A sector roller forging forming die and a rod blank tip rolling equipment

Abstract

The utility model belongs to the field of forging equipment technology relates to a fan -shaped roll forging forming die, the fan -shaped roll forging forming die is fan -shaped, and the outer surface is circular arc, the outer surface of fan -shaped roll forging forming die is set up the die cavity that has, the die cavity passes through both ends of fan -shaped roll forging forming die, and the depth of die cavity along the radial is successively decreased from one end of fan -shaped roll forging forming die to the other end. The fan -shaped roll forging forming die of the utility model has the depth gradual change die cavity, by adopting the fan -shaped roll forging forming die of reverse rotation cooperation die cavity depth gradual change, realized copper -clad aluminum bar blank single -time tip forming, replaced traditional multistage gradient rolling process, greatly promoted the tip efficiency and reduced the energy consumption, and the copper -aluminum composite layer stress is evenly distributed in the rolling process, effectively solved the end cracking and copper layer bulging defects and other problems, improved the tip qualified rate.

Description

Technical Field

[0001] This utility model relates to a fan-shaped roll forging die and a billet tip rolling device, belonging to the field of forging equipment technology. Background Technology

[0002] In recent years, copper-aluminum composite materials have become an energy-saving conductor material. They possess the conductivity of copper and the lightweight properties of aluminum. Replacing copper busbars can effectively save copper resources, and they have become an indispensable alternative in the electrical engineering field.

[0003] In the rolling process of copper-clad aluminum billets, the rolling bite angle is strictly limited, making the rolling bite process extremely difficult. In order to achieve successful rolling, the existing billets must be tipped to reduce the rolling difficulty and ensure that the rolling process can proceed stably.

[0004] However, the existing tipping technology has the following drawbacks: First, due to the inherent properties of copper-aluminum composite materials, traditional roll forging processes require sequential rolling operations according to a gradient dimension. Rolling the billet to the target size often necessitates 8-10 repeated rolling passes, which not only consumes a significant amount of time and extends the production cycle, but also results in extremely high energy consumption throughout the rolling process, significantly increasing production costs, hindering the improvement of production efficiency, and failing to meet market demands.

[0005] Secondly, high-strength copper alloys in copper-aluminum composites are highly susceptible to cracking at the ends during the rolling process, with crack depths sometimes reaching 1mm to 2mm. Furthermore, the copper layer is prone to bulging and cracking on the rolled sides. These surface defects not only affect the product's appearance but also reduce its performance and reliability.

[0006] In addition, conventional mold steels currently in use, such as Cr12MoV, are prone to cracking when subjected to high pressure during the rolling process.

[0007] Therefore, a method for rolling bar billets to the point is needed to solve the above problems. Utility Model Content

[0008] The purpose of this utility model is to provide a new technical solution to improve or solve the technical problems existing in the prior art as described above.

[0009] The technical solution provided by this utility model is as follows: a fan-shaped roll forging die, wherein the fan-shaped roll forging die is fan-shaped and the outer surface is arc-shaped, and a die cavity is opened on the outer surface of the fan-shaped roll forging die, the die cavity passes through both ends of the fan-shaped roll forging die, and the depth of the die cavity in the radial direction decreases continuously from one end of the fan-shaped roll forging die to the other end.

[0010] Compared with the prior art, the technical solution provided by this utility model has the following beneficial effects: The fan-shaped roll forging die of this utility model has a depth-gradient die cavity. By adopting a fan-shaped roll forging die with reverse rotation and a depth-gradient die cavity, the single-pass tip forming of copper-clad aluminum billet is realized, replacing the traditional multi-pass gradient rolling process, which greatly improves the tip forming efficiency and reduces energy consumption. During the rolling process, the stress of the copper-aluminum composite layer is evenly distributed, effectively solving problems such as end cracking and copper layer bulging defects, and improving the tip forming qualification rate.

[0011] Based on the above technical solution, the present invention can be further improved as follows.

[0012] Furthermore, the cross-section of the mold cavity is an isosceles trapezoid, and the width of the bottom of the mold cavity is smaller than the width of the opening end of the mold cavity.

[0013] The advantages of adopting the above-mentioned further solutions are that it facilitates material feeding while ensuring the size of the billet and effectively controls the deformation.

[0014] Furthermore, the width of the mold cavity at the maximum depth end is greater than the width at the minimum depth end; and the width of the mold cavity is smallest at the position between the maximum depth end and the minimum depth end, forming a waisted structure that contracts in the middle.

[0015] The beneficial effect of adopting the above-mentioned further scheme is that, through the waist structure with central contraction, the metal flow of the billet is more uniform and reasonable during the rolling process, avoiding rolling defects such as flash and side cracks caused by local stress concentration, thereby improving the quality and pass rate of the billet after tipping.

[0016] Furthermore, the inner side of the fan-shaped roll forging die is provided with a keyway, which is used to engage with the key of the roll for installation.

[0017] The beneficial effect of adopting the above-mentioned further solution is that by installing the inner keyway and the roll with a key, zero-backlash transmission can be achieved, avoiding circumferential displacement of the die under rolling impact, and ensuring the stability and accuracy of the fan-shaped roll forging die during the rolling process.

[0018] Furthermore, the center angle θ of the fan-shaped roll forging die ranges from 30° to 60°.

[0019] Furthermore, the depth of the mold cavity gradually varies from 41.5 mm to 69 mm, and the depth change is linearly decreasing.

[0020] The advantage of adopting the above-mentioned further scheme is that linear gradient can ensure a constant compression ratio.

[0021] A bar forging equipment includes a drive device, an upper roll and a lower roll, and a fan-shaped roll forging die. The two fan-shaped roll forging dies are respectively installed on the upper roll and the lower roll, and are arranged vertically opposite each other. The drive device is used to drive the upper roll and the lower roll to rotate relative to each other, so that the fan-shaped roll forging die can roll forge the bar.

[0022] Furthermore, it also includes a conveyor roller, which is provided with multiple rotatable rollers and is located on one side of the lower roll for carrying the billet.

[0023] The beneficial effect of adopting the above-mentioned further solution is that the billet to be rolled is placed on the conveyor rollers, and during the rolling process, the conveyor rollers switch to a free-rotation state; because the rotation direction of the die is opposite to the feed direction of the billet, the rolled billet automatically exits from the die cavity. The design of the reverse rotation unloading mechanism allows the rolled billet to automatically exit from the die cavity without manual intervention. At the same time, the conveyor rollers switch to a free-rotation state during the rolling process, and during unloading, the conveyor rollers rotate freely with the billet without applying resistance, avoiding the risk of jamming and surface scratches during unloading. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] In the picture, Figure 1 This is a schematic diagram of the structure of the fan-shaped roll forging die of the present invention; Figure 2 For the present invention Figure 1 The main view; Figure 3 For the present invention Figure 2 The right view; Figure 4 For the present invention Figure 3 Sectional view along axis AA; Figure 5 For the present invention Figure 3 B-direction projection view; Figure 6 For the present invention Figure 3 C-direction projection view; Figure 7 This is a schematic diagram of the structure of the two fan-shaped roll forging dies of the present invention, which are rotated to align and close at the maximum depth of the die cavity to form a billet insertion port; Figure 8This is a three-dimensional structural diagram of the insertion port of the billet when the rolling process begins; Figure 9 For the present invention Figure 8 Side view; Figure 10 This is a schematic diagram of the tipping process of the present invention; Figure 11 This is a schematic diagram showing the tipping process after the present invention is completed; Figure 12 For the present invention Figure 11 A schematic diagram of the three-dimensional structure.

[0026] In the figure, 1. Fan-shaped roll forging die; 2. Die cavity; 21. End with maximum depth; 22. End with minimum depth; 3. Conveyor roll; 4. Upper roll; 5. Lower roll; 6. Keyway; 7. Billet insertion port; 8. Billet. Detailed Implementation

[0027] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and do not imply any priority in order or any specific technical meaning. Furthermore, the concepts of "connection" and "linkage" mentioned in this application, unless otherwise specified, are considered to include both direct connection (linkage) and indirect connection (linkage).

[0028] When interpreting the description of this application, it should be clarified that terms such as "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating directions or positional relationships, are based on the perspective and layout shown in the accompanying drawings. They are intended to facilitate explanation and simplify the description process, and are not absolute limitations on the actual location, construction method, or operating mode of the described device or element. Therefore, these terms should not be construed as restrictive interpretations of the content of this application.

[0029] The principles and features of this utility model are described below with reference to examples. The examples are only used to explain this utility model and are not intended to limit the scope of this utility model.

[0030] like Figures 1-6 As shown, a fan-shaped roll forging die is provided. The fan-shaped roll forging die is fan-shaped with an arc-shaped outer surface. A die cavity is formed on the outer surface of the fan-shaped roll forging die. The die cavity extends through both ends of the fan-shaped roll forging die, and the depth of the die cavity decreases continuously from one end of the fan-shaped roll forging die to the other end along the radial direction.

[0031] The cross-section of the die cavity is an isosceles trapezoid, with the width of the cavity bottom being smaller than the width of the cavity opening. This isosceles trapezoidal shape allows for smoother entry of the billet, as the wider opening provides sufficient space for feeding. During rolling, as the die cavity gradually closes from its deepest end to its shallowest end, the smaller bottom width allows for effective extrusion and shaping of the billet ends, ensuring the billet dimensions meet requirements. Furthermore, the die cavity shape of this invention allows for precise control of the billet's deformation during rolling, preventing excessive or insufficient deformation, thereby improving the quality and stability of the rolled tip.

[0032] The width of the die cavity at its maximum depth end is greater than its minimum depth end; and the die cavity width is smallest between the maximum and minimum depth ends, forming a waisted structure that contracts in the middle. This waisted structure allows for more uniform and rational metal flow during the rolling process, preventing rolling defects such as flash and side cracks caused by localized stress concentration, thereby improving the quality and yield of the rolled billet.

[0033] like Figure 3 - Figure 6 As shown, the maximum depth of cavity 2 is dmax, the minimum depth is dmin, and the depth at the AA-direction section is dmid, where dmax > dmid > dmin. At the maximum depth end 21, the width b1 of the opening of cavity 2 is greater than the width b2 of the bottom of cavity 2, i.e., b1 > b2; at the minimum depth end 22, the width c1 of the opening of cavity 2 is greater than the width c2 of the bottom of cavity 2, i.e., c1 > c2; at the AA-direction section, the width a1 of the opening of cavity 2 is greater than the width a2 of the bottom of cavity 2, i.e., a1 > a2; the width of cavity 2 reaches its minimum value at the position between the maximum depth end 21 and the minimum depth end 22, i.e., c1 > b1 > a1, c2 > b2 > a2.

[0034] The inner side of the fan-shaped roll forging die is provided with a keyway, which is used for key-fitting installation with the roll.

[0035] The central angle θ of the sector-shaped roll forging die ranges from 30° to 60°.

[0036] The depth of the mold cavity varies from 41.5 mm to 69 mm, and the depth decreases linearly.

[0037] A bar forging and sharpening device includes a drive unit, an upper roll, and a lower roll. It also includes two fan-shaped forging dies, one mounted on the upper roll and the other on the lower roll, arranged vertically opposite to each other. The drive unit drives the upper roll and the lower roll to rotate relative to each other, thereby forging the bar billet using the fan-shaped forging dies. A conveyor roll is also included, equipped with multiple rotatable rollers. The conveyor roll is located on one side of the lower roll and carries the bar billet. Through the relative rotation of the upper roll and the lower roll, the bar billet undergoes continuous forging action within the cavity of the fan-shaped forging dies, gradually forming the desired pointed shape.

[0038] A method for rolling a bar billet into a pointed shape includes the following steps: S1. Pretreatment: Embossing or roughening the surface of the end of the billet 8 to increase surface friction; the billet 8 is square with a side length ≥110mm, preferably 135mm.

[0039] S2. Install the molds: Install the two sector-shaped roll forging molds 1 on the upper roll 4 and lower roll 5 of the rolling mill, respectively. The sector-shaped roll forging molds 1 are arranged vertically opposite each other. Figure 1 and Figure 2 As shown; the inner side of the fan-shaped roll forging die 1 is provided with a keyway 6; the fan-shaped roll forging die 1 is installed with the roll through the keyway 6 on the inner side.

[0040] S3. Initial mold closing: Drive the two fan-shaped roll forging dies 1 to rotate until the maximum depth end 21 of the mold cavity 2 aligns and closes, forming the billet insertion port 7, such as... Figure 7 As shown, the length of the billet 8 extending into the mold cavity 2 ranges from 200mm to 300mm.

[0041] S4. Positioning of billet 8: Insert the end of billet 8 to be rolled into the closed die cavity 2 from the billet insertion port 7. The shape of the cross section of the closed die cavity 2 matches the square cross section of billet 8. S5. Reverse rolling forming: Drive the two fan-shaped roll forging dies 1 to rotate in opposite directions around their respective axes; make the die cavity 2 gradually close from the deepest end 21 to the deepest end 22, and simultaneously roll the end of the billet 8 into a point. At the same time, because the rotation direction of the die is opposite to the feeding direction of the billet 8, the billet 8 after rolling into a point automatically exits from the die cavity 2; place the billet 8 to be rolled into a point on the conveying roller 3. During the rolling process, the conveying roller 3 switches to a free rotation state; because the rotation direction of the die is opposite to the feeding direction of the billet 8, the billet 8 after rolling into a point automatically exits from the die cavity 2.

[0042] S6. Inspection: Check the surface quality and use vernier calipers to measure whether the rolled tip size is qualified. The surface quality inspection includes visual inspection of surface cracks, scratches and bulging defects.

[0043] like Figure 8 - Figure 12 As shown, in this embodiment, a copper-clad aluminum rod blank 8 with a side length of 135mm × 135mm is used as an example to further illustrate the specific implementation process and effects of the present invention: First, the ends of the copper-clad aluminum billet 8 with a side length of 135mm×135mm are embossed or roughened to increase surface friction, ensure a tight fit between the billet 8 and the die during rolling, prevent slippage, and thus improve the accuracy and efficiency of the rolling tip.

[0044] Next, the two fan-shaped roll forging dies 1 are installed on the upper roll 4 and lower roll 5 of the rolling mill, respectively.

[0045] During the initial mold closing stage, the two fan-shaped roll forging dies 1 are driven to rotate until the maximum depth end 21 of the mold cavity 2 is aligned and closed, forming the billet insertion port 7. At this time, the end of the pre-treated billet 8 to be rolled is inserted into the mold cavity 2 from the billet insertion port 7, with an insertion length of 270mm.

[0046] Subsequently, the reverse rolling forming stage begins. The rolling mill is started, driving the two sector-shaped roll forging dies 1 to rotate in opposite directions around their respective axes, causing the die cavity 2 to gradually close from the deepest end 21 to the deepest end 22. During this process, the end of the billet 8 is squeezed by the die, gradually forming a sharp shape. At the same time, since the rotation direction of the die is opposite to the feeding direction of the billet 8, the tipped billet 8 can automatically exit from the die cavity 2.

[0047] In addition, during the rolling process, the conveyor roller 3 switches to a free rotation state, rotating freely with the billet 8 without applying resistance, thus avoiding the risk of jamming and surface scratches during unloading.

[0048] After the tip is rolled, its dimensions are precisely measured using vernier calipers. The longitudinal dimension of the tip is 85 mm, and its length is 350 mm, achieving one-time forming. The forged material can achieve a maximum deformation rate of 60%, with a longitudinal elongation coefficient of approximately 0.65 and a length elongation coefficient of approximately 1.25.

[0049] The method for tipping copper-clad aluminum billet 8 of the present invention achieves single-pass tipping of copper-clad aluminum billet 8 by using a fan-shaped roll forging die 1 with a gradually varying depth in the cavity 2 and a reverse rotation, replacing the traditional multi-pass gradient rolling process, thereby improving tipping efficiency and reducing energy consumption. The split fan-shaped roll forging die 1 has a cavity 2 with a gradually varying depth, which makes the stress of the copper-aluminum composite layer uniformly distributed during rolling, solving the defects of end cracking and copper layer bulging. The crack depth is reduced from 1-2 mm to zero, and the surface defect rate is reduced from 15% to 0%, ultimately improving the tipping qualification rate. The reverse rotation ejection mechanism, in conjunction with the free rotation of the conveyor roller 3, allows the tipped billet 8 to automatically exit from the cavity 2 with zero resistance, completely eliminating the risk of ejection jamming and surface scratches.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0051] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A fan-shaped roll forging die, characterized in that, The fan-shaped roll forging die is fan-shaped with an arc-shaped outer surface. A mold cavity is formed on the outer surface of the fan-shaped roll forging die. The mold cavity extends through both ends of the fan-shaped roll forging die, and the depth of the mold cavity decreases continuously from one end of the fan-shaped roll forging die to the other end along the radial direction.

2. The fan-shaped roll forging die according to claim 1, characterized in that, The cross-section of the mold cavity is an isosceles trapezoid, and the width of the bottom of the mold cavity is smaller than the width of the opening end of the mold cavity.

3. The fan-shaped roll forging die according to claim 2, characterized in that, The width of the mold cavity at the maximum depth end is greater than the width at the minimum depth end; and the width of the mold cavity is smallest at the position between the maximum depth end and the minimum depth end, forming a waisted structure that contracts in the middle.

4. The sector-shaped roll forging die according to any one of claims 1 to 3, characterized in that, The inner side of the fan-shaped roll forging die is provided with a keyway, which is used for key-fitting installation with the roll.

5. The fan-shaped roll forging die according to claim 4, characterized in that, The central angle θ of the sector-shaped roll forging die ranges from 30° to 60°.

6. The fan-shaped roll forging die according to claim 1, characterized in that, The depth of the mold cavity varies from 41.5 mm to 69 mm, and the depth decreases linearly.

7. A bar rolling mill, comprising a drive unit, an upper roll, and a lower roll, characterized in that, It also includes the fan-shaped roll forging die according to any one of claims 1 to 6, wherein the two fan-shaped roll forging dies are respectively installed on the upper roll and the lower roll, and the two fan-shaped roll forging dies are arranged in a vertically opposite manner. The driving device is used to drive the upper roll and the lower roll to rotate relative to each other, so that the fan-shaped roll forging die can roll forge the bar billet.

8. The bar rolling mill tipping equipment according to claim 7, characterized in that, It also includes a conveyor roller, which is equipped with multiple rotatable rollers and is located on one side of the lower roll to carry the bar billet.

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