JP2011191201A - Method and device for evaluating slidability of steel wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for evaluating slidability of a steel wire, capable of evaluating easily on the field before using a wire-twisting machine, slidability of the steel wire before twisting the wire after a final wire drawing process. <P>SOLUTION: In the method for evaluating slidability of the steel wire, one end of the steel wire 1 wound on a spool 2 is drawn out from the spool 2, and wound again around the spool 2 through a weight 20, and then the steel wire 1 is fitted to a measuring means 12 to measure a resistance when being pulled through the measuring means 12, and the resistance is used as an index of the slidability of the steel wire 1. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for evaluating the slipperiness of a steel wire and a slippery evaluation device (hereinafter also referred to as “evaluation method” and “evaluation device”), and more particularly for the production of steel cords as reinforcing materials for various rubber articles. The present invention relates to a slip property evaluation method and a slip property evaluation apparatus for steel wires used.

  Steel cords used for reinforcing materials for various rubber articles such as tires are generally obtained by sequentially performing the steps of primary wire drawing, primary heat treatment, secondary wire drawing, secondary heat treatment, plating and final wire drawing. It is manufactured by appropriately twisting a plurality of steel wires. In the production of a steel cord having such a twisted structure, the twist property is an important management item.

  The stranded wire of the cord is usually performed by unwinding and twisting a predetermined number of steel strands through a guide while applying a predetermined tension (tension) in a twisting machine. At this time, if the tension of the strands fluctuates at the sliding portion with the guide and the tension varies between the strands, the desired twisting property may not be obtained or the twisting property of the twisted cord may deteriorate. And quality will deteriorate. Therefore, in order to obtain a desired twist property with high quality, it is important to reduce the resistance of the steel wire at the sliding portion with the guide and to equalize the tension of each wire to a predetermined value. .

  Means for reducing the resistance of the strands at the guide portion include improving the lubricity of the guides or steel strands. Among these, what is important when considering the improvement of lubricity on the steel strand side is the slip property of the steel strand after the final wire drawing and before the stranded wire. In this regard, when a buncher type is used as the stranding machine, a method of adjusting the slipperiness of the strand by applying oil to the strand is considered. When twisting using a machine, the oil coating method is difficult to apply because of its structure, which is problematic.

  On the other hand, for example, a method is known in which the tension of each strand is set to be low and the variation in the tension of each strand during twisting due to the variation in the slipperiness of the strand is suppressed (for example, Patent Documents). 1).

JP 2006-152527 A (paragraph [0008] etc.)

  As described above, especially when twisting is performed using a tubular type twisting machine, additional slipperiness cannot be adjusted by oil application. It becomes an important factor that determines the quality of the twist property. Further, even in the buncher type twisted wire machine, there is a problem that additional application of oil leads to an increase in cost. Therefore, it can be said that it is preferable if the slipperiness of the steel wire itself can be reliably evaluated.

  However, conventionally, there is no means for accurately grasping the slip property before placing the strand on the stranding machine, and after the strand is placed on the stranding machine in the twisting process, For the first time, twist properties were known. Therefore, it has been desired to establish a technique for evaluating the slip property of a steel wire before setting it to a twisting machine and predicting the twist property of the steel cord finally obtained.

  Therefore, an object of the present invention is to provide a slip property of a steel wire that can be easily evaluated in the field after the final wire drawing step and before the twisted wire machine before the twisted wire machine. An object is to provide an evaluation method and a slip evaluation device.

  As a result of diligent study, the present inventor has drawn out the wire from the spool with respect to the steel wire that has been wound on the spool after the final wire drawing step, and the surface of the wire that has been drawn out and the wire wound on the spool. The present invention has been completed by finding that the above problem can be solved by using a method of detecting resistance when the strands are rubbed together as a slippage index.

  That is, in the method for evaluating the slipperiness of the steel wire of the present invention, one end of the steel wire wound around the spool is pulled out from the spool, wound around the spool again through the weight, and then attached to the measuring means. The resistance at the time of pulling through the measuring means is measured, and the resistance is used as an index of the slipperiness of the steel element wire.

  In the evaluation method of the present invention, it is preferable to use a spring balance or a load cell as the measuring means. The resistance can be detected as a load.

  Further, the slip evaluation apparatus for steel wire according to the present invention includes a holding portion for holding a spool around which the steel wire is wound, and an interval in the direction perpendicular to the spool axial direction with respect to the holding portion. The measuring means is arranged, and driving means for pulling the measuring means from the holding portion in a direction perpendicular to the spool axis direction.

  In the evaluation apparatus of the present invention, it is preferable that the measuring means is a spring balance or a load cell. As the driving means, a manual or motor can be used preferably.

  According to the present invention, it is possible to easily measure and evaluate the slip property of the steel element wire before the stranded wire after the final wire drawing process on site before setting to the stranded wire machine. At the time after the wire process, it becomes possible to predict the twist properties in the next twist process. Therefore, this makes it possible to prevent the steel wire having poor slip properties from being sent to the next process, to prevent the twisting property of the cord from being deteriorated, and to improve the productivity of the steel cord.

It is a schematic explanatory drawing which shows an example of the slipperiness evaluation apparatus of the steel strand of this invention. It is a schematic explanatory drawing which shows the winding state around the spool of the steel strand in this invention. It is a graph which shows the measurement result of the slip value of each steel strand in an example. (A)-(D) is a graph which shows the measurement result of the twisted wire tension of each steel strand in an Example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, the schematic explanatory drawing of an example of the slip property evaluation apparatus of the steel strand of this invention is shown. The evaluation device 10 shown in the figure includes a holding unit 11 that holds a spool 2 around which a steel wire 1 is wound, and a measuring unit 12 that is arranged with respect to the holding unit 11 at an interval in a direction perpendicular to the spool axial direction. And a driving means 13 for pulling the measuring means 12 from the holding portion 11 in a direction orthogonal to the spool axis direction.

  In the present invention, as shown in FIG. 2, first, one end of the steel wire 1 wound around the spool 2 is pulled out from the spool 2 and wound around the spool 2 again via the weight 20. Thereafter, one end of the wound steel wire 1 is further attached to the measuring means 12 as shown in FIG. 1 and the resistance when this is pulled through the measuring means 12 is measured. This is an index of the slipperiness of the wire 1.

  As shown in the figure, when the steel wire 1 is wound around the spool 2 as shown in the drawing, the resistance measured is as follows: (weight of weight 20/2) + (elements of one turn of the spool) This parameter reflects the frictional force. Therefore, when the weight of the weight 20 is set to a constant value and the spool 2 having the same diameter is used, the frictional force between the steel strands, that is, the slipperiness of the strands is evaluated numerically by the resistance. Is possible. Specifically, if the upper limit value to be satisfied by the resistance value (slip value) is determined from the relationship between the tension value of the strands at the time of stranded wire and the state of occurrence of defects, it can be used as an index of slipperiness. Good. Here, the amount of winding of the steel wire 1 around the spool 2 is not limited to one round, but may be any number of rounds, but it is preferable that it is only one round for convenience of work.

  According to the present invention, since it is possible to quantify the slipperiness of steel strands, it is possible to clarify the evaluation criteria for slipperiness that easily causes variations in the sensory evaluation of the operator. It is possible to more reliably prevent bad strands from flowing out and effectively suppress the occurrence of a twisting property failure of the cord. In practice, for example, when the steel strand is manufactured, it is conceivable to periodically perform the above slip evaluation at intervals of several days.

  In addition, according to the present invention, not only the effect of preventing the occurrence of poor twisting properties of the cord can be obtained, but the index can also be used as a standard for equipment evaluation in the wire drawing process in the production of steel strands. Is possible. In other words, in the wet wire drawing process, which is a process during the manufacture of steel wire, a steel wire having a predetermined small diameter is obtained by drawing a large diameter steel wire through a die in a lubricant. However, the smoothness of the surface of the obtained steel wire changes depending on the deterioration of the lubricant and the wear state of the die. If the smoothness of the surface of the steel wire deteriorates, the slipperiness also deteriorates. Therefore, it is important to manage the lubricant and the die in a good state. In other words, by evaluating the slipperiness of the strands, it is possible to evaluate the condition of the lubricant and the die in the wire drawing process reflected in the slipperiness. By exchanging the agent and the die, it is possible to prevent the occurrence of a steel wire having poor slip properties.

  In the present invention, as long as slip properties are evaluated using the above-described apparatus or method, the detailed conditions can be appropriately set, and are not particularly limited.

  In the evaluation apparatus 10 shown in FIG. 1, the holding unit 11, the measuring unit 12, and the driving unit 13 are installed on a support column 15 fixed on a pedestal 14, and the measuring unit 2 is connected via two pulleys 16. Although it is pulled upward, the evaluation apparatus of the present invention is not limited to this, and if the holding unit 11, the measuring unit 12, and the driving unit 13 are provided, for example, the steel strand 1 The pulling direction may be the horizontal direction (not shown). In the illustrated example, the wheel 17 is attached to the pedestal 14 and the device is formed to be movable. However, this is not essential and may be a fixed device. Furthermore, when the apparatus is movable, a handle for movement may be provided, although not shown.

  The holding part 11 may be any spool having a load resistance sufficient to hold the spool 2 in which the steel wire 1 has been wound, in particular, the fully wound spool 2. Although there is no particular restriction, in the fully wound state, the spool 2 is extremely heavy, and thus does not necessarily have a fixing means. The installation height of the holding unit 11 is not particularly limited in evaluating the slipperiness, but is preferably about the height of an adult male's waist for convenience in work.

  As shown in the figure, the measuring means 12 is arranged with a space in the direction in which the steel wire 1 is pulled out with respect to the spool 2 and is held by a holder 18 provided on the support column 15 so as to be movable in this pulling direction. Is formed. The measuring means 12 may be any means as long as it can pull the steel wire 1 in the pulling direction with the steel wire 1 drawn out from the spool 2 attached. May be connected by a wire rod or the like and pulled by the drive means 13, or may be integrated with the drive means 13 and move in the pull-out direction (not shown). Specifically, for example, a spring balance or a load cell can be suitably used as the measuring means 12. When a spring balance or a load cell is used as a measuring means, the resistance as a slippage index can be detected as a load. For example, an average value of a load when a certain length is pulled is taken, and this average value is used. A technique for evaluating slipperiness can be used.

  Any drive means 13 may be used as long as it can pull the measurement means 12 in the pulling direction of the steel strand 1. Specifically, for example, manual operation or a motor can be used. In the case of manual operation, in addition to the method of directly pulling the measuring means 2 or the wire connected thereto, a method of indirectly pulling by arranging a reel or the like is used. Can do.

  In addition, as the weight 20 suspended from the steel wire 1, a load having an appropriate load may be used in consideration of work convenience, and there is no particular limitation. For example, a weight of about several tens g to several hundred g is used. Can be used.

Hereinafter, the present invention will be described in more detail with reference to examples.
Using the evaluation apparatus shown in FIG. 1, the slipperiness evaluation of the steel strand was performed. As the apparatus conditions, a mechanism for holding the spool 2 via the shaft hole of the spool 2 is used as the holding unit 11, a spring balance (weighing: 500 g, minimum scale: 10 g) is used as the measuring means 12, and the drive member 13 is A manual reel that pulls and moves the measuring means by winding the wire connecting the measuring means 12 and the driving means 13 was used. Further, the distance from the holding unit 11 to the measuring means 12 was about 200 mm.

  As a specific evaluation method, first, as shown in FIG. 2, after pulling out one end of the steel strand 1 from the fully wound spool 2 and winding it once around the spool 2 again through a weight 20 of 100 g. Attached to the spring balance 12. Next, the reel 13 is manually wound, and the average value of the displayed load of the spring balance 12 when the steel wire 1 is pulled 400 mm through the spring balance 12 is read, and this is used as a slip index (slip value). did.

  For 4 types of fully wound spools with different strand manufacturing conditions (wire diameter of the strand: 0.3 mm, each referred to as “steel strands A to D”), the slip value was measured for each two according to the above procedure. The results are shown in the graph of FIG. Moreover, the result of having measured the fluctuation | variation of the twisted wire tension about each of the steel strands A to D is shown in FIGS. 4 (A) to (D). In addition, from the tension and the occurrence of defects during stranded wire, under the above evaluation conditions, the slip value of 160 g is the upper limit value that is a non-defective product, and the steel wire with a slip value of 300 g Even when they were rubbed together, the surface of the wire was found to be rough. Also, the difference between the steel wire with a slip value of 160g and the steel wire with 180g is not obvious by hand, but the twist tension measuring instrument can clearly detect the difference. When used for, the twist properties were clearly different.

  As can be seen from the results of FIGS. 3 and 4, among the four types of steel strands A to D, in the steel strands B to D whose slip value is about 150 g, the stranded wire tension is stable at around 2.5 kg. And there is little variation in values. On the other hand, in the steel strand A having a slip value as high as about 180 g, the stranded wire tension is higher than in the other steel strands B to D, and the variation (variation) in the tension value is large. From this, it can be seen that the higher the slip value, the higher the value of the stranded wire tension and the greater the variation (variation) in the value. Thus, it was confirmed that by evaluating the steel element wire based on the slip value, it is possible to predict the stranded wire tension in the subsequent stranded wire process, and thus the twist property of the cord.

  In addition, using the test element wire having a wire diameter of 0.34 mm, the slip value measured by the evaluation apparatus shown in FIG. A twisted cord having a 1 + 6 structure was manufactured by a twisting machine. For stranded wires, one of the sheath strands is a test strand having a slip value shown in the table below, and the other sheath strands and core strands have a slip value of 150 g. A certain wire was used. Moreover, the value of the twisted wire tension of each test element wire was measured, and the average value and variation (variation width) were calculated.

  Also, check the cord properties of each of the obtained twisted cords by visual inspection, and those with uniform twist properties are good, those with uneven portions of twist properties are partially defective, and the twist properties as a whole are uneven. Some were evaluated as bad. The results are also shown in the table below.

  In this case, since the twist tensions of the five sheath strands other than the test strands are substantially the same, an example of the experiment using the test strands having a slip value of 150 g which is the same as the other five sheath strands. In No. 1, there is no variation in the stranded wire tension between all the sheath wires. On the other hand, in Experimental Examples 2 to 4 using the test strands whose slip values are different from those of the other five sheath strands, the stranded wire tension varies among the sheath strands. From the results in the above table, under the above evaluation conditions, the slip value of 200 g is an upper limit value that is a non-defective product as a steel wire used for a twisted cord having an average slip value of other strands of 150 g, and a slip value of 200 g By managing steel strands up to the upper limit, twisting cords with good twisting properties can be achieved by suppressing both variation (variation) in the value of twisted wire tension in each strand and variation in twisted wire tension between strands. It was confirmed that

DESCRIPTION OF SYMBOLS 1 Steel strand 2 Spool 10 Slip property evaluation apparatus 11 Holding part 12 Measuring means 13 Driving means 14 Base 15 Strut 16 Pulley 17 Wheel 18 Holder 20 Weight

Claims (6)

  One end of the steel wire wound on the spool is pulled out from the spool, wound around the spool again through a weight, attached to the measuring means, and measured when pulled through the measuring means. Then, the resistance is used as an index of the slipperiness of the steel strand.   The method for evaluating the slipperiness of a steel wire according to claim 1, wherein a spring balance or a load cell is used as the measuring means.   The method for evaluating the slipperiness of a steel wire according to claim 1 or 2, wherein the resistance is detected as a load.   A holding unit for holding a spool around which a steel wire is wound, a measuring unit arranged at a distance from the holding unit in a direction perpendicular to the spool axial direction, and the measuring unit, the holding unit And a driving means for pulling in a direction perpendicular to the spool shaft direction.   5. The steel strand slippage evaluation apparatus according to claim 4, wherein the measuring means is a spring balance or a load cell.   6. The steel wire slippage evaluation apparatus according to claim 4, wherein the driving means is manual or a motor.

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