wire drawing die

Abstract

A wire drawing die includes a blank that is a wear-resistant member provided with a die hole for wire drawing processing of a wire, and a die shell that supports the blank. The blank has a higher thermal conductivity than the die shell. The blank has an upstream side end surface in the wire drawing direction and a downstream side end surface between which the die hole is provided, and the downstream side end surface is exposed from the die shell.

Description

Technical Field

[0001] This disclosure relates to wire drawing dies. This application claims priority to Japanese Patent Application No. 2021-080723, filed on May 12, 2021. The entire contents of that Japanese patent application are incorporated herein by reference. Background Technology

[0002] Previously, for example, a wire drawing die was disclosed in Japanese Patent Application Publication No. 9-108726 (Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 9-108726 Summary of the Invention

[0006] The wire drawing die disclosed herein comprises: a wear-resistant component having a die hole for drawing wire; and a die shell supporting the wear-resistant component, the wear-resistant component having a higher thermal conductivity than the die shell, the wear-resistant component having an upstream end face and a downstream end face in the wire drawing direction, a die hole being provided between the upstream end face and the downstream end face, and the downstream end face being exposed from the die shell. Attached Figure Description

[0007] [ Figure 1 ] Figure 1 This is a plan view of the wire drawing die 100 according to the embodiment.

[0008] [ Figure 2 ] Figure 2 It is along Figure 1 A cross-sectional view of the drawing die 100 for the II-II line.

[0009] [ Figure 3 ] Figure 3 It shows the settings in detail. Figure 2 A cross-sectional view of the inner surface shape of the die hole 103 on the blank 120.

[0010] [ Figure 4 ] Figure 4 This is a plan view of the cover 200 installed on the wire drawing die 100 according to the embodiment.

[0011] [ Figure 5 ] Figure 5 It is along Figure 4 A cross-sectional view of the cover 200 of the VV line in the diagram.

[0012] [ Figure 6 ] Figure 6This is a cross-sectional view showing a wire drawing die 100 with a cover 200 installed and a wire drawing process using the wire drawing die 100.

[0013] [ Figure 7 ] Figure 7 This is a cross-sectional view showing the heat diffusion path in the wire drawing die 100 with the cover 200 installed.

[0014] [ Figure 8 ] Figure 8 This is a cross-sectional view of the previous wire drawing die 100. Detailed Implementation

[0015] [The problem this disclosure aims to solve]

[0016] In the past, it was difficult to fully dissipate the heat generated during wire drawing.

[0017] [Description of embodiments of this disclosure]

[0018] First, the embodiments of this disclosure are listed and described.

[0019] The wire drawing die disclosed herein comprises: a wear-resistant component having a die hole for drawing wire; and a die shell supporting the wear-resistant component, the wear-resistant component having a higher thermal conductivity than the die shell, the wear-resistant component having an upstream end face and a downstream end face in the wire drawing direction, a die hole being provided between the upstream end face and the downstream end face, and the downstream end face being exposed from the die shell.

[0020] In this type of wire drawing die, the thermal conductivity of the wear-resistant component is higher than that of the die shell, and the downstream end face of the wear-resistant component is exposed from the die shell, thus allowing heat to diffuse from the downstream end face. As a result, the heat generated during the wire drawing process can be effectively dissipated.

[0021] Preferably, the wire drawing die further comprises a cover having a through hole through which the wire can pass, the cover having a heat dissipation component with the through hole in contact with a wear-resistant component, and a support component supporting the heat dissipation component, the heat dissipation component having a higher thermal conductivity than the support component.

[0022] In this case, since the heat dissipation component is in contact with the wear-resistant component, the heat from the wear-resistant component can be efficiently transferred to the heat dissipation component.

[0023] Preferably, the heat dissipation component comprises at least one selected from the group consisting of diamond, CBN, and composite materials containing diamond or CBN.

[0024] In this case, the heat dissipation component can dissipate heat efficiently because of its particularly high thermal conductivity.

[0025] Preferably, the support component is any of the following: at least one element selected from the group consisting of copper, silver, tungsten and molybdenum, or an alloy containing such element; or a monomer of ceramic material or a composite of such ceramic material and metal.

[0026] In this case, the strength of the supporting components increases.

[0027] Preferably, the heat dissipation component and the support component are joined by brazing filler metal or screw clamps.

[0028] In this configuration, the heat dissipation component and the support component are securely joined by brazing filler metal or screw clamps. As a result, the heat dissipation component is prevented from detaching from the support component.

[0029] Preferably, a plating layer is provided on the mating surface between the heat dissipation component and the support component.

[0030] In this case, the heat dissipation component and the support component are firmly joined at the mating surface.

[0031] In a typical wire drawing die, the heat generated at the processing area is transferred and dissipated in the following order: billet (diamond), mounting material (NiCu or Cu alloy), SUS housing, and external components (lubricant, etc.).

[0032] To improve heat dissipation, the following drawing die is used: holes are provided on the SUS housing or the like for coolant to pass through, through which cooling water or coolant flows to dissipate heat.

[0033] In a typical wire drawing die, the thermal conductivity of the stationary material is several hundred W, which is much lower than the thermal conductivity of diamond, the blank material, which is 1500 W. As a result, the temperature of the stationary material rises, and the blank part also has difficulty dissipating heat.

[0034] Furthermore, the fixing material is surrounded by an SUS shell, which has a thermal conductivity of tens of W and low heat dissipation performance. Therefore, from this point of view, the temperature of the fixing material is also prone to rise.

[0035] Therefore, the area near the machining holes of the mold becomes hot, resulting in thermal wear or breakage of the lubricant film, which can cause wire drawing failure.

[0036] Preferably, the diameter D of the bearing portion of the die hole is 10 μm or more and 1.0 mm or less. Within this range, the lifespan of the wire drawing die is expected to be maximized.

[0037] The length L of the sizing section of the die orifice is between 20%D and 100%D. If it falls within this range, the lifespan of the wire drawing die is expected to be maximized. 20%D represents 20% of D.

[0038] [Details of the embodiments disclosed herein]

[0039] Figure 1 This is a plan view of the wire drawing die 100 according to the embodiment. For example... Figure 1 As shown, the wire drawing die 100 has a die shell 110 and a blank 120, which serves as a wear-resistant component, supported on the die shell 110. A die hole 103 is provided in the blank 120 located at the center. In this embodiment, the die hole 103 is circular, but the die hole 103 can also be square.

[0040] The blank 120 is made of materials with high wear resistance, such as diamond, CBN, or cemented carbide. A fixing material such as Ni alloy or Cu alloy is provided between the blank 120 and the mold shell 110.

[0041] Figure 2 It is along Figure 1 A cross-sectional view of the drawing die 100 for line II-II. (See attached image.) Figure 2 As shown, a blank 120 is embedded in the central part of a rectangular mold shell 110.

[0042] The wire is inserted into the die hole 103 provided on the blank 120 in the direction indicated by arrow 100a. The wire contacts the inner surface of the die hole 103 and is subjected to diameter reduction processing through the blank 120. The blank 120 has an upstream end face 121 located upstream relative to the wire drawing direction indicated by the arrow and a downstream end face 122 located downstream.

[0043] The mold shell 110 has a first surface 101 located upstream of the wire insertion direction indicated by arrow 100a and a second surface 102 on the opposite side of the first surface 101. A blank 120 is positioned between the first surface 101 and the second surface 102.

[0044] Figure 3 It shows the settings in detail. Figure 2 A cross-sectional view of the inner surface shape of the die hole 103 on the blank 120. (See figure) Figure 3 As shown, the die hole 103 has, from the upstream side, a bell-shaped opening 1a, an approach section 1b, a reduction section 1c, a sizing section 1d, an exit angle section 1e, and an exit section 1f.

[0045] In the sizing section 1d, the diameter of the die hole 103 is the smallest. The wire is plastically processed through the sizing section 1d. The inner diameter of the sizing section 1d is determined according to the diameter of the wire after processing.

[0046] The wire drawing die 100 includes: a blank 120, which is a wear-resistant component and has a die hole 103 for drawing wire, and a die shell 110 that supports the blank 120. The blank 120 has a higher thermal conductivity than the die shell 110.

[0047] The blank 120 has an upstream end face 121 and a downstream end face 122 in the wire drawing direction. A die hole 103 is provided between the upstream end face 121 and the downstream end face 122, and the downstream end face 122 is exposed from the die shell 110.

[0048] Figure 4 This is a plan view of a cover 200 mounted on a wire drawing die 100 according to an embodiment. The wire drawing die 100 further includes a cover 200 having a through hole 203 through which wire can pass. The cover 200 has a heat dissipation member 220 having the through hole 203 in contact with the blank 120, and a support member 210 supporting the heat dissipation member 220, the heat dissipation member 220 having a higher thermal conductivity than the support member 210.

[0049] The heat dissipation component 220 comprises at least one selected from the group consisting of diamond, CBN, and composite materials containing diamond or CBN. The support component 210 is, for example, composed of any of the following: at least one element or alloy containing copper, silver, tungsten, and molybdenum; or a monomer of ceramic material or a composite of ceramic material and metal.

[0050] Figure 5 It is along Figure 4 A cross-sectional view of the cover 200 of the VV line in the diagram. (See attached image.) Figure 5 As shown, the cover 200 has a first surface 201 located on the upstream side in the drawing direction and a second surface 202 located on the downstream side in the drawing direction.

[0051] The heat dissipation component 220 is exposed from the first surface 201. The through hole 203 of the heat dissipation component 220 is connected to the through hole 204 of the support component 210.

[0052] The heat dissipation component 220 and the support component 210 can be joined by solder or screw clamp.

[0053] Alternatively, a plating layer can be provided on the mating surface between the heat dissipation component 220 and the support component 210. In this case, the bonding strength between the heat dissipation component 220 and the support component 210 is increased.

[0054] Figure 6 This is a cross-sectional view showing a wire drawing die 100 with a cover 200 mounted on it and a wire drawing process using the wire drawing die 100. (See diagram below.) Figure 6 As shown, the first surface 201 of the cover 200 is installed on the second surface 102 of the wire drawing die 100. The center of the die hole 103 is aligned with the center of the through holes 203 and 204.

[0055] During the wire drawing process, the wire 1 flows in the direction indicated by arrow 100a. At this time, the wire 1 is reduced in diameter by contacting the sizing section 1d.

[0056] Figure 7 This is a cross-sectional view showing the heat diffusion path in the wire drawing die 100 with the cover 200 mounted. (See diagram below.) Figure 7 As shown, heat is generated because the sizing section 1d comes into contact with the wire 1. As indicated by arrow 10, this heat is transferred from the blank 120 to the heat dissipation component 220. As a result, heat accumulation in the blank 120 can be suppressed.

[0057] Below the diamond blank 120, a plate-shaped heat dissipation member 220, made of a material with high thermal conductivity, is provided as a first component in contact with the blank 120. Below and around the heat dissipation member 220, a support member 210, also with high thermal conductivity, is provided in contact with the heat dissipation member 220. Above the support member 210, a mold shell 110, also with high thermal conductivity, is provided as a third component. This forms a structure in which the mold shell 110 and the support member 210 sandwich and surround the blank 120 and the heat dissipation member 220.

[0058] For example, by making the first component diamond and the second and third components CuW, the thermal conductivity is improved. As a result, heat can be dissipated to the outside through the blank 120, the diamond (heat dissipation component 220), and the CuW (support component 210).

[0059] The heat dissipation component 220, which is located on the lower side of the blank 120 which will be the hottest, is made of diamond, and the support component 210 acts as a heat sink. As a result, heat dissipation is achieved rapidly.

[0060] Furthermore, when CuW is used for the heat dissipation component 220 and the support component 210 and mold shell 110 surrounding the blank 120, heat dissipation to the outside is also excellent. Since the first to third components can be reused, the cost is also excellent.

[0061] Diamond is the material with the best thermal conductivity. By using diamond as a heat dissipation component 220 (heat sink) to directly cool the blank 120, the heat generated during wire drawing can be rapidly dissipated to the outside. Furthermore, by making the support component 210 supporting the heat dissipation component 220 CuW, the heat dissipation performance is further improved.

[0062] The embodiments have been described above, but the embodiments shown here can be modified in various ways. For example, in the embodiment, the blank 120 is in contact with the heat dissipation component 220, but it is also possible to make the blank 120 in contact with the refrigerant without providing the cover 200 and the heat dissipation component 220.

[0063] In one embodiment, the cover 200 is detachable from the wire drawing die 100, but it is also possible to form a structure in which the cover 200 is fixed to the wire drawing die 100.

[0064] Example 1

[0065] [Performance Evaluation of Radiator Molds]

[0066] To confirm the performance of the radiator mold, molds of the following specifications were prepared and evaluated.

[0067] (Mold Specifications)

[0068] A. Radiator mold (refer to) Figures 1 to 7 )

[0069] B. Typical molds (with) Figure 8 The shape. No cover 200 is provided. (The blank 120 is not exposed from the second side 102)

[0070] Mold shape (Molds A and B are identical)

[0071] Compression: 13 degrees

[0072] The diameter D of the sizing section 1d of the mold is 80.00 μm (with a set area reduction rate of 16%).

[0073] The axial length L of the sizing section 1d is 30% of D.

[0074] Regarding the axial length of the sizing section 1d, the region within 1.022D of the minimum diameter D of the sizing section 1d is defined as the sizing section 1d, and its length is calculated.

[0075] (Stripping conditions)

[0076] Cable: SUS316L

[0077] Line speed: 500m / minute

[0078] Lubrication: Oily

[0079] Wire drawing distance: 30km

[0080] (Lifespan Determination Criteria)

[0081] A surface roughness Ra of 40 nm or higher after processing is considered the lifespan of the wire (the location where the wire scratch occurs). Wire scratch is also known as shining wire. When light shines on imperfections on the wire surface or on the edge of the wire (where roundness deteriorates), the light undergoes diffuse reflection, causing the wire to sparkle; hence the term "sparkle."

[0082] (Surface roughness measurement conditions)

[0083] Measuring apparatus: OLYMPUS MEASURING LASER MICROCOPE OLS4000

[0084] Image size (pixels): 1024×1024

[0085] Image size: 258×258μm

[0086] Scanning mode: XYZ high precision + color

[0087] Objective lens: MPLAPONLEXT × 100x

[0088] DIC: Close

[0089] Zoom: ×1

[0090] Measurement range: 40μm

[0091] Measurement direction: circumferential direction of the wire (rotated 90 degrees from the wire drawing direction).

[0092] Measurement locations: a total of 10 locations within a ±20μm range centered on the wire tip.

[0093] Cutoff: 8μm

[0094] The evaluation results are shown in Table 1.

[0095] [Table 1]

[0096]

[0097] Sample B, using a standard die, exhibits a decrease in wire diameter with increasing drawing distance, showing a reduction of 0.09 μm in diameter compared to the initial value at 30 km. This is presumably due to circumferential wear on the inner surface of the die, with the worn edges effectively cutting the wire. Furthermore, while the drawing force initially stands at 154 cN, it increases to 200 cN at 30 km, again likely due to circumferential wear and the die cutting the wire, thus increasing the drawing force. Accompanying this, the wire surface roughness deteriorates, with flashes occurring at 20 km, serving as a lifespan criterion. Ultimately, at 30 km, the surface roughness deteriorates to 44 nm.

[0098] The heatsink mold of sample A, by improving heat dissipation, suppressed thermal reactive wear, thereby reducing the increase in drawing force to about one-third of that of a typical mold, and minimizing the impact of increased drawing force caused by ring wear. Consequently, regarding the change in wire diameter, the typical mold increases by 0.09 μm, while the heatsink mold increases by 0.03 μm, a reduction to one-third. Furthermore, the surface roughness of the wire was also improved; the typical mold showed flashing at 20 km, while the heatsink mold showed it at 30 km, achieving a 1.5-fold increase in lifespan.

[0099] In addition, molds numbered 1A to 5B were prepared to obtain samples with various variations in the diameter D and length L of the sizing section 1d.

[0100] [Table 2]

[0101]

[0102] Samples with a sample number ending in "A" have Figures 1 to 7 The shape shown, the specimens with the specimen number ending in "B" have Figure 8 The shape shown.

[0103] These specimens were tested under the same conditions as samples A and B to determine their lifespan. The area reduction rate for all specimens was 15%. The results are shown in Table 2.

[0104] As can be seen from Tables 1 and 2, Figures 1 to 7 The lifespan of the structure shown is... Figure 8 The structure has a long lifespan.

[0105] It should be understood that the embodiments and examples described herein are exemplary in all respects and not restrictive. The scope of the invention is defined by the claims rather than the foregoing embodiments and is intended to include all modifications within the scope and equivalent meaning of the claims.

[0106] Explanation of symbols

[0107] 1. Wire, 1a. Bell-shaped nozzle, 1b. Deformation section, 1c. Compression section, 1d. Sizing section, 1e. Exit angle, 1f. Exit section, 10, 100a. Arrowhead, 100. Drawing die, 101, 201. First surface, 102, 202. Second surface, 103. Die hole, 110. Die shell, 120. Blank, 121. Upstream end face, 122. Downstream end face, 200. Cover, 203, 204. Through hole, 210. Support component, 220. Heat dissipation component

Claims

1. A wire drawing die, comprising: A wear-resistant component is provided with a die hole for drawing wire; and The mold shell supporting the wear-resistant component, The wear-resistant component has a higher thermal conductivity than the mold shell. The wear-resistant component has an upstream end face and a downstream end face in the wire drawing direction, and the die hole is provided between the upstream end face and the downstream end face. The downstream end face protrudes from the die shell. The wire drawing die further includes a cover with a through hole through which the wire can pass. The cover has a heat dissipation component with the through hole that contacts the wear-resistant component, and a support component that supports the heat dissipation component. The heat dissipation component has a higher thermal conductivity than the support component. The heat dissipation component comprises at least one selected from the group consisting of diamond, CBN, and composite materials containing diamond or CBN.

2. The wire drawing die according to claim 1, wherein, The support component includes any of the following: Select at least one element or alloy containing copper, silver, tungsten, and molybdenum; or A single ceramic material or a composite of the ceramic material and a metal.

3. The wire drawing die according to claim 1 or 2, wherein, The heat dissipation component and the support component are joined by brazing filler metal or screw clamps.

4. The wire drawing die according to claim 1 or 2, wherein, A plating layer is provided on the mating surface between the heat dissipation component and the support component.

5. The wire drawing die according to claim 1 or 2, wherein, The diameter D of the sizing section of the die hole is more than 10 μm and less than 1.0 mm.

6. The wire drawing die according to claim 1 or 2, wherein, The length L of the sizing section of the die hole is more than 20% and less than 100% of the diameter D of the sizing section of the die hole.

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