KR810000221B1 - Apparatus for improving the tensile properties of wire - Google Patents

Abstract

The apparatus is developed to improve the tensile properties of wire which is with no martensite structure. The apparatus has two rotary mumbers(11)(12), consisting of V-grooves pulleys of different diameter, and the electric brushes(27) (28) (29) (30) which supply electric current through V-grooves. For the permanent tensile strengthen of wire, the wire passes a rotary mumber(12) and then passes the next mumber(11) by extending the length of wire through V-grooves pulleys of different diameter.

Description

Device to improve the tensile strength of wire

1 is an elevational view of an apparatus of one embodiment of the present invention.

2 is a plan view of the apparatus shown in FIG.

FIG. 3 is an end elevation view in the direction of arrow 3 in FIG.

4 is an enlarged sectional view taken along the line 4-4 of FIG.

5 is a partially enlarged elevational view of the structure shown in FIG. 1 showing the placement of a brush.

FIG. 6 is a cross-sectional view of line 6-6 of FIG. 5 in which one of the breaks is shown in enlarged detail.

FIG. 7 is an elevational view of the structure shown in FIG. 1 showing a brush and electrical connection device. FIG.

FIG. 8 is a partial detailed view of FIG. 7 showing the electrical resistance arrangement more clearly in the conducting wire of the commutator piece.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for permanently stretching wires made of martensate-generating steel, improving creep resistance of wires under tensile load, such as cables of suspension bridges. Structures requiring high tensile stress, as well as devices for producing wires which are particularly effective as prestress elements of concrete structures.

As used herein, "martensite generation strength" means a steel that turns into martensite when quenched in the martensite generation temperature range.

In particular, the creep resistance of the wire is improved by the apparatus of the present invention, and the wire may be one wire, a plurality of parallel wires, or a spirally wound strand or rope type wire.

The apparatus comprises at least one rotating member through which a wire passes through its circumference, and a device for applying a heating current to a predetermined length of the wire. The heating current supply device includes at least one rotating member through which the wire passes. The rotating member is provided with a commutator segment and a current supply brush connected to a heating current source.

For the sake of convenience, the length of the wire refers to the length of the wire to be heated, but for example, at least a slight heating has already been performed even with respect to the length of the wire passing through the rotating member.

Conventionally, there have been many difficulties in the operation of the conventional apparatus due to sparks or arcs generated when the wire to be heated passes through the circumferential contact portion of the rotating member in the apparatus.

In the conventional apparatus, a heating current is supplied to the rotating member so that electricity is free to pass through the rotating member at a position where the wire passes over the rotating member. In addition, due to the natural phenomenon that the heating current tries to take the shortest distance, the wire moves and starts to contact the rotating member, or at the position where the contact is terminated, an appropriate amount of current of all the current is supplied to the wire to be heated. This difficulty arises from the fact. To obtain the required heating temperature, a relatively large current must be used, which was about 900 amps in the past, but in the future, it is expected to reach a large current of 4,000-5,000 amps, so that the spark or arc generated is quite high. I think it will be. This spar or arc is particularly prone to occur when the wire is in the form of strands or rope wound in a spiral with an uneven outer circumferential surface. Furthermore, this spark or arc flows circumferentially even when the wire is pressed against the rotating member and as a result of the shunt current flowing between the wire and the adjacent circumference of the rotating member to allow it to flow back from the rotating member to the wire. Occurs. This is because the cross section of the circumferential surface of the rotating member to which the wire is coupled is relatively large. This shunt current is particularly likely to generate sparks or arcs, especially in the case of strands or ropes, and occurs between circumferentially spaced positions because the spiral windings of the strands or ropes are locally coupled to the rotating member.

In addition, these sparks or arcs, which may cause unintentional damage on the surface of the wires regardless of the use of the wires, are particularly dangerous in the case of high tensile steel wires.

This is because local, instantaneous sparks or arcs heat the steel to a high temperature and the heat is momentarily conduction-cooled in the vicinity of which is not locally heated to generate martensite in the steel. As a result, the wire is locally weak and the required tensile properties are severely impaired.

It is an object of the present invention to improve an apparatus which can avoid the difficulties mentioned above. In order to achieve such an object, the present invention constitutes an apparatus as described in the specification. A feature of this device is that each rotating member with commutator segments has a wire engaging circumferential surface and forms a set of commutator segments spaced apart from the circumferential surface, the adjacent segments being insulated from each other and connected to the electrical The break consists of at least one electric brush, and each break is in contact with the commutator segment on the circumference, and the electric break is the part of the wire coupling circumference of the rotating member which passes momentarily by passing the wire to be heated. Deviating from the electrical connection, the arrangement causes a current to flow between each of the commutators and commutator segments in electrical contact with a portion of the outer circumference of the rotating member to which the wires are instantaneously crimped, with each commutator segment being slightly parallel to the wire. It has a circumferential length and is sparse by a positive current that can generate local martensite. A shunt resistor with a value capable of sufficiently eliminating arc or arc is connected to its outer circumferential surface.

In fact, it has been found that the amount of shunt current sufficient to generate martensite in the wire to be treated can be avoided by making the circumferential length of each commutator section at the wire connecting circumferential surface six times less than the manufactured wire diameter.

According to the present invention, a heating current is prevented from flowing from the wire to the circumferential surface of the rotating member near the inlet or outlet point of the wire from the rotating member, that is, the position where the wire passes through the circumferential surface of the rotating member.

This is because the commutator segments are connected only to the portion where the wires in the wire connection circumferential surface of the rotating member are already instantaneously crimped. Thus, the segment of the commutator present briefly near the entry or exit point of the wire is electrically insulated from the heating current circuit without contacting the electrical breakdown. Therefore, a heating current separate from the small amount of shunt current tolerated is forced to flow along the wire other than the entry point or the exit point of the wire, and there is a fear that a position where the wire is pressed against the rotating member, that is, arc or spark is generated. Passes to the circumferential surface of the rotating member in the missing position.

The above-described desired effect is further promoted by forming each electric brush connecting the respective commutator segments and the plurality of brushes according to the characteristics of the present invention, and each of the brushes is less than or equal to the circumferential length of each commutator segment. It has a circumferential width and makes a current path at each break from a power source of different electric resistance, and the maximum electric resistance makes an electric path at the closest point to the inlet or outlet of the wire, and from this inlet or outlet For the farthest brushes, there is a minimum of resistance.

This arrangement of different electrical resistances ensures that the current between the wire and the circumferential surface of the rotating member becomes nearly uniform over the proper length of the wire over the entire circumferential length of the adjacent commutator segments, and the multiple commutator segments Undesired contact with several brushes at the same time, reducing the current between the circumferential surface of the rotating member and the wire at a particular position of the wire compared to an arrangement without these different electrical resistances, thus resulting in the above-mentioned martensite generation Prevent local overheating. In short, this different electrical resistance deals with the natural phenomena of the shortest path, i.e., the current that takes the closest and most effective path to the point where the wire passes through the rotating member when no resistance is provided.

The present invention as described above will be described in more detail with reference to the accompanying drawings.

As shown in FIG. 1 to FIG. 2, an apparatus in which two rotating members 11, 12 are rotatably supported on the frame 10 along a horizontal axis parallel to each other, wherein each rotating member includes a plurality of rotating members. It is in the form of a pulley having a V-shaped groove 13 of which the two rotating members have the same diameter and are mechanically connected to each other so as to rotate at the same direction and at the same circumferential speed. For this purpose, the two rotating members 11 and 12 are provided with sprocket wheels 14 on one side thereof and both sprocket wheels are connected by sprocket chains 15.

The rotating member 11 provided near one end of the frame 10 is rotated by the electric motor 16, and the electric motor drives the main drive shaft 17 provided with the sprocket wheel 18, and the sprocket wheel 18 ) Is connected to the sprocket wheel 20 connected to the rotating member 11 via a chain (19).

At the end of the frame 10 away from the rotating member 11, a third rotating member 21 is provided on the side of the rotating member 12 away from the member 11, and the rotating member 21 is heated. It is in the form of a pulley with a single V-shaped groove 22 through which a wire passes.

The wire 23 to be permanently stretched first passes around the rotating member 12, then passes around the next member 11, then returns to the member 12 and sequentially passes through the member 11, a circular arc. One passes through one of each of the grooves 13 of these members continuously in such a way as to make contact with the angular groove approximately 180 °.

As shown in FIG. 4, the cross-sectional shape of each V-shaped groove 13 is similar, that is, the angle between both sides of each groove is the same. The diameter of several grooves of the rotating members 11 and 12 through which the wire 23 passes gradually increases in the wire traveling direction to gradually increase the tension of the wire.

However, in the case of the groove 13a of the rotating member 11 which is the last groove in the wire traveling direction among the grooves of gradually increasing diameter, the wire is rotated along the wire passage 23a from the groove 13a. It passes directly through and then returns from the pulley member 21 to the groove 13a of the member 11 along the wire passage 23b. The groove 13b is the last groove in the wire traveling direction among the grooves whose diameter gradually increases in the wire traveling direction. Thereafter, the wire turns around the groove 13 and passes between the members 11 and 12. Some of the grooves gradually decrease in diameter in the direction of the wire, but in the direction of the wire the final groove 13 has the same diameter and acts as a drawing capstan to give sufficient tension to pull the wire out of the device. do. The wire first passing over the rotating member 12 passes through the guide portion 24 and passes through a pre-tensioning reel 25 rotatably installed about a vertical axis (not shown). Supplied from. The brake 25 is provided with a brake 26, and the wire under the initial tension provided by the brake is supplied from the rail 25 to the member 12.

In this way, the heated wire, i.e., the wire shown by 23a, 23b, turns the rotary pulley member 21 from the groove 13a of the rotary member 11, and does not pass around the member 12. Returning to the groove 13b of (11), this is reliably done by the mounting member 21 rotatable about the axis inclined with respect to the horizontal as shown in FIG. 3, and the wires 23a and 23b are The outer circumferences of the passing member 21 are located in the vertical plane and placed on the corresponding end face of each member 12 of the outer circumference.

Electric brushes 27 and 28 on the member 11 and electric brushes 29 and 30 on the member 21 to supply heating current to the wires 23a and 23b to be heated. Is installed. Accordingly, these two rotating members 11 and 21 form current supply rotating members.

Each of the brushes 27 and 28 is adapted to supply current to the V-shaped grooves 13a and 13b of the rotating member 11, respectively, and for this purpose, these two grooves 13a, Each of 13b is formed in a corresponding conducting ring 31, 32, and each ring is formed of a plurality of commutator segments 33 (FIG. 5). For example, in one preferred embodiment, each ring has 90 or 135 segments and a diameter of about 2.1 m.

With respect to the commutator segments of the circumferential surface parallel to the wires with the risk of martensite generation formed as described above, each commutator segment on the edge of the wire contact circumference may be It was found that the circumferential length of 33) should not exceed 6 times the wire diameter. If this circumferential length is exceeded, the contact surface between the wire and the V groove of each section 33 is made large so as to encourage undesired large current.

Here, as in the case of good operation of the device, the wires are in the form of strands or ropes of the spiral windings formed of the above-described types of steel, the outer circumferences of which are V grooves 13a, 13b at circumferentially spaced positions. Connected to each of the two sides, the spaced position corresponds to the axially adjacent ridges of each wire or strand forming the strand or rope. Typically, these axially adjacent containers are spaced at least twice the spacing of the strand or rope diameter to form the circumferential length of each segment 33 not more than four times the strand or rope diameter, so that the strands or ropes are securely V in two positions. Make contact with each side of the groove. Thus, in reality, it is a shunt current of about 1/30 times the heating current, and becomes a very small and acceptable value. If the above-mentioned ratio of the circumferential length to the diameter of the strands or ropes is reduced to 2 or less, each side of the V-groove will contact only one ridge for one segment, so that the shunt current effect is substantially As a result, the ratio of intercept length to strand or rope diameter is at the desired theoretical maximum.

As shown in Fig. 4, the two rings 31 and 32 are provided so as to form grooves 34 at right angles on each side close to the circumferential surface of each of the rotary members 31, 32, and the shaft thereof. The annular flange 35 is provided on the surface wide in the direction. Each of these flanges has a row of holes 36 extending circumferentially, and bolts 37 penetrate the holes to fix the sections 33 at predetermined positions.

An electrically insulating material layer 38 is provided between the two surfaces of each piece 33 and the right angle groove 34, and the same insulating material is provided between the bolt 37 and the piece 33. Thus, each of the two rings 31 and 32 forming the grooves 13a and 13b is electrically insulated from the main body of the rotating member 11.

The circumferential length of each piece which comprises each ring 32 is as long as the small space 39 is provided between adjacent pieces.

Thus, each section is insulated from the adjacent section as well as insulated from the rotating member 11. Each section 33 has a flat, broken joint surface 40 facing outward with respect to the axial direction.

The wire receiving groove 22 of the rotary pulley member 21 is in the annular ring 32 assembled as a plurality of pieces insulated from each other and from the body of the member 21, like the ring 32 of the rotary member 11. have. One of the two axially facing side surfaces 41 of the ring 32 of the member 21 is flat and connects the electric brushes 29 and 30.

The structure of each pair of electric brushes connected to the rotating members 11 and 12 will be described next. As shown in FIG. 1, the wire 23a is advanced away from the contact of the groove 13a of the member 11 at the circumferential position A, and moves forward to the groove 22 of the member 21 at the circumferential position B. As shown in FIG. . Similarly, the heated wire 23b leaves the groove 22 of the rotating member 21 substantially at the circumferential position C and passes through the groove 13b of the member 11 substantially at the circumferential position D. FIG. The two positions A, B are slightly deviated from the circumference as the wire 23a passes over the tension meter of the pulley 42, so that portions of the wire 23a approaching and releasing the pulley 42 are mutually Slightly inclined with respect to the pulley 42 is subjected to a load proportional to the tension of the wire 23a. The pulley 42 supports such a load by means of a measuring device, such as an accurate spring balance, so that the maximum tension the wire can receive is observed.

The brushes 27, 28, 29, and 30 are all circumferentially spaced apart from the above-described positions A, B, C, and D by a distance longer than the circumferential length of the commutator segment 33.

As a result, the particular segment in which the groove instantaneously contacts the wire at positions A, B, C, D is not electrically connected to any of the adjacent electrical brushes at this time. This means that at each of the positions A, B, C, and D, where the heated wire is pressed against the sides of the V-shaped grooves 13a, 13b, and 22, between the surface of the wire and the side of the V-shaped groove, except for the shunt current effect. Do not cause any spar or arc at all.

Each pair of brushes consists of a number of individual brushes, each of which is attached to a brush support 44 which is simply electrically insulated from an arc-shaped mounting bar 45, and the opposite side is frame 10 It is connected to the support of the bracket with the bracket 46 in between. Each support 44 is provided with the axial brush 43 connected to the adjacent side surface of the fan-shaped ring 31 or 32 or 51. As shown in FIG.

Each of the brushes 43 is arranged in angular intervals with adjacent brushes on the circumference, so that they are not in direct electrical contact with each other. In each brush, the wire 47 of the current supply conductor 48 is provided. In this case, in the case of the rotating member 11, a pair of bus bars are provided one by one on both sides thereof, and in the case of the rotating member 21, one bus is provided.

Each brush 43 has a width as short as possible without exceeding the circumferential length of each commutator segment 33. Thus, each brush is always never connected to more than one commutator segment.

Several broken lead wires 47 of each group of brushes are combined with electrical resistors 49 of different values, and each resistor is optionally a group of individual brushes of the circumference closest to A, B, C, and D in some cases. To be connected to the broken wire 47 of the larger electrical resistance. In each case, the electrical resistance of the conductive wire 47 gradually decreases in the circumferential direction from the contact or break points A, B, C, and D of the wire.

In the above reasons and facts that each brush never connects to two or more commutator segments at the same time, the natural tendency of the heating current to take the shortest distance between each pair of brushes and the wires 23a or 23b is taken care of. Also, by appropriately selecting the value of each brush lead resistance 49 in consideration of the diameter of the wire to be heated and the heating current selected, various breaks in which the current between the wire and the outer circumference of the rotating member are broken in each pair are broken. It is easy to make it almost uniform over a wire of a length corresponding to the entire length of the adjacent section 33 which is in contact with the time. Thus, unwanted local high current can be avoided between the wire receiving groove and the adjacent surface of the overheated wire.

This is particularly important because the wire actually has a substantially circular cross section, and the grooves 13a, 13b or 22 are made of a V-shaped cross section to minimize slip between the wire and the rotating member. Thus, the contact surface between the groove and the wire becomes small. In addition, by installing these different resistors 49, each brush passes the maximum current so that the brush can be used most economically.

As shown in FIG. 7, several buses 48 are connected to a lead 50 which is connected to a transformer of power supply (not shown), which, if desired, has a heating current of about 4,000-5,000 amps at about 50 volts or More current may be supplied. The specific voltage and current depends on the size, ie cross-sectional area, of the wire or strand or rope being processed.

For this reason, if desired, the individual brushes of two sets of brushes 28 and 30 may be smaller than the brushes of two sets of brushes 27 and 29. This is because, inevitably, the temperature of the wire to be heated increases gradually between the positions A to D. Thus, since the average electrical resistance of the steel wire that increases with increasing temperature is greater in the wire 23b than in the wire 23a, the current through the wire 23b is therefore less than in the wire 23a. Thus, if imposed on the entire brush at the maximum current density and thus used most economically and effectively, then the brushes 28, 30 are smaller than the brushes 27, 29. do.

If desired, the rotating pulley member 21 needs to install only one set of brushes instead of the two sets of brushes shown, wherein the resistance of each conductor is at the maximum on both sides of the single set of brushes and minimum at the midpoint. It should be adjusted as much as possible.

If necessary, immediately before reaching the rotating member 11, the heating wire 23b is cooled by known means and prevents undesired heating of the rotating members 11, 12, while at the same time the wire is heated. When passing through it to prevent the curved to correspond to the bending of the rotary member (11), (12).

Such a device acts to impart controlled permanent stretching to the wire, and is sufficient to generate an arc or spark that is sufficient to generate martensite between the heated wire surface and the outer circumference of the rotating members 11 and 12 through which the heating current flows. Completely prevent occurrence.

If necessary, the wire may be passed between the two rotating members 11 and 12 in eight different postures to increase the circumferential length of each member connected to the wire passing through the circumference of the rotating member. At that time, it is necessary to mechanically connect the two members 11 and 12 so as to rotate in opposite directions at the same circumferential speed instead of rotating in the same direction.

Claims (1)

One or more rotating members 11, 12, 21 through which the wire 23 passes, and a device for supplying a heating current to a predetermined length of the wire, the heating current supply device having at least one rotation through which the wire passes. Member 11 and 21, and the rotating member is connected to the commutator fragment 33 and the electric brushes 27, 28, 29 and 30 connected to the power source, and the rotating member of each rotating member provided with the commutator fragment is installed. A set of adjacent commutator segments insulated from each other at intervals around the circumference forms a wire coupling circumferential surface, wherein at least one electric brush contacts each commutator segment at a circumferential position in the electrical break and the wire joint circumferential surface of the rotating member In such a way that the wire to be heated does not come into contact with the part through which the wire is to be momentarily passed, and the arrangement is such that the commutator segment is electrically connected to a part of the circumferential surface of the rotating member to which the wire is pressed momentarily The current flows between rushes, and each commutator segment is formed short in the circumferential direction parallel to the wire, and generates a spark or arc of shunt current sufficient to generate martensite locally on the wire. A device for improving the elongation of the wire, by connecting a resistor (49) of a value sufficient to prevent a break in the circumferential surface of the section.

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