A cold upsetting forming process for a special-shaped winding pulley

Abstract

The application discloses a special-shaped winding pulley cold upsetting forming process, a first station part bottom end cold upsetting is a conical frustum structure, a transition area of the bottom end conical frustum structure and an upper end cylindrical structure is a first arc surface structure; a second plane structure and left and right side surfaces of a second station part have transition surfaces; a third station part top surface edge cold upsetting forms a fillet structure; first notches are formed on top and bottom two end surfaces of a fourth station part along a stamping direction through cold upsetting; second notches are formed on the first notches on the top and bottom two end surfaces along the stamping direction through cold upsetting; a fifth station part appearance cold upsetting is processed into a special-shaped winding pulley structure; and connecting holes are formed through cold upsetting cutting of the second notches on the top and bottom two end surfaces along the stamping direction.

Description

Technical fields: This invention belongs to the field of irregular-shaped wound pulley forming technology, and in particular relates to a cold heading forming process for irregular-shaped wound pulleys. Background technology: Irregularly shaped winding pulleys are used for winding and coiling steel wire ropes for automotive seat belts. The existing processing technologies for irregularly shaped winding pulleys include: CNC machining center cutting forming process; powder metallurgy process; and hot forging process.

[0001] The CNC machining center cutting and forming process involves clamping a metal block blank onto a fixture, milling the blank to form a non-circular winding pulley, then cutting the formed non-circular winding pulley off the blank, and finally grinding the surface of the formed non-circular winding pulley. This process is very inefficient because it requires not only milling the blank but also grinding the formed non-circular winding pulley, and only one non-circular winding pulley can be formed per clamping and fixing of the blank.

[0002] Powder metallurgy uses metal powder as raw material. The cost of metal powder is significantly higher than that of bulk metal blanks. Powder metallurgy involves hot-pressing the metal powder under high pressure to form the shape, followed by sintering. While the forming quality of irregularly shaped wound pulleys is very high, it also suffers from low production efficiency, and the cost of forming irregularly shaped wound pulleys using powder metallurgy is very high. Hot forging is a process in which metal block blanks are forged at high temperatures. The surface of the hot-forged irregular-shaped winding pulleys has a lot of gray edges and burrs, which requires secondary grinding or cutting. This results in low production efficiency and poor surface smoothness of the produced irregular-shaped winding pulleys.

[0003] Furthermore, the cold heading process for conventional symmetrical parts is relatively simple. Especially for symmetrical parts, such as bolts and nuts with circular cross-sections, the stress is uniform throughout the cold heading process. Therefore, the material in the blank moves evenly to the periphery during cold heading, resulting in a high cold heading success rate for symmetrical parts. However, for cold heading of irregularly shaped parts, it is necessary to rationally design the deformation dimensions and locations of each cold heading station. Otherwise, the cold heading process for irregularly shaped parts may result in excessive or insufficient material in certain areas, making cold heading difficult or producing poor forming quality. Summary of the Invention: The technical problem to be solved by the present invention is to realize the cold heading process of irregularly shaped winding pulley parts with special design by using a cylindrical blank through a five-step asymmetrical material distribution upsetting process and a final punching and cold heading process.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: a cold heading forming process for an irregularly shaped wound pulley, wherein the irregularly shaped wound pulley includes a blank to be processed, the blank having a cylindrical structure, and includes the following steps: The blank is cold-forged into the first station part: the bottom cold-forged part of the first station part is a frustum-shaped structure, and the transition area between the bottom frustum-shaped structure and the upper cylindrical structure is a first arc surface structure. The first station part is cold-forged into the second station part: the first arc surface structure and the bottom conical truncated structure are cold-forged into the second arc surface structure, the bottom surface of the second station part is the first planar structure, the rear side of the second station part is cold-forged into the third arc surface structure, the front side of the second station part is cold-forged into the second planar structure, and there is a transition surface between the second planar structure and the left and right sides of the second station part; The part at the second station is cold-forged into a part at the third station: the top edge of the part at the third station is cold-forged to form a rounded corner structure; The part at the third station is cold-forged into a part at the fourth station: the top and bottom end faces of the part at the fourth station are cold-forged to form the first notch along the stamping direction; The part at the fourth station is cold-forged into the part at the fifth station: the first notch on the top and bottom end faces is cold-forged along the stamping direction to form the second notch, and the shape of the part at the fifth station is cold-forged into an irregular winding pulley structure. The fifth station part is cold-forged into a sixth station part: the second notch on the top and bottom end faces is cold-forged along the stamping direction to form a connecting hole, and the connecting hole is in a non-coaxial position with the third arc-shaped structure.

[0005] Furthermore, during the process of cold heading the part at the third station into the part at the fourth station, the outer ends of the first notch on both the top and bottom end faces are cold-headed into an angled structure.

[0006] Furthermore, during the process of cold heading the part at the second station into the part at the third station, the rounded corner structure and the third arc-shaped surface structure are in a coaxial position.

[0007] Furthermore, during the process of cold heading the part from the fourth station into the part from the fifth station, the outer ends of the second notch on both the top and bottom end faces are cold-headed into an angled structure.

[0008] Furthermore, during the process of cold heading the part from the second station into the part from the third station, the transition surface is composed of a fourth arc surface structure, a fifth arc surface structure, and an intermediate connecting plane structure.

[0009] Furthermore, during the cold heading process of the blank into the first station part, the cone angle of the frustum-shaped structure is 90°. Compared with the prior art, the advantages of the present invention are: by adopting cold heading forming, the plastic deformation characteristics of metal materials are utilized to gradually cold head the irregularly shaped winding pulley, which can improve the strength of the irregularly shaped winding pulley.

[0010] This forming process cold-forging irregularly shaped parts. Compared to the conventional cold-forging method for symmetrical parts, it requires reasonable design of the shape changes of each cold-forging process for each blank to ensure stable stress on the blank and facilitate control of processing accuracy. During cold forging, the blank is formed by pressure through a six-station cold forging mold. It has the advantages of high yield and high production efficiency, and can produce 50-100 irregularly shaped winding pulleys per minute. The irregularly shaped winding pulleys have smooth surfaces and high forming quality. Because it uses metal block blanks, its production cost is reduced by 70%-80% compared to powder metallurgy forming process. Attached image description: The invention will be further described below with reference to the accompanying drawings.

[0011] Figure 1 This is the front view of the process where the blank to be processed is cold-forged sequentially up to the sixth station part.

[0012] Figure 2 This is a top view of the process from the second station part to the sixth station part, where parts are cold-forged sequentially.

[0013] Figure 3 This is a structural schematic diagram of the part at the second workstation.

[0014] Figure 4 This is a structural diagram of the part at the third workstation.

[0015] Figure 5 It is a three-dimensional drawing of the parts from the first to the third station, and a drawing of the cold heading die.

[0016] Figure 6 It is a three-dimensional drawing of the parts from the fourth to the sixth workstation, along with the cold heading die drawing. Detailed implementation method: The present invention will now be described in detail with reference to specific embodiments: Example 1 like Figure 5 and Figure 6 The diagram illustrates a cold heading process for an irregularly shaped wound pulley. The irregularly shaped wound pulley includes a blank to be processed, the blank having a height-to-diameter ratio of 0.7 to 1.2. In this embodiment, the blank to be processed is a cylindrical structure with a diameter of φ9.7mm. The process includes the following steps: The blank part 0 is cold-forged into part 1 of the first station: the bottom end of part 1 of the first station is cold-forged into a frustum-shaped structure 11 with a cone angle of 90°, the transition area between the bottom frustum-shaped structure 11 and the upper cylindrical structure is a first arc surface structure 12 with R4mm, and the upper cylindrical structure is cold-forged to φ9.75. like Figure 1 As shown, the first station part 1 is cold-forged into the second station part 2: the first arc surface structure 12 and the bottom conical truncated structure 11 are cold-forged into a second arc surface structure with an R3mm diameter, and the bottom surface of the second station part 2 is a first planar structure. like Figure 2 As shown and Figure 3 As shown, the rear side of the second station part 2 is cold-forged into a third arc-shaped structure 22, and the front side of the second station part 2 is cold-forged into a second planar structure 21. There is a transition surface 23 between the second planar structure 21 and the left and right sides of the second station part 2. The transition surface 23 is composed of a fourth arc-shaped structure 24 with an R2mm radius and a fifth arc-shaped structure 25 with an R3mm radius, connected by a plane 26 in the middle. The second station part 2 is cold-forged to φ12mm and 6.8mm in height. The bottom surface is the first planar structure with a cold-forged dimension of φ6. The second station part 2 is cold-forged to a dimension of φ12.6 between the third arc-shaped structure 22 and the fifth arc-shaped structure 25.

[0017] like Figure 1 As shown, the second station part 2 is cold-forged into the third station part 3: the top edge of the third station part 3 is cold-forged to form a rounded corner structure 31 with an R1mm radius, and the rounded corner structure 31 and the third arc-shaped surface structure 22 are in a coaxial position; the third station part 3 has a width of 12.5mm, a height of 6.6mm, and the first planar structure on the bottom surface is cold-forged to a size of φ6.5. As shown in Figure 2, the part 2 at the third station is cold-forged to the third arc-shaped structure 22 and the fifth arc-shaped structure 25 with a dimension of φ13.1.

[0018] like Figure 1 and Figure 4 As shown, the third station part 3 is cold-forged into the fourth station part 4: the top and bottom end faces of the fourth station part are cold-forged to form a first notch 41 with a diameter of φ7.3mm. The outer ends of the first notch on the top and bottom end faces of the fourth station part 4 are cold-forged into a beveled structure with a diameter of d0.42mm. The width of the third station part 3 is 12.8mm and the height is 6mm. The width of the second planar structure 21 in the left and right directions is cold-forged to 12.5mm. like Figure 1 As shown, the fourth station part 2 is cold-forged to the third arc-shaped structure 22 and the fifth arc-shaped structure 25 with a dimension of φ13.3.

[0019] The fourth station part 4 is cold-forged into the fifth station part 5: the first notch 41 on the top and bottom end faces is cold-forged along the stamping direction to form the second notch 51, and the shape of the fifth station part 5 is cold-forged into an irregular winding pulley structure; during the process of cold-forging the fifth station part into the sixth station part, the outer ends of the second notch 51 on the top and bottom end faces are cold-forged into a chamfered structure with d0.42mm; The fifth station part 5 is cold-forged into the sixth station part 6: along the stamping direction, the second notch 61 on the top and bottom end faces is cold-forged to cut off the φ7.3mm connecting hole 61, which is in a non-coaxial position with the third arc surface structure 22.

[0020] It should be emphasized that, as will be apparent to those skilled in the art, the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of the equivalents of the claims be included within the present invention.

Claims

1. A cold heading process for an irregularly shaped wound pulley, wherein the irregularly shaped wound pulley includes a blank to be processed, the blank having a cylindrical structure, characterized in that, Includes the following steps: The blank is cold-forged into the first station part: the bottom cold-forged part of the first station part is a frustum-shaped structure, and the transition area between the bottom frustum-shaped structure and the upper cylindrical structure is a first arc surface structure. The first station part is cold-forged into the second station part: the first arc surface structure and the bottom conical truncated structure are cold-forged into the second arc surface structure, the bottom surface of the second station part is the first planar structure, the rear side of the second station part is cold-forged into the third arc surface structure, the front side of the second station part is cold-forged into the second planar structure, and there is a transition surface between the second planar structure and the left and right sides of the second station part; The part at the second station is cold-forged into a part at the third station: the top edge of the part at the third station is cold-forged to form a rounded corner structure; The part at the third station is cold-forged into a part at the fourth station: the top and bottom end faces of the part at the fourth station are cold-forged to form the first notch along the stamping direction; The part at the fourth station is cold-forged into the part at the fifth station: the first notch on the top and bottom end faces is cold-forged along the stamping direction to form the second notch, and the shape of the part at the fifth station is cold-forged into an irregular winding pulley structure. The fifth station part is cold-forged into the sixth station part: the second notch on the top and bottom end faces is cold-forged along the stamping direction to form a connecting hole, and the connecting hole is in a non-coaxial position with the third arc surface structure. During the process of cold heading the part from the third station to the fourth station, the outer ends of the first notch on both the top and bottom end faces are cold-headed into an angled structure. During the process of cold heading the part at the second station into the part at the third station, the rounded corner structure and the third arc-shaped surface structure are in a coaxial position. During the process of cold heading the part from the fourth station to the part from the fifth station, the outer ends of the second notch on both the top and bottom end faces are cold-headed into an angled structure. During the process of cold heading the part at the second station into the part at the third station, the transition surface is composed of a fourth arc surface structure, a fifth arc surface structure, and an intermediate connecting plane structure. During the cold heading process of the blank into the first station part, the cone angle of the frustum-shaped structure is 90°.

Images