KR101316180B1 - Die - Google Patents

Abstract

It is an object of the present invention to provide a die which increases the strain rate of a material to obtain a desired strength, and includes a channel through which the material passes, the channel having an intersection configured to cause shear deformation of the material; Supplying a die and a raw material to a die; and a cross-sectional reducing portion formed of a release cross-section and reducing a cross section of the channel behind the intersection along a traveling direction of the raw material. Through the die, a processing step of shearing and drawing the material by changing the shape of the material passing through, the processing step provides a rigid plastic processing method for changing the cross-sectional shape of the material to release.

Description

Die {D}

The present invention relates to a die for rigidly processing a material, and to reduce the material by rolling together with the deformation of the material by drawing, and to realize the compressive force, having a release cross-section to give more material deformation while having the same reduction rate It is possible for the die to obtain a high strength product.

One way to improve the strength of the material is to refine the final austenite grain size (hereinafter referred to as 'AGS') using controlled rolling and / or controlled cooling of the material.

By the way, such AGS microstructure is mainly implemented in hot rolling and rapid cooling processes, so that the scale of rolling equipment or rapid cooling equipment is large and the rolling load increases due to low temperature rolling. Because it is made, the advantage of enabling mass production is provided.

On the other hand, another method of miniaturizing AGS without going through such a large-scale facility or process, is that nano-size (nano-size) by imparting shear strain at room temperature without complex thermal changes (ie, cooling process) In order to intentionally create a microstructure of the () and to increase the strength, for example, there is a severe plastic deformation (hereinafter referred to as 'SPD').

For example, one of the methods of such an SPD, as shown in Figure 1, by using a punch (P) to generate a compressive force of the material (M) to give a material shear deformation in the die (D), Equal Channel Angular Pressing (hereinafter referred to as 'ECAP') to refine the tissue.

That is, such an ECAP method is known to improve various mechanical properties such as strength increase due to micronization of tissue during shearing, formation of specific tissues, and improvement of fatigue characteristics.

However, this ECAP method has a problem that continuous processing is difficult, for example, as shown in Figure 1, because the length of the punch (P) is limited, the size of the material (sample) that can be processed is limited, additional processing after Extraction of specimens for processing was also a difficult problem.

In addition, a method of drawing shear instead of compressive force to impart shear deformation, although there is an Equal Channel Angular Drawing (hereinafter referred to as 'ECAD'), the cross section of the material is reduced due to the tension, in particular the contact between the die and the material There was a problem that it was difficult to maintain the raw material cross-sectional area at the initial stage of processing.

That is, the ECAD method is difficult to maintain the cross-section during the processing of the material, the shear deformation was not implemented enough.

On the other hand, a shear drawing method is known to solve the problem of ECAD, i.e., the shear drawing implements shear deformation by drawing like the ECAD method, but at the channel exit side of the die The reduction of material is provided to increase the contact force between the material and the die.

However, such shear drawing also implements processing through drawing, so that continuous machining (processing) is possible to some extent, but it is difficult to fabricate the actual die because it requires a reduction in the cross-section of the exit side of the channel in the die. ..

In addition, there is an ECAP-conform method, although not shown in a separate drawing, such an ECAP-conform method combines the conform process used in the existing extrusion process and the ECAP process described above.

In other words, the die is rotatably provided, and the shear deformation of the material is realized by inserting the material into the die using a frictional force between the material and the rotating die, and maintaining an appropriate angle at the channel exit.

However, such an ECAP-conform method has a problem that requires further processing of fresh wire, and in fact, continuous processing was impossible.

Accordingly, the inventors of the present invention, the compressive force for the shear deformation of the material in the die is implemented by rolling to enable the continuous processing, while based on ECAP, to enable productivity improvement through high-speed processing, patent application No. 10-2010-0115292 has been proposed.

As shown in FIG. 2, the compressive force is generated by the rolling rolls 10a and 10b to process the material 2 in the die 30 so as to continuously process the material.

However, by using a die having an intersection portion 32 for rigidity machining as shown in FIG. 2, the workpiece is asymmetrically processed, thereby causing a locally large contact pressure (at the intersection portion 32 of the die 30). Contact pressure). That is, the largest tensile stress occurs in the region where the channels intersect, i.e., the inner edge of the intersection 32, where the die exceeds the tensile strength of the material constituting the die 30. Not only is the intersection portion 32 of 30 more likely to be broken, but also there is a problem that wear of the corresponding portion is rapidly increased.

In the case where the die 30 is broken or the intersection 32 of the die 30 is worn, the entire die 30 must be replaced even if some breakage or wear occurs. The same die has a problem that in processing the entry and exit channels 31 and 33, not only the machining is easy because the die 30 is integral, but also it is difficult to confirm whether the machining is properly performed.

In addition, in the case of including a cross-sectional reduction portion for reducing the cross-section at the same cross-section for drawing, for example, a cross-sectional reduction portion with a reduced diameter in the case of a circular channel, the amount of deformation due to the draw is not sufficient to achieve the desired strength improvement. There was a problem that can not.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a die capable of replacing only a portion where wear occurs mainly in the die.

In addition, an object of the present invention is to provide a die having a structure capable of injecting lubricating oil that can relax the stress at the intersection of the die where the stress is concentrated.

Furthermore, an object of this invention is to provide the die which can raise the strain rate of a raw material and can obtain desired strength.

The present invention provides the following die in order to achieve the above object.

The present invention includes a channel through which a workpiece passes and a plurality of dividers including a portion of the channel, the channel comprising: an intersection configured to cause shear deformation of the workpiece; And a cross-sectional reduction part formed of a heteromorphic cross-section and reducing a cross section of the channel behind the intersection along the advancing direction of the material, wherein a part of the channel included in the partition is formed in a straight line, and the plurality of partitions. The intersecting portion is formed by the abutment surfaces of the two divided bodies, and the release cross-section has convex portions and concave portions around an imaginary circle, and the areas of the convex portions and the concave portions provide the same dies.

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In addition, one or more of the partitions may include a lubricant injection portion for applying the lubricant to the material.

Specifically, in the present invention, the partitions include first to fourth partitions sequentially arranged from the inflow direction of the material, and the first and second partitions include the entrance channel, and the third and The fourth segment may include the exit channel, and the fourth segment may include the cross-sectional reduction part.

In addition, the first divided part may include a lubricating oil injection part positioned on a surface in contact with the second divided part, and may apply lubricating oil to a surface of a material passing through an intersection between the second and third divided parts.

In addition, the fourth divided body may include a lubricating oil injecting portion positioned on a surface in contact with the third divided body, and may apply lubricating oil to a surface of a material passing through a cross-sectional reduction portion between the fourth divided bodies.

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The present invention can provide a die and a rigid plastic processing method capable of increasing the material strain rate, while replacing only the portion where the wear mainly occurs in the die through the above configuration.

In addition, the present invention can provide a die having a structure capable of injecting lubricating oil that can relax the stress at the intersection of the die where the stress is concentrated.

Furthermore, it is an object of the present invention to provide a die and a rigid plastic working method which can increase the strain of a material to obtain a desired strength.

1 is a view showing a conventional shearing apparatus.
2 is a diagram illustrating a shear drawing apparatus prior to the present invention.
3 is a cross-sectional view of the die of the present invention.
4 is an exploded perspective view of the die of the present invention.
5 is an assembly view of the die of the present invention.
6 is an enlarged cross-sectional view of the cross-sectional reduction portion of the fourth segment in the die of FIG.
FIG. 7 is a partial plan view of the fourth segment in the die of FIG. 3. FIG.
8 is a view illustrating the shape of the cross-sectional reduction part of FIG. 5.
9 illustrates a shear drawing device including a die of the present invention.
10 is a graph showing the distance and hardness from the center of the wire rod when processed with a die according to the present invention and a conventional die.

Hereinafter, with reference to the accompanying drawings, it will be described a specific embodiment of the present invention.

3 shows a cross-sectional view of the die 100 of the present invention, FIG. 4 shows an exploded perspective view of the die 100 of the present invention, and FIG. 5 shows an assembly view of the die 100 of the present invention.

As can be seen in Figures 3 to 5, the die 100 of the present invention is a first and second container 110, 115 having a curved shape as a mounting means and the first to fourth partitions located therein. (120, 130, 140, 150), and the first to fourth segments 120, 130, 140, and 150 include entry channels 121 and 131 or exit channels 141 and 151 therein. do.

The entry channels 121 and 131 and the exit channels 141 and 151 are inclined with a predetermined angle θ, and the material passes through the channels 121, 131, 141 and 151 connected with the inclination angle θ. While shear deformation occurs.

In addition, when shear deformation occurs, the first and fourth divisions are used to alleviate the rapid progress of partial wear of the second and third divisions 130 and 140 due to the large stress at the intersection 132. The sieves 120 and 150 and the first and second containers 110 and 115 are provided with lubricating oil injection parts 112, 113, 122 and 152.

Since the lubricant is supplied to the material passing through the die 100 through the lubricant injection parts 112, 113, 122, and 152, wear due to the stress of the cross-section 132 or the cross-sectional reduction part 154 may be reduced. As well, the molding load can be reduced, and accordingly, the life of the die 100 can be increased.

In addition, at one point of the exit channels 141 and 151, a cross-sectional reduction part 154 including a release cross-section 154b (see FIG. 6) is provided, so that the material is drawn after shear deformation. The configuration of the section reducing unit 154 will be described later in detail with reference to FIGS. 6 to 8.

As shown in FIG. 3, the die 100 includes first and fourth partitions 120, 130, 140, which divide the first and second containers 110 and 115 and the spaces inside the containers 110 and 115. 150).

The partitions 120, 130, 140, and 150 are preferably two or more, and are connected to the entry channels 121 and 131 or the exit channels 141 and 151, or the entrance channels 121 and 131 and the exit channels 141 and 151. In consideration of the connection of), in the present embodiment, four partitions 120, 130, 140, and 150 are configured, but may be more than that.

In the present embodiment, the first and second partitions 120, 130 include entrance channels 121, 131. The entrance channel 121 of the first partition 120 is connected to the introduction holes 111 and 116 of the containers 110 and 115 so that the material passes through the introduction holes 111 and 116 to form the first partition 120. It may enter the entrance channel 121 of.

The first partition 120 has a substantially rectangular parallelepiped shape and includes a lubricant injection portion 122 opened to a surface 125 (see FIG. 4) opposite to a surface contacting the introduction hole 111. The lubricant injection unit 122 is connected to the lubricant injection units 112 and 117 of the containers 110 and 115, which is connected to a lubricant providing unit (not shown) so that the lubricant injection unit 122 may be filled with lubricant. have.

In addition, the lubricating oil injecting part 122 may be lubricating oil on the opposite surface of the lubricating oil injecting parts 112 and 117 of the containers 110 and 115 so that the lubricating oil may be applied to all surfaces of the material passing through the lubricating oil injecting part 122. The storage unit 123 is provided.

On the other hand, the material passing through the lubricating oil injecting portion 122 enters the inlet channel 131 of the upper surface 135 of the second divided body 130. The second partition 130 has an upper surface 135 contacting the surface 125 on which the lubricating oil injecting portion 122 of the first partition 120 is formed, and a lower surface contacting the upper surface 145 of the third partition 140. 136 and an entrance channel 131 formed through the upper surface 135 and the lower surface 136.

Since the intersection 132 is formed in the case of the lower surface 136, the upper surface 135 may be inclined at a predetermined angle, and the second and second partitions 130 and 140 may be inclined. In the present embodiment having the same shape, the angle φ of the upper surface 135 and the lower surface 136 is 90-θ with respect to the angle θ formed between the entry channels 121 and 131 and the exit channels 141 and 151. Becomes / 2.

In this embodiment, the entry channels 121 and 131 and the exit channels 141 and 151 are formed in a straight line. Intersections 132 of the entry channels 121 and 131 and the exit channels 141 and 151 are formed at the lower surface 136 of the second partition 130 and the upper surface 145 of the third partition 140. Therefore, the channels 121, 131, 141, and 151 are not bent in any of the partitions 120, 130, 140, and 150. Therefore, in the processing of the divided body (120, 130, 140, 150), all can be processed by drilling (drilling) work, easy to check the processing state can not only increase the processing precision, but also ease of processing Is raised.

In the case of the third partition 140, the second partition 130 has the same outer shape. However, unlike the second partition 130, the exit channel 141 is formed instead of the entrance channel 131. Formed. That is, in the case of the third partition 140, the exit channel 141 receives the material passing through the entrance channel 131 of the second partition 130, and the bottom surface 136 of the second partition 130. The upper surface 145 and the lower surface 146 in contact with the surface 155, the lubricating oil injection portion 152 of the fourth partition 150 is formed.

Similar to the first partition 120, the fourth partition 150 has a substantially rectangular parallelepiped shape, and an exit channel 151 is formed therein, and a lubricant injection portion is formed on a surface facing the third partition 140. 152 is provided. In this case, the lubricating oil injecting unit 152 includes a lubricating oil storage unit 153 to apply lubricating oil to the entire surface of the material.

Unlike the first segment 120, the fourth segment 150 includes a cross-sectional reduction part 154 in which a cross section of the exit channel 151 is reduced, thereby making it possible to freshen the shear deformed material. . In the present invention, the cross-sectional reduction portion 154 includes a release cross-section portion 154b, whereby it is possible to impart a larger deformation amount while having the same reduction ratio.

In addition, the exit channel 151 of the fourth partition 150 is connected to the discharge holes 114 and 119 of the containers 110 and 115, and passes through the exit channel 151 of the fourth partition 150. The material may exit from the containers 110 and 115.

As can be seen in Figures 3 to 5, in the present invention, the container 110, 115 accommodates and surrounds the first to fourth partitions 120, 130, 140, 150, so that the die 100 of the present invention is a container. It can be formed integrally by (110, 115). Therefore, the die 100 may not be caught by the material.

In addition, in the present invention, since the die 100 is composed of the partitions 120, 130, 140, and 150, even if abrasion occurs, some of the partitions, for example, crossover, do not need to be replaced. It is possible to replace only the second and third segments 130, 140 forming the portion 132. In terms of maintenance of the die 100, such a configuration makes it possible to maintain the die 100 at low cost.

In addition, the fourth division 150 having the cross-sectional reduction portion 154 including the release cross-sectional portion 154b has a fourth cross-section having the same cross-sectional shape as the material but having a cross-sectional reduction portion 154 for reducing the cross section. By changing to sieve 150 it is possible to adjust the reduction and strain rates performed by die 100.

FIG. 6 is an enlarged cross-sectional view of the cross-sectional reduction part 154 in the fourth segment 150 of the die 100 of FIG. 3, and FIG. 7 is a plan view of the cross-sectional reduction part 154. 8 shows the shape of the release cross-section 154b.

6 to 7, the cross-sectional reduction portion 154 of the present invention is a cross-sectional deformation portion 154a which is deformed into a shape while the cross-section is reduced in a shape corresponding to the cross-sectional shape of the material and a release cross-section having a release shape ( 154b and an extension 154c having the same cross-sectional shape as the release cross-section 154b but larger in cross section than the release cross-section 154b.

8 illustrates the configuration of the release cross-section 154b in the present invention. As shown in FIG. 8, the shape of the release cross-section 154b is determined so that the release cross-section 154b of the present invention has the same reduction rate as that of the reduction of the material diameter (R '> R). . In this embodiment, the convex portion 154b1 and the concave portion 154b2 are formed at the same angle φ and the same height d, so that the area of the convex portion 154b1 and the concave portion 154b2 are the same. The cross section 154 is configured.

Since the release cross-section 154b is configured as described above, the release cross-section 154b provides a larger material strain rate while having the same reduction ratio as compared to when the material is reduced to the same cross-sectional shape (R '> R). It is possible to thereby improve the rigidity of the material passing through the release cross-section 154b.

Meanwhile, FIG. 9 illustrates a shear drawing apparatus to which the die 100 of the present invention is applied.

The compressive force is generated by the rolling rolls 10a and 10b to process the material 2 in the die 100 so as to continuously process the material 2 passed through the die 100 by drawing means (not shown). Is drawn.

Lubricating oil is supplied to the raw material 2 passing through the die 100 through the lubricating oil injecting parts 112, 113, 122, and 152. Accordingly, the material 2 can be shear drawn without causing significant wear to the die 100.

Thus, since the raw material 2 which passed through the die 100 is processed into mold release by the mold release cross-section part 154b, it can pass through the die 100 again according to the shape of the desired raw material 2.

In this case, the fourth segment 150 may be replaced with a cross-sectional reduction part 154 that fits the shape of the desired material 2 and may pass through the roll rolls 10a and 10b and the die 100 in the same manner. Has a die 100 'having separate rolling rolls 10a' and 10b 'and a cross-sectional reduction portion 154 that fits the shape of the desired material 2, so that the material 2 can be processed continuously. .

That is, through the supply step of supplying the raw material to the die 100 through the rolling rolls 10a and 10b and through the die 100 including the release cross-section 154b, the raw material is changed by changing the cross-sectional shape of the raw material passing therethrough. A step of shearing and freshening to a mold release, and in addition to this, the workpiece processed into mold release is supplied to the die 100 'via the rolling rolls 10a' and 10b ', and thereafter, a die including a circular cross section. It may include a processing step of processing to (100 ').

Such processing may be performed using alternating die 100 and circular die 100 'alternately to achieve a desired reduction rate.

Example

A graph testing the performance of the present invention through a die according to the present invention is shown in FIG. 10. In the present invention, the initial diameter of the initial material is 10 mm, and the die 100 including a release cross-section 154b having the same cross-sectional area as the diameter of 9 mm for an alloy steel of 0.45 wt% C is used in one pass. As a comparative example, the same material and the die were used, but the die was processed in one pass using a die to which a circular cross section having a diameter of 9 mm was applied, instead of the release cross section 154. In two passes, the wire diameter of the raw material of the present invention and the comparative example were 8 mm, using a die having a circular cross section of the present invention and the comparative example. In addition, the lubricating oil supplied to the lubricating oil injector was a water-soluble wet Houghto Draw 7500.

Here, in FIG. 9, the X axis means a distance from the center of the material, and the Y axis indicates the strength at the corresponding portion.

As can be seen in Figure 9, when the material is reduced to release, it can be seen that the hardness of the final material is higher over the entire material than to reduce the circular.

Thus, the die of the present invention can obtain the hardness of the material placed further from the same reduction rate of the same material. In addition, the die of the present invention includes a split die and a lubricating oil injection portion in order to reduce the molding load which is increased due to the increased strain, thereby allowing higher strength in the final product without increasing the overall molding load.

Furthermore, in the present invention, by applying a divided die, it is possible to change the mold die and the circular die by using only a part of the divided bodies.

In the above, the specific configuration of the present invention has been described through the embodiment of the present invention. However, the scope of the present invention is not limited to the above embodiment, and various modifications are possible without changing the spirit of the present invention.

For example, in the specific embodiment of the present invention, the second and third partitions are separated based on the intersection for workability, but the second and third partitions are formed as one partition, so that the die of the present invention is divided into three dies. It may also comprise a partition.

In addition, in the specific embodiment of the present invention, although the lubricant injection portions of the first and fourth partitions are shown and described as being formed on the surface in contact with the second or third partitions, the lubricant injection portions may be formed at other positions without being limited thereto. In addition, the lubricating oil injection portion may be formed in the second and third partitions.

In addition, although the container is illustrated as a mounting means for mounting the partitions in the present invention, other means may be used as long as the partitions can be held integrally without being limited thereto.

100, 100 ': Die 110, 115: Container
111, 116: inlet 112, 113: lubricating oil injection portion
114 and 119: discharge holes 120: first split body
121, 131: Entry channel 122: Lubricant inlet
123: lubricating oil storage unit 130: the second divided body
132: intersection 140: third segment
141 and 151: exit channel 150, fourth segment
152: lubricating oil inlet 153: lubricating oil reservoir
154: section reduction part 154a: section deformation part
154b: release section 154b1: convex
154b2: recess 154c: extension

Claims (7)

A channel through which the material passes and a plurality of partitions including a portion of the channel,
The channel includes an intersection configured to cause shear deformation of the material;
It includes a cross-sectional reduction portion formed of a release cross-sectional portion while reducing the cross section of the channel behind the intersection along the direction of the material,
A portion of the channel included in the partition is formed in a straight line, the intersection is formed by the abutment surface of the two partitions of the plurality of partitions,
The release cross section has a convex portion and a concave portion around an imaginary circle, wherein the areas of the convex portion and the concave portion are equal to each other. delete The method of claim 1,
At least one of the partitions includes a lubricant inlet opened out of the die to reduce wear due to processing of the material. The method of claim 3, wherein
And the lubricating oil injecting unit applies lubricating oil to a surface of the material which is located between the crossing portion and the cross-sectional reducing unit and passes through the cross-sectional reducing unit. The method according to claim 1 or 3,
And a container surrounding the plurality of partitions such that the partitions are fixed in position with respect to each other. delete delete

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