CN107377653A - The flat prod cast of extruding metal - Google Patents

Abstract

The invention provides a kind of flat prod cast of extruding metal, the flat prod cast of extruding metal includes：The nib and die orifice being connected up and down successively；The nib has upper port and lower port, and the upper port of the nib is the entrance of nib, and the lower port of the nib is the outlet of nib, and the lower port of the nib connects the entrance of the die orifice；A diameter of R of the upper port of the nib, the sectional area of the lower port of the nib is S₂, the diameter of the upper port of the nib is more than the diameter of the lower port of the nib, and the height of the nib is H, and the taper of the nib is a；The sectional area of the porch of the die orifice is S₁；The lower port of the nib and the entrance of the die orifice are in the same plane；The radius R of the upper port of the nib is equal to the internal diameter of recipient, S₂More than S₁, S₂With S₁Between for the ring-shaped platform region at die orifice.Power needed for can the reducing during extrusion process of the present invention.

Description

Metal Extrusion Flat Cone Die

technical field

The invention relates to the field of profile extrusion processing, in particular to a die for extruding metal, that is, a metal extruding flat cone die.

Background technique

During the extrusion process, the metal is carried out under the state of three-dimensional compressive stress, which can fully exert the plastic properties of the metal, and can well improve the grain refinement of the metal, and the deformation is more uniform, so that the fiber changes from loose to It is more compact, thus improving the performance of the metal. However, the force required by the extrusion process is also relatively large. In order to reduce the extrusion force, the structure of the mold must be adjusted.

The current extrusion dies can be divided into three categories according to the overall structure: flat die, cone die, and flat cone die. Among them, the extrusion force required by the flat die is the largest, and the extrusion force required by the cone die and the flat cone die is a little smaller; But in the actual production process, even if the cone die and the flat cone die are used, as shown in Figure 1, the required extrusion force is still very large, which exceeds the capacity of the equipment.

To sum up, the following problems exist in the prior art: the extrusion force required by the existing cone die and flat cone die is relatively large, which exceeds the capability range of the equipment, and is not conducive to the miniaturization of the extrusion equipment.

Contents of the invention

The invention provides a metal extrusion flat cone die, which can provide proper extrusion force under the condition of satisfying the extrusion ratio of extrusion deformation, and reduce the extrusion force required in the extrusion process.

For this reason, the present invention proposes a kind of metal extrusion flat cone die, and described metal extrusion flat cone die comprises:

Die holes and die openings connected up and down in turn; the axes of the die holes coincide with the axes of the die openings;

The die hole is a frustum-shaped cavity, and the die opening is a columnar cavity or a stepped columnar cavity;

The die hole has an upper port and a lower port, the upper port of the die hole is the entrance of the die hole, the lower port of the die hole is the outlet of the die hole, and the lower port of the die hole is connected to the mouth of the die hole. Entrance;

The diameter of the upper port of the die hole is R, the cross-sectional area of the lower port of the die hole is S ₂ , the diameter of the upper port of the die hole is greater than the diameter of the lower port of the die hole, and the die hole The height is H, and the taper of the die hole is a;

The cross-sectional area at the entrance of the die opening is S ₁ ; the lower port of the die hole is located on the same plane as the entrance of the die opening;

The diameter R of the upper port of the die hole is equal to the inner diameter of the extrusion cylinder, S ₂ is larger than S ₁ , and the area between S ₂ and S ₁ is an annular platform area at the die opening.

Further, the taper a of the die hole ranges from 25° to 30°.

Further, it is characterized in that the parameters of the metal extrusion flat cone die are determined according to the following formula:

Among them, the unit of a is degrees, C is the proportional coefficient, the units of H, R and r are millimeters, r represents the circumscribed circle radius of the entrance of the die opening, and R represents the diameter of the upper port of the die hole or the diameter of the blank.

Further, the value of C is 3 to 5.

Further, a is further 30°, and H is further 30 to 50 mm.

Further, the value of C is further from 3.3 to 5.

Further, the extrusion ratio of the metal extrusion flat cone die is greater than 12.

Further, R is 80mm, S ₂ is 784.27mm2, S ₁ is 132.73mm2, r is 6.5mm, a is 30°, and H is 48mm.

The metal extruding flat cone die of the invention is optimized in structure, can reduce the thickness of the dead zone, and reduce the force required in the extrusion process. The present invention is not only suitable for extruding round rod profiles, but also applicable to other solid structure profiles. The present invention can be applied to copper, copper alloy, aluminum, or aluminum alloy and other metals suitable for extrusion deformation.

Description of drawings

Fig. 1 is the working principle diagram of existing flat cone die;

Fig. 2 is the working principle figure of metal extrusion flat cone die of the present invention;

Fig. 3 is the top view structural representation of metal extrusion flat cone die of the present invention;

Fig. 4 is a schematic diagram of the cross-sectional structure of A-A in Fig. 3;

Fig. 5 is the extrusion force comparison figure of existing flat cone die and metal extrusion flat cone die of the present invention;

Fig. 6 is the variation trend diagram of the extrusion force of the metal extrusion flat cone die with the taper a of the present invention;

Fig. 7 is when the taper a is kept at 30 °, the extrusion force of the metal extrusion flat cone die of the present invention varies with the height H of the die hole;

Fig. 8 is a schematic diagram of the blank dead zone during the extrusion process of the metal extrusion flat cone die of the present invention;

Fig. 9 shows the relationship between the extrusion dead zone e and C value of the metal extrusion flat cone die of the present invention.

Explanation of reference numbers:

1. Die hole; 2. Ring platform area; 3. Die mouth;

11. Upper port; 13. Lower port

31. The entrance of the die mouth;

detailed description

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the present invention will now be described with reference to the accompanying drawings.

As shown in Fig. 2, Fig. 3 and Fig. 4, the present invention proposes a kind of novel mold, namely novel flat cone die, that is, metal extrusion flat cone die, and described metal extrusion flat cone die comprises:

Die hole 1 and die opening 3 connected up and down in turn; the axis of said die hole 1 coincides with the axis of die opening 3;

The die hole 1 is a frustum-shaped cavity, and the die opening 3 is a columnar cavity or a stepped columnar cavity;

Described die hole 1 has upper port 11 and lower port 13, and the upper port 11 of described die hole is the inlet 31 of die hole, and the lower port 13 of described die hole is the outlet of die hole, and the lower port of described die hole 13 is connected to the inlet 31 of the die mouth;

The diameter of the upper port 11 of the die hole is R, the cross-sectional area of the lower port 13 of the die hole is S ₂ , the diameter of the upper port of the die hole is greater than the diameter of the lower port of the die hole, the The height of the die hole is H, and the taper of the die hole is a;

The cross-sectional area at the entrance of the die opening is S ₁ ; the lower port of the die hole is located on the same plane as the entrance of the die opening;

The radius R of the upper port of the die hole is equal to the inner diameter of the extrusion cylinder, S ₂ is larger than S ₁ , and the area between S ₂ and S ₁ is the annular platform area 2 at the die opening.

The same point of the present invention and the cone die is that the blank enters the mold through the extrusion cylinder, and the blank also directly enters the die hole as a whole, while in the flat cone die, a part of the blank is pushed near the die hole, which is different from the cone die. The most important thing is that there is a flat angle area near the die mouth, that is, the ring platform area 2.

The most prominent function of the flat cone die of the present invention is to reduce the required extrusion force in the extrusion process. First of all, the reason why the structure removes the B area in Figure 1 is that a large part of this area will form an extrusion dead zone, which will affect the fluidity of the metal. In addition, the existence of the B area will prevent the billet from entering the die hole. The resistance will increase, increasing the extrusion force required for the extrusion process. Therefore, this part is removed in the present invention, and the die hole is enlarged like a cone die, allowing the blank to directly enter the die cavity from the die hole. Secondly, the reason why the present invention sets a section of flat angle area (annular platform area 2) at the die opening is because of the following two considerations; one, it can increase the amount of metal near the die opening and reduce the die opening. The resistance of the nearby die to the metal, thereby reducing the extrusion force; although this flat-angle area also has a certain resistance to the metal, the metal in this flat-angle area near the die mouth has a fast flow rate and good fluidity, so the effect of obstruction is not great. Not obvious. Second, the purpose of setting a section of flat angle area is to form a dead zone near the die wall to accommodate the skin part of the billet; if the skin of the billet is extruded into the profile, it will cause defects and affect the quality of the product.

In order to further select various parameters and dimensions of the die to obtain a more ideal extrusion force, it is necessary to further refine and optimize the above-mentioned metal extrusion flat cone die.

Considering the mold structure, the factors affecting the extrusion force are not only the type of the mold, but also some structural size parameters under each structure, such as the parameters a, H, S1, S2, and R in Figure 2. Among them, a represents the cone angle of the mold, H represents the height of the cone die part, and S1 represents the cross-sectional area of the extruded profile. R represents the diameter of the blank. In the actual production process, S1 and R are generally fixed, while other parameters are adjustable. Therefore, to obtain the best process, a, H, and S2 must be controlled within a reasonable range.

Figure 5 compares the variation of the extrusion force of the flat cone die and the new flat cone die with h when R, S1 and a are the same.

It can be seen that H is in this region, and the extrusion force required by the novel flat cone die proposed by the present invention is smaller than that required by the common flat cone die. In addition, it should be noted that the point where the two lines overlap represents When H is at the value, both molds have evolved into cone molds, that is, when the ordinary flat cone mold B=0, the new flat cone mold S2=S1; therefore the curve in the figure also shows that under the new flat cone mold structure The extrusion force required is also less than that of a cone die structure. As for the reason why the extrusion force changes with h when H is less than 30mm is not depicted in Figure 5, it is because under this condition, when H continues to decrease, the two molds are closer to the flat mold, and the extrusion force will definitely increase. .

In order to further explore the relationship between the extrusion force and various parameters under the new flat cone die structure, the following two sets of simulation experiments were done using DEFORM software:

When H is kept at 33.5mm, the variation trend of extrusion force with a is shown in Figure 6; it can be seen from the figure that when the cone angle a is between 10° and 30°, the required extrusion force is small, but In the follow-up analysis of the size of the extrusion dead zone, it was found that when a is less than 25°, the skin defects of the billet are easy to flow into the profile, thereby affecting the quality of the extruded profile, so it is more appropriate to keep a between 25° and 30°; In addition, the analysis of the size of the dead zone mentioned above is to use the "point tracking" command in the DEFORM software to select a series of representative points in the billet and observe whether these points will be squeezed during the extrusion process. Out of the mold, so as to judge the dead zone. In order to further explore the relationship between extrusion force and each parameter under the flat cone die structure of the present invention, utilize DEFORM software to do following two groups of simulation experiments:

When H remained at 33.5mm, the variation trend of the extrusion force of the flat cone die of the present invention with a is shown in Figure 6; as can be seen from the figure, when the cone angle a is between 10° and 30°, the required The extrusion force is small, but in the subsequent analysis of the size of the extrusion dead zone, it is found that when a is less than 25°, the skin defects of the billet are easy to flow into the profile, thereby affecting the quality of the extruded profile, so a is kept at 25° to 30° °; in addition, the analysis of the size of the dead zone mentioned above is to use the "pointTracking" command in the DEFORM software to select a series of representative points in the billet and observe whether these points will Extrude the die to judge the dead zone.

When a remained at 30°, the variation trend of flat cone die extrusion force of the present invention with H is shown in Figure 7; as can be seen from the figure, the required extrusion force when H is very small; when H is in the medium The extrusion force is small at about 30 to 50mm, but when H exceeds this range, the extrusion begins to increase rapidly.

From the previous experiments, it can be found that within a certain range, the extrusion force is more sensitive to the change of a than H; in addition, the dead zone thickness e is shown in Figure 8, and the shaded part in the figure shows that for a billet , it will form the part of the dead zone in the extrusion process, and judge the size of the dead zone according to the thickness e; the specific verification method for the thickness e of the dead zone is to use the "point tracking" command in the DEFORM software mentioned earlier, from the distance Select a series of representative points in the area after the front end surface L of the blank (as shown in Figure 8). The reason why the points in this area before L are not selected is that most of the blanks in this area will fill the cavity and A dead zone is formed near the mold corner area, so it is not representative; considering the size of the blank and the mold, L is taken as 15mm in the subsequent simulation experiments. It is related to S2, and under different R and S1, that is, the extrusion ratio is different, and the size of e is also different. Based on the above findings, a proportional coefficient C value is derived: C=S2/S1. By studying the related proportional coefficient The size of the C value, the relationship between e and C (the relationship between the proportional coefficient C and the size of the dead zone) is obtained under different extrusion ratios. According to this relationship, a more suitable value of C is found under different extrusion ratios. Finally, adjust the size of a and H according to the obtained C value to achieve optimization. The relationship between C and related parameters is shown in the formula (1-1):

r: Indicates the radius of the circumscribed circle of the die opening, which can also be said to be the radius of the circumscribed circle of the section area of the extruded profile; R: the diameter of the upper port of the die hole or the diameter of the billet;

It can be seen from the first three sets of experiments that the extrusion force is small when a is around 25° to 30°, so in the design process, first select a within this range, and finally only need to adjust H to realize the optimization.

Table 1 is a table of dead zone thickness experiments performed by extruding a round bar profile with a diameter of 13 mm from a round bar with a diameter of 80 mm. In order to obtain a more suitable value range of C value under different extrusion ratios, as shown in Figure 9, the dead zone size e and C value under the three extrusion ratios of 12, 25, and 38 were studied respectively. relationship, the results are shown in Figure 8 and Figure 9; it can be seen from the figure that for the new flat cone die, the greater the extrusion ratio, the greater the thickness e of the dead zone, and the thickness e of the dead zone increases with the increase of C And increase, under different extrusion ratios, the change rule is still consistent; in addition, when C is between 3 and 5, the dead zone thickness B changes greatly, comprehensive consideration, the value of C is between 3.3 and 5 If the extrusion ratio exceeds 38, the value of C should be slightly less than 3.3, but not less than 3, otherwise the surface defects of the billet will enter the profile . The value range of the extrusion ratio in the present invention is, for example, 12 to 38, and the value of C is 3.3 to 5.

The present invention is used, for example, to extrude an aluminum alloy round bar with a diameter of 80 mm into a 13 mm round bar profile. Considering that the extruded profile is small, it is hoped to realize production on equipment with small tonnage, so it is hoped to design a set of extrusion dies that can make its extrusion force as small as possible, so as to reduce costs, reduce energy consumption, and reduce equipment footprint . However, it is found through simulation that the extrusion force required by the existing cone die and the flat cone die is relatively close to the maximum extrusion force that the equipment can provide. For this reason, adopted the novel flat cone die of the structure of the present invention, can make small-sized equipment under the condition of less extrusion force, extrude required bar.

After selecting the flat cone die of the present invention, it is necessary to further select reasonable die parameters, otherwise, different die parameters will also affect the size of the extrusion force. The factors affecting the extrusion force are not only the structure and type of the mold, but also some structural size parameters under each structure. For example, parameters a, H, S1, S2, R. Among them, a represents the cone angle of the mold, H represents the height of the cone die part, and S1 represents the cross-sectional area of the extruded profile. S2 represents the size of the flat angle section near the die (including the S1 part), and R represents the diameter of the blank. In the actual production process, S1 and R are generally fixed, while other parameters are adjustable. Therefore, to obtain the best process, a, H, and S2 must be controlled within a reasonable range.

For this reason, utilized DEFORM software to do two groups of simulation experiments, obtained the extrusion force of flat cone die of the present invention with the variation trend of a, the extrusion force of flat cone die of the present invention with the variation trend of H, thereby determined The value range of a, and then through the finite element method, the Pythagorean theorem, and the size and distribution structure of the dead zone in the extrusion process, the parameter formula of the mold is obtained:

Among them, a represents the cone angle of the mold, H represents the height of the cone die part, and S1 represents the cross-sectional area of the extruded profile. S2 represents the size of the flat angle section near the die (including the S1 part), and R represents the diameter of the blank. In the actual production process, S1 and R are generally fixed, while other parameters are adjustable. Therefore, to obtain the best process, a, H, and S2 must be controlled within a reasonable range.

According to the experiment, firstly, the value range of a is 25° to 30°.

Then according to the extrusion ratio and the dead zone thickness, the range of the proportional coefficient C is further determined through experiments. Considering comprehensively, the value of C is more suitable between 3.3 and 5. When the extrusion ratio is large, the C value takes the lower limit; The upper limit is taken in hours; if the extrusion ratio exceeds 38, the value of C should be slightly less than 3.3, but not less than 3.

Then, according to the formula 1-1, the height H of the cone die part can be obtained.

Table 1 is the dead zone thickness experimental verification form of extruding a round bar profile with a diameter of 13 mm using a round bar with a diameter of 80 mm:

Table 1: Table of Dead Zone Thickness Experiment Using 80mm Diameter Round Bar to Extrude 13mm Diameter Round Bar Profile

The data selection in Table 1 is optimized based on the feedback results in Figure 7. First set H in the range of about 10-50mm (because the extrusion force is small in this range), and based on H, get The change of the corresponding C value and dead zone thickness e under different H, where the specific size selection of H in each set of data is adjusted based on the feedback results from the previous set of data.

For extruding an aluminum alloy round bar with a diameter of 80mm into a round bar with a diameter of 13mm, according to Table 1, the value range of C can be determined according to the reasonable dead zone thickness, and the dead zone size of the third and fourth groups is more appropriate. In order to further determine the optimal value of C.

For extruding an aluminum alloy round bar with a diameter of 80mm into a round bar with a diameter of 13mm, the specific parameters of a preferred embodiment of the flat cone die of the present invention are: C is 3.58, S ₂ is 784.27mm ² , and S ₁ is 132.73 mm ² , r is 6.5mm, a is 30°, H is 48mm, extrusion force is 221 tons, dead zone thickness e is 6mm. As a comparison, another embodiment using Fig. 4, that is, in the embodiment before optimization, the proportional coefficient C is 5.91, the extrusion force is 219 tons, and the thickness e of the dead zone is 9 mm. Although there is basically no change in the extrusion force before and after optimization, the thickness of the dead zone has been reduced, which not only reduces waste, but also gives full play to the forming performance of the billet in the mold cavity; compared with ordinary flat cone die and cone die, The flat cone die of the present invention is more labor-saving. The flat cone die of the present invention is more evenly stressed, which increases the life of the die. In addition, the present invention proposes a brand new c value optimization method, which realizes the further optimization of the new flat cone die. The present invention can be applied to copper, copper alloy, aluminum, or aluminum alloy or other metals suitable for extrusion deformation.

The above descriptions are only illustrative specific implementations of the present invention, and are not intended to limit the scope of the present invention. Because the various components of the present invention can be combined with each other under the condition of no conflict, any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall belong to the protection of the present invention. range.

Claims (9)

1. A metal extrusion flat cone die is characterized in that, the metal extrusion flat cone die comprises: Die holes and die openings connected up and down in turn; the axes of the die holes coincide with the axes of the die openings; The die hole is a frustum-shaped cavity, and the die opening is a columnar cavity or a stepped columnar cavity; The die hole has an upper port and a lower port, the upper port of the die hole is the entrance of the die hole, the lower port of the die hole is the outlet of the die hole, and the lower port of the die hole is connected to the mouth of the die hole. Entrance; The diameter of the upper port of the die hole is R, the cross-sectional area of the lower port of the die hole is S ₂ , the diameter of the upper port of the die hole is greater than the diameter of the lower port of the die hole, and the die hole The height is H, and the taper of the die hole is a; The cross-sectional area at the entrance of the die opening is S ₁ ; the lower port of the die hole is located on the same plane as the entrance of the die opening; The diameter R of the upper port of the die hole is equal to the inner diameter of the extrusion cylinder, S ₂ is larger than S ₁ , and the area between S ₂ and S ₁ is an annular platform area at the die opening. 2. The metal extrusion flat cone die according to claim 1, characterized in that, the value of the taper a of the die hole is 25° to 30°. 3. metal extrusion flat cone die as claimed in claim 1, is characterized in that, described metal extrusion flat cone die determines parameters according to the following formula: <mrow><mi>H</mi><mo>=</mo><mfrac><mrow><mi>R</mi><mo>-</mo><mn>2</mn><mi>r</mi><msqrt><mi>C</mi></msqrt></mrow><mrow><mn>2</mn><mi>tan</mi><mi></mi><mi>a</mi></mrow></mfrac><mo>;</mo></mrow> ; <mrow><mi>C</mi><mo>=</mo><mfrac><msub><mi>S</mi><mn>2</mn></msub><msub><mi>S</mi><mn>1</mn></msub></mfrac><mo>;</mo></mrow> ; Among them, the unit of a is degree, C is the proportional coefficient, the units of H, R and r are millimeters, r represents the radius of the circumscribed circle of the entrance of the die opening, R represents the diameter of the upper port of the die hole, S ₂ and S ₁ The units are square millimeters. 4. The metal extrusion flat cone die as claimed in claim 3, wherein the value of C is 3 to 5. 5. The flat cone die for metal extrusion according to claim 3, wherein a is further 30°, and H is further 30 to 50 mm. 6. The metal extrusion flat cone die as claimed in claim 3, wherein the value of C is further 3.3 to 5. 7. The metal extrusion flat cone die according to claim 1, characterized in that, the extrusion ratio of the metal extrusion flat cone die is greater than 12. 8. The metal extrusion flat cone die as claimed in claim 1, characterized in that, R is 80 mm, S ₂ is 784.27 mm ² , S ₁ is 132.73 mm ² , r is 6.5 mm, a is 30°, and H is 48mm. 9. The flat cone die for metal extrusion according to claim 1, characterized in that, the flat cone die for metal extrusion is suitable for extruding rods of copper, copper alloys or aluminum, aluminum alloys.