Processing method for drawstring housing

Abstract

This application relates to the field of processing technology for electrified railway catenary components, specifically disclosing a processing method for a guy wire shell. The method includes six steps: material preparation, initial water expansion, sawing, cutting, final forming, and annealing. The initial forming uses a water expansion mold and a multi-directional hydraulic press to process an intermediate blank. A forming mold and a multi-directional hydraulic press are then used to process the intermediate blank to form the guy wire shell. This technical solution uses a water expansion mold and a forming mold to quickly process a flat tube into a guy wire shell. The hot-press forming technology avoids process defects such as porosity, shrinkage, and stress concentration in the guy wire shell, improving the product's safety performance and quality, and reducing potential safety hazards.

Description

Technical Field

[0001] This invention relates to the field of processing technology for overhead contact line components of electrified railways, and specifically to a processing method for a guy wire housing. Background Technology

[0002] Guy wire housings, also known as double-eared wedge clamps, are used in electrified railway contact network systems to connect the terminals of metal stranded wires as catenary wires, transverse catenary wires, upper and lower positioning ropes, and compensating ropes to ear-shaped parts. They are widely used in railway and high-speed rail electrified lines. Currently, guy wire housings are manufactured by steel casting. Casting is prone to defects such as porosity, shrinkage, and stress concentration, which reduces the safety factor of the component and increases the risk of accidents. Therefore, companies are considering using pressure processing to integrally machine the guy wire housing. Compared with casting, pressure-processed guy wire housings have a denser structure, higher mechanical properties, and enhanced safety. However, pressure processing cannot form the guy wire housing in one step; it requires multiple pressure processing steps. These multiple pressure processing steps require the coordination of multiple sets of processing molds. Therefore, designing corresponding molds for multiple processing steps of the guy wire housing is one of the urgent problems to be solved. Summary of the Invention

[0003] The purpose of this invention is to provide a method for processing wire drawing shells to solve the problem that current pressure processing does not have multiple processing molds.

[0004] To address the above issues, the following technical solution is provided:

[0005] A wire drawing shell processing mold includes a water-expanding mold and a forming mold. The water-expanding mold includes an upper water-expanding mold and a lower water-expanding mold. The lower water-expanding mold has an ejector pin hole in the middle. After the upper water-expanding mold and the lower water-expanding mold are closed, mandrels are slidably inserted at both ends. The mandrels have water injection holes. The forming mold includes an upper forming mold and a lower forming mold. After the upper forming mold and the lower forming mold are closed, a forming mandrel is slidably inserted at one end, and a shaping mold with a forming opening is slidably inserted at the other end.

[0006] A method for processing a wire-drawn housing, the method comprising the following steps:

[0007] 1) Material preparation: Q355 round steel pipes with a volume of 110% of the final formed parts are processed into flat pipes;

[0008] 2) Single-stage water expansion: The flat tube is placed in the water expansion mold, the upper and lower water expansion molds are closed and pressed together, the mandrel seals both ends of the flat tube, and liquid medium is pressurized into the flat tube through the water injection hole of the mandrel. The flat tube expands to form an intermediate blank with the middle part expanding.

[0009] 3) Sawing: Cut the middle blank into two equal sections, with one end of the cut blank becoming the larger end and the other end becoming the smaller end;

[0010] 4) Cutting: The two ends of the blank are cut with a laser cutting machine to obtain a blank to be shaped with a material volume equal to the material volume of the formed wire shell;

[0011] 5) Final shaping: The blank to be shaped is placed into the cavity of the lower forming mold, the upper forming mold and the lower forming mold are closed and pressed together, the forming mandrel and the shaping mold move simultaneously into the cavity in the middle of the forming mold, and pressure is applied to the blank to be shaped to obtain the formed wire shell.

[0012] 6) Annealing: After processing, the wire shell is placed in an annealing furnace to relieve stress.

[0013] The beneficial effects of this technical solution are as follows:

[0014] 1. Compared with the existing casting method for producing wire drawing shells, this technical solution uses a water-expanding mold and a forming mold to extrude flat tubes to quickly form wire drawing shells. The water-expanding mold and the forming mold are molds in hot pressing forming technology. The resulting wire drawing shells have high mechanical properties and do not produce process defects such as porosity, shrinkage, and stress concentration, which improves their safety performance and quality and reduces the risk of safety accidents.

[0015] 2. Compared with traditional casting methods, the water-expanding mold and forming mold can quickly extrude the flat tube to form a wire shell. The process generates less waste, the forming quality is high, and the hot pressing process is quiet and has little impact on the environment.

[0016] Furthermore, the upper hydraulic mold has a first mold groove that can conform to the intermediate blank, and the lower hydraulic mold has a second mold groove that can conform to the intermediate blank. The first mold groove and the second mold groove can be combined to form the shape of the intermediate blank. The closing of the upper and lower hydraulic molds allows the intermediate blank to be formed in one step.

[0017] Furthermore, the upper forming mold has a third mold groove that conforms to the outer shell of the drawstring, and the lower forming mold has a fourth mold groove that conforms to the outer shell of the drawstring. The third and fourth mold grooves can be combined to form the shape of the drawstring outer shell. The closing of the upper and lower forming molds allows the drawstring outer shell to be formed in one step.

[0018] Furthermore, a positioning sleeve is tightly attached to one side of the molding die. The molding mandrel first passes through the positioning sleeve and then is inserted into the third mold groove. The positioning sleeve can restrict the rapid insertion of the molding mandrel into the mold cavity formed after the molding die is closed.

[0019] Furthermore, the upper and lower water-expanding molds, as well as the upper and lower forming molds, are provided with strip-shaped positioning grooves on their outer peripheries. These grooves, in conjunction with the multi-directional hydraulic press, allow the upper and lower water-expanding molds, as well as the upper and lower forming molds, to be securely mounted on the press.

[0020] Furthermore, a layer of graphite powder is coated onto the surface of the flat tube in step 1). The graphite powder makes the surface of the flat tube more smooth, making it easier to remove after molding.

[0021] Furthermore, the liquid pressure used for water expansion in step 2) is 20-30 MPa.

[0022] Furthermore, the annealing furnace temperature in step 6) is set at 800-900℃. Annealing furnaces within this temperature range are most effective in eliminating internal stress in the wire drawing shell and improving its plasticity and toughness. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the water-expanding mold of the present invention;

[0024] Figure 2 This is a schematic diagram of the molding die of the present invention;

[0025] Figure 3 This is a schematic diagram of the disassembled structure of the molding die of the present invention;

[0026] Figure 4 This is a schematic diagram of the intermediate blank.

[0027] Figure 5 This is a schematic diagram of the structure of the pull cord casing.

[0028] The reference numerals in the accompanying drawings include: water-expanding mold 1, forming mold 2, water-expanding upper mold 11, water-expanding lower mold 12, ejector pin hole 121, mandrel 13, water injection hole 131, strip positioning groove 3, forming upper mold 21, forming lower mold 22, forming mandrel 23, positioning sleeve 24, shaping mold 25, forming opening 251. Detailed Implementation

[0029] The following detailed description illustrates the specific implementation method:

[0030] The basic implementation examples are as follows: Figure 1-5 As shown:

[0031] The processing molds for the wire drawing housing include a water-expansion mold 1 and a forming mold 2, such as... Figure 1As shown, the water-expanding mold 1 includes an upper water-expanding mold 11 and a lower water-expanding mold 12. The upper water-expanding mold 11 has a first mold groove that can fit the intermediate blank, and the lower water-expanding mold 12 has a second mold groove that can fit the intermediate blank. The first mold groove and the second mold groove can be combined to form the shape of the intermediate blank. The lower water-expanding mold 12 has ejector pin holes 121 machined through the upper and lower parts of the mold. After the upper water-expanding mold 11 and the lower water-expanding mold 12 are closed, mandrels 13 are slidably inserted at both ends. The mandrels 13 have water injection holes 131 machined in them to connect to external liquid media. The upper water-expanding mold 11 and the lower water-expanding mold 12 have strip-shaped positioning grooves 3 on their outer periphery that cooperate with a multi-directional hydraulic press.

[0032] like Figure 2-3 As shown, the molding die 2 includes a cuboid upper molding die 21 and a lower molding die 22. The lower molding die 22 has recessed grooves at its four corners. The upper molding die 21 has protrusions at its four corners that fit the grooves. The upper molding die 21 has a third groove that fits the outer shell of the middle pull wire. The lower molding die 22 has a fourth groove that fits the outer shell of the pull wire. The third and fourth grooves can be combined to form the shape of the outer shell of the pull wire. After the upper molding die 21 and the lower molding die 22 are closed, a molding mandrel 23 is slidably inserted into the left end. The molding mandrel 23 first passes through the positioning sleeve 24 and then is inserted into the molding die 2. The positioning sleeve 24 fits tightly against the side of the molding die 2. After the mold is closed, a shaping die 25 with a molding opening 251 is slidably inserted into the right end. The outer periphery of the upper molding die 21 and the lower molding die 22 is also provided with a strip-shaped positioning groove 3 that cooperates with a multi-directional hydraulic press.

[0033] The processing method for the drawstring housing includes the following steps:

[0034] 1) Material preparation: Q355 round steel pipes with a volume of 110% of the final formed parts are processed into flat pipes, and a layer of graphite powder is coated on the surface of the flat pipes.

[0035] 2) Single-stage water expansion: The strip positioning grooves 3 on the outer periphery of the upper and lower water expansion molds 11 and 12 cooperate with the multi-directional hydraulic press to place the water expansion mold 1 in the multi-directional hydraulic press. The flat tube is placed into the lower water expansion mold 12, and the upper and lower water expansion molds 11 and 12 are closed and pressed together. Then, the mandrel 13 is used to seal both ends of the flat tube, and liquid medium is pressurized into the flat tube through the water injection hole 131 of the mandrel 13. The liquid pressure is 23 MPa, and the flat tube is water-expanded to form the shape shown in the figure. Figure 4 The intermediate blank shown is expanded in the middle. The ejector pin on the multi-directional hydraulic press passes through the ejector pin hole 121 of the water-expanding lower mold 12 to eject the intermediate blank.

[0036] 3) Sawing: Cut the intermediate blank according to... Figure 4 The dotted line shown is cut in half, dividing the blank into two sections. One end of the cut blank is the larger end, and the other end is the smaller end.

[0037] 4) Cutting: The two ends of the blank are cut with a laser cutting machine to obtain a blank to be shaped with a material volume equal to the material volume of the formed wire shell;

[0038] 5) Final Forming: The upper forming mold 21 and the lower forming mold 22 are positioned in the multi-directional hydraulic press by cooperating with the outer peripheral strip positioning groove 3. The blank to be formed is then placed in the fourth mold groove of the lower forming mold 22. The upper forming mold 21 and the lower forming mold 22 are closed and pressed together. The forming mandrel 23 and the shaping mold 25 are inserted into the forming mold 2 and move simultaneously into the cavity in the middle of the forming mold 2, applying pressure to both ends of the cut blank to obtain the formed wire shell. The formed wire shell is as follows: Figure 5 As shown;

[0039] 6) Annealing: After processing, the wire shell is placed in an annealing furnace with the temperature set at 850℃ to relieve stress.

[0040] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method of processing a pull wire housing, comprising processing a mold, the processing mold comprising a hydroswell mold and a forming mold, the method characterized by: The water bulging mold comprises a water bulging upper mold and a water bulging lower mold, the water bulging lower mold is provided with a pinhole in the middle, and the water bulging upper mold and the water bulging lower mold are provided with a core rod at both ends after being combined, the core rod is provided with a water injection hole, the water bulging upper mold is provided with a first mold groove which can be attached to the middle blank, the water bulging lower mold is provided with a second mold groove which can be attached to the middle blank, and the first mold groove and the second mold groove can be combined into the shape of the middle blank; the forming mold comprises a forming upper mold and a forming lower mold, the forming upper mold and the forming lower mold are provided with a forming core shaft at one end and a shaping mold with a forming port at the other end after being combined, the forming upper mold is provided with a third mold groove which can be attached to the pull wire shell, the forming lower mold is provided with a fourth mold groove which can be attached to the pull wire shell, and the third mold groove and the fourth mold groove can be combined into the shape of the pull wire shell; The processing method comprises the following steps: 1) material preparation: a Q355 round steel pipe with a volume of 110% of two final forming pieces is processed into a flat pipe; 2) first water bulging: the flat pipe is placed into the water bulging mold, the water bulging upper mold and the water bulging lower mold are combined and pressed tightly, the core rod blocks both ends of the flat pipe, and the core rod is used to pressurize the liquid medium in the flat pipe through the water injection hole, the flat pipe is water bulged to form a middle blank with an expanded middle part; 3) sawing: the middle blank is equally divided into two sections by being sawed in the middle, one end of the sectioned blank is a large head, and the other end is a small head; 4) cutting: the sectioned blank is cut at both ends by using a laser cutting machine to obtain a to-be-shaped blank with a material volume equal to that of the pull wire shell after forming; 5) final forming: the to-be-shaped blank is placed into the mold cavity of the forming lower mold, the forming upper mold and the forming lower mold are combined and pressed tightly, the forming core shaft and the shaping mold are simultaneously moved to the cavity in the middle of the forming mold, and the to-be-shaped blank is pressed to obtain the formed pull wire shell; 6) annealing: the pull wire shell after processing is placed into an annealing furnace for annealing to remove stress.

2. The method of claim 1, wherein: The forming mold is tightly attached to a positioning sleeve on one side, the forming core shaft passes through the positioning sleeve first, and then is inserted into the third mold groove.

3. The method of claim 1, wherein: The water bulging upper mold and the water bulging lower mold, the forming upper mold and the forming lower mold are provided with a strip-shaped positioning groove on the outer periphery.

4. The method of claim 1, wherein: The surface of the flat pipe in step 1) is coated with a layer of graphite powder.

5. The method of claim 1, wherein: The liquid pressure for water bulging in step 2) is 20-30 Mpa.

6. The method of claim 1, wherein: The temperature of the annealing furnace in step 6) is set to 800-900℃.

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