JP4299604B2 - Drawing device - Google Patents

Description

  The present invention particularly relates to a wire drawing apparatus having excellent wire drawing properties such as a solid wire and a flux-cored (flux cored) welding wire.

  The arc welding wire for full-automatic or semi-automatic welding includes a solid (solid) wire and a flux cored wire (hereinafter simply referred to as a wire) in which a tubular outer steel strip (hereinafter also referred to as hoop or steel hoop) is filled with flux. (Also called FCW). Among these, there are two types of FCW: a type having a seam (hereinafter also referred to as a seam) to the hoop and a seamless type having no seam.

  These wires are basically wire rods, steel wires, or steel strips or steel pipes that are the raw materials, which are successively drawn by a drawing device such as a hole die group (row) or a roller die group (row). Manufactured as a small diameter welding wire.

  Of these, a roller die drawing device (hereinafter also simply referred to as a drawing device or a roller die) is generally a pair of rollers facing each other to form a drawing type hole, and each of these rollers is rotatably rotatable. It is comprised from bearings, such as a bearing to support, the bearing box which hold | maintains each of this bearing bearing, and the integral frame which supports these bearing boxes (for example, patent documents 1, 2, 3, 4, 5, 6). The rollers of these roller dies are supported by roller position adjusting bolts (see, for example, Patent Document 4). In addition, as a countermeasure against processing heat generated by the roller die drawing apparatus, it is also known to provide a copper plate or the like on the frame body to cool the frame body, thereby cooling the roller or the bearing (Patent Documents 4, 5, and 6). See). In addition, in the manufacturing method of FCW for stainless steel welding in which the hoop is stainless steel, it is also known to perform wire drawing while performing intermediate annealing using a roller die instead of a hole die (see, for example, Patent Document 7). )

Japanese Examined Patent Publication No. 58-17686 (Page 2, Fig. 3) JP 58-199618 (Page 2-3, Fig. 2) Japanese Patent Publication No. 3-49644 (Page 2, Fig. 2) Japanese Patent Laid-Open No. 10-225713 (Page 3, Fig. 1) Japanese Patent Laid-Open No. 11-290935 (Page 3, FIGS. 4 and 5) JP 11-290936 A (page 3-4, Fig. 2) Japanese Patent Laid-Open No. 11-285892 (Page 3, Figure 1)

  As described above, these roller dies are devices that draw a wire by sandwiching a wire in a mold hole formed by a pair of opposed roller dies. For this reason, the roller die is suitable for drawing at a higher speed than the hole die because of its structure. This is because the shearing force applied to the lubricating layer on the die surface is relatively small as compared with wire drawing using a hole die having a small mold hole, and the problem of running out of the lubricating coating is unlikely to occur. In addition, even when wire drawing is lubricated with a non-hydrogen inorganic dry lubricant that does not cause the problem of hydrogen increase, problems such as solidification and clogging of this lubricant occur, such as hole dies with small mold holes. It is because it does not.

  However, in such roller dies, in addition to ordinary mild steel, higher strength welding wires such as high tensile steel, alloy steel, and stainless steel are drawn as the wire material corresponding to the steel to be welded of the product welding wire. In this case, due to the structure, there has been a significant limit to increasing the drawing speed and accuracy (higher shape accuracy).

  Higher-strength welding wires such as high tensile steel, alloy steel, and stainless steel require a larger working force than a mild steel welding wire in wire drawing, and a large load is applied to the die. For this reason, the vibration of the die and the dent scar caused by the vibration of the wire and the contact with the die are likely to occur. For this reason, the drawing speed cannot be increased, and the drawing efficiency and the productivity of the welding wire are significantly lower than those of the mild steel welding wire.

  Therefore, when drawing high-strength welding wires using the conventional roller dies, higher speed will sacrifice higher accuracy (higher shape accuracy), and higher accuracy will result in higher speed. It was difficult to make the two compatible with each other.

  According to the knowledge of the present inventors, in the case of drawing a high-strength welding wire by the conventional roller die as described above, the major limitation of the high speed and high accuracy of the wire drawing is the roller die. This is a structural problem due to the lack of rigidity of the integrated frame that supports the frame. The proposal of the conventional roller die or the drawing apparatus has been continued from the proposal of the device configuration or the member structure, and there is nothing that clearly discloses the rigidity itself of the integrated frame that supports the roller die.

  That is, in the conventional roller die, there is no specific disclosure about the required rigidity for increasing the speed and accuracy of the drawing of the frame supporting the roller die. Of course, in the conventional roller die, it is naturally recognized that a certain high rigidity of the frame body supporting the roller die is necessary for actual wire drawing. In addition, the conventional roller die support structure and the proposal of an integral frame structure naturally increase the rigidity of the frame body indirectly.

  However, on the other hand, the recognition of the rigidity of the frame that supports the roller die must be constrained by how the roller die is used in actual wire drawing (use mode). That is, conventionally, in the wire drawing of a welding wire using a roller die, the wire shape is not a perfect circle required for the welding wire, but an elliptical shape, so that there is a problem in the shape accuracy of the drawn welding wire. It was recognized. As a result, in the wire drawing process of the welding wire, the roller die is used only partially or only in a portion where the processing rate is small. In other words, it has been necessary to use a hole die in the process where the processing rate is high at the initial stage of wire drawing (primary wire drawing) and in the wire drawing process where the wire drawing speed is high (for example, the final wire drawing process). It was recognition.

  Accordingly, the recognition of the rigidity of the frame body that supports the roller die is limited or restricted because the rigidity of the frame body is required to withstand the use in the portion where the processing rate is small.

  This is the same as the method of manufacturing FCW for stainless steel welding in which the conventional hoop is stainless steel, and the method of drawing using a roller die. In this stainless steel hoop drawing method using FCW roller dies, the processing rate is distributed between the first half and the second half of drawing, and FCW drawing is attempted. However, there is no specific disclosure about the rigidity of the frame that supports the roller die. This is because the recognition of the rigidity of the frame supporting the roller die is still limited or restricted. For this reason, with the stainless steel hoop wire drawing method using a roller die, the maximum possible wire drawing speed for obtaining a thin wire with a diameter of 0.8 mmφ is only about 300 m / min.

  In other words, the conventional technique for drawing a welding wire using these roller dies does not have the aggressiveness of using the frame body supporting the roller dies with higher rigidity. Rather, the existing roller die having a certain degree of rigidity of the supporting frame body is only depolarized within the usable range of the rigidity that it can hold. Therefore, the wire drawing speed and shape accuracy naturally have limits.

  The present invention has been made paying attention to such circumstances, and its purpose is to increase the speed and accuracy (high shape accuracy) particularly in the drawing of a high-strength welding wire. An object of the present invention is to provide a drawing apparatus that achieves both.

In order to achieve this object, the gist of the drawing device of the present invention is a device for drawing a wire with a roller die, and a bearing that rotatably supports a pair of rollers constituting the roller die, and this bearing. A bearing box for holding, and an integrated frame that supports the bearing box, and each of the bearing boxes is fixed to the frame via a bearing box fixing beam. This means that the frame body has high rigidity in the range of 20 to 150 μm when the frame body is expanded by applying a tensile load of 10000 N in the drawing load direction of the roller die to the body.

  In the present invention, in a wire drawing apparatus that draws a welding wire from an element wire to a substantially product diameter (a product diameter or a wire diameter close to the product diameter) using a roller die, the rigidity of the frame that supports the roller die It is a great feature to make it more rigid. Further, particularly in the drawing of a high-strength welding wire, the rigidity of the frame body required to achieve both high speed and high accuracy (high shape accuracy) is the so-called so-called frame body. The above quantified points are characteristic by a tensile test.

  In the above-described quantification of the rigidity of the frame supporting the roller die, the present inventors have increased the speed by drawing a solid (solid) welding wire of a high strength steel (high tensile steel) of 500 MPa class or higher. The rigidity of the frame required to achieve both high accuracy (high shape accuracy) was obtained. The obtained rigidity value of the frame body, including its critical significance, as described in the examples below, can be used to draw other high-strength welding wires such as high strength steel, alloy steel, and stainless steel. It can be applied to high-speed wire drawing of mild steel welding wire with lower strength. It can also be applied to high-speed wire drawing of flux cored wire (FCW) as well as solid wire. The wire drawing apparatus of the present invention performs all drawing from the wire of the welding wire to a substantially product diameter (product wire diameter or wire diameter close to the product wire diameter) with a roller die. For example, the drawing speed is 600 m / Applicable to high-speed wire drawing process of more than min.

  First, the rigidity of the frame body that supports the roller die will be described below. The integrated frame that supports the roller die plays an important role in ensuring the rigidity of the roller die during wire drawing. When the rigidity of the integrated frame is low, the integrated frame is easily deformed and the deformation amount is increased. For this reason, the fixing strength of the roller die is low and the roller die is easily deformed, and the roller itself is likely to vibrate during rotation during wire drawing. As a result, vibration of the welding wire during wire drawing is excited, intermittently comes into contact with the mold hole of the roller, and a dent is generated on the surface of the welding wire. Therefore, problems such as failure of the wire diameter accuracy and shape accuracy of the welding wire and the occurrence of rough skin of the wire easily occur. In particular, this tendency is stronger as the strength of the welding wire is increased. For this reason, especially a high-strength welding wire cannot be drawn, or even if it can be compared, the drawing speed has to be lowered.

  On the other hand, like the present invention, by increasing the rigidity of the integrated frame, it is possible to prevent the frame from being deformed with respect to a load during wire drawing. Accordingly, the fixing strength of the roller die can be increased, and the wire drawing speed and the shape accuracy can be improved even when the wire is drawn with a high-strength welding wire.

  The rigidity of the integral type frame is expressed by the amount of elongation of this single frame by conducting a tensile test of only the integral type frame in the drawing apparatus using a tensile test apparatus 20 as shown in FIG. This measurement method and the amount of elongation are the easiest to measure, and correspond well to the increase in speed and accuracy in the drawing of an actual high-strength welding wire.

  The tensile load applied to the frame body during the tensile test is determined by removing the support object of the frame body such as the roller die and bearing box from the wire drawing device actually used. Measure the elongation of the frame when it is expanded by applying a tensile load of 10000 N (Newton) in the direction of the load on the wire to the center of the frame. The amount of elongation of the integral frame only and the central portion of the frame indicates the maximum amount of deformation at which the integral frame is most deformed. When measuring the amount of elongation of the frame, the purpose of removing the frame support object such as the roller die and bearing box is to remove the influence of the support object on the frame rigidity, and This is for evaluating the rigidity of only the frame body (frame body alone) that greatly contributes to the drawn state of the welding wire.

  The tensile test apparatus 20 shown in FIG. 13 (a) basically includes a frame body 24 installed on a base 22, and tensile testers 21a and 21b installed in a vertical direction on the frame body 24. The configuration is basically the same as that of a normal tensile testing machine. The only difference is that the ordinary tensile test piece is replaced with the integrated frame of the drawing device, and the vertical mounting or fixing method for the tensile test of this integrated frame is the same as that of the integrated frame 9. The difference is that bolts 23a and 23b are provided at the center of the frame 9d and 9b (the vertical axis of the integrated frame 9). Note that the measurement-oriented integrated frame 9 shown in FIG. 13 (a) has the direction of the integrated frame 9 shown in FIG. 1 in order to set the tensile load direction as the load direction to the wire of the roller die drawing device. In contrast, it is tilted 90 degrees sideways. FIG. 13 (b) shows a plan view of the integrated frame 9 (view of the integrated frame 9 from above). As shown in FIG. 13 (b), a tensile load is applied at the central portion c of the frame 9d, which is the vertical axis of the integrated frame 9 or a position close to the vertical axis. If there is already a position adjusting bolt or the like as a drawing device at the central portion c of the frame 9d, it may be fixed using this instead of the fixing bolt 23a for the tensile test. If there is no fixing bolt or bolt hole for such a tensile test, a hole for inserting the fixing bolt 23a for the tensile test is newly provided in the central portion c of the frame 9d. The same applies to the other frame 9b. In any of these cases, it goes without saying that the fixing bolt for the tensile test needs to have a thickness and strength sufficient to withstand a tensile load of 10000 N.

The outer distance of the frame body (in the vertical axis direction of the frame body 9) at the center of the frame body 9 before applying the tensile load is L ₀ , and the frame distance at the center of the frame body after applying the tensile load is L L ₁ −L ₀ is determined as ₁ , and is defined as the amount of elongation of the frame outer distance. As described above, the extension amount of only the integral frame 9 indicates the maximum deformation amount at which the integral frame 9 is most greatly deformed. The distances L ₀ and L ₁ are measured in units of μm using a micrometer, a laser type distance measuring device, a dial gauge, a strain type gap measuring device, or the like.

  In the present invention, it is assumed that the integral frame body has a high rigidity in the range of 20 to 150 μm in such a tensile test. For example, even in the group of roller dies in the wire drawing process, even if one group (one row) of roller dies, if the amount of extension of the integral frame exceeds 150 μm, a particularly high-strength welding wire is used. When the wire is drawn, the rigidity of the integral frame and the fixing strength of the roller die are insufficient. For this reason, problems such as the occurrence of dent marks on the wire during wire drawing, loss of wire diameter accuracy and shape accuracy, and rough skin of the wire are likely to occur. In particular, this tendency is stronger as the strength of the welding wire is increased. For this reason, especially with the drawing of a high-strength welding wire, drawing cannot be performed, or even if it can be done, the drawing speed has to be lowered. As a result, it is impossible to achieve both high speed and high accuracy (high shape accuracy), particularly in the drawing of a high-strength welding wire.

  On the other hand, if the amount of extension of the integrated frame is less than 20 μm, the load on the roller die is excessively increased even if the wire is drawn relatively easily, such as FCW of a soft steel solid wire or a soft steel hoop. For this reason, even if the roller die is made of WC-Co carbide, the fatigue strength of the roller die is reduced, the roller die is easily broken, and the service life is greatly reduced. Therefore, the extension amount of the integrated frame is in the range of 20 to 150 μm.

  Here, structural analysis of deformation at the time of wire drawing of the integrated frame body in the roller die was performed. More specifically, when a roller die wire drawing device with a low rigidity of the integrated frame body is drawn, a roller vibration and displacement measuring device is attached, and the displacement amount of each part of the roller die is obtained by calculation, and the integrated frame A structural analysis of body deformation (displacement) was performed. The analysis results are shown in FIGS. 14 (a) and 14 (b) and FIGS. 15 (c) and 15 (d).

  The displacement amount is measured by using a wire drawing device 4a having a structure shown in FIG. 1 described later, and using a secondary wire drawing process by a roller die wire drawing device in a solid wire manufacturing process shown in FIG. 15 described later. It was. Then, the fifth-stage roller die drawing apparatus 405, which has the highest drawing speed in the secondary drawing process, was used as an object. As this secondary wire drawing condition, a high strength solid wire of 1.36mmΦ is converted to a solid wire of 1.28mmΦ with a processing force of 800 to 1000N (force to push the wire = force applied to the integrated frame), 900 to 1000m Performed by high speed wire drawing per minute. 14 was simplified by omitting the roller die and the details of the structure shown in FIG.

FIG. 14 (a) shows a deformation mode model in which the extension amount of the integral frame in the tensile test is 145 μm. Figures 14 (b), 15 (c) and 15 (d) show that the elongation of the integral frame in the tensile test exceeded 155 μm (Figure 14b), 200 μm ( FIG. 15c) shows each deformation mode model of the drawing apparatus in each case of 250 μm (FIG. 15d). 14 and 15, higher order deformation modes are shown in the order of FIGS. 14 (a), (b), FIGS. 15 (c) and (d). Note that the orientations of the frames in FIGS. 14 (b), 15 (c), and (d) are shifted by 90 degrees from the orientation of the frame in FIG. 14 (a). In these drawing devices 4a modeled in FIGS. 14 and 15, 7a, 7b, 7c and 7d are bearing boxes, 8a and 8b are bearing fixing beams (the bearing box fixing beams) , 9a, 9b, 9c, 9d shows each frame of an integrated frame.

  The actual drawing device is deformed by superimposing (combining) these component deformations. In each deformation mode in which the extension amount of the integral frame shown in FIG. 14 (a) is 145 μm, the frame is hardly deformed. On the other hand, in the integrated frame of FIGS. 14 (b), 15 (c) and 15 (d), the rigidity of the frame is low, exceeding 150 μm in terms of the elongation of the frame. Therefore, as shown in FIGS. 14 (b), 15 (c), and (d), these frames 9a, 9b, 9c, and 9d are easily and greatly deformed. Further, it can be seen that the deformation is transmitted to the bearing boxes 7a, 7b, 7c, 7d and the bearing fixing beams 8a, 8b. Therefore, when the elongation of the integrated frame exceeds 150 μm, the rigidity of the integrated frame and the fixing strength of the roller die are insufficient, especially when drawing a high-strength welding wire. That is supported.

  Based on the premise of increasing the rigidity of the frame body that supports the above roller die, an embodiment of a preferable basic structure of the drawing apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a drawing apparatus according to a preferred embodiment. FIG. 2 is an enlarged front view of a main part of the roller die in the drawing apparatus of FIG.

  First, in FIG. 1, a drawing device 4a basically includes a roller die 1, bearing boxes (bearing covers) 7a, 7b, 7c, 7d, bearing fixing beams 8a, 8b, and integral frames 9a, 9b, 9c. , 9d, etc.

  The roller die 1 includes a pair of left and right rollers 2a and 2b. The shafts (shafts) 6a and 6b of the rollers 2a and 2b are rotatably supported by bearings (bearings) (not shown) in the bearing boxes 7a, 7b, 7c and 7d. This bearing is held and accommodated in four bearing boxes 7a, 7b, 7c and 7d. The bearing boxes 7a, 7c and 7b, 7d are coupled and fixed to the two bearing fixing beams 8a, 8b, respectively, and the four frames 9a, 9b, 9c, 9d are connected through these beams, respectively. Each is fixed. These bearing fixing beams 8a and 8b are respectively fixed to the frames 9a, 9b, 9c and 9d via adjusting bolts which will be described later.

  In FIG. 1, 11a, 11b, 11c, and 11d are bolts for adjusting the position of the roller die 1 in the roller axial direction (vertical direction in the figure), and 12a, 12b, and 13a, 13b, 13c, 13d are roller gaps ( (Between rollers) This is an adjustment bolt. These adjusting bolts are composed of push screws, pull screws, and the like, and are coupled to the frames 9a, 9b, 9c, 9d and the bearing fixing beams 8a, 8b, respectively. These bolts are positioned in the roller axial direction relative to the welding wire at the time of wire drawing in the rollers 2a and 2b via the bearing fixing beam and the bearing box fixed to the beam. Control the gap. Thereby, the load and processing rate of the roller die with respect to the welding wire, and the shape and wire diameter of the welding wire are controlled.

  On the other hand, the frame bodies 9a, 9b, 9c, and 9d surrounding and supporting the roller die 1 are connected to each other by a group of bolts 10 and the like to form an integral rectangular frame body. In order to support the roller die 1 from four sides, it is reasonable that the overall shape of the integral frame has a substantially rectangular shape. 27, when the drawing device 4a is used as a drawing device row (group) 4 arranged in series with respect to the welding wire 5, the drawing devices 4a are stacked and fixed as shown in FIG. It is a hole group for fixed shafts for this purpose. These fixed shaft holes 27 are arranged at the four corners of the integrated frame (the corners of the frames 9a and 9c) so as not to hinder the configuration and function of the drawing device 4a.

  The pair of left and right rollers 2a and 2b constituting the roller die 1 shown in an enlarged manner in FIG. 2 have half-divided mold holes 3a and 3b, respectively. Then, the wire 5 is drawn by sandwiching the wire 5 (shown in the figure is a solid wire) in the mold hole 3 integrally formed by the mold holes 3a and 3b. At this time, the position of the rollers 2a and 2b in the roller axial direction (vertical direction in the figure) is adjusted by the bolts 11a, 11b, 11c and 11d shown in FIG. Further, the roller gap (in the horizontal direction in the figure) is adjusted by the bolts 12a, 12b and 13a, 13b, 13c, 13d in FIG.

  With the above preferred basic configuration, the required rigidity of the integrated rectangular frame 9a, 9b, 9c, 9d and the accompanying fixing strength of the roller die 1 at the time of wire drawing are included, including the design conditions described later. Basically easy to secure. Therefore, even when the high strength welding wire is drawn, deformation of the integral rectangular frames 9a, 9b, 9c, 9d can be prevented. This also increases the fixing strength of the roller die 1 and can improve the drawing speed and shape accuracy even when drawing a high-strength welding wire.

  The fixing strength (rigidity) of the roller die 1 in the wire drawing device 4a is the roller die 1, the bearing box 7, the bearing fixing beam 8, the strength of the components of the rectangular frame 9, the fixing strength to the rectangular frame, and The strength of the rectangular frame is determined in synergy with each other. In the present invention, among these elements, in particular, the strength (rigidity) of the integrated rectangular frame 9 having the greatest influence is increased to the predetermined level to increase the fixing strength of the roller die 1. Therefore, even when the drawing device 4a has such a preferable basic configuration, as shown in the deformation analysis results of FIGS. 14 and 15 described above, when the integral frame extends beyond 150 μm and the rigidity decreases. In particular, the rigidity of the integrated frame and the fixing strength of the roller die are insufficient when a high-strength welding wire is drawn.

  When the wire drawing device 4a having such a configuration is actually used for drawing a welding wire, a plurality of wire drawing device groups (groups) 4 arranged in series with respect to the welding wire 5 as shown in FIG. Used as In the case of FIG. 3, in order to draw the welding wire 5 with good shape accuracy, four drawing devices 4a having the same configuration and with the rollers 2a and 2b oriented at 90 degrees from each other are alternately arranged. It is arranged. Then, the fixed shafts 28a and 28b are passed through the fixed shaft holes (the fixed shaft holes 27 described in FIG. 1) of the respective drawing devices 4a to fix the fixed plate 29 (the support portion at the bottom of the drawing device 4a). In addition, the wire drawing device 4 is integrated. Note that the drawing direction in FIG. 3 is the direction from right to left in the figure.

  The drawing device 4 shown in FIG. 3 requires periodic replacement of bearings and the like. The operability at the time of replacement is also extremely important. If it is too large or too heavy, work efficiency will be significantly reduced. In this regard, the outer diameter of the integrated frame that determines the outer diameter of the wire drawing device 4 is about 200 to 300 mm square, less than 400 mm square, and the total mass of the integral frame when a pair of roller dies is attached It is preferably 20 kg or less.

  A preferred embodiment for increasing the strength (rigidity) of the integrated rectangular frame 9 will be described below.

Each frame The material of each frame (four frames) that make up the rectangular frame shall be composed of relatively high-strength steel such as carbon steel for machine structural use, alloy steel, stainless steel, and tool steel. Is preferred. Further, the cross-sectional shape of the individual frames constituting the rectangle may be I-type or hollow-rod-type, but a simple rectangle is sufficient in consideration of ease of processing. If the cross-sectional shape of each frame is rectangular, it is easy to adjust the moment of inertia of the integral frame (expressed by the following formula), and the elongation of the integral frame in the tensile test is reduced to increase the rigidity. Is easy.
Cross-section secondary moment I = (bh ³ ) / 12 of the integral frame
Where b: width of the integrated frame relative to the load direction, h: height of the integrated frame.

  Furthermore, among these rectangular cross-sectional shapes, a rectangular cross-sectional shape is preferable. When the cross-sectional shape of each frame is square or close to a square, the frame vibration frequency in the wire radial direction (direction in which the expansion force acts by processing) and the wire drawing direction are close to each other. Vibration is likely to occur. On the other hand, when the cross-sectional shape of each frame is a rectangle, the frame vibration frequencies in both directions are separated from each other, and the combined vibration of the frame is less likely to occur. For this reason, it becomes more difficult for the dent mark to stick to a wire.

  In addition, the deformation amount of each frame body is larger as the length is longer, even if the second moment of section is the same. Therefore, the length of each frame is preferably as short as possible after ensuring the length necessary for supporting the roller die 1 in design. In addition, even if there is a part where the thickness is partially reduced in the frame, it is sufficient that the amount of extension of the integral frame is within the predetermined range.

  Further, in drawing, as shown in FIG. 3, since a plurality of drawing devices 4 are used in an overlapping manner, if the frame is too thick, each roller shown in FIG. The shafts (shafts) 6a and 6b of 2a and 2b become longer and are easy to bend. In addition, the distance between adjacent roller mold holes that change by 90 ° at an angle increases, and the wire is likely to twist and high-precision machining cannot be performed. For these reasons, the thickness of each individual frame is preferably 70 mm or less. In addition to the above conditions, including the design items such as the thickness (plate thickness) and width of each frame material, the frame body in the tensile test should have high rigidity in the range of 20 to 150 μm. Design frames and rectangular frames.

  Further, in the case where the four frames constituting the rectangular frame are each integrally fixed, when using the bolt 10, in order to increase the rigidity of the integrated frame and the coupling force between the frames, Steel bolts having an outer diameter of 4 mm or more are preferred. Further, in addition to or instead of the bolt 10, the four frames may be firmly fixed by welding such as arc, plasma, or laser.

  FIG. 4 is a front view showing an example in which each frame is fixed to a rectangular (rectangular) integrated frame with bolts. The horizontal arrow in the figure indicates the direction in which the expansion force acts on the frame body by drawing. In the figure, 10 at the four corners of the frame indicate the fixing bolts shown in FIG. Figures 4 (a), (d), and (f) are examples in which the fixing bolt 10 is used in parallel to the expansion force, and Figures 4 (b), (c), and (e) are for fixing. This is an example in which the bolts 10 are used in the longitudinal direction with respect to the expansion force. 4 (a) and (b) are the types in which the frame ends are butted diagonally and joined, and FIGS. 5 (c) and (d) are the types in which the frame ends are fitted together and joined. 4 (e) and (f) respectively show types in which the frame ends are joined at right angles to each other. Further, the fixing bolt may be fixed from the vertical direction in the three-dimensional sense of FIG. An integral type frame is constituted by using any one of these fixing bolts and the type of joining between the frame ends, or a combination of any of these types.

  Next, in addition to the rectangular frame 9 described above, other elements that basically constitute the drawing device 4a are used to increase the fixing strength (rigidity) of the roller die, or to improve the drawing accuracy and speed. The preferred embodiment is described below.

Roller Dies The roller diameters of the rollers 2a and 2b of the roller die 1 used in the present invention are preferably in the range of 30 to 80 mm in view of the relationship with the integrated frame and practicality. When the roller diameter is reduced, the distance between adjacent rollers can be reduced, so that the wire diameter accuracy of the drawn wire is improved. On the other hand, when the roller diameter is reduced, the number of rotations of the roller per unit time is increased, the roller is likely to generate heat, and the roller life is shortened. The range in which the wire diameter accuracy and roller life are well balanced is the roller diameter range of 30 to 80 mm. Similarly, the diameter of the rotary shaft 6 of the roller is preferably selected from the range of 8 to 25 mm, the total length (axial direction) of the roller is 50 to 150 mm, and the thickness of the roller is preferably 5 to 25 mm.

The roller die 1 (rollers 2a, 2b) used in the present invention is preferably made of cemented carbide (made of cemented carbide material). With other materials, particularly with high-strength and high-speed wire drawing for welding, the fatigue strength of the roller die is lowered, the roller die is easily broken, and the life is likely to be greatly reduced. These cemented carbide materials include WC-based cemented carbide, TiC-based cemented carbide, and TiCN-based cermet. ZrC, HfC, TaC, NbC, VC, Cr ₃ C ₂ etc. Are appropriately dispersed, and many binders are sintered with Co and / or Ni.
However, the roller die 1 used in the present invention preferably has a composition in which fine WC particles having a particle diameter of 0.1 to 20 μm are sintered with Co or Co and Ni as binders among these superhard materials. Roller dies made of WC-Co cemented carbide, which is such a WC-based cemented carbide, have high hardness and rigidity. Even if the strength and hardness of the welding wire are high, the basic strength of roller die 1 is fixed. Secured. In addition, the finish of the surface of the welding wire after drawing is ensured, and there is an advantage that the wire supply property when the welding wire is supplied to the welding machine is improved. Furthermore, wear on the surface of the mold cavity of the roller can be prevented and stable wire drawing can be performed for a long time.

Bearing Fixing Beam The presence of the bearing fixing beams 8a and 8b in FIG. 1 improves the fixing strength between the rollers 2a and 2b and the integrated rectangular frames 9a, 9b, 9c and 9d. Without using these beams 8a, 8b, 8c, 8d, when the bearing box 7a, 7b, 7c, 7d is directly fixed to the integral rectangular frame 9a, 9b, 9c, 9d with the adjusting screw, a roller The fixing strength of 2a, 2b and the rectangular frame is significantly lower than in the case of the embodiment shown in FIG. For this reason, when a larger processing force is required, such as drawing of a higher-strength welding wire, die vibration and wire dents are likely to occur.

  5, 6, and 7 show an example of a specific configuration of the bearing fixing beam 8 a and the bearing boxes (boxes) 7 a and 7 c in the embodiment shown in FIG. 5, 6 and 7, each (a) is a front view and each (b) is a side view. Here, FIGS. 5, 6 and 7 show only one side of the bearing box 7a, 7c side (the bearing fixing beam 8a side) of FIG. Although not shown, the other bearing box 7b, 7d side (bearing fixing beam 8b side) also has the same structure in a symmetrical manner.

  FIG. 5 shows an example in which bearing boxes 7a and 7c each having a cylindrical hole 15 into which a bearing 14 is fitted are brought into contact with a bearing fixing beam 8a and fixed to each other with a plurality of bolts 10 on 8a.

  FIG. 6 shows an example in which half of the bearing boxes 7a and 7c and the bearing fixing beam 8a are integrated, and the bearing box lid 16 is fixed to the bearing boxes 7a and 7c with the bolts 10.

  FIG. 7 shows an example in which the bearing fixing beam 8a and the bearing boxes 7a and 7c, and the bearing box lid 16 and the bearing boxes 7a and 7c are fixed with bolts 10 respectively.

  Each of these examples is characterized in that the bearing box and the bearing fixing beam are completely integrated with bolts. You may integrate both by the low distortion welding which used heat sources, such as a laser and an electron beam, besides a volt | bolt.

Bearing Here, the bearing 14 accommodated in the bearing box is preferably selected from the following bearing types in order to facilitate the rotational movement of the rollers 2a and 2b having the mold hole 3 in FIG. That is, a single row or double row deep groove ball bearing type, a single row, double row, or a combination angular ball bearing type, or a single row or double row tapered roller bearing type is selected. The outer rings of these bearings are inserted into the bearing boxes 7a and 7c, while the rotating shaft 6a of the roller 2a having the mold hole 3 is inserted into and supported by the inner rings of these bearings, so that the roller 2a is high. It can rotate with high accuracy and low resistance. This also applies to the rotating shaft 6b of the roller 2b.

Position Adjustment of Roller Dies An embodiment in which the fixing of the bearing box 7 in FIG. 1 and the roller die position adjustment are performed by adjusting bolts will be described below with reference to FIGS. FIG. 8 is a front view of the drawing device 4b, showing another embodiment of the drawing device of FIG. 1, and omitting the illustration of the rollers. FIG. 9 is a side view of the main part of FIG. 8, and shows an example of the arrangement of bolts 12 and 13a, 13b for adjusting the gap between the rollers 2a, 2b (lateral direction in the figure). FIG. 10 (a) is a cross-sectional front view of an essential part of FIG. 8, showing an example of arrangement of bolts 11a and 11c for adjusting the roller shafts 6a and 6b directions (vertical direction in the drawing) of the rollers 2a and 2b. FIG. 10 (b) is an enlarged view of the main part of 10 (a). FIG. 11 is also a cross-sectional front view of the main part of FIG. 8, showing another example of arrangement of the bolts 11a and 11c for adjusting the roller shafts 6a and 6b directions (vertical direction in the drawing) of the rollers 2a and 2b.

Adjustment of Roller Interval (Gap) In FIG. 8, 13a and 13b are steel push bolts having an outer diameter of 4 mm or more having lock nuts, and 12 is a steel pull bolt having an outer diameter of 4 mm or more. These bolts are inserted from the outside of the frame through the female screws 25 respectively drilled in the frames 9d and 9b and the bearing fixing beams 8a and 8b, and fixed to the bearing fixing beams 8a and 8b, respectively. ing. By finely adjusting these push bolts and pull bolts, the distance between the rollers can be optimally adjusted, and it can be firmly fixed using a lock nut.

  In FIG. 8, 18a, 18b, 18c, and 18d are vibration prevention keys. In this way, by fixing the bearing fixing beams 8a and 8b to the frames 9a and 9c with the key 18, the fixing strength of the rollers 2a and 2b to the integrated rectangular frames 9a, 9b, 9c and 9d can be increased. This can be further improved. The vibration preventing key 18 may be fixed to either the rectangular integrated frame 9 or the bearing fixing beam 8 with a bolt.

  FIGS. 9 (a), (b), (c), (d), and (e) respectively show push bolts 13a and 13b (FIG. 9) when the drawing device 4b in FIG. 8 is viewed from the side surface on the frame 9d side. Shows an example of arrangement of pull bolts 12 (indicated by white circles in FIG. 9). These push bolts 13a, 13b and pull bolt 12 may be arranged in the same straight line or in a geometrical form in a plane as shown in FIGS. 9 (a) to (e). . Further, the positions of the push bolt 13 and the pull bolt 12 may be interchanged. By using three or more push bolts 13 and pull bolts 12 in total, the integral rectangular frame 9 and the bearing box 8 can be firmly fixed. Then, by pushing the push bolt 13 and pulling the pull bolt 12, the gap between the rollers 2a and 2b (the horizontal direction in the figure) can be adjusted.

Adjustment of Roller Axial Position In the embodiment shown in FIG. 10 (a), the roller rotating shaft 6a is provided with two steps 26 having different shaft thicknesses symmetrically to the roller 2a. These steps 26 support the inner rings 14a of the two bearings 14, respectively. On the other hand, caps 17 abut on the outer ring 14b side of the bearing 14, respectively. The cap 17 is fixed to adjustment bolts 11a and 11c inserted through female screws 25 formed in the frames 9a and 9c. The positions of the roller 2a and the bearing 14 are fixed by the step 26 of the roller rotating shaft 6a.

  With this configuration, the bearings 14 can be moved within the bearing boxes 7a and 7c by pushing the adjustment bolts 11a and 11c and pushing the outer ring 14b side of the bearing 14 through the cap 17, respectively. it can. In accordance with this, the roller 2a can be moved in the direction of the roller rotation shaft 6a (the vertical direction in the figure), and the position of the roller 2a in the direction of the roller rotation shaft 6a can be adjusted and fixed. The configuration as described above is the same for the other roller 2b.

  As shown in FIG. 10 (b) in an enlarged view of the main part 10 (a), more specifically, the bearing 14 is composed of, for example, a single row tapered roller bearing type bearing 14c and an outer case 14d of the bearing 14, The outer case 14d of the bearing 14 forms the outer ring 14b of the bearing 14. Therefore, by pushing the adjusting bolts 11a and 11c and pushing the outer case 14d of the bearing 14 (on the outer ring 14b side of the bearing 14) through the cap 17, the bearing 14 is moved in the bearing boxes 7a and 7c, respectively. be able to. For the purpose of dust prevention, a dustproof cover 28 or the like may be attached to the bearing surface of the roller 2a, or a bearing that originally has such a dustproof cover may be used.

  In the embodiment shown in FIG. 11, two adjusting bolts 11a and 11c are attached in parallel, and the adjusting bolts 11a and 11c are brought into contact with the outer ring 14b side of the bearing 14 without the cap 17 (not provided). ing. The other configuration is basically the same as that of FIG. 10 (a) described above. With this configuration, as in FIG. 10 (a), the adjustment bolts 11a and 11c are pushed and the outer ring 14b side of the bearing 14 is pushed to move the bearing 14 within the bearing boxes 7a and 7c, respectively. Can be made. When the adjusting bolts 11a and 11c are directly brought into contact with the outer ring 14b side of the bearing 14 as described above, these adjusting bolts are respectively connected to the individual bearings like the adjusting bolts 11a and 11c. It is preferable to provide it. In addition, it is preferable to provide a plurality in total, and if there are three or more, the bearing 14 can be stably fixed.

Method of Cooling the Wire Drawing Device The roller die wire drawing device generates heat during wire drawing. For this reason, the roller surface and the bearing that come into contact with the welding wire serve as a heat source. When the wire drawing is performed with a wet lubricant such as an aqueous system, the roller and the bearing are efficiently cooled by the wet lubricant, so that it is not necessary to actively cool the drawing device itself. On the other hand, when wire drawing is performed using a dry lubricant such as a powder lubricant, cooling with the lubricant cannot be expected, so that the temperature rise of the drawing apparatus itself becomes a very big problem.
Further, in the case of high strength and high speed drawing as in the present invention, or in the case of drawing in a process with a high processing rate, this processing heat generation tends to increase. For this reason, there is a high possibility that the wire diameter accuracy is lowered due to the thermal expansion of the roller (mold hole).

  Furthermore, there is a limit of natural cooling due to the configuration of the drawing device. For example, as shown in FIG. 8 described above, if the integrated frame body 9 and the bearing fixing beam 8 are only in partial contact with the bolts 12 and 13, etc., the roller 2 surface and the bearing generate, The heat flow through the fixing beam 8 is shielded by the bolts 12 and 13. For this reason, the temperature on the side of the frame body 9 hardly rises, and the temperature of only the roller 2, the bearing box 7 and the bearing fixing beam 8 rises. As a result, since the outside is fixed by the integrated frame 9, only these members inside the frame 9 are thermally expanded, the distance between the rollers is reduced, and the diameter of the wire to be drawn is drawn. Becomes smaller. Therefore, the wire diameter accuracy of the welding wire is lowered, and the temperature of the bearing is increased, so that grease and the like are easily deteriorated.

In order to prevent these, it is preferable to cool the roller, the bearing, or the bearing box during the wire drawing.
As described above, it is known to cool the roller die drawing apparatus. However, the method is a method in which a copper plate or the like is provided on the frame body, the frame body is cooled, and thereby the rollers, the bearings, and the like are cooled. According to the knowledge of the present inventors, it is not necessary to cool the integrated frame as in these conventional techniques, and when the integrated frame is cooled, there is a temperature difference between the roller and the like. There is a high possibility that the wire diameter accuracy will decrease. Therefore, in the present invention, when the roller die drawing device is cooled, the roller, the bearing, or the bearing box is cooled.

  FIG. 12 shows an example of a cooling method in which a flow path (space) for passing a cooling medium is provided in the bearing box 7a, 7c and / or the bearing fixing beam 8a to cool the roller, the bearing, or the bearing box. Indicates. In FIG. 12, an arrow 19 indicates a cooling water channel. As shown in FIGS. 12 (a), (b), (c), (d), and (e), the water channel 19 is placed in the bearing boxes 7a and 7c and / or in the bearing fixing beam 8a. Is provided by perforation. In this way, by cooling the inside of the bearing boxes 7a and 7c and / or the inside of the bearing fixing beam 8a with water, it is possible to suppress an increase in temperature of the roller, the bearing, or the bearing box accompanying drawing. FIG. 12 shows the case of water cooling. A refrigerant such as air, other gas, or liquid may be used. Furthermore, as shown in FIG. 12 (f), a through hole passing through the center of the roller shaft is provided to form a coolant flow path 19 such as cooling water, and by attaching a rotary shaft seal to both ends of the through hole, the roller itself A cooling means can be provided in the interior. In this way, the roller can be cooled most efficiently, and the thermal expansion of the roller itself can be completely suppressed.

Below, the example which applied this invention roller die-drawing apparatus to the manufacturing process including the high-speed wire drawing process of a solid wire is demonstrated.
16 and 17 show, for example, a process of manufacturing a welding solid wire having a product diameter of 1.2 mmΦ from a high-strength steel wire strand of 5.5 mmΦ. The wire drawing process of the welding solid wire shown in FIGS. 16 and 17 includes a primary wire drawing (B) and a secondary wire drawing (C). And all the wire drawing from the wire diameter of the welding wire to the wire diameter close to the product wire diameter, including the primary wire drawing (B) and the secondary wire drawing (C), without using a hole die drawing device. The process performed by a roller die is shown.

  When a high strength steel wire rod of 500 MPa or more is drawn to a welding wire in a process using such a roller die drawing device, the drawing speed that can be said to be high is the primary drawing (B) and secondary drawing. Both lines (C) are 600 m / min or more, preferably 700 m / min or more. By applying the roller die drawing apparatus of the present invention, it is possible to increase the speed.

  In addition, in the solid wire for welding, it is possible to perform high-speed drawing of the solid wire for welding that does not have copper plating, which is particularly difficult to draw. Traditionally, copper-plated solid welding wires have a problem with the feeding performance of the welding wire at the time of welding, which is caused by abnormal feeding resistance due to peeling of the copper plating from the wire surface. It was a phenomenon that increased easily. However, since the copper plating layer of the copper plating welding wire has a function as a lubricating film for improving the drawability in the manufacturing process of the welding wire, it has occupied the general market as an industrial product. This is because it has been very difficult in the past to efficiently draw a solid wire for welding without copper plating at a high speed as in the case of the solid wire for welding with copper plating. However, by applying the roller die drawing apparatus of the present invention, it is possible to draw a solid wire for welding without copper plating at a high speed.

  In the process shown in FIG. 17, first, the coil 100 of a high-strength steel wire (A) of 500 MPa or more is rewound, and a plurality of stages (three stages or four stages) of roller dies are connected as shown in FIG. In the primary wire drawing step (B) in which the wire drawing devices 201, 202, 203, 204, 205, and 206 are sequentially arranged in six stages, a wire having a wire diameter of 2.4 mm Φ is used by using a wire drawing lubricant described later. The wire is drawn and then wound to form a coil 106. In FIG. 17, 111 is a take-up capstan appropriately disposed between the dies.

  Next, the coil 106 is rewound, and two drawing devices 401, 402, 403, 404, and 405, each of which is connected in series with a plurality of (three or four) roller dies as shown in FIG. In the next wire drawing step (C), a wire having a wire diameter of 2.4 mm and a wire having a wire diameter of 1.3 mm and having a wire diameter of 1.3 mm and having a wire drawing lubricant to be described later or not using a new wire drawing lubricant is used. Wire is drawn to a wire of approximately the product diameter (wire diameter close to the product diameter). After drawing the wire with this approximate product diameter, finish drawing D is performed to increase the wire diameter accuracy with a single-stage hole die 501, and a wire with a diameter of 1.3 mm Φ is finished with a final product diameter of 1.2 mm Φ. The wire is drawn. Whether or not to insert the finish drawing D by the hole die is appropriately selected from the necessity of product handling of the product welding wire and the required wire diameter accuracy of the product. You can select not only solid wire. In that case, the final product diameter of 1.2mm Φ can be finished with a roller die.

  After this wire drawing, the wire is cleaned in a cleaning step E by a simple cleaning tank 108 not containing an organic detergent and acid or alkali, and the wire drawing lubricant remaining on the wire surface is removed. After that, the wire is coated with a wire feeding lubricant on the wire surface in the oil application step E, and after performing a series of these processes in-line, the coil 110 is used as a product welding wire F having a wire diameter of 1.2 mmΦ. Rolled up. The cleaning step E includes a wiping roll having a polishing cloth, felt, etc. provided on the surface for removing the wire drawing lubricant, physical vibrations such as vibrating the wire and hitting the wire. You may wash | clean with an appropriate removal means or an appropriate combination of these removal means.

  Here, the lubricant used for wire drawing will be described. When drawing a high-strength steel wire rod to a welding wire, the necessary characteristics of the lubricant are that it exhibits good lubricity during roller die drawing, and further, after this roller die drawing, Although it depends on the amount of residual adhesion, it can be removed by an in-line cleaning process. Here, in-line means that the processing is continuously performed while the wire after drawing is conveyed in the same process as the drawing. On the other hand, after the wire is drawn, performing the process on the wire after the drawing in a process different from the drawing is called offline.

  In the present invention, a dry solid lubricant mainly composed of a stearic acid-based metal soap such as sodium stearate or potassium stearate is preferable as the lubricant satisfying this characteristic. These water-soluble stearic acid-based metal soaps exhibit good lubricity when drawn with a roller die, and are removed by annealing, alkaline degreasing, pickling, organic cleaning, etc. Therefore, it can be removed by an in-line cleaning process using hot water or the like. Further, this metal soap maintains the pH of the product welding wire surface at a weak alkali, suppresses oxidation of the wire surface, and can provide excellent rust prevention performance.

  However, the above-mentioned stearic acid soap alone has a low softening point, and when the roller die of a solid wire for welding without copper plating is drawn at high speed, the soap component is carbonized in the hole die and stretched at high speed. You may not be able to line. For this reason, it is preferable to increase the softening point of the lubricant in order to speed up the roller die drawing in order to increase the speed and efficiency of the entire process. For this reason, it is preferable to add a softening point adjuster to the stearic acid soap. As the softening point adjuster, one or more of sodium phosphate, sodium borate, sodium nitrite, potassium carbonate, potassium phosphate, potassium borate, potassium nitrite, and potassium carbonate are selected. By adding these softening point modifiers, high-speed wire drawing of a solid wire having no copper plating becomes possible.

Furthermore, one or more selected from a small amount of MoS ₂ , WS ₂ , BN, graphite, ZnS, etc. as a lubricity improver to supplement the drawability of the roller die and protect the roller die surface. It is preferable to contain the extreme pressure agent.

  The wire drawing lubricant having such a composition has an advantage that it does not affect the arc stability even if a trace amount remains on the surface of the product welding wire in the in-line cleaning after the roller die drawing. In other words, there is an advantage that a product welding wire with good arc stability can be manufactured by a simple in-line cleaning process described later without taking the complicated cleaning process off-line.

  In general, a dry solid lubricant containing a calcium stearate-based lubricant (calcium soap) used for drawing a wire that does not have copper plating has good lubricity. However, calcium stearate is difficult to remove by a simple in-line cleaning process, and even if Ca remains in a small amount on the surface of the product welding wire, it significantly affects the arc stability. For this reason, a trace amount residue on the surface of the product welding wire cannot be allowed. Therefore, a simple cleaning process by in-line after the roller die drawing cannot be applied. In other words, after completion of the drawing of the roller die, detailed removal processing suitable for off-line processing such as annealing, alkaline degreasing, pickling processing, and cleaning with an organic cleaning agent is required. There is a problem with.

  Examples of the present invention are shown below. According to the manufacturing process of the solid wire for welding shown in FIGS. 16 and 17 described above, a solid wire having no 1.2 mmφ copper plating was manufactured from a 5.5 mmφ high-strength steel wire. At this time, the rigidity of the integrated frame of a specific roller die drawing apparatus in the wire drawing process was changed to evaluate the wire drawability and the characteristics of the product welding wire. The strand was a high strength steel wire having a chemical composition equivalent to JIS Z3312 YGW12 of 5.5 mmΦ and a tensile strength of 500 MPa.

  More specifically, as a first case, in the primary wire drawing step (B) shown in FIG. 17, the integrated frame in the roller die wire drawing device 205 having the largest wire drawing force and the highest wire drawing speed. The rigidity (the amount of elongation in the tensile test described above) was changed. In the second case, the rigidity of the integrated frame body in the roller die drawing apparatus 405 where the wire drawing speed is the highest in the secondary wire drawing step (C) was changed. Here, the frame rigidity of the four roller dies arranged as shown in FIG. In each of these cases, the roller die drawing device other than the specific roller die drawing device described above has the rigidity of each integrated frame body to be 40 to 80 μm in the amount of elongation in the above-described tensile test of the integrated frame body. Of high rigidity within the scope of the present invention.

  At this time, as the roller die drawing device, the drawing device 4a shown in FIGS. 1 and 3 was used. In addition, the roller dies in all the drawing apparatuses were made of the above-described WC-Co based carbide material. Then, the wire was drawn by changing various conditions such as the structural condition in the wire drawing device 4a. The structural conditions of this drawing device are as follows: the presence / absence of the bearing box fixing beam 8 in FIG. 1, the presence / absence of the key 18 in FIG. 8, the presence / absence of the pulling bolt 12 for adjusting the roller gap in FIG. 1), the presence / absence of the position adjusting bolt 11 in the roller axial direction (vertical direction in FIG. 1) of the roller die in FIG. 1, and the presence / absence of water cooling (water channel) in FIG. 12 (a) were changed. It should be noted that other design conditions for the drawing apparatus 4a were within the ranges of the above-described preferred design conditions. In all cases, the outer shape of the integral frame was 250 × 250 mm, the thickness of each frame 9 was 60 mm, the diameter of the roller 2 was 65 mm, the diameter of the roller rotating shaft 6 was 17 mm, and the thickness of the roller was 15 mm.

Lubricant for wire drawing is 75% by weight of sodium stearate (metal soap) in both primary wire drawing process (B) and secondary wire drawing process (C)-sodium phosphate + sodium nitrite (softening point adjuster) total 25 A composition of mass% (appropriate amount is in the range of 10 to 30 mass%) was applied to the strand and the wire just before the roller die drawing devices 201 and 401 (before the primary and secondary wire drawing), respectively.
As a wire feeding lubricant, vegetable oil (rapeseed oil) was used, and 1.0 g per 10 kg of wire was applied. In addition, you may use synthetic oil instead of vegetable oil.

  For each wire drawing example with different design conditions for the roller die wire drawing device, evaluate the wire drawability in the primary wire drawing process (B) or secondary wire drawing step (C) using the roller die wire drawing device, and perform a tensile test on the frame. The relationship with design conditions such as elongation (μm) was investigated. The evaluation of wire drawing was performed by visual observation of the state of vibration of the die and the state of occurrence of dents on the wire during wire drawing. The wire drawing performance is the highest wire drawing speed (m / min) of the wire drawing device (not limited to the above 206 and 405) that has the highest wire drawing speed in the primary wire drawing or the secondary wire drawing. The wire amount (stable drawing dose: ton) in the primary or secondary wire drawing, which could be drawn stably, was performed.

  In addition, the characteristics of the product welding wire were also evaluated by wire diameter accuracy (maximum wire diameter error: ± μm) and visual surface skin observation. The surface skin was evaluated in three stages: one with large skin roughness: non-uniform, one with small skin roughness: slightly non-uniform, one with no skin roughness: uniform. The wire diameter accuracy greatly affects the efficiency of rewinding the product welding wire to a spool and the like, and the supply capability of the wire that enables the welding wire to be supplied from the wire supply machine to the welding machine without interruption.

  In the first case (the case in which the rigidity of the integrated frame in the roller die drawing device 205 in the primary wire drawing process (B) is changed), the design conditions of the wire drawing device, the wire drawability in the primary wire drawing process (B) The properties of the final product welding wire are listed in Table 1. In addition, the design conditions of the wire drawing device in the second case (the case where the rigidity of the integrated frame in the roller die wire drawing device 405 in the secondary wire drawing step (C) is changed), the secondary wire drawing step (B) Table 2 shows the drawability and the properties of the final product welding wire.

  First, regarding the first case, as is apparent from Table 1, Invention Examples 1 to 11 in which the elongation amount of the frame body is in the range of 20 to 150 μm are basically the drawability and product in the primary wire drawing. The characteristics of the welding wire are also good. As a result, both high speed and high accuracy (high shape accuracy) can be achieved at the time of drawing a solid wire for welding with high strength without copper plating.

  On the other hand, Comparative Examples 14, 15, and 16 in which the amount of elongation exceeds 150 μm are basically the same in primary wire drawing, although the other design conditions of the roller die wire drawing device are the same as those of the invention example. The drawability and the characteristics of the product welding wire were significantly inferior to those of the inventive examples.

  That is, in Comparative Examples 14, 15, and 16, since the amount of elongation of the frame body exceeds 150 μm, the roller die drawing device that increases the drawing force and drawing speed in the primary drawing step (B). In 205, the rigidity of the integral frame and the fixing strength of the roller die are insufficient. For this reason, in the roller die drawing apparatus 205, at the stage of a slow drawing speed of 500 to 600 m / min, the vibration of the die was strongly generated, and dents were generated on the wire being drawn. Therefore, Comparative Examples 14, 15, and 16 were unable to increase the drawing speed to 600 m / min or more. As a result, even when the drawing speed is 500 to 600 m / min, the wire diameter accuracy and the shape accuracy are not obtained as products, and as a problem before that, stable wire drawing itself is impossible.

  On the other hand, Invention Example 1 having an elongation of 145 μm, which is close to the upper limit of 150 μm, is superior to the comparative example in terms of wire drawability and product welding wire characteristics. However, in Invention Example 1, although the wire drawing speed is 700 m / min and no wire dents are generated, in the roller die drawing device 205, some die vibration is generated. At wire drawing speeds higher than this, there is a possibility of reaching the wire dents, so Invention Example 1 could not increase the wire drawing speed to 700 m / min or more. For this reason, the maximum wire drawing speed and the stable wire drawing amount in the primary wire drawing are relatively small as compared with Invention Examples 2 to 6 and the like other than the elongation amount of the frame body. Also, the wire diameter accuracy and the wire surface skin are relatively poor. Therefore, from these results, there is a critical significance of the upper limit value of the amount of elongation of the frame body, which is the rigidity of the integrated frame body of the wire drawing device in high-speed wire drawing with a roller die of a high-strength welding wire. I understand.

  On the other hand, in Comparative Examples 12 and 13 in which the elongation amount was less than 20 μm, the load on the roller die of the roller die drawing device 205 was too high when the high-strength welding wire was drawn. For this reason, when the drawing speed was 900 m / min, the fatigue strength of this roller die decreased during drawing, and the surface of the roller die made of a WC-Co carbide tool was destroyed early. Accordingly, the amount of wire that can be stably drawn was significantly smaller than that of the inventive examples. In Comparative Examples 12 and 13, if the maximum primary drawing speed is reduced to, for example, 600 m / min or less, the life of the roller die is further extended, but the drawing efficiency is remarkably lowered, and is not practical. On the other hand, Invention Example 5 in which the amount of elongation of the frame body is 25 μm, which is close to the lower limit of 20 μm, has relatively good wire drawing properties and product welding wire characteristics. Therefore, the critical significance of the lower limit value of the elongation amount of the frame body, which is the rigidity of the integral frame body of the wire drawing device, in high-speed wire drawing by a roller die of a high-strength solid wire for welding is understood.

  Furthermore, among the inventive examples, even if the elongation amount in the tensile test of the frame body described above is within the range, other structural design conditions of the roller die drawing apparatus deviate from the preferable conditions of the present invention. Compared with the invention examples within the range, the wire drawing property and welding characteristics were inferior. Therefore, the significance of preferable design conditions of the drawing apparatus of the present invention is supported.

That is, Example 7 in which the bearing box fixing beam 8 is not provided , Example 8 in which the key 18 in FIG. 8 is not provided, Example 9 in which the pulling bolt 12 for adjusting the roller gap (inter-roller distance) is not provided, and FIG. (a) Inventive Example 10 in which no water cooling (water channel) is provided and Inventive Example 11 in which the bolt 11 for adjusting the position of the roller die in the roller axial direction (vertical direction in FIG. 1) is not provided. Compared to Invention Example 6 with the same conditions, the wire drawability and the characteristics of the solid wire for welding are relatively inferior. In particular, Invention Example 11 can be cared for on the surface of the wire, but some fine burrs were generated.

  Next, regarding the second case, as is apparent from Table 2, Invention Examples 17 to 27 in which the amount of elongation of the frame body is 150 μm or less are basically the wire drawing property in the primary wire drawing and the wire for product welding. The characteristics are also good. As a result, both high speed and high accuracy (high shape accuracy) can be achieved at the time of drawing a solid wire for welding with high strength without copper plating.

  On the other hand, in Comparative Examples 30 to 32 in which the amount of elongation exceeds 150 μm, the drawability in the primary wire drawing is basically the same even though the other design conditions of the roller die drawing apparatus are the same as those of the invention example. And the characteristics of the product welding wire were significantly inferior to those of the inventive examples.

  That is, in Comparative Examples 30 to 32, since the amount of elongation of the frame exceeds 150 μm, the integrated frame in the roller die drawing apparatus 405 in which the wire drawing speed is the highest in the secondary wire drawing step (C). The rigidity of the body and the fixing strength of the roller die are insufficient. For this reason, in the roller die drawing apparatus 405, at the stage of a slow drawing speed of 500 to 600 m / min, the vibration of the die was strongly generated, and dents were generated on the wire being drawn. Therefore, Comparative Examples 30 to 32 could not increase the drawing speed to 500 to 600 m / min or more. As a result, even when the drawing speed is 500 to 600 m / min, the wire diameter accuracy and the shape accuracy are not obtained as products, and as a problem before that, stable wire drawing itself is impossible.

  In contrast, Invention Example 17, which has an elongation of 145 μm, which is close to the upper limit of 150 μm, has a drawing speed of 800 m / min. In the drawing device 205, some vibration of the die is generated. At wire drawing speeds higher than this, there is a possibility of reaching the wire dents, so Invention Example 17 could not increase the wire drawing speed to 800 m / min or more. For this reason, the maximum wire drawing speed and the stable wire drawing amount in the secondary wire drawing are relatively small as compared with Invention Examples 18 to 22 and the like other than the elongation amount of the frame. Also, the wire diameter accuracy and the wire surface skin are relatively poor. Therefore, from these results, the critical significance of the upper limit value of the elongation amount of the frame body, which is the rigidity of the integrated frame body of the wire drawing device, in the drawing of the high-strength welding wire by the roller die is understood. .

  On the other hand, in Comparative Examples 28 and 29 in which the elongation amount is less than 20 μm, when the drawing speed is 1000 m / min, the load on the roller die of the roller die drawing device 405 is increased when the high-strength welding wire is drawn. It was too high. For this reason, the fatigue strength of this roller die decreased during wire drawing, and the surface of the roller die made of a WC-Co carbide tool was destroyed early. Therefore, the amount of wire that can be stably drawn is extremely small. In Comparative Examples 28 and 29, if the maximum primary drawing speed is reduced to 600 m / min or less, the life of the roller die is further extended, but the drawing efficiency is remarkably lowered, which is not practical. On the other hand, Invention Example 21 in which the elongation amount of the frame body is 25 μm, which is close to the lower limit of 20 μm, has relatively good wire drawing properties and product welding wire characteristics. Therefore, the critical significance of the lower limit value of the elongation amount of the frame body, which is the rigidity of the integral frame body of the wire drawing device, in high-speed wire drawing by a roller die of a high-strength solid wire for welding is understood.

  Furthermore, among the inventive examples, even if the elongation amount in the tensile test of the frame body described above is within the range, other structural design conditions of the roller die drawing apparatus deviate from the preferable conditions of the present invention. Compared with the invention examples within the range, the wire drawing property and welding characteristics were inferior. Therefore, the significance of preferable design conditions of the drawing apparatus of the present invention is supported.

  That is, Invention Example 23 in which the bearing box fixing beam 8 is not provided, Invention Example 24 in which the key 18 in FIG. 8 is not provided, Invention Example 25 in which the roller gap (inter-roller distance) adjusting pull bolt 12 is not provided, FIG. Inventive Example 26 in which the water cooling (water channel) of 12 (a) was not provided, and Inventive Example 27 in which the bolt 11 for adjusting the position of the roller die in the roller axial direction (vertical direction in FIG. 1) was not provided. Compared with Invention Example 6 with the same conditions, the drawability and the characteristics of the product welding wire are relatively inferior. In particular, Invention Example 27 can be cared for on the surface of the wire, but some fine burrs are generated.

The results of the above two examples also correspond well with the structural analysis of the deformation of the integrated die frame in the roller die shown in FIGS. In particular, the results of the above example (second case) using the same secondary wire drawing roller die drawing device 405 agree well with the structural analysis. Therefore, this also supports the critical significance of the elongation range of the integrated frame of the drawing apparatus of the present invention.
In addition, from the above embodiments, either the primary wire drawing or the secondary wire drawing, either one or only one roller die wire drawing device among many roller die wire drawing device groups (rows) in the wire drawing process. It can be seen that even if the rigidity of the integrated frame body is out of the scope of the present invention, the overall drawing process is greatly affected. Therefore, this also supports the critical significance of the range of elongation of the integral frame in the present invention.

  According to the present invention, it is possible to provide a roller die drawing apparatus that achieves both high speed and high accuracy (high shape accuracy), particularly in drawing of a high-strength welding wire. Therefore, the drawing process of the high-strength welding wire can be significantly improved while maintaining the welding wire quality and characteristics.

It is a front view which shows one embodiment of this invention drawing apparatus. FIG. 2 is an enlarged front view of a main part of a roller die in the drawing device of FIG. It is a front view which shows the wire drawing apparatus row | line used for wire drawing. It is a front view which shows the integral type frame body of a roller die. FIG. 5 is an enlarged cross-sectional view of a main part showing a configuration example of a roller fixing bearing fixing beam and a bearing box, in which FIG. 5 (a) is a front view and FIG. 5 (b) is a side view. FIG. 6 is an enlarged cross-sectional view of a main part showing a configuration example of a roller fixing bearing fixing beam and a bearing box, in which FIG. 6 (a) is a front view and FIG. 6 (b) is a side view. FIG. 7 is an enlarged cross-sectional view of a main part showing a configuration example of a roller fixing bearing fixing beam and a bearing box, in which FIG. 7 (a) is a front view and FIG. 7 (b) is a side view. It is a front view which shows the other embodiment of this invention drawing apparatus. FIG. 9 is a side view of the main part of FIG. 10 (a) is a cross-sectional front view of the main part of FIG. 8, and FIG. 10 (b) is an enlarged view of the main part of 10 (a). FIG. 9 is a cross-sectional front view of the main part of FIG. It is explanatory drawing which shows an example of the cooling method which has the space for cooling medium circulation in the bearing box of a roller die, and / or the beam for bearing fixation inside. FIG. 13 (a) is a front view showing a tensile test apparatus for a roller die integrated frame, and FIG. 13 (b) is a plan view showing the test frame in FIG. 13 (a). FIG. 15 is an explanatory diagram showing a structural analysis result of deformation at the time of wire drawing due to a difference in rigidity of a roller die-integrated frame, and showing higher-order deformation modes in the order of FIGS. 14 (a) and (b). FIG. 16 is a diagram illustrating a structural analysis result of deformation at the time of wire drawing due to a difference in rigidity of the roller die-integrated frame, and is an explanatory diagram illustrating higher-order deformation modes in the order of FIGS. 15 (c) and (d). It is a flowchart figure which shows the manufacturing process of a solid wire. It is process drawing which shows the manufacturing process of a solid wire.

Explanation of symbols

1: Roller die, 2: Roller, 3: Mold hole, 4: Drawing device (row), 5: Wire,
6: Roller shaft, 7: Bearing box, 8: Beam for fixing bearing, 9: Frame
10: Bolt, 11: Adjustment bolt, 12: Adjustment bolt, 13: Adjustment bolt,
14: bearing, 15: hole, 16: lid, 17: cap, 18: key, 19: flow path,
20: Tensile test equipment, 21: Tensile tester, 22: Base, 23: Bolt, 24: Frame
25: Female thread, 26: Step, 27: Fixing shaft hole, 28: Dust cover,
100: Wire coil, 201 to 206, 401 to 405: Roller die drawing device (row),
106: Wire coil, 107: Wire, 108: Cleaning device, 109: Oiling device, 501: Hole die, 110: Wire coil for product welding, 111: Capstan

Claims (6)

A device for drawing a wire with a roller die, a bearing that rotatably supports a pair of rollers constituting the roller die, a bearing box that holds the bearing, and an integrated frame that supports the bearing box Each bearing box is fixed to the frame body via a bearing box fixing beam, and a tensile load of 10000 N is applied to the integral frame body in the drawing load direction of the roller die. A drawing apparatus characterized in that the frame body has high rigidity in a range of 20 to 150 μm when the frame body is expanded. The bearing box fixing beam is fixed to the frame body by bolts for adjusting the distance between the rollers, and the bearing is supported by a cap supported by a bolt for adjusting the position of the roller in the rotation axis direction. The wire drawing device according to claim 1, wherein the wire drawing device is held so as to be movable in the bearing box . The wire drawing apparatus according to claim 2 , wherein the bearing box fixing beam is fixed to the frame by a key . The wire drawing device according to any one of claims 1 to 3 , wherein a flow path of a cooling medium is formed in any one of the bearing box, the fixing beam, and the rotation shaft of the roller . The drawing apparatus according to any one of claims 1 to 4 , wherein the drawing apparatus is used for drawing a welding wire . The wire drawing device according to any one of claims 1 to 5 , wherein the wire drawing device is used for a wire drawing step in which all wire drawing from a wire of a welding wire to a substantially product diameter is performed by a roller die .