Wire drawing machine

Abstract

To provide a wire drawing machine capable of detecting the deflection of a metal wire.SOLUTION: A wire drawing machine includes a first capstan that conveys a metal wire, a wire drawing die that stretches the metal wire fed from the first capstan, a second capstan that conveys the metal wire fed from the wire drawing die, and a detector that is provided between the first capstan and the wire drawing die and detects bending of the metal wire fed from the first capstan.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wire drawing machine. [Background technology]

[0002] Some wire drawing machines that stretch (draw) metal wires such as copper wires include a drive capstan and a wire drawing die. Patent Document 1 discloses a wire drawing machine in which a metal capstan, to which lubricating oil is supplied, sends the metal wire to a wire drawing die, the metal wire is drawn by the wire drawing die, and the drawn metal wire is transported by a rubber capstan. The supply of lubricating oil to the metal capstan causes slippage between the metal capstan and the metal wire, and the metal wire is transported in a bent state by the metal capstan. As a result, the speed of the metal wire sent from the metal capstan to the wire drawing die and the speed of the metal wire sent from the wire drawing die to the rubber capstan are in a constant ratio. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-49507 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the degree of slippage of the metal wire on the metal capstan changes due to changes in the surrounding environment of the wire drawing machine, the amount of bending of the metal wire may fluctuate excessively, which causes fluctuations in the speed at which the metal wire is fed from the metal capstan, leading to problems such as the metal wire falling off the metal capstan or breaking. [Means for solving the problem]

[0005] A brief summary of a representative embodiment of the present invention will be given below.

[0006] A wire drawing machine according to a representative embodiment includes a first capstan for transporting a metal wire, a wire drawing die for drawing the metal wire fed from the first capstan, a second capstan for transporting the metal wire fed from the wire drawing die, and a detection unit disposed between the first capstan and the wire drawing die for detecting deflection of the metal wire fed from the first capstan. [Effects of the Invention]

[0007] According to one exemplary embodiment of the present application, deflection of a metal line can be detected. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram schematically illustrating a configuration of a wire drawing machine according to an embodiment. [Figure 2] FIG. 2 is a side view showing a configuration of a part of the wire drawing machine. [Figure 3] 10 is a diagram schematically illustrating the first capstan and the detection unit when the bending of the metal wire changes excessively. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described. Note that each embodiment described below is an example for carrying out the present invention, and does not limit the technical scope of the present invention.

[0010] <Overall structure> 1 is a block diagram showing a schematic configuration of a wire drawing machine 100 according to an embodiment. As an example, the wire drawing machine 100 will be described as a machine that draws a metal wire having a rectangular cross section (rectangular wire) from a metal wire having a circular cross section (round wire). The metal wire drawn by the wire drawing machine 100 is used for, for example, a reactor or a coil for a drive motor of an electric vehicle.

[0011] 1, the dashed arrows indicate that lubricating oil for wire drawing is supplied to the configuration at the end points of the arrows. In this specification, the horizontal direction is a direction intersecting (orthogonal to) the direction of gravity, and the vertical direction is a direction intersecting (orthogonal to) the horizontal direction.

[0012] 1, the wire drawing machine 100 includes a forming roll 1, a first capstan 2, a wire drawing die 3, a second capstan 4, a detection unit 9, and a control unit 10. A metal wire 20, which is a round wire, is wound around a roll (not shown), and the metal wire 20 is supplied from this roll to the wire drawing machine 100. The metal wire 20 supplied to the wire drawing machine 100 is transported via the forming roll 1, the first capstan 2, the wire drawing die 3, and the second capstan 4.

[0013] In the following explanation, feeding a metal wire into a capstan or die, etc., is called "wire-in," and feeding a metal wire out of a capstan or die, etc., is called "wire-out." When viewed from the wire drawing die 3 as the reference point, the first capstan 2 is the capstan on the wire-in side (upstream). Also, when viewed from the wire drawing die 3 as the reference point, the second capstan 4 is the capstan on the wire-out side (downstream).

[0014] <Forming roll 1> The forming roll 1 forms the cross-sectional shape of the supplied metal wire 20 into a substantially rectangular shape. Specifically, the forming roll 1 has, for example, a pair of rolls arranged vertically and a pair of rolls arranged horizontally. The supplied metal wire 20 is formed by passing through the area (space) sandwiched between the four rolls. That is, the round metal wire 20 supplied from a roll (not shown) is roughly formed by the forming roll 1 so that the cross-section becomes substantially rectangular. The cross-section of the formed metal wire 20 becomes substantially rectangular, but the corners of the rectangular cross-section are significantly rounded.

[0015] When the metal wire 20 passes through the space sandwiched between the four rolls, friction occurs between the forming roll 1 and the metal wire 20. For this reason, lubricating oil is supplied to the surface of the forming roll 1 and the metal wire 20.

[0016] <1st Capstan 2> The first capstan 2 has a pair of rolls 5 and 6 that are driven by a motor (not shown) or the like and rotate in a clockwise direction in FIG. 1. The metal wire 20 formed by the forming roll 1 is wound around the rolls 5 and 6 and then fed to the wire drawing die 3. The first capstan 2 functions as a speed adjustment mechanism that adjusts the speed (transport speed) of the metal wire 20 fed to the wire drawing die 3.

[0017] In the following description, the pair of rolls 5, 6 may be collectively referred to as a capstan. For example, when referring to the surface of a capstan, this surface refers to the surface of each of the rolls 5, 6 that constitute the capstan.

[0018] FIG. 2 is a schematic diagram showing a side view of the first capstan 2, which is a part of the wire drawing machine 100, as viewed from the right side of FIG. 1. FIG. 2 shows the metal wire 20 entering the first capstan 2 from the back side of the page, winding around the first capstan 2, and then exiting to the front side of the page. In FIG. 2, the rotation axes of the rolls 5 and 6 are indicated by dashed lines. Also, in FIG. 2, the traveling direction of the metal wire 20 is indicated by an arrow. In FIG. 2, only the cross section of the metal wire 20 at the point where it exits the first capstan 2 is shown.

[0019] The rolls 5 and 6 are made of metal, for example, with the metal exposed on their surfaces. The surfaces of the metal rolls 5 and 6 may have a metal plating layer. The rolls 5 and 6 are arranged at positions spaced apart from each other in the vertical direction. The metal wire 20 is wound around the spaced apart rolls 5 and 6 so as to go around them. The metal wire 20 is transported by friction between the rolls 5 and 6, which are driven to rotate. In other words, the metal wire 20 is transported by being wound around each of the rolls 5 and 6 of the first capstan 2.

[0020] The metal wire 20 makes about half a turn around each of the roll 5 arranged vertically above and the roll 6 arranged vertically below, and then makes one turn around the pair of rolls 5, 6. When the metal wire 20 is wound multiple times around the first capstan 2 as shown in Fig. 2, the metal wire 20 makes multiple turns in this manner.

[0021] Rolls 5 and 6 are arranged with their rotation axes fixed. The rotation axis of roll 5 is aligned horizontally. The rotation axis of roll 6 is tilted downward at an angle θ relative to the horizontal. The tilt angle of the rotation axis of roll 6 is preferably approximately 3.0° at most, and more preferably greater than 0° and equal to or less than 2.5°.

[0022] Each of the rolls 5 and 6 is rotated at the same speed by a motor. As described above, the rotation axis of the roll 6 is tilted relative to the rotation axis of the roll 5. Therefore, when the metal wire 20 is wound multiple times around the rolls 5 and 6, the metal wire 20 on the first turn and the metal wire 20 on the second turn are spaced apart and do not come into contact with each other. The metal wire 20 wound around the first capstan 2 is fed from the first capstan 2 without coming into contact with itself.

[0023] That is, the metal wire 20 wound multiple times around the first capstan 2 is prevented from tangling with the wound metal wire 20. This allows the metal wire 20 to run smoothly around the first capstan 2 without stress.

[0024] Lubricating oil is supplied to the first capstan 2. That is, the surface of the first capstan 2, which is provided upstream of the wire drawing die 3, is coated with lubricating oil. As described above, the lubricating oil supplied to the metal wire 20 when it passes through the forming roll 1 remains without being removed. In addition, since the surfaces of the rolls 5 and 6 that come into contact with the metal wire 20 are made of metal as described above, the friction between the metal wire 20 and the first capstan 2 is smaller than when the surfaces of the rolls 5 and 6 are made of rubber, for example. Therefore, although the metal wire 20 is wound around the first capstan 2 and transported, slippage always occurs between the first capstan 2 and the metal wire 20.

[0025] For this reason, the metal wire 20 moving between the rolls 5 and 6 is not stretched in a straight line between the surfaces of the rolls 5 and 6, but is bent and bulges outward relative to the region between the rolls 5 and 6. In other words, in the first capstan 2 provided upstream of the wire drawing die 3, the metal wire (wire rod, copper wire) 20 runs around the circumference of the first capstan 2 in a bent state. For this reason, the winding length of the metal wire 20 in this embodiment is longer than the length (winding length) of the metal wire 20 when the metal wire 20 is stretched in a straight line between the surfaces of the rolls 5 and 6 and makes one turn around the circumference of the rolls 5 and 6.

[0026] <Wire drawing die 3> The wire drawing die 3 is, for example, a disk-shaped metal plate. The wire drawing die 3 has a rectangular hole penetrating the metal plate. The metal wire 20 fed from the first capstan 2 passes through this hole. The hole has a structure in which the diagonal length gradually decreases from the surface of the metal plate facing the first capstan 2. Therefore, when the metal wire 20 passes through the wire drawing die 3, it is narrowed by passing through the hole and is drawn thin before being drawn out from the wire drawing die 3. In other words, the wire drawing die 3 stretches the metal wire 20 fed from the first capstan 2. At this time, the cross-sectional shape of the metal wire 20 becomes more rectangular. In other words, the corners of the cross section of the metal wire 20 become less rounded.

[0027] Lubricating oil is supplied to the wire drawing die 3 to reduce friction with the metal wire 20. However, when the metal wire 20 passes through the wire drawing die 3, the lubricating oil is removed from the surface of the metal wire 20.

[0028] <Second Capstan 4> The second capstan 4 is driven by a motor (not shown) or the like and has a pair of rolls 7 and 8 that rotate clockwise in Fig. 1. The metal wire 20 drawn by the wire drawing die 3 is sent from the wire drawing die 3 to the second capstan 4, where it is wound around the second capstan 4 and transported. That is, the metal wire 20 is drawn out of the wire drawing die 3 by the second capstan 4. Note that no lubricating oil is applied to the surface of the second capstan 4 located downstream of the wire drawing die 3.

[0029] The rolls 7 and 8 are made of, for example, metal. The surfaces of the rolls 7 and 8 are covered with a film made of a material, such as rubber, that has higher friction than metal. The rolls 7 and 8 are arranged at positions spaced apart from each other in the vertical direction. The metal wire 20 is wound around the rolls 7 and 8 that are spaced apart from each other. The metal wire 20 is transported by friction between the rolls 7 and 8 that are driven to rotate. In other words, the metal wire 20 sent from the wire drawing die 3 is transported by being wound around each of the rolls 7 and 8 of the second capstan 4.

[0030] The metal wire 20 makes about half a turn around each of the rolls 7, 8, which are arranged vertically above the roll 7, and below the roll 8, and then makes one turn around the pair of rolls 7, 8. As in the case of the first capstan 2 shown in Figure 2, if the metal wire 20 is wound multiple times around the second capstan 4, the metal wire 20 will make multiple such turns.

[0031] 2, the rotation axis of roll 7 is horizontal, and the rotation axis of roll 8 is tilted downward at an angle θ with respect to the horizontal. Rolls 7 and 8 are arranged with the positions of their rotation axes fixed.

[0032] As with roll 6, the inclination of the rotation axis of roll 8 is preferably at an angle θ of up to about 3.0°, and more preferably at an angle θ greater than 0° and equal to or less than 2.5°. The inclination of the rotation axis of roll 8 may be the same as or different from the inclination of the rotation axis of roll 6. Furthermore, the rotation axes of rolls 6 and 8 are not limited to those inclined downward at an angle θ with respect to the horizontal direction. The rotation axes of rolls 6 and 8 may be inclined at an angle θ in a direction parallel to the horizontal direction (toward the viewer in FIG. 2), for example.

[0033] Each of the rolls 7 and 8 is rotated at the same speed by a motor. As described above, the rotation axis of the roll 8 is tilted relative to the rotation axis of the roll 7. Therefore, when the metal wire 20 is wound multiple times around the rolls 7 and 8, the metal wire 20 on the first turn and the metal wire 20 on the second turn are spaced apart and do not come into contact with each other. The metal wire 20 wound around the second capstan 4 is fed out from the second capstan 4 without coming into contact with itself. The metal wire 20 fed out from the second capstan 4 is then wound around a roll, for example, or proceeds to the next process (for example, a coating process to form an enameled wire).

[0034] 1, the metal wire 20 moving between the rolls 7 and 8 is stretched in a straight line between the rolls 7 and 8 and is not bent. In other words, at the second capstan 4 provided downstream of the wire drawing die 3, the metal wire (wire rod, copper wire) 20 runs around the circumference of the second capstan 4 in an unbent state.

[0035] This is because the lubricating oil is removed from the metal wire 20 fed to the second capstan 4 when it passes through the wire drawing die 3, and because no lubricating oil is supplied to the second capstan 4. Furthermore, the coefficient of friction between the material (rubber) that constitutes the surface of the second capstan 4 and the metal wire 20 is smaller than the coefficient of friction between the material (metal) that constitutes the surface of the first capstan 2 and the metal wire 20. In other words, the metal wire 20 slips on the first capstan 2, but does not slip on the second capstan 4. The coefficient of friction between the material and the metal wire 20 refers to the static coefficient of friction in the absence of lubricating oil.

[0036] The static friction coefficients include a first friction coefficient between the first capstan 2 and the metal wire 20, and a second friction coefficient between the second capstan 4 and the metal wire 20. One method for measuring the first friction coefficient is to place the metal wire on the surface of the first capstan 2, and then feed the metal wire at a constant speed while applying a constant load Fp to the metal wire in the normal direction to the metal wire. This determines the maximum load Fs when the metal wire begins to slide on the surface of the first capstan 2. The first friction coefficient is then calculated as the ratio of the maximum load Fs to the load Fp.

[0037] The second coefficient of friction can be measured, for example, by placing a metal wire on the surface of the second capstan 4 and feeding the wire at a constant speed while applying a constant load Fp to the wire in the normal direction to the wire. This determines the maximum load Fs when the metal wire begins to slide on the surface of the second capstan 4. The second coefficient of friction is then calculated from the ratio of the maximum load Fs to the load Fp.

[0038] <Detection unit 9> The detection unit 9 is disposed between the first capstan 2 and the wire drawing die 3. As shown in FIG. 1, the detection unit 9 has a rod 51, a support 52, an angle detector 53, and a weight 54.

[0039] The rod 51 is a rod-shaped member, and is supported by a rotation shaft 510 so as to be rotatable in the R1 direction or the R2 direction shown in Fig. 1. The position of the rotation shaft 510 may be configured to be changeable along the direction in which the rod 51 extends.

[0040] The support part 52 is provided at one end of the rod 51. The support part 52 is, for example, a roller, and is rotatably supported on the rod 51 by a rotation shaft 520. The support part 52 supports the metal wire 20 fed from the first capstan 2 from below. At this time, the support part 52 rotates around the rotation shaft 520, thereby supporting the metal wire 20 without interfering with its movement toward the wire drawing die 3.

[0041] The weight 54 is detachably attached to the other end of the rod 51. The support load of the support part 52 that supports the metal wire 20 facing upward is adjusted by attaching or detaching the weight 54 and adjusting the distance from the rotation shaft 510. The support load of the support part 52 is preferably adjusted to, for example, about several grams, so that the metal wire 20 is slightly lifted by the support part 52.

[0042] Because the support load of the support unit 52 is adjusted as described above, the rod 51 rotates in the R1 direction or the R2 direction in response to the deflection of the metal wire 20 fed from the first capstan 2, as will be described in detail later. The angle detector 53 is, for example, a rotary sensor or a rotary encoder, and is disposed near the rotation axis 510. The angle detector 53 detects the rotation angle of the rod 51 around the rotation axis 510, converts it into an electric signal (angle signal), and outputs it to the control unit 10, which will be described later. In other words, the detection unit 9 detects the deflection of the metal wire 20 fed from the first capstan 2.

[0043] <Control unit 10> The control unit 10 is a calculation device having, for example, a CPU, a memory, etc. The control unit 10 controls the operation of each unit of the wire drawing machine 100 based on the calculation results. As will be described in detail later, the control unit 10 controls the speed (conveying speed) of the metal wire 20 coming out of the first capstan 2 and the speed (conveying speed) of the metal wire 20 coming out of the second capstan 4 so that they become preset set values. Furthermore, as will be described in detail later, the control unit 10 controls the conveying speed of the metal wire 20 coming out of the first capstan 2 based on an electric signal (angle signal) output from an angle detector 53 of the detection unit 9.

[0044] <Control of the conveying speed of the metal wire 20> The metal wire 20 is drawn thinner and longer after passing through the wire drawing dies 3 than before passing through the wire drawing dies 3. For this reason, the speed at which the metal wire 20 is transported (transport speed) after being drawn out of the wire drawing dies 3 is faster than the speed at which the metal wire 20 is transported (transport speed) before entering the wire drawing dies 3. In other words, the length of the metal wire 20 transported per unit time after being drawn out of the wire drawing dies 3 is greater than the length of the metal wire 20 transported per unit time before entering the wire drawing dies 3.

[0045] Specifically, when the area reduction rate of the metal wire 20 through the wire drawing die 3 is 20%, the conveying speed of the metal wire 20 coming out of the wire drawing die 3 is 10 m / min, and the conveying speed of the metal wire 20 entering the wire drawing die 3 is 8 to 9 m / min. The conveying speed of the metal wire 20 may be, for example, several hundred meters to several thousand meters per minute.

[0046] The area reduction rate is the rate at which the cross-sectional area of ​​the metal wire 20 exiting the wire drawing die 3 decreases relative to the cross-sectional area of ​​the metal wire 20 before entering the wire drawing die 3. For example, if the cross-sectional area of ​​the metal wire 20 is reduced to 80% by being stretched by the wire drawing die 3, the area reduction rate before and after passing through the wire drawing die 3 is 20%.

[0047] In this embodiment, as described above, lubricating oil is supplied to the first capstan 2, reducing friction on the surface of the first capstan 2. As a result, the metal wire 20 slips on the first capstan 2. This makes it possible to feed the metal wire 20 to the wire drawing die 3 at a constant speed.

[0048] However, the transport speed of the metal wire 20 entering the wire drawing die 3 may fluctuate due to a slight change in slippage on the first capstan 2 or the metal wire 20 getting caught as it enters the wire drawing die 3. Even in such cases, the metal wire 20 is bent on the first capstan 2, so the amount of wire stored on the first capstan 2 is automatically adjusted. This makes it possible to stabilize the transport speed of the metal wire 20 sent from the first capstan 2 to the wire drawing die 3.

[0049] The stored wire amount is the length of the metal wire 20 wound around the first capstan 2 or the second capstan 4 when the wire drawing machine 100 is in operation. In other words, the stored wire amount is the length of the metal wire 20 stored around the first capstan 2 or the second capstan 4.

[0050] When the conveying speed of the metal wire 20 on the inlet side of the wire drawing die 3 decreases, the deflection of the metal wire 20 between the rolls 5 and 6 automatically decreases. That is, the deflection of the metal wire 20 is displaced in the direction of R3 shown in FIG. 1. As a result, the amount of wire stored in the metal wire 20 decreases, and the speed of the metal wire 20 increases. That is, the conveying speed of the metal wire 20 becomes the desired speed.

[0051] Furthermore, when the speed of the metal wire 20 on the inlet side relative to the wire drawing die 3 increases, the deflection of the metal wire 20 between the rolls 5 and 6 automatically increases. That is, the deflection of the metal wire 20 is displaced in the direction R4 shown in FIG. 1. As a result, the amount of wire stored in the metal wire 20 increases and the speed of the metal wire 20 decreases. That is, the conveying speed of the metal wire 20 becomes the desired speed.

[0052] In order to suppress fluctuations in the transport speed of the metal wire 20 on the inlet side relative to the wire drawing die 3 as described above, in this embodiment, a lower limit of the transport speed of the metal wire 20 on the inlet side is set (determined) depending on the area reduction rate of the metal wire 20 by the wire drawing die 3. When the area reduction rate by the wire drawing die 3 is 20%, the relationship between the cross-sectional area S1 before the area reduction by the wire drawing die 3 and the cross-sectional area S2 after the area reduction by the wire drawing die 3 is expressed as S1×0.8=S2. Furthermore, the volume V1 of the metal wire 20 before the area reduction and the volume V2 of the metal wire 20 after the area reduction are expressed as V1=V2. Furthermore, the length H1 of the metal wire 20 before the area reduction and the length of the metal wire 20 after the area reduction are expressed as H1=H2×0.8. Here, the relationship between the transport speed Ve1 of the metal wire 20 coming out of the first capstan 2 and the transport speed Ve2 of the metal wire 20 coming out of the second capstan 4 is expressed as Ve2>Ve1≧Ve2×0.8.

[0053] In this embodiment, the relationship between the transport speed of the metal wire 20 on the entry side (upstream) of the wire drawing die 3 and the transport speed of the metal wire 20 on the delivery side (downstream) of the wire drawing die 3 is set according to the area reduction rate. Specifically, the lower limit of the transport speed of the metal wire 20 on the delivery side of the wire drawing die 3 is set (determined) based on the transport speed of the metal wire 20 on the delivery side of the wire drawing die 3, that is, the required wire drawing production speed.

[0054] In other words, the ratio of the conveying speed Ve1 of the metal wire 20 conveyed between the first capstan 2 and the wire drawing die 3 to the conveying speed Ve2 of the metal wire 20 fed from the second capstan 4 is equal to or greater than the ratio of the cross-sectional area S2 to the cross-sectional area S1. This is expressed by the following equation 1.

[0055] Ve1 / Ve2≧S2 / S1 (Formula 1) Here, it is also conceivable to set the conveying speeds on the entry side and exit side of the wire drawing die 3 to speeds that completely correspond to the area reduction rate. In other words, when the cross-sectional area of ​​the metal wire 20 becomes 4 / 5 after wire drawing, it would seem that stable wire drawing would be possible if the value of the conveying speed Ve1 was set to the product of the conveying speed Ve2 and 5 / 4, which is the reciprocal of 4 / 5. However, in reality, since minute speed changes of the metal wire 20 can occur at each capstan and wire drawing die 3, etc., in order to prevent breakage of the metal wire 20, it may not be possible to set the conveying speeds on the entry side and exit side of the wire drawing die 3 to speeds that completely correspond to the area reduction rate.

[0056] Therefore, for example, in the case where the area reduction rate is 20% and the conveying speed Ve2 on the outlet side is 10 m / min, the lower limit of the conveying speed Ve1 on the inlet side is set to 8 m / min, and in practice, the conveying speed Ve1 is set to, for example, 9.0 m / min to operate the wire drawing machine 100. Specifically, the set value of the conveying speed Ve2 is set to 10 m / min. As a result, the actual measured value of the conveying speed of the metal wire 20 coming out of the second capstan 4 is approximately 10 m / min. Furthermore, the set value of the conveying speed Ve1 is set to 9.0 m / min. As a result, the actual measured value of the speed of the metal wire 20 coming out of the first capstan 2 is approximately 9.0 m / min, although there is some fluctuation. Because the area of ​​the metal wire 20 is reduced by wire drawing and the conveying speed Ve2 becomes faster than the conveying speed Ve1, the upper limit of the conveying speed Ve1 is less than the conveying speed Ve2.

[0057] The control unit 10 rotates the rolls 5 and 6 at a rotational speed corresponding to the conveying speed Ve1 set as described above. Similarly, the control unit 10 rotates the rolls 7 and 8 at a rotational speed corresponding to the conveying speed Ve2 set as described above. In this case, the control unit 10 rotates the rolls 5 and 6 slower than the rolls 7 and 8. When the wire drawing die 3 is replaced with one having a different area reduction rate or a different cross-sectional shape of the metal wire, the settings of the rotational speeds of the rolls 5 and 6 and the rolls 7 and 8 can be changed accordingly.

[0058] The conveying speed Ve1 set as described above may fluctuate excessively with respect to the deflection of the metal wire 20 on the first capstan 2. This is presumably due to changes in the ambient environment of the wire drawing machine 100, such as temperature and humidity throughout the year, changing the degree of slippage of the metal wire 20 relative to the first capstan 2, causing excessive fluctuations in the deflection of the metal wire 20. If the deflection increases excessively, the metal wire 20 may fall off the first capstan 2. If the deflection decreases excessively and disappears, the tension in the metal wire 20 may increase, causing the metal wire 20 to break. If the metal wire 20 falls off or breaks, this may lead to an interruption in the production of the metal wire 20. To prevent the occurrence of such problems, the control unit 10 performs control (adjustment control) to adjust the conveying speed Ve1 of the metal wire 20 coming out of the first capstan 2 based on the detection results of the detection unit 9. The adjustment control will be described in detail below.

[0059] <Adjustment control of conveying speed Ve1> 3 is a diagram schematically illustrating a case where the deflection of the metal wire 20 at the first capstan 2 and the deflection of the metal wire 20 coming out of the first capstan 2 fluctuate in the wire drawing machine 100 shown in FIG. 1. In the following description, the state of the wire drawing machine 100 when the conveying speed Ve1 of the metal wire 20 coming out of the first capstan 2 is the above-mentioned set value is referred to as the normal state.

[0060] When the wire drawing machine 100 is operating normally, as described above, the metal wire 20 is bent at the first capstan 2. The amount of bending of the metal wire 20 at the first capstan 2 at this time is called the reference amount of bending. The metal wire 20 coming out of the first capstan 2 is supported by the support part 52 of the detection part 9 and transported in a bent state.

[0061] If the slippage between the first capstan 2 and the metal wire 20 is large, the transport speed Ve1 of the metal wire 20 on the inlet side relative to the wire drawing die 3 drops excessively, and the deflection of the metal wire 20 between the rolls 5 and 6 automatically becomes smaller than the standard deflection amount. In other words, the deflection of the metal wire 20 at the first capstan 2 is displaced in the direction R3 shown in FIG.

[0062] As the deflection of the metal wire 20 at the first capstan 2 fluctuates, the amount by which the metal wire 20 drawn out from the first capstan 2 deflects between the first capstan 2 and the wire drawing die 3 also fluctuates. In this case, the deflection of the metal wire 20 drawn out from the first capstan 2 becomes smaller, and the metal wire 20 is displaced in the direction R5 (downward) in FIG. 3.

[0063] As described above, the support part 52 of the detection unit 9 supports the metal wire 20 upward with a load of about several grams. Therefore, when the metal wire 20 is displaced in the R5 direction, the support part 52 also displaces downward following the metal wire 20. In other words, the rod 51 rotates in the R1 direction. The angle detector 53 detects this rotation of the rod 51 and outputs it to the control unit 10 as an angle signal.

[0064] Based on the input angle signal, the control unit 10 adjusts the conveying speed Ve1 of the metal wire 20 coming out from the first capstan 2. Specifically, the control unit 10 calculates the difference between the angle of the rod 51 indicated by the input angle signal and the angle of the rod 51 under normal conditions. If the calculated difference exceeds a predetermined threshold, the control unit 10 determines that the deflection of the metal wire 20 is smaller than the reference deflection amount and that the conveying speed Ve1 of the metal wire 20 has excessively decreased.

[0065] In this case, the control unit 10 increases the conveying speed Ve1 of the metal wire 20 coming out of the first capstan 2 above the set value of 9.0 m / min. For example, the control unit 10 sets the conveying speed Ve1 to 9.5 m / min. In this case, the control unit 10 increases the rotational speed of the rolls 5 and 6 of the first capstan 2. The amount of increase in the rotational speed of the rolls 5 and 6 may be a predetermined value, or may be a value that changes depending on the difference between the angle detected by the angle detector 53 and the normal angle.

[0066] As described above, the control unit 10 controls (adjusts) the conveying speed Ve1 of the metal wire 20 fed to the wire drawing die 3 based on the deflection of the metal wire 20 detected by the detection unit 9. Specifically, the control unit 10 increases the conveying speed Ve1 when the deflection of the metal wire 20 detected by the detection unit 9 is smaller than the reference deflection amount. As a result, the metal wire 20 enters the wire drawing die 3 with the conveying speed Ve1 increased, thereby preventing defects such as breakage due to excessive tension acting on the metal wire 20.

[0067] On the other hand, if the slippage between the first capstan 2 and the metal wire 20 is small, the transport speed Ve1 of the metal wire 20 on the inlet side relative to the wire drawing die 3 increases excessively, and the deflection of the metal wire 20 between the rolls 5 and 6 automatically becomes larger than the standard deflection amount. As a result, the deflection of the metal wire 20 at the first capstan 2 displaces in the direction R4 shown in Figure 3. In this case, the deflection of the metal wire 20 between the first capstan 2 and the wire drawing die 3 also increases, and it displaces in the direction R6 (upward) in Figure 3.

[0068] When the metal wire 20 is displaced in the R6 direction, the support part 52 is also displaced upward following the metal wire 20. That is, the rod 51 rotates in the R2 direction. The angle detector 53 detects this rotation of the rod 51 and outputs it as an angle signal to the control unit 10. As in the case described above, the control unit 10 calculates the difference between the angle of the rod 51 indicated by the input angle signal and the angle of the rod 51 under normal conditions. If the calculated difference exceeds a predetermined threshold, the control unit 10 determines that the deflection of the metal wire 20 is greater than the reference deflection amount and that the conveying speed Ve1 of the metal wire 20 has increased excessively.

[0069] In this case, the control unit 10 reduces the conveying speed Ve1 of the metal wire 20 coming out of the first capstan 2 from the set value of 9.0 m / min to, for example, 8.5 m / min. In this case, the control unit 10 reduces the rotational speed of the rolls 5 and 6 of the first capstan 2. The amount of reduction in the rotational speed of the rolls 5 and 6 may be a predetermined value, or may be a value that changes depending on the difference between the angle detected by the angle detector 53 and the normal angle.

[0070] As described above, the control unit 10 controls (adjusts) the conveying speed Ve1 of the metal wire 20 fed to the wire drawing die 3 based on the detection result by the detection unit 9. Specifically, the control unit 10 reduces the conveying speed Ve1 when the deflection of the metal wire 20 at the first capstan 2 is greater than the reference deflection based on the deflection amount of the metal wire 20 detected by the detection unit 9. As a result, the metal wire 20 enters the wire drawing die 3 with the conveying speed Ve1 reduced, and therefore the deflection of the metal wire 20 at the first capstan 2 increases excessively, thereby preventing problems such as the metal wire 20 falling off the first capstan 2.

[0071] As described above, the wire drawing machine 100 increases the conveying speed Ve1 when the deflection of the metal wire 20 is smaller than the reference deflection amount based on the detection result by the detection unit 9, and decreases the conveying speed Ve1 when the deflection of the metal wire 20 is larger than the reference deflection amount. In other words, it is possible to provide a wire drawing machine 100 that detects the deflection of the metal wire 20 and automatically adjusts the conveying speed Ve1 of the metal wire 20.

[0072] According to the above-described embodiment, at least one of the following advantageous effects can be obtained.

[0073] (1) The wire drawing machine 100 is provided with a detection unit 9 that is provided between the first capstan 2 and the wire drawing die 3 and detects the deflection of the metal wire 20 fed from the first capstan 2. This eliminates the need for an operator to monitor the deflection of the metal wire 20, thereby reducing the number of steps required to manufacture the metal wire 20.

[0074] As described above, as the deflection of the metal wire 20 at the first capstan 2 changes in the R3 or R4 direction, the deflection of the metal wire 20 emerging from the first capstan 2 also changes in the R5 or R6 direction. When a sensor is disposed near the first capstan 2 to detect the displacement of the deflection of the metal wire 20 in the R3 or R4 direction, accurate detection is difficult due to the influence of, for example, the splashing of lubricating oil supplied to the first capstan 2. Furthermore, labor such as maintenance of the sensor that has been splashed with lubricating oil is required. In contrast, in this embodiment, the detection unit 9 detects the deflection of the metal wire 20 at a position away from the first capstan 2, so the influence of, for example, the lubricating oil is small, and a decrease in detection accuracy is suppressed. Furthermore, the labor required for maintenance of the detection unit 9, as in the case of disposing the sensor near the first capstan 2, can be suppressed.

[0075] (2) The wire drawing machine 100 includes a control unit 10 that controls the conveying speed Ve1 of the metal wire 20 fed to the wire drawing die 3 based on the detection result by the detection unit 9. This allows the conveying speed Ve1 to be automatically adjusted even when the deflection of the metal wire 20 fluctuates excessively due to a change in the surrounding environment of the wire drawing machine 100, which changes the degree of slippage of the metal wire 20 relative to the first capstan 2. This prevents malfunctions such as the metal wire 20 falling off the first capstan 2 or the metal wire 20 being broken while being conveyed to the wire drawing die 3. As a result, the stoppage of production of the metal wire 20 due to malfunctions is prevented. Furthermore, since an operator does not need to monitor the deflection of the metal wire 20 and adjust the conveying speed Ve1, the number of steps required to manufacture the metal wire 20 can be reduced.

[0076] (3) The detection unit 9 includes a rod 51 rotatably supported by a rotation shaft 510, a support unit 52 provided at one end of the rod 51 and supporting the metal wire 20, and an angle detector 53 that detects the rotation angle of the rod 51. The rod 51 rotates in response to changes in the deflection of the metal wire 20 supported by the support unit 52 in the R5 direction or the R6 direction. This makes it possible to detect the deflection of the metal wire 20 with a simple structure, thereby keeping the equipment costs of the wire drawing machine 100 low.

[0077] (4) Based on the detection result by the detection unit 9, the control unit 10 increases the conveying speed Ve1 when the deflection of the metal wire 20 at the first capstan 2 is smaller than a reference deflection amount. Based on the deflection of the metal wire 20 detected by the detection unit 9, the control unit 10 decreases the conveying speed Ve1 when the deflection of the metal wire 20 at the first capstan 2 is larger than the reference deflection amount. This makes it possible to automatically set the conveying speed Ve1 to a desired speed without relying on monitoring or adjustment by an operator.

[0078] (5) A weight 54 is detachably provided on the other end of the rod 51 to adjust the load when the support part 52 supports the metal wire 20. This prevents the detection part 9 from applying an excessive load to the metal wire 20, allowing the rod 51 to rotate in response to the bending of the metal wire 20. This allows the detection part 9 to accurately detect the bending of the metal wire 20.

[0079] Although various embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and includes various modified examples. Furthermore, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, numerical values ​​and the like included in the text and figures are merely examples, and the effects of the present invention will not be impaired even if different values ​​are used.

[0080] For example, the wire drawing machine 100 is not limited to drawing a rectangular wire. The cross-sectional shape of the metal wire 20 after drawing by the wire drawing machine 100 may be any shape. For example, the cross-sectional shape of the drawn metal wire 20 may be circular.

[0081] Furthermore, the wire drawing machine 100 does not necessarily have to include the control unit 10. In this case, when the detection unit 9 detects a change in the deflection of the metal wire 20, it may issue a warning to the worker by a warning unit, such as a sound or lighting a lamp, indicating that the deflection has changed. Then, upon recognizing the warning, the worker may manually adjust the conveying speed Ve1 of the metal wire 20. [Explanation of symbols]

[0082] 1 forming roll, 2 first capstan, 3 wire drawing die, 4 second capstan, 9 detection unit, 10 control unit, 20 metal wire, 51 rod, 52 support unit, 53 angle detector, 54 weight, 100 wire drawing machine

Claims

1. a first capstan for conveying the metal wire; a wire drawing die for drawing the metal wire fed from the first capstan; a second capstan for conveying the metal wire fed from the wire drawing die; a detection unit provided between the first capstan and the wire drawing die, which detects deflection of the metal wire fed from the first capstan.

2. The wire drawing machine according to claim 1, A wire drawing machine comprising: a control unit that controls a conveying speed of the metal wire to be fed to the wire drawing die based on a detection result by the detection unit.

3. The wire drawing machine according to claim 2, the detection unit includes a rod rotatably supported by a rotation shaft, a support unit provided at one end of the rod and supporting the metal wire, and an angle detector that detects a rotation angle of the rod, The rod rotates in accordance with the deflection of the metal wire supported by the support portion.

4. The wire drawing machine according to claim 3, the first capstan conveys the metal wire in a bent state; The control unit increases the conveying speed when the deflection of the metal wire at the first capstan is smaller than a reference deflection amount based on the detection result by the detection unit, and decreases the conveying speed when the deflection of the metal wire at the first capstan is larger than the reference deflection amount.

5. The wire drawing machine according to claim 4, A weight is detachably provided on the other end of the rod to adjust the load when the support portion supports the metal wire.

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