Mounting member and method for manufacturing the mounting member

Abstract

The present invention provides a mounting member and a method for manufacturing the mounting member, both of which allow for easy removal of the portion covering the outer circumference of a steel material. [Solution] The mounting member 1 comprises a bottom portion 10, a mounting portion 20 that covers the outer circumference of the steel material 100, and a weak portion 30 that connects the bottom portion 10 and the mounting portion 20 and breaks as the mounting portion 20 is pressed along the longitudinal direction of the steel material 100. The mounting portion 20 has multiple arc-shaped walls 21 divided in the circumferential direction, and each arc-shaped wall 21 has a tapered portion 22 connected to the bottom portion 10 by the weak portion 30, and a side wall portion 23 extending from the tapered portion 22 to the side opposite to the bottom portion 10.

Description

Technical Field

[0001] The present invention relates to a mounting member and a method for manufacturing the mounting member.

Background Art

[0002] As a method for joining a pair of steel materials, the gas pressure welding method is widely used. In the gas pressure welding method, a pair of steel materials such as reinforcing bars are pressed in the axial direction while being abutted, and the joint portion is heated by a flame, and the steel materials are integrated by compressing the joint portion so as to form a bulging portion, and the joint strength can be stabilized. Further, when a pair of steel materials are gas pressure welded facing each other, there is a method in which a member formed in a ring shape with substantially the same shape as the end face and substantially the same material as the steel material is sandwiched between the end faces of the steel materials, heated, and joined.

[0003] Patent Document 1 discloses an annular body holding member used when gas pressure welding a pair of steel materials. The annular body holding member is configured to include a holding container that covers the outer periphery of the steel material and a lid body that adheres to the end face of the steel material, and the holding container has an annular body formed of the same material as the steel material. The annular body is sandwiched between a pair of steel materials whose end faces are abutted, and is axially pressed by a jack or the like, and the periphery of the abutted portion is heated to about 1300 ° C using an oxygen-combustion gas flame and joined in a red-hot state without melting. By being pressurized and heated, the annular body melted together with the steel material is integrated, so that the periphery of the abutted portion bulges, and a knob-shaped bulging portion (welded portion) having a diameter about 1.5 times that of the steel material is formed. Since the pair of steel materials including the bulging portion are integrally joined by metal bonding along the longitudinal direction, the joint strength at the joint portion between the steel materials is good.

[0004] Furthermore, Patent Document 2 discloses a polymer reducing agent for gas pressure welding used when performing gas pressure welding. Based on the premise that when gas pressure welding is performed with a steel metal sandwiched between the end faces of steel materials, the integration of the steel materials is inhibited, resulting in insufficient strength at the welded joint and causing fracture of the welded surface, it is stated that by using a polymer reducing agent for gas pressure welding having an air-blocking ring, a reduction sheet, and a reduction ring, the formation of residues such as oxide films and metal residues between the end faces of the steel materials can be suppressed, and a weld with sufficient strength can be performed. The contents described in Patent Document 2 are not based on technical evidence, and the steel metal sandwiched between the end faces of steel materials when performing gas pressure welding, such as the ring-shaped object disclosed in Patent Document 1, does not inhibit the integration of the steel materials. Rather, the integration of metallic bonds between the pair of steel materials and the ring-shaped object is promoted, resulting in a good bonding state between the steel materials and a stable bond strength obtained by gas pressure welding. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 5197652 [Patent Document 2] Patent No. 6879609 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, in the gas pressure welding method described in Patent Document 1, it was sufficient to burn the portion of the lid that is in close contact with the end face of the steel ring-holding member, and it was not necessarily required to burn the portion of the holding container that covers the outer circumference of the steel. However, since the portion covering the outer circumference of the steel is integrated with the lid, removing it from the lid required laborious work, such as having to work with bare hands after removing gloves.

[0007] Therefore, the present invention aims to provide a mounting member and a method for manufacturing a mounting member that allows for easy removal of the portion covering the outer circumference of a steel material. [Means for solving the problem]

[0008] To address the above problems, the present invention provides a mounting member that is attached to the end of one of a pair of steel materials when gas pressure welding is performed with the longitudinal end faces of the steel materials butted together, and comprises a flat plate-shaped bottom portion sandwiched between the pair of end faces, a cylindrical mounting portion that covers the outer circumference of the steel material, and a weak portion that connects the bottom portion and the mounting portion and breaks as the mounting portion is pressed along the longitudinal direction of the steel material, wherein the mounting portion has multiple arc-shaped walls divided in the circumferential direction, and each of the arc-shaped walls has a tapered portion connected to the bottom portion by the weak portion, and a side wall portion erected from the tapered portion on the opposite side from the bottom portion.

[0009] Here, it is desirable that the weak portions are arranged at intervals around the bottom portion, and that each of the tapered portions is connected to the bottom portion by the weak portions at multiple points in the circumferential direction.

[0010] Furthermore, it is desirable that the mounting portion protrudes toward the adjacent side wall portion and has a projection that connects the side wall portions together, and that the projection portion is provided with a breaking portion that releases the connection between the side wall portions when a longitudinal pressing force is applied to the tapered portion.

[0011] Furthermore, the method for manufacturing the mounting member is characterized by comprising the steps of: placing a steel ring in an injection molding die; and forming the mounting member by injecting molten resin into the injection molding die in which the steel ring is placed and allowing it to harden. [Effects of the Invention]

[0012] Thus, the mounting member of the present invention comprises a bottom portion, a mounting portion that covers the outer circumference of the steel material, and a weak portion that connects the bottom portion and the mounting portion and breaks as the mounting portion is pressed along the longitudinal direction of the steel material. The mounting portion has multiple arc-shaped walls divided in the circumferential direction, and each arc-shaped wall has a tapered portion connected to the bottom portion by the weak portion, and a side wall portion erected from the tapered portion on the side opposite to the bottom portion.

[0013] Therefore, when performing gas pressure welding, the mounting portion expands radially outward as the steel material presses against the tapered portion, making it easier to remove the mounting portion from the steel material. Consequently, the portion covering the outer circumference of the steel material can be easily removed when the steel materials are pressed together axially using a jack (not shown) or the like.

[0014] Here, the weak points are arranged at intervals around the base, and each tapered section is connected to the base by the weak points at multiple points in the circumferential direction. This ensures a certain connection strength between the base and the mounting section, while also making it easy to remove the mounting section from the base. Consequently, the entire mounting member has an elastic deformation function, and when the mounting member is attached to the steel material, a position correction function can be obtained between the mounting member and the steel material.

[0015] Furthermore, the mounting portion protrudes toward the adjacent side wall portion and has a projection that connects the side wall portions together. The projection portion is provided with a breakable portion that releases the connection between the side wall portions when a longitudinal pressing force is applied to the tapered portion. Therefore, radial strength can be ensured when the mounting member is attached to the steel material.

[0016] In the manufacturing method of the mounting member, a steel ring is placed in an injection molding die, and molten resin is injected into the injection molding die containing the steel ring and cured to form the mounting member. This allows each component constituting the mounting member to be molded as a single unit. Therefore, the mounting member can be formed by a simple method. [Brief explanation of the drawing]

[0017] [Figure 1]It is a diagram for explaining a state of performing gas pressure welding using a mounting member according to an embodiment of the present invention. [Figure 2] It is a perspective view of a mounting member according to an embodiment of the present invention. [Figure 3] It is a top view of a mounting member according to an embodiment of the present invention. [Figure 4] It is a side view of a mounting member according to an embodiment of the present invention. [Figure 5] It is a perspective view of a mounting member according to the first modification. [Figure 6] It is a perspective view of a mounting member according to the second modification. [Figure 7] (a) is a diagram showing an enlarged state before the steel material presses the tapered portion, and (b) is a diagram showing an enlarged state where the steel material is pressing the tapered portion. [Figure 8] It is a diagram for explaining a state where the mounting portion is removed. ' [Figure 9] It is a flowchart showing a manufacturing method of the mounting member.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0019] FIG. 1 is a diagram for explaining a state of performing gas pressure welding using the mounting member 1 according to an embodiment of the present invention, FIG. 2 is a perspective view of the mounting member 1, FIG. 3 is a top view of the mounting member 1, and FIG. 4 is a side view of the mounting member 1.

[0020] As shown in FIG. 1, when performing gas pressure welding, the end faces 101 in the longitudinal direction of a pair of steel materials 100 are arranged in a state of being abutted against each other. Note that the mounting member 1 is mounted on one of the steel materials 100. The steel material 100 is, for example, a deformed reinforcing bar or a steel bar. The mounting member 1 has a steel ring 2 made of the same material as the steel material 100.

[0021] The steel ring 2 is pressed axially by a jack or the like while sandwiched between a pair of end faces 101, and heated by the flame of a burner (not shown). The flame of the burner heats the ends of the pair of steel materials 100 and the steel ring 2, causing these parts to melt and promoting the integration of metallic bonding between the steel materials 100 and the steel ring 2, resulting in a good bond between the steel materials 100. A gap is formed in the steel ring 2 to serve as a gas vent 2a.

[0022] Furthermore, since the mounting member 1 is made of synthetic resin, reducing gas is generated when the mounting member 1 burns. The generation of reducing gas prevents air from entering the joint between the steel materials 100 from the outside, thereby preventing oxidation of the end faces of the steel materials 100. This suppresses the formation of oxides on the end faces of the steel materials 100, promoting integration between the steel materials 100 and improving the strength after bonding.

[0023] Incidentally, the mounting member 1 is a cap-shaped member made of translucent synthetic resin, but when heated by the flame of a burner, the part covering the outer circumference of the steel material 100, other than the part sandwiched between the end faces 101, may burn and fall to the work site. Here, the part sandwiched between the end faces 101 is a part that actively contributes to the integration of the steel materials 100, while the part covering the outer circumference of the steel material 100 is merely a part used when attaching it to the steel material 100 and does not particularly contribute during gas pressure welding. Therefore, the part covering the outer circumference of the steel material 100 is removed in advance before heating with a flame.

[0024] As shown in Figures 2 to 4, the mounting member 1 is composed of a bottom portion 10, a mounting portion 20, and a fragile portion 30. The bottom portion 10, the mounting portion 20, and the fragile portion 30 are all integrally molded from synthetic resins such as polystyrene, polyethylene, or polypropylene, but are not limited to these materials. The method of integral molding will be described later.

[0025] The bottom portion 10 is a flat plate-shaped member that is sandwiched between a pair of end faces 101 of the steel material 100. The bottom portion 10 is formed in a circular shape in plan view and has an area sufficient to cover the end faces 101.

[0026] The mounting portion 20 is a cylindrical part formed to cover the outer circumference of the steel material 100 and has a certain height so as to rise from the bottom portion 10. The mounting portion 20 is divided into three equal parts in the circumferential direction, and each divided part constitutes an arc-shaped wall 21. Each arc-shaped wall 21 has a tapered portion 22 connected to the bottom portion 10 by a weak portion 30, and a side wall portion 23 that rises from the tapered portion 22 on the opposite side from the bottom portion 10. Note that the mounting portion 20 does not necessarily have to be divided equally in the circumferential direction.

[0027] The tapered portion 22 is formed in a tapered shape that widens radially outward as it moves away from the bottom portion 10, away from the axis O passing through the center of the bottom portion 10. The inclination angle of the tapered portion 22 with respect to the axis O is preferably 45 degrees, but is not limited to this.

[0028] The tapered portion 22 is connected to the bottom portion 10 at two points in the circumferential direction by the weak portion 30, and the tapered portions 22 are arranged with gaps between them along the circumferential direction. As shown in Figure 2, the weak portion 30 is provided at only two points along the circumferential direction for each tapered portion 22, and the tapered portion 22 and the weak portion 30 are not in contact in areas other than the weak portion 30. Therefore, the tapered portion 22 can be removed from the weak portion 30 with relatively little force.

[0029] The side wall portion 23 is erected from the end of the tapered portion 22 opposite to the bottom portion 10. The side wall portion 23 has a tapered shape that widens slightly radially outward as it moves away from the tapered portion 22 along the direction of erection, moving away from the axis O passing through the center of the bottom portion 10. The inclination angle of the side wall portion 23 with respect to the axis O is gentler than the inclination angle of the tapered portion 22. The tapered shape of the side wall portion 23 makes it easier to attach to the end of the steel material 100.

[0030] The tip of the side wall portion 23 located on the side opposite to the tapered portion 22 has a projection 23a that protrudes toward the adjacent side wall portion 23. In addition, a notch 23b is formed in either side wall portion 23 at a location that coincides with the gas vent portion 2a of the steel ring 2 in the circumferential direction, as shown in Figures 2 and 3.

[0031] The mounting portion 20 may also have a breaking portion 24 that connects the arc-shaped walls 21 together and releases the connection between the side wall portions 23 when a pressing force is applied to the tapered portion 22 toward the bottom portion 10. Specifically, adjacent protruding portions 23a may be connected by the breaking portion 24.

[0032] The fractured portions 24 are provided at locations that coincide with the positions where the mounting portion 20 is divided into three sections in the circumferential direction. That is, the fractured portions 24 are provided at equal intervals, i.e., every 120 degrees, in the circumferential direction of the mounting portion 20. Gaps are formed between the arc-shaped walls 21 where the fractured portions 24 are not provided.

[0033] The fractured portion 24 is a portion of the integrally molded mounting portion 20 in the circumferential direction that is thinner and easier to fracture compared to the surrounding area. That is, the multiple arc-shaped walls 21 are integrally connected in the circumferential direction without being divided via the fractured portion 24. Note that the fractured portion 24 may be a portion where the divided arc-shaped walls 21 are bonded together with an adhesive or the like.

[0034] Thus, the arc-shaped walls 21 are connected to each other only by protruding portions 23a via fractured portions 24 in the vertical direction, and gaps are formed in the parts other than the protruding portions 23a. Therefore, because the connecting force between the arc-shaped walls 21 is weak, the arc-shaped walls 21 can be easily expanded radially outward. Note that adjacent arc-shaped walls 21 do not necessarily have to be connected to each other; they may simply be touching or have gaps between them. In short, as long as the arc-shaped walls 21 can be easily expanded in response to a force acting radially outward on the mounting portion 20, it does not matter whether the arc-shaped walls 21 are connected to each other or not.

[0035] The weak portion 30 is a strip-shaped member that connects the bottom portion 10 and the tapered portion 22. Between the tapered portion 22 and the bottom portion 10, the weak portion 30 is provided at two locations spaced apart in the circumferential direction, and in the parts where the weak portion 30 is not provided, a gap is formed between the tapered portion 22 and the bottom portion 10.

[0036] Here, in order to provide the mounting portion 20 with a position adjustment function when the mounting member 1 is attached to the steel material 100 in a radially shifted state, it is required that the mounting portion 20 be elastically deformable relative to the bottom portion 10, and that the mounting portion 20 be easily removed from the bottom portion 10. Accordingly, considering the strength and ease of removal of the mounting portion 20, the weak points 30 are provided at only two locations in the circumferential direction.

[0037] As shown in Figure 4, if the inner diameter of the part of the mounting portion 20 into which the steel material 100 is inserted is D1, and the inner diameter of the bottom portion 10 is D2, then the inner diameter of the steel material 100 is larger than D2 and smaller than D1. Therefore, when the two steel materials 100 are brought close together, the end faces 101 inevitably come into contact with the tapered portion 22.

[0038] Figure 5 is a perspective view of the mounting member 201 according to the first modified example, and Figure 6 is a perspective view of the mounting member 301 according to the second modified example. In the first and second modified examples, the same reference numerals are used for components identical to those in the above embodiment, and detailed explanations are omitted.

[0039] As shown in Figure 5, the mounting member 201 has an attachment portion 220 that rises from the bottom 10, and the attachment portion 220 is evenly divided into two in the circumferential direction. Each arc-shaped wall 221 is connected to the bottom 10 at two points in the circumferential direction via a weak portion 30. The arc-shaped wall 221 has a notch 221b that indicates the position of the gas vent portion 2a formed in the steel ring 2.

[0040] As shown in Figure 6, the mounting member 301 has an attachment portion 320 that rises from the bottom 10, and the attachment portion 320 is divided into four equal parts in the circumferential direction. Each arc-shaped wall 321 is connected to the bottom 10 at two points in the circumferential direction via a weak portion 30. The attachment portion 320 has a notch 320b that spans across adjacent arc-shaped walls 321.

[0041] In addition, in both the first and second modified examples, the mounting portion 220 or the mounting portion 320 only needs to be divided into multiple parts in the circumferential direction, and does not necessarily need to be divided evenly.

[0042] Figure 7(a) is an enlarged view showing the state before the steel material 100 presses against the tapered portion 22, and Figure 7(b) is an enlarged view showing the state after the steel material 100 is pressing against the tapered portion 22. Figure 8 is a diagram illustrating the removal of the mounting portion 20.

[0043] When gas pressure welding is performed, for example, the steel material 100 gradually moves toward the bottom 10 (in the direction of the white arrow in the figure) due to the pressurization by a jack. Here, since the inner diameter of the steel material 100 is larger than the inner diameter D2 of the bottom 10 (see Figure 4), the end face 101 comes into contact with the tapered portion 22 before the bottom 10.

[0044] Since the arc-shaped wall 21 (side wall portion 23) is elastically deformable relative to the bottom portion 10, the arc-shaped wall 21 expands radially outward. Specifically, as shown in Figure 8, the fracture portion 24 connecting adjacent arc-shaped walls 21 breaks, and each arc-shaped wall 21 expands radially outward. As a result, adjacent arc-shaped walls 21 become easier to expand radially outward (in the direction of the arrow in the figure), making it easier to separate each arc-shaped wall 21 independently.

[0045] Furthermore, when the connection between the arc-shaped walls 21 is released, the mounting portion 20 is only connected to the bottom portion 10 via the fragile portion 30. Therefore, each arc-shaped wall 21 can be easily removed from the bottom portion 10, thus preventing the mounting portion 20 from being heated and burning by the flames and falling into the surrounding area.

[0046] Next, the manufacturing method of the mounting member 1 according to the embodiment will be described with reference to the flowchart in Figure 9. First, a steel ring 2, which is partially cut out and formed into a circular shape, is placed in the injection molding die (S1). Note that a steel ring 2 that has been pre-formed to conform to the shape and dimensions of the outer shape of the bottom portion 10 may be placed in the injection molding die.

[0047] Next, molten synthetic resin is injected into the injection molding die and cooled and cured (S2). As the synthetic resin hardens, the bottom portion 10, the mounting portion 20, and the fragile portion 30 are formed, and these are integrated to form the mounting member 1. After that, the mold is removed from the hardened mounting member 1.

[0048] According to conventional methods, in order to manufacture mounting component 1, it was necessary to perforate a polystyrene cup with a laser cutter, set a steel ring in the polystyrene cup, cover it with a circular polystyrene film, and weld the circular film to the bottom of the cup using ultrasonic welding. After that, the cut positions of the steel ring were marked with an oil-based pen, and holes were punched in the bottom to adjust the mass.

[0049] On the other hand, in the manufacturing method of the mounting member 1 according to the embodiment, the mounting member 1 can be molded simply by supplying molten synthetic resin to one type of injection molding die. Therefore, since the mounting member 1 can be integrally molded in a single injection molding, the troublesome work of combining multiple members is unnecessary, and the mounting member 1 can be manufactured efficiently and easily.

[0050] As described above, the mounting member 1 of the embodiment comprises a bottom portion 10, a mounting portion 20 that covers the outer circumference of the steel material 100, and a fragile portion 30 that connects the bottom portion 10 and the mounting portion 20 and breaks as the mounting portion 20 is pressed along the longitudinal direction of the steel material 100. The mounting portion 20 has multiple arc-shaped walls 21 divided in the circumferential direction, and each arc-shaped wall 21 has a tapered portion 22 connected to the bottom portion 10 by the fragile portion 30, and a side wall portion 23 that is erected from the tapered portion 22 on the opposite side from the bottom portion 10.

[0051] Therefore, when performing gas pressure welding, as the steel material 100 presses against the tapered portion 22, the mounting portion 20 expands radially outward, making it easy to grasp the expanded portion of the mounting portion 20 even while wearing gloves. Consequently, the portion covering the outer circumference of the steel material 100 can be easily removed before heating the joint portion between the two steel materials 100.

[0052] Here, the weak portions 30 are arranged at intervals around the base portion 10, and each tapered portion 22 is connected to the base portion 10 by the weak portions 30 at two (or more) points in the circumferential direction. This ensures a certain connection strength between the base portion 10 and the mounting portion 20, while also making it easy to remove the mounting portion 20 from the base portion 10. Consequently, the entire mounting member 1 has an elastic deformation function, and when the mounting member 1 is attached to the steel material 100, a position correction function can be obtained between the mounting member 1 and the steel material 100.

[0053] Furthermore, the mounting portion 20 has a projection 23a that protrudes toward the adjacent side wall portion 23 and connects the side wall portions 23 together. The projection 23a is provided with a break portion 24 that releases the connection between the side wall portions 23 when a longitudinal pressing force is applied to the tapered portion 22. Therefore, radial strength can be ensured when the mounting member 1 is attached to the steel material 100.

[0054] In the manufacturing method of the mounting member 1, a steel ring 2 is placed in an injection molding die, and molten resin is injected into the injection molding die containing the steel ring 2 and cured to form the mounting member 1. This allows each component constituting the mounting member 1 to be molded as a single unit. Therefore, the mounting member 1 can be formed by a simple method.

[0055] While embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and any design modifications that do not depart from the spirit of the present invention are included in the present invention.

[0056] For example, in the above embodiment, the fractured portions 24 were provided at equal intervals in the circumferential direction of the mounting portion 20, but the invention is not limited to this, and the fractured portions 24 may be provided at any location in the circumferential direction of the mounting portion 20. In other words, the mounting portion 20 does not have to be divided evenly in the circumferential direction.

[0057] Furthermore, in the above embodiment, the side wall portion 23 does not have to be tapered and inclined to widen radially outward, but may be provided parallel to the axis O. Also, the fracture portion 24 may connect the side wall portions 23 at positions other than the tip of the side wall portion 23. Moreover, the side wall portions 23 may be connected by the fracture portion 24 at more than one location.

[0058] Furthermore, in the above embodiment, the weak portion 30 is connected to the tapered portion 22 and the bottom portion 10 at two locations in the circumferential direction, but it may also be connected to the tapered portion 22 and the bottom portion 10 at only one location in the circumferential direction or at three or more locations in the circumferential direction. In other words, the weak portion 30 can be connected to the tapered portion 22 and the bottom portion 10 at multiple locations in the circumferential direction. [Explanation of Symbols]

[0059] 1: Mounting member 2: Steel ring 10: Bottom 20: Mounting part 21 :Arc-shaped wall 22: Tapered section 23: Side wall section 24: Fracture 30: Vulnerable parts 100: Steel material 101: End face

Claims

1. A mounting member that is attached to the end of one of the steel materials when gas pressure welding is performed with the longitudinal end faces of a pair of steel materials butted together, A flat plate-shaped bottom portion sandwiched between the pair of end faces, A mounting portion formed in a cylindrical shape to cover the outer circumference of the steel material, The bottom portion and the mounting portion are connected, and the mounting portion is a fragile portion that breaks as the mounting portion is pressed along the longitudinal direction of the steel material, The mounting portion is characterized by having an arc-shaped wall divided into a plurality of sections in the circumferential direction, and each of the arc-shaped walls having a tapered section connected to the bottom by the weak section, and a side wall section erected from the tapered section on the opposite side from the bottom.

2. The aforementioned vulnerable parts are arranged at intervals around the bottom, The mounting member according to claim 1, characterized in that each of the tapered portions is connected to the bottom portion by the weak portion at multiple locations in the circumferential direction.

3. The mounting portion has protrusions that extend toward the adjacent side wall portion and connect the side wall portions together. The mounting member according to claim 1 or 2, characterized in that the protruding portion is provided with a breaking portion that releases the connection between the side wall portions when a longitudinal pressing force is applied to the tapered portion.

4. A method for manufacturing a mounting member according to claim 1 or 2, The steps include: placing a steel ring in the injection molding die, A method for manufacturing a mounting member, comprising the step of forming the mounting member by injecting molten resin into the injection mold in which the steel ring is placed and curing it.

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