A method for forming a straight-angle trapezoidal belt corner free forging

Abstract

This invention belongs to the field of forging technology and relates to a forming method for a right-angled trapezoidal free forging with a corner. The method includes: Step 1, placing the first right-angled end of a rectangular billet into the V-shaped cavity of a die, with the two faces of the first right-angled end respectively adhering to the two faces of the V-shaped cavity, and forging the diagonal end of the first right-angled end; Step 2, flipping the billet 180° and placing the second right-angled end into the V-shaped cavity of the die, with the two faces of the second right-angled end respectively adhering to the two faces of the V-shaped cavity, and forging the diagonal end of the second right-angled end; Step 3, flipping the billet 180° again, and repeating Step 1 and Step 2 in sequence until the two forged faces reach the high surface and the bottom surface of the small right-angled trapezoidal plate, obtaining an intermediate billet with an upper corner; Step 4, forging the long face of the second right-angled end of the intermediate section through a pressure plate, forging the corner between the long face and the bottom surface of the small right-angled trapezoidal plate, obtaining a formed part with an upper and lower corner, i.e., a right-angled trapezoidal free forging with a corner.

Description

Technical Field

[0001] This invention belongs to the field of forging technology and relates to a method for forming a right-angled trapezoidal free forging with a corner. Background Technology

[0002] The forming method of irregularly shaped forgings has always been a challenge in free forging hammers. To obtain irregularly shaped forgings with regular shapes and suitable dimensions, die forging is generally used. The free forging method for irregularly shaped forgings with corners typically involves adding a spacer block in the middle of the billet, placing the forging on the spacer block, and directly bending it on a free forging hammer. However, since the bending portion of this forging is small, bending on the hammer is not feasible. Die forging requires the fabrication of specialized molds, resulting in a complex production process, long production cycle, and high production costs. To save costs and shorten the production cycle, based on the characteristics of the forging shape, this invention proposes a method that can produce products that meet dimensional requirements on a free forging hammer, significantly shortening the production cycle and improving production efficiency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is that the present invention uses a free forging die forging method to produce irregular forgings, which can save mold costs, save raw materials, improve forging production efficiency, and reduce forging costs.

[0004] The technical solution of this invention is:

[0005] A method for forming a right-angled trapezoidal free forging with a corner, wherein the corner of the forging cannot be obtained by bending, and the forging is an irregularly shaped part obtained by splicing a large right-angled trapezoidal plate and a small right-angled trapezoidal plate as the corner at the hypotenuse; the length of the upper base of the small right-angled trapezoidal plate is less than or equal to 1 / 5 of the length of the upper base of the large right-angled trapezoid; the length of the lower base of the small right-angled trapezoid is less than or equal to 1 / 3 of the length of the lower base of the large right-angled trapezoid;

[0006] The method includes:

[0007] Step 1: Place the first right-angle end of the rectangular billet into the V-shaped cavity of the mold, with the two sides of the first right-angle end fitting into the two sides of the V-shaped cavity respectively. The long side of the rectangular billet fits into the long side of the mold cavity. Forge the diagonal end of the first right-angle end so that the forged surface is close to the high surface of the small right-angle trapezoidal plate.

[0008] Step 2: Flip the billet 180° and place the second right-angle end into the V-shaped cavity of the mold. The two faces of the second right-angle end should be attached to the two faces of the V-shaped cavity respectively. The short face of the second right-angle end should be attached to the long face of the mold cavity. Forge the diagonal end of the second right-angle end so that the forged surface is close to the bottom surface of the small right-angle trapezoidal plate. The short side of the second right-angle end is adjacent to the short side of the first right-angle end.

[0009] Step 3: Flip the billet 180° again, and repeat Step 1 and Step 2 in sequence until the two forged surfaces reach the high surface and the bottom surface of the small right-angled trapezoidal plate, to obtain an intermediate billet with an upper corner.

[0010] Step 4: Forge the corner between the long face and the bottom face of the small right-angled trapezoidal plate through the second right-angled end of the middle section of the pressure plate to obtain a formed part with an upper corner and a lower corner, namely a right-angled trapezoidal free forging with a corner.

[0011] The tire model cavity is V-shaped. The length of the left side of the tire model cavity is designed to be greater than the length of the bottom surface of the large right-angled trapezoidal plate, and the length of the right side of the tire model cavity is designed to be greater than the length of the bottom surface of the large right-angled trapezoidal plate; the length of the left side is less than the length of the right side.

[0012] The V-shaped angle inside the cavity is designed to be 90° according to the workpiece drawing. The angle between the left side and the vertical direction is the angle between the large right-angled trapezoidal plate and the small right-angled trapezoidal plate, and the angle between the right side and the vertical direction is the complementary angle of the angle between the large right-angled trapezoidal plate and the small right-angled trapezoidal plate.

[0013] The pressure plate is rectangular in shape, with its length designed to be twice the thickness of the forging. The cross-section of the pressure plate is designed to be 0.4 and 0.2 times the thickness of the forging.

[0014] The mold cavity is V-shaped, and the angle of the mold cavity is designed according to the angle of the corner. The width of the mold is 10-20mm larger than the thickness of the workpiece. The thickness at the sharp points on both sides of the mold is 30-60mm. The shape of the mold can reduce its weight, ensuring that the center of gravity of the mold after weight reduction coincides with the forging center.

[0015] All of the forging processes described above are performed on a hammer and anvil.

[0016] The center of gravity of the mold and the center of hammering are on the same vertical line.

[0017] Forgings are made of aluminum alloy, titanium alloy, stainless steel and structural steel, and the die material is 5CrNiMo with a hardness of HRC=38~43.

[0018] The feed rate of the pressure plate is 30-60mm.

[0019] The beneficial effects of this invention are:

[0020] For forming irregularly shaped parts, in addition to die forging, free forging can also be performed using a die and pressure plate during forging, resulting in more precise dimensions of the irregularly shaped forgings on a free forging hammer. Producing irregularly shaped forgings on a free forging hammer significantly reduces forging costs and die manufacturing costs, while also shortening the production cycle. This provides a new forging method and tooling design concept for forming forgings with complex dimensions.

[0021] Before using the mold and pressure plate of the present invention for forging and shaping, the tools should be preheated to 150°C to 300°C. Attached image description:

[0022] To more clearly illustrate the technical solutions implemented in this invention, the accompanying drawings used in the examples of this invention will be briefly explained below. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0023] Figure 1 This is a schematic diagram of a forging.

[0024] Figure 2 This is a schematic diagram of the tire mold of the present invention.

[0025] Figure 3 This is a schematic diagram of the pressure plate of the present invention. Detailed implementation method:

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] A method for forming a right-angled trapezoidal free forging with a corner includes two forging steps. The forming tooling includes a die and a pressure plate. The method ensures the forming of the forging through free forging.

[0028] The details are as follows:

[0029] A method for forming an irregular free forging, wherein the forging is an irregularly shaped part obtained by splicing a large right-angled trapezoidal plate and a small right-angled trapezoidal plate as a corner at the hypotenuse; the forging has a small corner along the hypotenuse of the large trapezoidal plate, the forging is relatively thick, and the corner is small, so the hammer bending method cannot be used. In order to ensure the forming of the forging at various angles and dimensions, a die is required to assist in the forming of the forging. The forging is formed by forging and shaping at various angles in the die. Therefore, the present invention is proposed as follows:

[0030] Step 1: Calculate the appropriate bar stock cutting dimensions based on equal volume, and forge the raw material bar stock into a rectangular billet with the same width and thickness as the forging for later use;

[0031] Step 2: Based on the shape characteristics of the forging, design a mold to shape the square billet described in Step 1;

[0032] The mold base height is h, the cavity is V-shaped, and the lower corner is designed as a right angle. The α angle of the forging is the same as the α angle of the mold. Due to the influence of the forging center of gravity, the upper two sides of the mold are asymmetrical, one side shorter and the other longer. The chamfer at the root of the cavity is R3~R8. The length L of the long side of the mold cavity is L1+L3, and the dimension can be increased by 0~70mm. The length B of the short side of the mold cavity is B1+(30~80)mm. The forging center of gravity of the mold is calculated based on the forging dimensions to determine the length dimensions of the two sides of the mold cavity, and the thickness at the apex of both sides (e.g., ...). Figure 2 The S1 and S2 in the mold are 30-60mm in diameter, with both ends chamfered to R10-R15, and the sides are not chamfered.

[0033] Step 3: Forging is completed in two steps;

[0034] Place one corner of the billet described in step one into the die and forge the B2 corner dimension. The long side of the billet is at the long side of the die. Forge the height of the forging to H. Then flip the forging and forge the other side angle. Forge the height of the forging to H1. Then take out the forging and forge the shaping thickness dimension on the free forging hammer anvil so that the billet thickness is forged to the forging thickness. Repeat the above steps to flatten the bulge of each end face and shape the corner dimension of the forging. Be careful to hammer lightly.

[0035] Step 4: Design a pressure plate to perform final shaping of the blank from Step 2;

[0036] The length of the pressure plate is 2 to 2.5 times the width of the forging. The width of the pressure plate is designed to be 0.2 to 0.4 times the L2 dimension. The thickness of the pressure plate is designed to be 0.1 to 0.2 times the L2 dimension. Last week, the chamfers on each side were R3 to R5. Next Monday, the chamfers on the side will be consistent with the L4 angle of the forging. The chamfer on the other side will be R10 to R25.

[0037] Example 1

[0038] A method for forming a right-angled trapezoidal free forging with a corner is provided, which uses a die and a pressure plate to assist in free forging, with the center of gravity of the die coinciding with the impact center of the forging.

[0039] Step 1: As Figure 1 The forging material shown is LD5. The blanking size of the forging is calculated based on the volume of the forging and the positive tolerance of the forging size. The width of the forging is δ. The bar stock is forged into a cuboid: B1×δ×L (L is calculated based on the equal volume).

[0040] Step Two: Design as follows Figure 2The mold dimensions shown are S1 = 35mm, S2 = 40mm, mold base height h = 90mm, C1 = 90mm, C2 = 250mm. Place one corner of the cuboid into the mold and forge at position B2 until the height from the inner corner of the mold cavity to B2 is L1. Then, without moving the mold, rotate the forging 180° and place the lower corner of B1 into the inner corner of the mold cavity and forge at position L3 until the height from the inner corner of the mold cavity to the L3 plane is (L1 + L3). Note that the hammering position and the center of gravity of the mold are on the same straight line. Place the forging on the free forging hammer anvil and flatten both side ends to dimension δ. Repeat the above operation two or three times until the corner of the forging is reached. The forging should have a flat shape and no bulging on any surface.

[0041] Step 3: Design as follows Figure 3 The dimensions of the pressure plate shown are as follows: the length of the pressure plate is 2δ, the width of the pressure plate is (0.3×L2), and the thickness of the pressure plate is (0.12×L2). Last week, all sides were chamfered with R3. Next Monday, the side will be aligned with the L4 position of the forging, and the other side will be chamfered with R10.

[0042] Place the L1 dimension of the billet forged in step two on a free forging hammer anvil and forge the L2 and L4 dimensions using a pressure plate. After forging, place the forging on the free forging hammer anvil and flatten the two side end faces to the δ dimension.

[0043] The forging process and die and pressure plate of the present invention can be used to forge forgings. The dimensions of the forgings meet the requirements of the forging drawings and do not require machining or die forging or other processes.

Claims

1. A method for forming a right-angled trapezoidal free forging with a corner, characterized in that, The corners of the forging cannot be obtained by bending. The forging is an irregularly shaped part obtained by splicing a large right-angled trapezoidal plate and a small right-angled trapezoidal plate as the corner at the hypotenuse. The length of the upper base of the small right-angled trapezoidal plate is less than or equal to 1 / 5 of the length of the upper base of the large right-angled trapezoidal plate. The length of the lower base of the small right-angled trapezoidal plate is less than or equal to 1 / 3 of the length of the lower base of the large right-angled trapezoidal plate. The method includes: Step 1: Place the first right-angle end of the rectangular billet into the V-shaped cavity of the mold, with the two faces of the first right-angle end fitting into the two faces of the V-shaped cavity respectively, and the long face of the rectangular billet fitting into the long face of the mold cavity. Forge the diagonal end of the first right-angle end so that the forged surface is close to the high face of the small right-angle trapezoidal plate. Step 2: Flip the blank 180° and place the second right-angle end into the V-shaped cavity of the mold. The two faces of the second right-angle end should be attached to the two faces of the V-shaped cavity respectively. The short face of the second right angle should be attached to the long face of the mold cavity. Forge the diagonal end of the second right angle end so that the forged surface is close to the bottom surface of the small right-angled trapezoidal plate. The second right-angle end is adjacent to the short side of the first right angle end. Step 3: Flip the billet 180° again, and repeat Step 1 and Step 2 in sequence until the two forged surfaces reach the high surface and the bottom surface of the small right-angled trapezoidal plate, to obtain an intermediate billet with an upper corner. Step 4: The second right-angle end of the intermediate billet is forged by the pressure plate to form the corner between the long surface and the bottom surface of the small right-angle trapezoidal plate, thus obtaining a formed part with an upper and lower corner, namely a right-angled trapezoidal free forging with a corner.

2. The method according to claim 1, characterized in that, The tire model cavity is V-shaped. The length of the left side of the tire model cavity is designed to be greater than the length of the bottom surface of the large right-angled trapezoidal plate, and the length of the right side of the tire model cavity is designed to be greater than the length of the bottom surface of the large right-angled trapezoidal plate; the length of the left side is less than the length of the right side. The V-shaped angle inside the cavity is designed to be 90° according to the workpiece drawing. The angle between the left side and the vertical direction is the angle between the large right-angled trapezoidal plate and the small right-angled trapezoidal plate, and the angle between the right side and the vertical direction is the complementary angle of the angle between the large right-angled trapezoidal plate and the small right-angled trapezoidal plate.

3. The method according to claim 1, characterized in that, The pressure plate is rectangular in shape, with its length designed to be twice the thickness of the forging. The cross-section of the pressure plate is designed to be 0.4 and 0.2 times the thickness of the forging.

4. The method according to claim 2, characterized in that, The mold cavity is V-shaped, and the angle of the mold cavity is designed according to the angle of the corner. The width of the mold is 10-20mm larger than the thickness of the workpiece. The thickness at the sharp points on both sides of the mold is 30-60mm. The shape of the mold can reduce its weight, ensuring that the center of gravity of the mold after weight reduction coincides with the forging center.

5. The method according to claim 1, characterized in that, The forging process is all carried out on a hammer and anvil.

6. The method according to claim 1, characterized in that, The center of gravity of the mold and the center of hammering are on the same vertical line.

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