Method for cold heading of building inner forced t-shaped expansion anchor bolt sleeve blank

Abstract

The application provides a cold upsetting manufacturing method of a building inner forced T-shaped expansion anchor bolt sleeve blank. The building inner forced T-shaped expansion anchor bolt sleeve blank is directly manufactured through cold upsetting seven-mold manufacturing. Through the method, raw material utilization and quality can be improved, and production efficiency can be improved. In addition, the outer shape size is uniform, and the product strength is high.

Description

Technical Field

[0001] This invention relates to the field of multi-station cold heading technology, specifically to a cold heading manufacturing method for a blank of an internally forced T-type expansion anchor bolt for construction. Background Technology

[0002] Internally forced T-type expansion anchors for construction are commonly used fasteners in the construction industry.

[0003] The blank for an internally forced T-type expansion anchor bolt for construction includes a cylindrical shape with a central hole. The cylindrical shape comprises a sleeve body and an expansion-plate-shaped sleeve at one end of the sleeve body. The length of the expansion-plate-shaped sleeve is shorter than the length of the sleeve body, accounting for 32-46% of the total length of the blank. The other end of the sleeve body has a radially protruding edge, which is circular. The difference between the maximum radius of the protruding edge and the radius of the cylinder is slightly smaller than the wall thickness of the sleeve body, and the axial thickness of the protruding edge is 1.3- greater than the wall thickness of the sleeve body. The thickness is 1.6 times that of the cylindrical body and transitions to the inclined surface of the cylindrical outer wall. The central hole includes a cylindrical hole section corresponding to the sleeve body and a conical hole section corresponding to the front sleeve body of the expansion piece. The conical hole section is divided into two segments: a transition conical hole section and a main conical hole section. The angle between the conical surface of the main conical hole section and the center line is smaller than the angle between the conical surface of the transition conical hole section and the center line. The minimum wall thickness of the main conical hole section is 1.65-1.85 times that of the sleeve body, and the maximum wall thickness of the main conical hole section is 1.16-1.26 times that of the minimum wall thickness.

[0004] In the past, internally forced T-type expansion anchor sleeves for construction were all manufactured by machine tools, resulting in low production efficiency and unstable quality. Summary of the Invention

[0005] The purpose of this invention is to provide a cold heading manufacturing method for internally forced T-type expansion anchor bolt sleeve blanks used in construction, which can improve product quality and efficiency. To this end, this invention adopts the following technical solution: A cold heading manufacturing method for a blank of an internally forced T-type expansion anchor bolt sleeve for construction, characterized in that the blank of the internally forced T-type expansion anchor bolt sleeve for construction has a cylindrical shape containing a central hole. The cylindrical shape includes a sleeve body and an expansion-plate front sleeve body located at one end of the sleeve body. The length of the expansion-plate front sleeve body is shorter than the length of the sleeve body, accounting for 32-46% of the length of the blank of the internally forced T-type expansion anchor bolt sleeve for construction. The other end of the sleeve body has a radial flange. The flange is circular, and the difference between the maximum radius of the flange and the radius of the cylinder is slightly smaller than the wall thickness of the sleeve body. The axis of the flange... The thickness is 1.3-1.6 times greater than the wall thickness of the sleeve body, and transitions to the inclined surface of the cylindrical outer wall. The central hole includes a cylindrical hole section corresponding to the sleeve body and a conical hole section corresponding to the front-shaped sleeve of the expansion piece. The conical hole section is divided into two sections: a transition conical hole section and a main conical hole section. The angle between the conical surface of the main conical hole section and the center line is smaller than the angle between the conical surface of the transition conical hole section and the center line. The minimum wall thickness of the main conical hole section is 1.65-1.85 times the wall thickness of the sleeve body, and the maximum wall thickness of the main conical hole section is 1.16-1.26 times the minimum wall thickness. The manufacturing method includes the following steps: (1) The coiled material is fed into the cold heading forming machine and automatically cut into individual building internal T-type expansion anchor sleeve blanks. The diameter of the coiled material is close to the diameter of the cylindrical body. The length of the blank is longer than the length of the expansion plate front sleeve and shorter than the length of the sleeve body. (2) The raw material is transferred to the No. 1 mold opening of the cold heading forming machine. After cold heading in the No. 1 mold, the front end of the No. 1 molded product is flattened and the rear end is rounded. The diameter of the No. 1 molded product is consistent with the diameter of the cylindrical shape of the blank of the building internal forced T-type expansion anchor bolt sleeve. (3) Transfer the No. 1 molded product to the No. 2 mold opening. After cold heading in the No. 2 mold, the front end of the No. 2 molded product is flattened, the rear end is rounded, and the front end is shaped into a positioning hole. (4) The No. 2 molded product is transferred to the No. 3 mold opening and cold-forged in the No. 3 mold to flatten the rear end of the No. 3 molded product and forge a positioning hole; the front end of the No. 3 molded product is forged with a first large hole, the diameter of the first large hole is the same as the diameter of the cylindrical hole section, the depth of the first large hole is slightly longer than the length of the cylindrical hole section in the sleeve body, and the wall thickness of the greater part is used to form the convex edge; the length of the No. 3 molded product is slightly shorter than the length of the blank of the internal forced T-type expansion anchor bolt sleeve for construction. (5) Transfer the No. 3 molded product to the No. 4 mold opening, and cold forging in the No. 4 mold to forge the port of the main conical hole section of the expansion piece front shape sleeve based on the positioning hole of the rear end of the No. 3 molded product. The diameter of the port is consistent with the minimum diameter of the main conical hole section. Furthermore, punch a hole at the bottom of the first large hole of the No. 3 molded product to form a transition conical hole section and an extension hole section at the bottom of the first large hole. The diameter of the extension hole section is greater than or equal to the diameter of the port. The extension hole section is separated from the port by the iron core to be punched. The length of the cylindrical shape corresponding to the transition conical hole section, the extension hole section, the iron core to be punched, and the port is basically the same as the length of the expansion piece front shape sleeve. (6) The No. 4 molded product is transferred to the No. 5 mold opening and cold-forged in the No. 5 mold. The No. 4 molded product is then passed through an iron core to form the front hole of the main body conical hole section, thus producing the No. 5 molded product. (7) Transfer the No. 5 molded product to the No. 6 mold opening, and through cold heading in the No. 6 mold, the front hole of the main conical hole section of the No. 5 molded product is headed into the main conical hole section, and the No. 6 molded product is made. (8) The No. 6 molded product is transferred to the No. 7 mold opening. After cold forging in the No. 7 mold, the No. 6 molded product is shortened to the length of the building internal forced T-type expansion anchor sleeve blank. The length of the first large hole is shortened to the cylindrical hole section. The metal transfer amount generated by the shortened part is formed into the convex edge to make the building internal forced T-type expansion anchor sleeve blank.

[0006] This invention enables the manufacture of internally forced T-type expansion anchor sleeves for construction using a cold extrusion process. It uses coiled material instead of straight bars or cut pieces, employing a pre-treatment process that involves spheroidizing annealing, phosphate and film surface treatment, and precision drawing and sizing. This process is more suitable for cold heading technology. The material then flows into a cold heading machine, where it is sheared into individual elliptical T-type bushing blanks for electric vehicle braking systems using a multi-station shearing process. Subsequently, it is transferred to a multi-station cold heading machine, which, based on engineering mechanics principles, uses compound extrusion. Both ends are simultaneously stressed within the mold, completing the shaping and leveling, center hole setting, punching of tapped holes, punching of small holes, through holes, punching of inner hole bevels, and upsetting processes in one operation. This produces the product shape with three stepped outer diameters and a central through hole, allowing the internally forced T-type expansion anchor sleeve blanks for construction to be directly formed. This invention employs a 7-station cold extrusion molding process, which reduces drilling and machining processes compared to the original process. It also ensures dimensional stability and significantly reduces material consumption, achieving a material utilization rate of 95% and saving 65.6% of material, thus substantially lowering costs. Furthermore, the cold-extruded material has a denser microstructure, exhibiting superior tensile, yield, elongation, and impact properties compared to machined materials, ensuring product quality. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the process flow before the fourth mold in the manufacturing method of the present invention.

[0008] Figure 2 This is a schematic diagram of the process flow for the fifth to seventh molds of the manufacturing method of the present invention.

[0009] Figure 3 A top view of the blank of the internally forced T-type expansion anchor sleeve for construction manufactured by the manufacturing method of the present invention. Detailed Implementation

[0010] Referring to the accompanying drawings, the external structure of the building internal-compression T-type expansion anchor sleeve blank 100 manufactured according to the present invention includes a cylindrical shape with a central hole. The cylindrical shape includes a sleeve body 101 and an expansion-flange front sleeve body 102 located at one end of the sleeve body. The length of the expansion-flange front sleeve body 102 is shorter than the length of the sleeve body 101, and the length of the expansion-flange front sleeve body 102 accounts for 32-46% of the length of the building internal-compression T-type expansion anchor sleeve blank. The other end of the sleeve body 101 has a radially protruding edge 103. The protruding edge 103 is circular, and the difference between the maximum radius of the protruding edge 103 and the radius of the cylinder is slightly smaller than the wall thickness of the sleeve body 101. The axial direction of the protruding edge 103 is... The thickness is 1.3-1.6 times greater than the wall thickness of the sleeve body 101, and transitions to the inclined surface 104 of the cylindrical outer wall. The central hole includes a cylindrical hole section 105 corresponding to the sleeve body and a conical hole section corresponding to the front sleeve of the expansion piece. The conical hole section is divided into two sections: a transition conical hole section 106 and a main conical hole section 107. The angle between the conical surface of the main conical hole section 107 and the center line is smaller than the angle between the conical surface of the transition conical hole section and the center line. The minimum wall thickness of the main conical hole section 107 is 1.65-1.85 times the wall thickness of the sleeve body, and the maximum wall thickness of the main conical hole section 107 is 1.16-1.26 times the minimum wall thickness.

[0011] The manufacturing method includes the following steps: (1) The coiled material is fed into the cold heading forming machine and automatically cut into individual building internal T-type expansion anchor sleeve blanks 10. The coiled material is first heat-treated to spheroidize, then subjected to phosphate surface treatment, and fine drawing and sizing treatment. The diameter of the coiled material is close to the diameter of the cylindrical shape. The length of the raw material 10 is longer than the length of the expansion plate front sleeve 102 and shorter than the length of the sleeve body 101.

[0012] (2) The raw material 10 is transferred to the first mold opening of the cold heading forming machine. After cold heading in the first mold, the front end face 11 of the first molded product 1 is flattened and the rear end is rounded 12. The diameter of the first molded product is consistent with the diameter of the cylindrical shape of the building internal forced T-type expansion anchor sleeve blank 100. The diameter will only change slightly naturally when the mold is applied.

[0013] (3) Transfer the No. 1 molded product to the No. 2 mold opening. After cold forging in the No. 2 mold, the front end face 21 of the No. 2 molded product 2 is flattened, the rear end is forged with rounded corners 22, and the front end face is forged with positioning holes 23.

[0014] (4) The No. 2 molded product 2 is transferred to the No. 3 mold opening and cold-forged in the No. 3 mold, so that the rear end of the No. 3 molded product 3 is flattened and a positioning hole 31 is forged out; the front end of the No. 3 molded product is forged out with a first large hole 32. The diameter of the first large hole 32 is the same as the diameter of the cylindrical hole section 105 in the sleeve body 101. The hole depth of the first large hole 32 is slightly longer than the length of the cylindrical hole section 105. The wall thickness of the greater part is used to form the convex edge 103, which can enable the building internal forced T-type expansion anchor sleeve blank 100 to be cold-forged in sections, reduce the metal transfer distance, and improve the appearance quality; the length of the No. 3 molded product 3 is slightly shorter than the length of the building internal forced T-type expansion anchor sleeve blank 100.

[0015] (5) Transfer the No. 3 molded product 3 to the No. 4 mold opening, and cold forge it in the No. 4 mold to forge the port 41 of the main conical hole section 107 of the expansion piece front sleeve based on the positioning hole of the rear end of the No. 3 molded product 4. The diameter of the port 41 is consistent with the minimum diameter of the main conical hole section 107. Furthermore, punch a hole at the bottom of the first large hole of the No. 3 molded product 4 at the rear end of the No. 4 molded product 4, so that a transition conical hole section 106 and an extension hole section 42 are formed at the bottom of the first large hole. The diameter of 42 is greater than or equal to the diameter of the port 41. The extension hole section 42 is separated from the port by the iron core 43 to be punched. The length of the cylindrical outer shape corresponding to the transition conical hole section 106, the extension hole section 42, the iron core 43 to be punched, and the port 41 is basically the same as the length of the expansion plate front sleeve 107. Thus, the forming of the internal structure of the expansion plate front sleeve 107 does not affect the shape of the sleeve body 101, and the forming of the convex edge 103 does not affect the shape of the expansion plate front sleeve 107. This facilitates segmented manufacturing and ensures that the structure formed first is not affected by subsequent cold extrusion.

[0016] (6) The No. 4 molded product is transferred to the No. 5 mold opening and cold-forged in the No. 5 mold to form the front hole 51 of the main conical hole section of the No. 4 molded product 4 through iron core 43, thus producing the No. 5 molded product 5. (7) The No. 5 molded product is transferred to the No. 6 mold opening and cold-forged in the No. 6 mold to forge the front hole of the main conical hole section of the No. 5 molded product into the main conical hole section 107, thus producing the No. 6 molded product 6. (8) The No. 6 molded product 6 is transferred to the No. 7 mold opening and cold-forged in the No. 7 mold to shorten the No. 6 molded product 6 to the length of the building internal forced T-type expansion anchor sleeve blank 100, wherein the length of the first large hole 32 is shortened to the cylindrical hole section 105, and the metal transfer amount generated by the shortened part is formed into the convex edge 103 to make the building internal forced T-type expansion anchor sleeve blank 100.

[0017] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present invention are covered by the protection scope of the present invention.

Claims

1. A cold heading manufacturing method for blanks of internally forced T-type expansion anchor bolts for construction, characterized in that, The blank material for the internally forced T-type expansion anchor bolt for construction includes a cylindrical shape with a central hole. The cylindrical shape comprises a sleeve body and an expansion-plate-shaped sleeve at one end of the sleeve body. The length of the expansion-plate-shaped sleeve is shorter than the length of the sleeve body, accounting for 32-46% of the total length of the blank material. The other end of the sleeve body has a radially protruding edge, which is circular. The difference between the maximum radius of the protruding edge and the radius of the cylinder is slightly smaller than the wall thickness of the sleeve body, and the axial thickness of the protruding edge is 1.3- greater than the wall thickness of the sleeve body. The thickness is 1.6 times that of the cylindrical body and transitions to the inclined surface of the cylindrical outer wall. The central hole includes a cylindrical hole section corresponding to the sleeve body and a conical hole section corresponding to the front sleeve body of the expansion piece. The conical hole section is divided into two sections: a transition conical hole section and a main conical hole section. The angle between the conical surface of the main conical hole section and the center line is smaller than the angle between the conical surface of the transition conical hole section and the center line. The minimum wall thickness of the main conical hole section is 1.65-1.85 times that of the sleeve body, and the maximum wall thickness of the main conical hole section is 1.16-1.26 times that of the minimum wall thickness. The manufacturing method includes the following steps: (1) The coiled material is fed into the cold heading forming machine and automatically cut into individual building internal T-type expansion anchor sleeve blanks. The diameter of the coiled material is close to the diameter of the cylindrical body. The length of the blank is longer than the length of the expansion plate front sleeve and shorter than the length of the sleeve body. (2) The raw material is transferred to the No. 1 mold opening of the cold heading forming machine. After cold heading in the No. 1 mold, the front end of the No. 1 molded product is flattened and the rear end is rounded. The diameter of the No. 1 molded product is consistent with the diameter of the cylindrical shape of the blank of the building internal forced T-type expansion anchor bolt sleeve. (3) Transfer the No. 1 molded product to the No. 2 mold opening. After cold heading in the No. 2 mold, the front end of the No. 2 molded product is flattened, the rear end is rounded, and the front end is shaped into a positioning hole. (4) The No. 2 molded product is transferred to the No. 3 mold opening and cold-forged in the No. 3 mold to flatten the rear end of the No. 3 molded product and forge a positioning hole; the front end of the No. 3 molded product is forged with a first large hole, the diameter of the first large hole is the same as the diameter of the cylindrical hole section, the depth of the first large hole is slightly longer than the length of the cylindrical hole section in the sleeve body, and the wall thickness of the greater part is used to form the convex edge; the length of the No. 3 molded product is slightly shorter than the length of the blank of the internal forced T-type expansion anchor bolt sleeve for construction. (5) Transfer the No. 3 molded product to the No. 4 mold opening, and cold forging in the No. 4 mold to forge the port of the main conical hole section of the expansion piece front shape sleeve based on the positioning hole of the rear end of the No. 3 molded product. The diameter of the port is consistent with the minimum diameter of the main conical hole section. Furthermore, punch a hole at the bottom of the first large hole of the No. 3 molded product to form a transition conical hole section and an extension hole section at the bottom of the first large hole. The diameter of the extension hole section is greater than or equal to the diameter of the port. The extension hole section is separated from the port by the iron core to be punched. The length of the cylindrical shape corresponding to the transition conical hole section, the extension hole section, the iron core to be punched, and the port is basically the same as the length of the expansion piece front shape sleeve. (6) The No. 4 molded product is transferred to the No. 5 mold opening and cold-forged in the No. 5 mold. The No. 4 molded product is then passed through an iron core to form the front hole of the main body conical hole section, thus producing the No. 5 molded product. (7) Transfer the No. 5 molded product to the No. 6 mold opening, and through cold heading in the No. 6 mold, the front hole of the main conical hole section of the No. 5 molded product is headed into the main conical hole section, and the No. 6 molded product is made. (8) The No. 6 molded product is transferred to the No. 7 mold opening. After cold forging in the No. 7 mold, the No. 6 molded product is shortened to the length of the building internal forced T-type expansion anchor sleeve blank. The length of the first large hole is shortened to the cylindrical hole section. The metal transfer amount generated by the shortened part is formed into the convex edge to make the building internal forced T-type expansion anchor sleeve blank.

Images