%.
When a deformed wire is used as the metal wire 20, the width-thickness ratio of the metal wire 20 is equal to the width-thickness ratio of the flat-rolled wire rolled in the range of 20 to 40%. Set. The width and thickness of the metal wire 20 are as shown in FIG.

〔effect〕
In the hollow tubular body 10 according to the present embodiment, the non-intersecting portion 23 located in the same wire rod layer L as the intersecting portions 22 and 22 located on both sides in the longitudinal direction is deformed into another wire rod layer. It is in axial contact with the metal wire 20 to which it belongs. Therefore, the strength of the hollow cylindrical body 10 is improved in the axial direction.
The axial strength of the hollow tubular body 10 can be improved by compressing the precursor 30 in the axial direction in the compression step. Therefore, it is possible to improve the axial strength of the hollow cylindrical body using a metal material that is difficult to sinter.
Conventionally, a cylindrical member in which a metal wire is wound in a spiral and a multilayer shape may be subjected to a sintering process in order to increase the rigidity. According to this embodiment, since the strength in the axial direction of the hollow tubular body can be improved without performing the sintering process, it is possible to reduce the cost and the manufacturing time by omitting the sintering step.

[Modification Embodiment]
In the above embodiment, the case of obtaining a hollow cylindrical body having a cylindrical shape (the cross-sectional shape orthogonal to the axial direction is a perfect circle) has been shown, but the present invention also shows the case of obtaining a hollow tubular body having a shape other than the above shape. Applicable. Specifically, the present invention obtains a hollow cylindrical body having various cross-sectional shapes such as an elliptical cylinder, a square cylinder, and a star-shaped cylinder (the cross-sectional shape is elliptical, rectangular, or star-shaped). It can also be applied to cases.
For example, a hollow tubular shape having a convex cross-sectional shape by winding a metal wire spirally and in multiple layers around a mandrel having a convex cross-sectional shape (eg, a mandrel having an elliptical columnar shape or a prismatic shape). You may try to obtain a precursor of. Alternatively, a metal wire is spirally and multi-layered around a mandrel having an appropriate shape, and a hollow cylindrical member removed from the mandrel is pressed in the radial direction to form a desired cross section such as a star shape. A hollow cylindrical precursor having a surface shape may be obtained. In these cases, the compression molding die used in the compression step is one having a compression space having a shape corresponding to the shape of the precursor.

Further, the present invention can be applied not only to a hollow cylindrical body having a constant inner / outer diameter in the axial direction, but also to a hollow cylindrical body having a tapered shape (eg, a weight shape, a weight base shape) in which the inner / outer diameter changes in the axial direction. .. The present invention can also be applied to a hollow cylindrical body having a flange portion protruding in the outer diameter direction at least at one end in the axial direction. The present invention can also be applied to a hollow cylindrical body having a bottomed cylinder in which at least one end surface in the axial direction is closed.
Processing to make notches (knurled stitches) on one or both of the surfaces where the metal wires 20 come into contact with each other in the radial direction with respect to the metal wire 20 in order to keep the intersection 22 fixed by utilizing the frictional force. May be applied. Such processing can be performed by the rolling apparatus 110.
Further, in order to keep the intersection 22 fixed, the metal wires 20 and 20 may be fixed to each other by using roller welding or the like.

[Test result 1]
In order to carry out the axial compression test and the pressure loss measurement, five hollow cylindrical test pieces 1 and five hollow cylindrical comparative examples 1 were prepared.
For the test body 1 and Comparative Example 1, a metal wire having a thickness of 0.42 mm was used by rolling a metal wire (round wire) having a wire diameter of φ0.6 mm and SUS304 by 30%. The test body 1 and Comparative Example 1 have a hollow cylindrical shape having an inner diameter of 8 mm, an outer diameter of 18.1 mm, and an axial length of 35 mm, and the weight thereof is 19 g. The number of intersections formed in the test body 1 and the comparative example 1 is the same. Further, the tension applied to the metal wire when winding the metal wire is the same in the test piece 1 and the comparative example 1.
The test body 1 is a hollow cylindrical body produced by the method according to the embodiment of the present invention. That is, the test body 1 prepares a cylindrical precursor 30 having an axial length of 55 mm by winding the metal wire in a spiral and multilayer shape, and then in a compression step (step S3), a cylinder having an axial length of 35 mm. The precursor 30 is compression-molded in the axial direction so as to have a shape.
In Comparative Example 1, the metal wire is spirally and multi-layered so as to have a cylindrical shape. Comparative Example 1 has not undergone a compression step. The appearance of the cylindrical member as in Comparative Example 1 varies depending on the wire diameter of the metal wire used, the rolling ratio, the winding angle of the metal wire, the separation of the metal wire in the axial direction, etc., but the wire of the comparative example used in the test The state of the layer is almost the same as the reference example shown in FIG.
The test piece 1 and Comparative Example 1 were not sintered.

The following test results show the average values of Test Body 1 and Comparative Example 1.
<Axial compression test>
FIG. 11 is a diagram showing the results of the axial compression test. FIG. 11A is a table showing the relationship between displacement and load, and FIG. 11B is a displacement-load curve.
In the axial compression test, the amount of axial displacement was measured when an axial compressive load was applied to each of the test piece 1 and Comparative Example 1.
As can be seen from FIG. 11, when the displacement is 6 mm or more, the test piece 1 has about twice the axial strength as that of Comparative Example 1.

<Pressure loss measurement>
FIG. 12 is a diagram showing the results of pressure loss measurement. FIG. 12A is a table showing the relationship between the volumetric flow rate and the pressure loss, and FIG. 12B is a graph showing the relationship.
As can be seen from FIG. 12, no significant difference was observed in the pressure loss between the test piece 1 and the comparative example 1.
The number of intersections is the same in the test body 1 and the comparative example 1, and in the test body 1, the relative positional relationship between the intersections is maintained even after compression. Therefore, the number of holes (mesh) formed by the crossing of the metal wires within the wall thickness of the test body 1 and the comparative example 1 is the same in the test body 1 and the comparative example 1. For this reason, it is probable that there was no significant difference in pressure loss between the test piece 1 and Comparative Example 1.

<Conclusion>
As described above, according to the present embodiment, by compressing the hollow tubular precursor 30 in the axial direction, the cylindrical member not compressed in the axial direction and the inner / outer diameter, the weight, and the number of intersections are present. , And a hollow cylinder with improved axial strength can be obtained while having the same or equivalent pressure loss. That is, according to the present embodiment, it is possible to obtain a hollow cylindrical body having the same shape, function, and raw material cost, but with improved axial strength.

[Summary of Examples of Embodiments of the Present Invention, Actions, and Effects]
<First embodiment>
In the hollow cylindrical body 10 according to the present embodiment, the metal wire 20 is spirally and multi-layered, and the metal wires constituting the adjacent wire layer L are in fixed contact with each other in the radial direction. It is obtained by deforming a hollow cylindrical member (precursor 30) in which 22 and a non-intersection portion 23 located between two intersections arranged adjacent to each other along the longitudinal direction of a metal wire are formed. ..
In the hollow tubular body according to this embodiment, at least a part of the non-intersecting portion has entered a wire rod layer different from the intersecting portions located on both sides in the longitudinal direction of the non-intersecting portion, and the wire rod layer to which the non-intersecting portion belongs. It is characterized in that it is deformed so as to come into contact with a metal wire belonging to a wire layer different from that in the axial direction.

At the intersection, the metal wires are in fixed contact with each other, so that the deformation of the metal wire at the intersection is limited. The term "fixed" as used herein includes both cases where the metal wires constituting the intersection are separable and non-separable. Separable means, for example, the movement of metal wires is restricted by frictional force, and inseparable means, for example, the case where the intersections are integrated by sintering or the like. Since the intersection is fixed, the non-intersection mainly between the intersections is deformed according to the deformation of the hollow cylindrical member.
In the present embodiment, the non-intersection portion belonging to the same wire rod layer as the intersection located on both sides in the longitudinal direction is in axial contact with the metal wire rod belonging to the other wire rod layer. As described above, in the present embodiment, since the metal wires constituting the different wire rod layers are brought into contact with each other in the axial direction, the strength of the hollow tubular body in the axial direction is improved.

<Second embodiment>
The hollow cylindrical body 10 according to this aspect is characterized in that the contact state between the metal wires 20 at the intersection 22 is maintained before and after the deformation.
In this embodiment, the intersection formed in the hollow tubular member (precursor 30) maintains a state in which the metal wires are in contact with each other before and after the deformation of the hollow tubular member. That is, the metal wires forming the intersection are restrained from each other so that the position of the intersection with respect to the longitudinal direction of the metal wire does not move before and after the deformation of the hollow tubular member. However, it is permissible that the crossing angle between the metal wires at the intersection changes according to the deformation of the hollow tubular member as long as the metal wires constituting the different wire layers come into contact with each other in the axial direction.
According to this aspect, since the contact state between the metal wires at the intersection is maintained before and after the deformation of the hollow tubular member, the deformation of the non-intersection portion according to the deformation of the hollow tubular member is promoted. ..

<Third embodiment>
In the hollow cylindrical body 10 according to this embodiment, the number of axial contact portions 24 in which the metal wire rods 20 constituting the different wire rod layers L are in axial contact with each other increases from the inner diameter side to the outer diameter side. It is characterized by that.
The distance between the intersections adjacent to each other in the longitudinal direction of the metal wire is larger on the outer diameter side than on the inner diameter side. Therefore, the non-intersecting portion located on the outer diameter side is more likely to enter another wire layer due to deformation than the non-intersecting portion located on the inner diameter side, and the axial contact portion is more likely to be formed.

<Fourth embodiment>
In the hollow tubular body 10 according to this embodiment, the axial contact portion 24 in which the metal wires 20 constituting the different wire layers L are in contact with each other in the axial direction is formed by the metal wires having the same winding direction. It is characterized by.
In this embodiment, a metal wire that extends in the same direction as the spiral space and constitutes a wire layer different from the wire layer to which the spiral space belongs is made to enter into the spiral space S. As a result, the metal wires constituting the different wire layers are brought into axial contact with each other to improve the axial strength of the hollow cylindrical body.

<Fifth Embodiment>
In the method for manufacturing the hollow cylindrical body 10 according to this aspect, the metal wire 20 is wound spirally and in a multilayer shape, and the metal wires constituting the adjacent wire layer L are radially contacted with the intersection 22. , A wire winding step of forming a hollow cylindrical member (precursor 30) in which a non-intersecting portion 23 located between two intersecting portions arranged adjacent to each other along the longitudinal direction of the metal wire is formed. A step S2) and a compression step (step S3) of axially compressing the hollow cylindrical member in which the metal wires constituting the intersection are in fixed contact with each other are included.
The compression step is characterized in that at least a part of the non-intersection portion 23 is deformed so as to be in axial contact with a metal wire material belonging to a wire rod layer different from the intersection portion 22 located on both sides of the non-intersection portion in the longitudinal direction. And.

As shown in the first embodiment, the intersection formed in the hollow tubular member (precursor 30) may be fixedly configured by utilizing the frictional force between the metal wires, or may be a compression step. It may be fixedly configured by integrating the metal wires with each other by sintering or the like performed before the above.
If the hollow tubular body is manufactured without going through the sintering step (step S4), the manufacturing cost of the hollow tubular body is reduced and the manufacturing time is shortened by omitting the sintering step. Further, it is possible to fabricate a hollow cylindrical body having improved axial strength from a metal that is difficult to sinter.
According to this aspect, since the metal wires constituting the different wire rod layers are brought into contact with each other in the axial direction, the strength of the hollow tubular body in the axial direction is improved.

<Sixth Embodiment>
In the method for manufacturing the hollow tubular body 10 according to this aspect, in the compression step (step S3), at least a part of the non-intersection portion 23 is a wire rod layer different from the intersection portion 22 located on both sides in the longitudinal direction of the non-intersection portion. It is characterized in that it is deformed so as to enter L.
In this embodiment, the non-intersection portion is deformed so as to enter a wire rod layer different from the wire rod layer to which the non-intersection portion belongs, and the metal wire rods 20 constituting the different wire rod layers are brought into axial contact with each other. The strength of the tubular body in the axial direction is improved.

<Seventh Embodiment>
The tension applied to the metal wire 20 in the wire winding step (step S2) of the method for manufacturing the hollow tubular body 10 according to this embodiment is such that the metal wires meet each other at the intersection 22 before and after the compression step (step S3). It is characterized in that it is set to a size that can maintain a contact state.
The intersection formed in the hollow tubular member (precursor 30) in this embodiment is fixedly formed by utilizing the frictional force between the metal wires. Even if the sintering step (step S4) is not included in the manufacturing process of the hollow tubular body, the hollow tubular body having improved strength in the axial direction can be obtained. If the sintering step is omitted, the manufacturing cost of the hollow cylindrical body can be reduced, and the manufacturing time can be shortened. In addition, it is possible to produce a hollow cylindrical body having improved axial strength from a metal that is difficult to sinter.

<Eighth embodiment>
In the method for manufacturing a hollow tubular body 10 according to this aspect, the amount of deformation from the hollow tubular member (precursor 30) is larger in the non-intersection portion 23 than in the intersection portion 22.
The hollow cylindrical body has an intersecting portion whose deformation is limited when the hollow tubular member is compressively deformed, and a non-intersecting portion which is largely deformable by the compressive deformation of the hollow tubular member. The non-intersecting portion greatly contributes to the modification of the properties of the hollow cylindrical body due to deformation. In this embodiment, by deforming the non-intersecting portion, the axial contact portion 24 in which the metal wires constituting the different wire rod layers L are in axial contact with each other is formed. By forming the axial contact portion, the axial strength of the hollow cylindrical body is improved.

<Ninth embodiment>
In the compression step (step S3) of the method for manufacturing the hollow tubular body 10 according to this embodiment, the compression molding mold 300 for molding the hollow tubular member (precursor 30) has an enlarged outer diameter and an inner diameter of the hollow tubular member. It is characterized by having a shape capable of performing at least one of the reductions of.
That is, the compression molding die has a gap between the hollow cylindrical member and the hollow tubular member that can perform at least one of expansion of the outer diameter and reduction of the inner diameter of the hollow tubular member. The compression molding mold not only controls the amount of change in the inner and outer diameters, but also functions as a means for controlling the deformation mode of the non-intersecting portion 23.
According to this aspect, it is possible to obtain a hollow cylindrical member having desired properties by appropriately controlling the deformation mode of the non-intersecting portion.

L ... Wire layer, S ... Spiral space, 10 ... Hollow cylinder, 11 ... Hollow part, 20 ... Metal wire, 21 ... Metal wire, 22 ... Crossed part, 23 ... Non-crossed part, 24 ... Axial contact part , 30 ... precursor (hollow tubular member), 31 ... hollow portion, 40 ... reference example, 100 ... manufacturing apparatus, 110 ... rolling apparatus, 111a, 111b ... rolling roller, 112 ... pressurizing portion, 120 ... tension unit, 121 ... fixed roller, 122 ... movable roller, 130 ... winding device, 131 ... mandrel, 132 ... guide member, 140 ... transfer roller, 150 ... buffer unit, 151 ... fixed roller, 152 ... movable roller, 200 ... gas generator , 201 ... housing, 203 ... igniter, 205 ... combustion chamber, 207 ... gas generator, 209 ... cup member, 211 ... gas passage hole, 213 ... opening, 215 ... diffuser, 217 ... case, 217a ... bottom surface, 219. ... gas discharge hole, 300 ... compression molding mold, 310 ... cavity, 311 ... compression space, 313 ... outer cylinder, 315 ... columnar body, 317 ... bottom plate, 320 ... stamp, 321 ... insertion part

Claims (9)

1. The metal wire is spirally and multi-layered, and is adjacent to the intersection where the metal wires constituting the adjacent wire layers are in fixed contact with each other in the radial direction along the longitudinal direction of the metal wire. It is a hollow cylindrical body obtained by deforming a hollow cylindrical member in which a non-intersecting portion located between the two intersecting portions arranged apart from each other is formed.
   The at least a part of the non-intersection portion has entered a wire rod layer different from the intersection portion located on both sides in the longitudinal direction of the non-intersection portion, and belongs to a wire rod layer different from the wire rod layer to which the non-intersection portion belongs. A hollow cylindrical body characterized in that it is deformed so as to be in axial contact with a metal wire.
2. The hollow cylindrical body according to claim 1, wherein the contact state between the metal wires at the intersection is maintained before and after the deformation.
3. The invention according to claim 1 or 2, wherein the number of axial contact portions in which the metal wire rods constituting the different wire rod layers are in axial contact with each other increases from the inner diameter side to the outer diameter side. Hollow tubular body.
4. Any of claims 1 to 3, wherein the axial contact portion in which the metal wires constituting the different wire layer are in contact with each other in the axial direction is formed by the metal wires having the same winding direction. The hollow tubular body according to item 1.
5. The metal wire is wound spirally and in a multi-layered manner, and is arranged adjacently and separately along the longitudinal direction of the metal wire from the intersection where the metal wires constituting the adjacent wire layers are in contact with each other in the radial direction. A wire winding step of forming a hollow tubular member in which a non-intersection portion located between the two intersections is formed, and a wire winding step.
   A compression step of axially compressing the hollow tubular member in which the metal wires constituting the intersection are in fixed contact with each other is included.
   In the compression step, at least a part of the non-intersection portion is deformed so as to be in axial contact with the metal wire rod belonging to a wire rod layer different from the intersection portion located on both sides of the non-intersection portion in the longitudinal direction. A method for manufacturing a hollow tubular body.
6. The fifth aspect of the present invention is characterized in that, in the compression step, at least a part of the non-intersections is deformed so as to enter a wire rod layer different from the intersections located on both sides of the non-intersections in the longitudinal direction. How to manufacture a hollow tubular body.
7. A claim characterized in that the tension applied to the metal wire in the wire winding step is set to a size capable of maintaining a state in which the metal wires are in contact with each other at the intersection before and after the compression step. Item 5. The method for manufacturing a hollow tubular body according to Item 5 or 6.
8. The method for manufacturing a hollow tubular body according to any one of claims 5 to 7, wherein the amount of deformation from the hollow tubular member is larger in the non-intersecting portion than in the intersecting portion.
9. 5. The compression molding mold for forming the hollow tubular member in the compression step is characterized by having a shape capable of at least one of expansion of the outer diameter and reduction of the inner diameter of the hollow tubular member. The method for producing a hollow cylindrical body according to any one of 8 to 8.

Images