KR100900630B1 - An apparatus for taper-rolling an end of wire rod - Google Patents

Abstract

The present invention effectively prevents split end phenomena in which the wire end part splits and spreads in various forms during hot rolling of Bi-S free cutting steel, thereby improving wire rod productivity and error rate of free cutting steel and greatly reducing the workload. The present invention relates to a tapered rolling device for a tip end portion of a wire rod that can reduce production costs by preventing excessive maintenance costs without contaminating an environment of a workplace.

The present invention, on the surface of the upper and lower rolls to form a pressing angle that gradually increases the width and depth at a predetermined angle in the circumferential direction of the upper and lower rolls from the portion where the groove starts, and subsequent to the pressing angle, Atmospheric angles of greater width and depth than the reduction angle are formed at a predetermined angle in the circumferential direction of the upper and lower rolls, and the rolling angle of the upper and lower rolls is reduced simultaneously with the rewinding of the wire rod. After the rolling, the tapered rolling of the end portion of the wire rod portion is configured to have a margin than the size of the wire rod so that the wire rod portion after the tapered tip can be passed in the non-rotating state of the upper and lower rolls without rolling. Provide a device.

Upper and lower rolls, free cutting steel (Bi-s), wire rolling, split end, tapered rolling equipment

Description

Tapered rolling device of end of wire rod {AN APPARATUS FOR TAPER-ROLLING AN END OF WIRE ROD}

1 is a production line flow diagram illustrating a typical wire rod rolling process;

2 is an explanatory view showing a state in which a split end portion is formed at the tip of the material in the wire rod rolling line according to the prior art;

3 is a side view showing the tip tapered rolling device of the wire rod according to the present invention;

4 is an external perspective view showing the tip tapered rolling device of the wire rod according to the present invention;

5 is a cross-sectional view showing the tip tapered rolling device of the wire rod according to the present invention;

6 is an explanatory diagram showing an operating state of the tip tapered rolling device of the wire rod according to the present invention;

7 is an explanatory view showing a cross-sectional reduced state in the tapered rolling device of the tip end portion of the wire rod according to the present invention;

8 is an explanatory view showing the pressure reduction angle and the atmospheric angle provided in the tapered rolling device of the tip end portion of the wire rod according to the present invention;

9 is an explanatory view showing a stepwise operating state by the tapered rolling device of the tip end portion of the wire rod according to the present invention;

10 is a chart showing the reduction ratio of a typical wire rod.                 

       <Description of the symbols for the main parts of the drawings>

5 ..... reducer 10 ..... drive motor

13 .... Base 15 ..... Housing

20a, 20b ... Roll 22 ..... Choke Bearing

30 ..... tapered end 32 ..... eccentric weight

40 ..... Fly Wheel 50 ..... Object Proximity Sensor

52 ..... Hole 60a, 60b .... Water Spray Nozzles

200 .... Wire Rod θ1 ..... Reduction Angle

θ2 .... atmospheric angle

The present invention relates to an apparatus for hot rolling production of wire rod products of free-cutting steel (Bi-s) material, which are widely used to easily process products for automotive hydraulic parts, including small parts such as office equipment, cameras, watches, and the like. By effectively preventing the split end phenomenon in which the wire end part splits and spreads in various forms during hot rolling of Bi-S free cutting steel, it can improve the wire productivity and the error rate of free cutting steel and greatly reduce the workload. The present invention relates to a tapered rolling device for a tip end portion of a wire rod which can reduce production costs without contaminating an environment of a workplace and preventing excessive maintenance costs.                         

In general, Bi free-cutting steel with Mns retension with Mns and Bi constricted is a high value-added steel wire widely used to machine parts requiring good machinability and precision.

In the past, as the production of automobile electrical equipment increased, the free cutting steel containing Pb, Te, Ca, and other elements was used in the S-type free cutting steel. However, a large amount of chips were generated, which resulted in poor machinability. Pb-S-based free-cutting steels have been developed and are used as steels suitable for high speed and automation in cutting operations.

However, lead (Pb) free-cutting steel is a Bi-S-based free-cutting steel, which is harmless to the human body and developed to be excellent in workability because it is toxic to the human body.

These MnS inclusions act as stress concentrators during cutting, facilitating the formation of voids and growth of cracks at the interface between the inclusions and the iron, reducing the force required for cutting, and the metallic inclusion, bismuth It is softened or melted by the cutting process heat and acts as a lubricant at the interface between the chip and the cutting tool, thereby suppressing the wear of the tool.

Therefore, while improving the cutting force, while acting as a stress concentration source during machining, the curvature of the chip

The steel grade is also improved by reducing the radius. As such, the MnS inclusions are a kind of defect that has an inconsistent distribution in the steel, and in the process of forming the product form by hot rolling, the tip part is due to the difference in the degree of stretching with the base structure against external stress. It is the starting point of cracking of the gap and is a major factor in causing larger tissue destruction by being associated with surrounding inclusions.                         

In general, in the wire manufacturing rolling process, as shown in FIG. 1, the billet 100 heated at the tip is rolled on the No. 1 stand 110 by an extraction pinch roll and reaches the initial shearing machine 112. And it is rolled in the No. 1 stand 110 to cut the tip crop (Crop) 115 in the first cutter 112 to achieve the intermediate rough rolling in the No. 2 stand (120).

Next, the crop 115 is cut again in the intermediate shearing machine 125, and then the final rolling is performed in the rolling mill group of the No. 3 stand 130.

In this process, the wire rod 200 leaving the rolling pass line (Cass) (Cobble) 150 is generated by scraping the wire rod (Scrap), scratches on the surface of the roll by the progress of the wire speed and torque ( Mark).

In addition, the billet changed into a hot state in the heating furnace is a plurality of continuous rolling mills 110, 120 and 130 in which box rolls, ovals, and round rolls are different from each other in the same direction. The product shape is created by stretching and spreading by rolling while passing, and in each rolling mill, an inlet and outlet roll guide (Guide) 160, which is a guide device for the wire rod 200 being rolled, is attached to the corresponding mill caliber (groove). Induces the wire 200 in, and the center (Central) is maintained during rolling. The outlet guide allows the wire rod 200 to easily enter the next rolling mill.

In such a wire rolling mill structure, Bi-S free-cutting steel is a strip end phenomenon 210 in which the tip end portion of the wire rod 200 is unrolled due to the split end phenomenon 210. At the same time the wire wound 200 must be scrap (Scrap) treatment.                         

In addition, while maintaining the rolling speed, it collides with other facilities, resulting in equipment damage, operation obstacles, and decreased productivity. Another problem is a box-shaped, mis-rolled, round-shaped roll design of a rough rolling section with high rolling pressure. In continuous rolling of the Bi-S free-cutting steel billet of ultra-high temperature state), the wire rod 200 going straight is pressed down from the beginning.

In the above, the split end shape generated at the tip of the wire 200 is more than the cross section of the billet to be drawn when the upper and lower rolls are rotated in the same direction as the rolling direction, as shown in FIG. It will come out as a smaller, reduced billet, so you will be forced to open outward from the center.

As shown in Table 1 of FIG. 10, the diameter of the rolling stand gradually decreases while passing through the rolling stands, and the reduction rate of rolling is expressed as (initial diameter-diameter after rolling) * 100 / initial diameter, Gradually the diameter decreases.

In this rolling process, when working with Bi-S free-cutting steel, unlike ordinary carbon steel, MnS inclusions are continuously distributed in the matrix structure, and the presence of the inclusions acts as an element causing embrittlement during hot rolling. When stress is applied to the tip and the end of the 200, the split end 210 easily breaks apart in various forms at the center of the cross section.

In addition, when the tip of the wire rod 200 is opened, pinching or dent in the guide guide of rough rolling, intermediate rough rolling, and finishing rolling appears, and is also caught in the gap between the inlet guide and the roll, The wire rod 200 is wound around the roll in the circumferential direction, such as several types of failures such as deterioration of the quality of the wire rod, falling error rate, deterioration in productivity due to the occurrence of coble, excessive operation failure time occurs.

In order to solve such a conventional problem, a method in which the tip of the wire rod 200 is sharply polished with a grinder (not shown) has been proposed, but excessive power consumption is generated due to the long time operation of the grinder, and the wheel of the grinder (WHEEL) ) As usage increases, it causes cost increase, and billet wire polishing causes a lot of wire processing chips, which pollutes the surrounding environment, and costs are high due to environmental cleanup cost.

The present invention is to solve the conventional problems as described above, the object is to prevent the split end phenomenon by splitting and spreading the wire end portion in various forms during hot rolling of Bi-S free cutting steel, By eliminating the problems of the rolling process caused by the rolling process, it is possible to improve the wire rod productivity and error rate of free-cutting steel, greatly reduce the work load, reduce the production cost by preventing excessive maintenance cost without contaminating the environment of the workplace. It is to provide a tapered rolling device for the tip of the wire rod.

In order to achieve the above object, the present invention is provided with a pair of upper and lower rolls and a motor for driving the same, the apparatus for hot rolling production of wire rod products made of free cutting steel (Bi-s) material, the upper and lower parts On the surface of the roll, a rolling angle is formed in which the width and depth of the upper and lower rolls are gradually increased from the portion where the groove starts, and the width and depth of the roll are gradually increased. Atmospheric angles of the upper and lower rolls are formed at a predetermined angle in the circumferential direction of the upper and lower rolls, and in the pressing angle portions of the upper and lower rolls, the tip of the wire rod is tapered and rolled at the same time as the rewinding of the wire rod. In the part is characterized in that the wire portion after the tapered end is configured to have a gap more than the size of the wire rod so that it can pass in the non-rotating state of the upper and lower rolls without pressing. The tapered distal end of the wire rolling apparatus that is caused by maryeonham.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The tip tapered rolling device 1 of the wire rod according to the present invention uses a reduction gear 5 for driving two rolls as shown in FIG. 3 and a driving motor 10 is provided on one side of the reduction gear 5. In addition, two upper and lower rolls 20a and 20b are disposed in the housing 15 formed in the shape of a U-shape on the base 13, and are provided at both ends of the rolls 20a and 20b. Each of the roll supporting choke bearings 22 is arranged to smoothly rotate the rolls 20a and 20b.

Carrier balls (grooves) 25a and 25b provided in the upper and lower rolls 20a and 20b may roll the tip of the wire 200 into a tapered end portion 30 having a pointed shape. The wire rod 200 is symmetrically arranged in a shape having atmospheric angles θ2 to which the wire rod 200 can be bypassed after the rolling angle θ1 and the tip control rolling of the wire rod 200.

On the other hand, the roll 20a is rotated once on both ends of the upper roll 20a to form an eccentric weight 32 so that the moment of inertia (Monent) can be applied when the tip roll is controlled. It is formed to receive a lot of force, and the flywheel (40) on the shaft (shaft) at one end of the upper roll (20a), that is, the outer end of the housing 15 on the opposite side of the reducer (5) And this, with the eccentric weight 32 attached to both sides of the upper roll (20a) so that the inertia maximum is the same position so that a large amount of load can be given to the tip of the wire rod 200.

In addition, an object proximity sensor 50 is mounted to the side of the flywheel 40, and the flywheel 40 stops the rotation by the sensor 50 after the roll 20a is rotated once. To form a hole (Hole) 52 of the arc.

Further, in the process in which the billet wire rod 200 is rolled in a taper shape only at the tip end of the pair of rolls 20a and 20b, the rolls 20a and ( In order to prevent the surface heat conduction damage of 20b), water spray nozzles 60a and 60b are installed to spray water, so that the cooling water is cut off at the tip rolling of the wire rod 200, and then the cooling water is sprayed upon passing through the wire rod. It is.

Meanwhile, in FIG. 5, the grooves 25a and 25b formed in the upper and lower rolls 20a and 20b are illustrated in detail.

The rolls 20a and 20b are symmetrically formed, and each of the rolls 20a and 20b has a rolling angle θ1 formed such that the width and depth gradually increase from the point where the grooves 25a and 25b start. Bar), the pressing angle θ1 corresponds to 0 ° to 270 ° in the circumferential direction of the rolls 20a and 20b from the part P1 at which the grooves 25a and 25b start. In the end portion of the wire rod 200 is tapered control rolled.

That is, a single wire 200 enters the roll center axis (dashed line), and gradually tapers gradually from the state in which the grooves 25a and 25b are formed in the same standard as the rolled wire 200 during tapered rolling operation. As the width and depth of the grooves 25a and 25b are reduced, the two rolls 20a and 20b are engaged with each other and rotated so that the tip of the wire rod 200 is sharply rolled.

In addition, in the 270 ° to 360 ° section formed in the circumferential direction of the rolls 20a and 20b after the rolling angle θ1, the rolls 20a and 20b having the rolled ends of the wire rod 200 completed by 1 are 1. When the wheel rotates and stops, the atmospheric angle (θ2) having a gap (gap) more than the size of the wire rod so that the portion of the wire rod 200 after the tapered tip can pass even without the rotation of the upper and lower rolls 20a and 20b. ) Is formed.

Therefore, the wire rod 200 passes through the upper and lower rolls 20a and 20b through the atmospheric angle θ2.

FIG. 6 shows a state where the wire rod 200 is inserted between the upper and lower rolls 20a and 20b at the start of rolling.

6 is a cross-sectional view of the upper and lower rolls 20a and 20b, and a plurality of wires 25a and 25b are formed in the upper and lower rolls 20a and 20b. (200) is to be able to roll the tip portion in a tapered shape.

That is, by forming a collar 65 between the grooves 25a and 25b to distinguish the grooves 25a and 25b, each wire 200 is formed through the grooves 25a and 25b. ) And allow it to roll into a tapered shape.

7 and 8, when the wires 200 are rolled along the grooves 25a and 25b of the upper and lower rolls 20a and 20b, the symbol P2 is used to compare the cross-sectional reduction widths. The wire rod 200 is a portion where the atmospheric angle θ2 is formed so that the wire 200 can pass freely without rolling, and the tip portion of the shape rolled in the rolling angle θ1 becomes sharper from the ab section to the bc section, and roll 1 In the rotation, 0 ° to 270 ° is the reduction angle θ1, and 270 ° to 360 ° is the atmospheric angle θ2.

That is, FIG. 7 is an explanatory view showing a state in which the tip portion of the wire rod 200 is rolled in a tapered shape according to the width and depth of the grooves 25a and 25b formed in the upper and lower rolls 20a and 20b. to be. This is hardly rolled in the portion of the grooves 25a and 25b of the rolls 20a and 20b that extends from the atmospheric angle θ2 to the reduction angle θ1, but gradually enters the reduction angle θ1. The end of the wire rod 200 is rolled into a tapered shape by reducing the cross section.

8 is an exploded view in which the grooves 25a and 25b are unfolded with respect to the circular rolls 20a and 20b. From the left side of the rolling angle θ1 of the grooves 25a and 25b, which is the starting point of the tip rolling, The grooves 25a and 25b, which are rectangular balls, have the width L and the height H reduced together, and at the atmospheric angle θ2, the tip portion of the wire rod 200 made of free cutting steel can pass freely. It is configured to be larger than the maximum width and height of the reduction angle (θ1).

In the present invention configured as described above, as shown in FIG. 3 and FIG. 4, the driving force of the motor 10 is transmitted to the upper and lower rolls 20a and 20b at the same speed via the reducer 5 and the choke bearing 22. Only when the tip end is rolled, the rolls 20a and 20b are rotated by one rotation, and then stopped, and the wire rod 200 thereafter proceeds through the roll angles 20a and 20b through the atmospheric angle θ2.

In this rolling operation, in order to obtain a high rotational torque of the rolls 20a and 20b, the left and right eccentricity of the eccentric fly wheel 40 and the upper roll 20a provided to the outside of the upper roll 20a. When the weight 32 acts and the wire 200 in the hot state other than the tip portion is rolled, the cooling water is sprayed from the water spray nozzles 60a and 60b to the wire rod 200 and the wire rod 200. The rolls 20a and 20b are prevented from deteriorating.

Taper rolling of the wire rod 200 by the upper and lower rolls 20a and 20b proceeds as follows.

In FIG. 5, when the tip of the hot (1200 ° to 1300 °) wire rod 200 reaches 315 ° from the groove 25a and 25b forming points of the upper and lower rolls 20a and 20b, It is located at the center of the angle θ2. In this state, the wire rod 200 is further advanced as shown by a dotted line in FIG. 5, and the upper and lower rolls 20a and 20b are further rotated to further reduce the reduction angle θ1 and the atmospheric angle θ2. The connected point P2 is rotated to be a pressing point of the upper and lower rolls 20a and 20b.

In this arrangement, the upper and lower rolls 20a and 20b are the starting point P1 of the reduction angle θ1 from the point P2 where the reduction angle θ1 and the atmospheric angle θ2 are connected, that is, The roll 20a, 20b is rotated to a point formed in the grooves 25a, 25b. At the same time, the wire rod 200 is gradually reversed by the portion shown by the dotted line in FIG.

In this rolling process, the front end of the wire rod 200 is rolled into a tapered shape while the surfaces of the rolls 20a and 20b and the front end of the wire rod 200 are rubbed.

In the rolling process, the rolling angle θ1 from 0 ° to 270 ° at which the upper and lower rolls 20a and 20b starts to drive is wide and deep in the grooves 25a and 25b at the inlet. When the two rolls 20a and 20b are engaged with each other in a structure in which the width is narrower and the depth becomes shallower as the rotation progresses, the flywheel 40 and the left and right eccentric weights provided on the upper roll 20a are deep. 32 have a large moment of inertia to provide a rolling torque that increases as the width and depth of the grooves 25a and 25b become narrower and shallower, so that the free-cutting steel tip at high temperature can be easily rolled into a square cone. .

That is, as shown in FIG. 6, the two rolls 20a and 20b are driven at the a-a 'position of the wire rod 200 to start rolling, and b-b' denotes the wire rod 200 and the roll 20a ( 20b) is in contact with the rolling point at the cone angle, c-c 'is the wire rod 200 is greatly reduced.

9 is a step-by-step machining operation of the tip of the wire rod 200 according to the present invention.

In FIG. 9A, the front end of the wire rod 200 enters between the upper and lower rolls 20a and 20b, and the front end of the wire rod 200 is positioned at the atmospheric angle θ2 to prevent rolling. Not in condition.

In addition, as shown in FIG. 9B), rolling is started, and the upper and lower rolls 20a and 20b are rotated to start rolling at the rolling angle θ1, and the wire is gradually rolled back as the wire is moved backward. This is done, and the rolling is made in the intermediate width and depth.

In addition, the upper and lower rolls 20a and 20b are rotated to almost the end of the reduction angle θ1, and the wire rod 200 is reversed so that the tapered tip portion 30 of the wire rod 200 is almost provided. As described above, when the rolling angle θ1 of the upper and lower rolls 20a and 20b is rolled on the tip of the wire 200, the sensor 50 located outside the upper rolls 20a and 20b is rolled up. ) Detects the grooves 25a and 25b formed on the side of the flywheel 40 to prevent further rotation of the upper and lower rolls 20a and 20b, and the backward movement of the wire rod 200 is also stopped.

And, as shown in Figure 9d, in the state in which the tapered rolling of the front end of the wire rod 200 is completed, the upper and lower rolls (20a, 20b) are additionally rotated by a predetermined angle to the atmospheric angle (θ2) It is disposed to face each other, the wire rod 200 is advanced between the atmospheric angle (θ2) formed between the upper and lower rolls (20a, 20b) to exit between the upper and lower rolls in a no-load state.

That is, in the present invention, the upper and lower rolls 20a and 20b are rotated over 0 ° to 270 ° to finish rolling through the reduction angle θ2, and then the 270 ° to 360 ° section in the circumferential direction, that is, the atmosphere. It is additionally rotated without rolling over the angle θ2 so that the wire rod 200 passes between the atmospheric angles θ2.

Since the atmospheric angle θ2 forms a groove having a width and a depth greater than that of the grooves 25a and 25b of the reduction angle θ1, when the wire rod 200 is moved backward after completion, the upper and lower rolls ( 20a and 20b allow passage of the wire rod 200 through the atmospheric angle θ2.

According to the present invention as described above, by rolling the tip end portion of the wire rod 200 in a tapered shape to pass the wire rod rolling process, it is possible to effectively prevent the split end phenomenon of the wire rod end portion after the rough rolling section.

Therefore, the gap of the tip is effectively prevented and the Cobble is prevented by the normal rolling process, thereby significantly reducing the downtime of the equipment and improving productivity.

In addition, it is possible to prevent the failure of rolling, to obtain great effects such as equipment accidents and work load reduction, to prevent the pollution of the surrounding environment, and to prevent the excessive cost of maintenance, thereby improving the equipment cost. It is.

Claims (3)

In the apparatus for hot rolling production of wire rod products of free-cutting steel (Bi-s) material having a pair of upper and lower rolls (20a, 20b) and a motor (10) for driving them, The width and depth of the upper and lower rolls 20a and 20b are formed at a predetermined angle in the circumferential direction of the upper and lower rolls 20a and 20b from the portion P1 at which the grooves 25a and 25b start. Is formed to gradually increase the reduction angle θ1, and subsequent to the reduction angle θ1, the atmospheric angle θ2 of a width and depth larger than the reduction angle θ1 is obtained in the upper and lower rolls 20a ( 20b) is formed at a predetermined angle in the circumferential direction, and at the reduction angle θ1 of the upper and lower rolls 20a and 20b, the reduction of the wire rod 200 is performed at the same time and the tip of the wire rod 200 is tapered. After rolling, the size of the wire rod 200 is such that the wire rod 200 after the tapered tip can pass through the non-rotating state of the upper and lower rolls 20a and 20b at the atmospheric angle θ2 after rolling. Tip tapered rolling device of the wire rod, characterized in that configured to have a more clearance gap (Gap). According to claim 1, At both ends of the upper roll (20a) roll 20a is rotated once to form an eccentric weight (32) so that the moment of inertia (Monent) can be applied when the tip control rolling, At one end of the upper roll 20a, a flywheel 40 is installed on the shaft, so that the maximum inertia position is the same with the eccentric weight 32 attached to both sides of the upper roll 20a. Tip taper rolling device of the wire rod, characterized in that for rolling the end of the wire rod 200. According to claim 1 or claim 2, wherein the reduction angle (θ1) is 0 ° in the circumferential direction of the upper and lower rolls (20a, 20b) from the portion (P1) from which the grooves (25a, 25b) begins It is formed in a section ~ 270 °, characterized in that the atmospheric angle (θ2) is formed in the 270 ° to 360 ° section in the circumferential direction of the upper and lower rolls (20a, 20b) subsequent to the pressing angle (θ1) Tapered rolling device at the tip of the wire rod.

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