KR101289153B1 - Shear Drawing Apparatus - Google Patents

Abstract

The present invention can be continuously processed while reducing the wear of the die due to the material by extending the replacement cycle of the die supply means that is provided to apply a compressive force for shear deformation to the material; A shear die including a channel that is sheared as the material passes through the feed means, the channel comprising: an inlet channel into which the material from the feed means flows; An intermediate channel connected to the entry channel and having a first intersection angle having a first intersection angle; Provided is a shear drawing device connected to the second channel having a second crossing angle with the intermediate channel and including an exit channel through which the material is drawn.

Description

Shear Drawing Apparatus {Shear Drawing Apparatus}

The present invention relates to a shear drawing apparatus and a method for rigidly processing a material, and to reduce the wear of the die and the material at the intersection of the die, while providing a material reduction by rolling along with the deformation of the material by the drawing, and the generation of compressive force It is about a shear drawing device in which the structure of the die is modified so that it can be made.

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.

The present invention is to solve the conventional problems as described above, and can be continuously processed while reducing the wear of the die due to the purpose of extending the replacement cycle of the die.

The present invention provides the following shear drawing device to achieve the above object.

The present invention provides a supply means for applying a compressive force for shear deformation to the material; A shear die including a channel that is sheared as the material passes through the feed means, the channel comprising: an inlet channel into which the material from the feed means flows; An exit channel through which the material is drawn out; And at least one intersection where adjacent channels are connected while having an intersection angle.

In this case, the channel includes an intermediate channel connected to the entry channel and the exit channel, wherein the intersection portion includes a first intersection portion in which the entrance channel and the intermediate channel cross at a first crossing angle, the intermediate channel, and the exit channel. The channel may comprise a second intersection that intersects at a second intersection angle.

In the present invention, the first crossing angle and the second crossing angle are preferably greater than the crossing angle of the extension line of the center of the entry channel and the extension line of the center of the exit channel.

In this case, the center of the first crossing portion is located a predetermined distance (L) along the center of the entry channel from the intersection of the extension line of the center of the entry channel and the extension line of the center of the exit channel, the center of the second intersection portion May be located apart from the intersection of the extension line of the center of the entry channel and the extension line of the center of the exit channel at a distance equal to the distance between the first intersection and the intersection along the center of the exit channel.

Further, in the present invention, the material is circular or rectangular, and the distance L from the intersection to the center of the first or second intersection is 1.5 of the wire diameter or width d of the material supplied to the supply means. It is preferable that it is twice or less.

Further, in the present invention, it is preferable that the distance L from the intersection to the center of the first intersection portion or the second intersection portion is 0.5 times or more of the wire diameter or width d of the material supplied to the supply means.

Further, the intermediate channel may comprise one or more intermediate intersections, and one or more of the entry and exit channels may include extensions tapered outwardly of the shear die.

The present invention can extend the replacement cycle of the die by reducing the wear of the die due to the material through the shear drawing device as described above.

1 is a schematic diagram showing a conventional material shearing process.
2 is an overall configuration diagram showing a continuous shear drawing device.
3 is an overall configuration diagram showing a shear drawing apparatus according to the present invention.
4 is a cross-sectional view of the shear die, FIG. 4A is a cross-sectional view of the shear die of FIG. 2, and FIG. 4B is a cross-sectional view of the shear die of FIG.
Fig. 5 is a sectional view of a raw material, Fig. 5 (a) is a sectional view of a circular raw material, and 5 (b) is a sectional view of a rectangular raw material.
6 is a view for showing the tensile stress at the intersection of the invention example and the comparative example of the present invention.
7 is a cross-sectional view of a shear die of another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

The inventors of the present invention, the compressive force for the shear deformation of the material in the die is implemented through rolling to enable continuous machining, while enabling the productivity, through high-speed processing, Patent Application No. 10 -2010-0115292 was 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 shearing die 30 so as to be continuously processed. Through this technique, the continuous processing is possible.

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 large contact pressure locally at the intersection portion 32 of the transfer die 30. (Contact pressure) is working. That is, the largest tensile stress is generated at the inner edge portion of the intersection portion 32, which is the portion where the entry channel and the exit channel intersect, and the tensile stress exceeds the tensile strength of the material constituting the shear die 30. In this case, there is a problem that the intersection of the shear die 30 is not only likely to be broken, but also the wear of the corresponding part is rapidly increased even when no fracture occurs.

Figure 3 shows the overall configuration of the shear drawing device 100 according to the present invention, Figure 4 (a) is a cross-sectional view of the shear die 30 shown in Figure 2, Figure 4 (b) 3 is a cross-sectional view of the shear die 130 shown in FIG. 3.

As shown in FIG. 3, the shearing apparatus 100 according to the present invention generates a compressive force with the rolling rolls 110 and 120 so as to continuously process, and supplies the material 2 to the shearing die 130. Continuous machining is possible through

The material 2 which is supplied and formed by the rolling rolls 110 and 120 to the shear die 130 passes through the first crossing portion 134 and the second crossing portion 135 in an asymmetrical manner for rigidity machining. Processing. The front end die 130 includes: an entrance channel 131 into which material from a supply means flows, an intermediate channel 132 connected to a first intersection 134 having a first crossing angle θ1 with the entrance channel; The intermediate channel 132 is connected to the second crossing portion 135 having a second crossing angle θ2, and includes an exit channel 133 through which the material is drawn.

The workpiece 2 which has passed through the shear die 130 including the first and second intersections 134, 135 passes through a fresh die 140 which reduces the cross section of the workpiece 2 to a desired shape. Although not shown behind the drawing die 140, tension is provided to the material 2 through drawing.

In the embodiment of the present invention of FIG. 3, the raw material is supplied to the shear die 130 by the compressive force by the rolling rolls 110 and 120 having the grooves 111 and 121 corresponding to the raw material 2.

The specific shape of the shear die 130 is shown in FIG. 4 (b). The configuration of the shear die 30 of FIG. 2 is shown in FIG. 4A for comparison. As shown in FIG. 4 (b), when the material 2 having the diameter d is supplied, the entrance channel 131 opened to the outer surface of the front die 130 so that the material 2 flows in, the entry channel ( 131 and an intermediate channel 132 connected with a first crossing angle θ1, and an exit channel 133 connected with the intermediate channel 132 with a second crossing angle θ2. Channel 131 and exit channel 133 include extensions 136 and 137 tapered to the outer surface of front end die 130.

At this time, since the entry channel 131 and the exit channel 133 are connected to the first crossing angle θ1 and the second crossing angle θ2 through the intermediate channel 132, an extension line of the center of the entry channel 131. It has an angle greater than the crossing angle θ at which the extension line of the center of the exit channel 133 crosses. Therefore, in FIG. 4A, the shear deformation amount at the intersection portion 32 is divided by the first intersection portion 134 and the second intersection portion 135 in the present invention, so that the shear deformation amount is changed. While the shear strain is reduced at each intersection 134 and 135. Therefore, it is possible to reduce the contact pressure between the corner where the wear occurs the most, that is, the inner surface of the intersections 134 and 135 and the material.

The degree of wear is affected by various variables, but is most affected by the contact pressure, thereby lowering the contact pressure between the intersections 134 and 135 and the material 2, thereby reducing the wear of the shear die 130. Can be reduced.

However, when the intermediate channel 132 between the first and second intersections 134 and 135 where the shear deformation occurs in the present invention is lengthened, the friction surface may increase to increase the total load. In addition, when the intermediate channel 132 is shortened, the friction surface may not be dispersed and thus the contact pressure may not be reduced.

The length of the intermediate channel 132 is the first intersection point P1 of the centerline of the intermediate channel 132 and the centerline of the entrance channel 131, the second intersection point of the centerline of the intermediate channel 132 and the centerline of the exit channel 133. Distance between P2, that is, the distance between the center of the first intersection 134 and the center of the second intersection 135.

At this time, the center P1 of the first intersection portion is a predetermined distance L along the center of the entry channel from the intersection Pc of the extension line of the center of the entry channel 131 and the extension line of the center of the exit channel 133. Located as far away. Further, the center P2 of the second crossing portion is formed along the center of the exit channel 133 from the intersection Pc of the extension line of the center of the entry channel 131 and the extension line of the center of the exit channel 133. It is located at a distance equal to the distance between the center P1 of the first intersection 134 and the intersection point Pc.

Therefore, the first crossing angle θ1 and the second crossing angle θ2 have the same angle, and apply the same shear deformation. In the present invention, the distance between the center (P1, P2) of the first intersection or the second intersection and the intersection point (Pc) of the extension line of the center of the entry channel 131 and the extension line of the center of the exit channel 133 ( By adjusting L), the distance of the intermediate channel 132 can be adjusted.

Regarding the distance of the intermediate channel 132, it is preferable to satisfy the range 0.5d ≤ L ≤ 1.5d (where d is the diameter of the material 2), and the center P1 of the first intersection or the second intersection. When the distance L between the extension line of the center of the entry channel 131 and the intersection Pc of the extension line of the center of the exit channel 133 is less than 0.5 d, the contact pressure is not reduced and wear occurs. There is no reduction effect, and if it is more than 1.5 d, the length of the intermediate channel 132 is long, so that the overall friction increases and the load increases.

5 (a) and 5 (b) show a cross section of a material 2 that can be used in the present invention. The shear drawing device 100 of the present invention can be applied to not only the circular material 2 but also the rectangular material 2. At this time, with respect to the distance of the intermediate channel 132, in the case of a square d means the width d of the square material (2).

(Example)

A die 30 having a cross-sectional diameter of 10 mmφ, a material diameter of 9.8 mmφ, and a cross angle θ of 120 ° is shown in FIG. 6A, in which the entry channel 131 and the exit channel 132 of the die 30 are located. The die of the present invention in which the intermediate channel 132 is formed so that the centers P1 and P2 of the first crossing portion 134 and the second crossing portion 135 are positioned at a position separated by 0.5 d from the intersection point Pc of the extension line ( 130 is shown in FIG. 6B.

The strain generated in the material 2 is 0.6 in FIG. 6A and 0.56 in FIG. 6B of the present invention, and shows almost the same value. When the material (2) was processed to 0.8% C carbon steel on the dies 30 and 130, the tensile stresses acting on the dies were compared.

The tensile stress value at the inner surface A of the intersection of FIG. 6A is 2400 MPa, but the tension of the inner surface B of the first intersection 134 and the inner surface C of the second intersection 135 of FIG. 6B. The stress values were greatly reduced to 1800 MPa and 1550 MPa, respectively. Therefore, wear of the die 130 can be greatly reduced, and accordingly, the life of the die 130 can be increased.

(Modified example)

7 shows a variant of an embodiment of the invention.

The shear die 130 of FIG. 7 is similar to FIG. 3 when the material 2 having the diameter d is supplied, the entrance channel 131 and the entrance channel 131 into which the material 2 is introduced. An intermediate channel 132 connected with a first crossing angle θ1, and an exit channel 133 connected with the intermediate channel 132 with a second crossing angle θ2. ) And exit channel 133 include extensions 136, 137 tapered to the outer surface of shear die 130.

In the modified example of FIG. 7, the intermediate channel 132 includes the first intermediate channel 132a and the second intermediate channel 132b, and the first intermediate channel 132a and the second intermediate channel 132b include the first intermediate channel 132a and the second intermediate channel 132b. The third intersection 138 is connected with a third intersection angle θ3.

At this time, since the third channel 132 is included in the intermediate channel 132 in the modification of FIG. 7, the intersection angles θ1, θ2, and θ3 of the respective intersections 134, 135, and 138 are original. It becomes larger than the crossing angle [theta], and accordingly, the tensile stress applied to each of the crossing portions 134, 135 and 138 can be reduced.

Even in this variant. The center P1 of the first crossing portion is a predetermined distance L along the center of the entry channel from the intersection Pc between the extension line of the center of the entry channel 131 and the extension line of the center of the exit channel 133. The center P2 of the second intersection portion is located apart from the intersection Pc of the extension line of the center of the entry channel 131 and the extension line of the center of the exit channel 133. Therefore, the distance is equal to the distance between the center P1 of the first intersection 134 and the intersection point Pc.

In addition, as in the embodiment of FIG. 3, it is preferable to satisfy the range of 0.5d ≦ L ≦ 1.5d (where d is the diameter of the material 2) with respect to the distance of the intermediate channel 132.

In FIG. 7, a configuration in which the intermediate channel 132 further includes one intersection portion 138 is described as a modification. However, the intermediate channel 132 may further include a plurality of intersection portions 138 as necessary. In addition, as well as the embodiment of Figure 3 can be applied not only to the circular material (2) but also to the rectangular material (2).

100: shear drawing device 110, 120: rolling roll
111, 121: Groove 130: Shear die
131: incoming channel 132: intermediate channel
132a: first intermediate channel 132b: second intermediate channel
133: exit channel 134: first intersection portion
135: second intersection 136, 137: extension
138: third intersection 140: fresh die
142: cross section reduction portion Pc: intersection
P1: center of first intersection P2: center of second intersection

Claims (8)

Supply means provided to apply a compressive force for shear deformation to the material;
And a shear die including a channel that is shear-deformed as the material passed through the supply means passes through.
The channel includes an inlet channel into which material from the supply means flows; An exit channel through which the material is drawn out; And at least one intersection where adjacent channels are connected with an intersection angle,
The channel may include an intermediate channel connecting the entry channel and the exit channel, and the intersection may include a first crossing portion where the entry channel and the intermediate channel cross at a first crossing angle, and the intermediate channel and the exit channel. A second intersection intersecting at a second intersection angle,
The center of the first crossing portion is located a predetermined distance (L) along the center of the entry channel from the intersection of the extension line of the center of the entry channel and the extension line of the center of the exit channel,
The center of the second intersection is the same distance (L) as the distance between the center of the first intersection and the intersection along the center of the exit channel from the intersection of the extension of the center of the entry channel and the extension of the center of the exit channel. Away from
The material is round or square,
And a distance (L) from the intersection point to the center of the first intersection portion and the second intersection portion is not less than 0.5 times and not more than 1.5 times the wire diameter or width d of the material supplied to the supply means.
delete The method of claim 1,
And the first crossing angle and the second crossing angle are greater than the crossing angle of the extension line of the center of the entry channel and the extension line of the center of the exit channel.
delete delete delete The method according to claim 1 or 3,
Wherein said intermediate channel comprises at least one intermediate intersection. The method of claim 1,
Wherein at least one of the entry channel and the exit channel comprises an extension tapered toward the outside of the shear die.

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