Multi-directional forging die and forming process for railway locomotive coupler tongue forging

Abstract

The present invention relates to the technical field of plastic forming of complex parts, in particular to a multi-directional die forging die and forming process of a railway locomotive hook tongue forging, comprising an upper die assembly, a lower die assembly and two horizontal punches, wherein the upper die assembly comprises an upper die, an upper punch and a side punch; the lower die assembly comprises a lower die, and the upper die, the upper punch, the side punch, the lower die and the two horizontal punches are combined to form a cavity in the shape of a hook tongue. The present invention has a small machining allowance, and the upper punch directly extrude the blank into the traction curved surface of the hook tongue, thereby improving the tissue density of this part, improving its wear resistance and impact resistance, and extending the service life of the hook tongue.

Description

Technical Field

[0001] The invention relates to the technical field of plastic forming of complex parts, in particular to a multi-directional die forging die for a railway locomotive coupler tongue forging and a forming process thereof. Background Art

[0002] The main function of the hook tongue is to connect two carriages, transmit traction and impact force, and keep a certain distance between vehicles. Its use conditions are harsh, resulting in deformation, cracks, wear and other three-state failures in various parts. The performance of the hook tongue is directly related to the operational reliability and safety of railway trains. As my country's railway transportation continues to develop towards high and heavy loads, the longitudinal impact force of the train has increased sharply, and the friction and wear of the contact surface of the hook tongue are serious. Its performance has become increasingly difficult to meet the needs of modern railway transportation, seriously affecting the safety and efficiency of railway transportation.

[0003] In the past, hook tongue manufacturing was mainly based on casting. The structural defects formed during the casting process, such as pores, slag inclusions, shrinkage cavities, and looseness, formed cracks under the action of alternating stress, causing the hook tongue to break directly, posing a serious threat to the operation safety of railway vehicles. Although hook tongues are currently produced by forging, the manufacturing process is complicated and requires multiple heating, die forging, and trimming. In addition, the shape and size of the forged blank and the finished product are very different. It must rely on mechanical processing to be processed into the shape and size of the hook tongue product, which wastes energy and materials and causes high manufacturing costs. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a multi-directional forging die and a forming process for a railway locomotive coupler tongue forging, which only requires heating the blank once and the forging equipment to work once, has a simple process, high forming accuracy and small processing allowance.

[0005] The present invention adopts the following technical solution:

[0006] A multi-directional die forging die for a railway locomotive coupler tongue forging comprises an upper die assembly, a lower die assembly and two horizontal punches, wherein the upper die assembly comprises an upper concave die, an upper punch and a side punch; the lower die assembly comprises a lower concave die, and the upper concave die, the upper punch, the side punch, the lower concave die and the two horizontal punches are combined to form a cavity in the shape of a coupler tongue.

[0007] Compared with the prior art, the hook tongue manufactured by the mold provided by the present invention has high precision and small processing allowance. The upper punch directly extrude the blank into the traction surface of the hook tongue, which improves the density of the structure of this part, improves its wear resistance and impact resistance, and extends the service life of the hook tongue.

[0008] Further, the preferred embodiment adopted by the present invention is:

[0009] The lower end of the upper punch is arranged as an arc-shaped protrusion adapted to the traction curved surface of the hook tongue, and the bottom surface of the upper die is provided with a cavity adapted to the upper punch; a groove structure 1 is arranged at the middle position of the bottom of the upper die corresponding to the traction platform of the hook tongue, and the side punch is placed in the groove structure 1;

[0010] The upper surface of the lower die is provided with an arc-shaped groove matched with the front face of the hook tongue, and a corresponding groove structure 2 is provided in the arc-shaped groove corresponding to the hook tongue body connecting the hook head and the traction platform, and a convex structure 1 matched with it is arranged at a position inside the arc-shaped groove corresponding to the groove structure 3 on the front face of the hook tongue.

[0011] The two horizontal punches are respectively provided with protruding structures 2 matched therewith on the two side surfaces of the hook tongue.

[0012] The present invention also provides a multi-directional die forging process for a railway locomotive coupler tongue forging, which is performed according to the following steps:

[0013] S1. Blank cutting: The blank is made of round bar;

[0014] S2. Die installation: Install the lower die assembly and the upper die assembly on the forging platform respectively to ensure the positioning accuracy of the die during installation and the centering accuracy of the upper and lower die assemblies;

[0015] S3. Billet heating: Use gas furnace, medium frequency furnace or resistance furnace to heat the billet to the initial forging temperature of 1200℃±20℃. When using gas furnace and resistance furnace for heating, the holding time is 0.5h; when using medium frequency furnace for heating, there is no holding time, which can realize continuous production;

[0016] S4, placing the blank into the mold cavity: placing the heated blank into the arc groove of the lower concave mold;

[0017] S5. Clamping of upper and lower dies: The upper die moves downward by the control method of "displacement first, pressure later". Displacement control is adopted before contacting with the lower die, and pressure control is adopted after contact to provide the clamping load required for the forming stage.

[0018] S6, the upper punch extrude downward: the upper punch moves downward and passes through the hole in the middle of the upper die to upset the blank;

[0019] S7, horizontal punches extrusion: two horizontal punches move toward each other along their horizontal axes to extrude the blank until the horizontal punches reach the set end point and stop extruding. During the extrusion process, the metal first fills the horizontal end surface of the hook tongue forging, and the excess metal enters the upper traction table position of the upper die and the lower die;

[0020] S8, side punch back pressure: the side punch squeezes the excess metal at the traction table position in step S7 to complete the forging;

[0021] S9, die return: first the two horizontal punches return, then the upper punch and upper die return in sequence;

[0022] S10. Take out the forging: the upper punch moves downward to eject the hook tongue forging from the upper die. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a cross-sectional view of the forming die of the present invention;

[0024] Figure 2 This is the main view of the forming mold in the mold opening state;

[0025] Figure 3 It is a cross-sectional view of the forming mold in the mold opening state;

[0026] Figure 4 Schematic diagram of the structure of the upper die;

[0027] Figure 5 Schematic diagram of the structure of the upper punch;

[0028] Figure 6 It is a structural schematic diagram of the lower concave die;

[0029] Figure 7 It is a schematic diagram of the structure of the side punch;

[0030] Figure 8 It is a structural schematic diagram of a horizontal punch;

[0031] Fig. 9 The structure of the hook tongue is shown in Figure 1. Figure 1 ;

[0032] Fig.10 The structure of the hook tongue is shown in Figure 1. Figure 2

[0033] In the figure: upper die 1; lower die 2; upper punch 3; side punch 4; horizontal punch 5; blank 6; cavity 7; groove structure one 8; arc groove 9; arc protrusion 10; protrusion structure two 11; traction platform 12; hook tongue body 13; hook head 14; traction curved surface 15; groove structure three 16; hook tongue front 17; groove structure two 18. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0035] like Fig. 9 , Fig.10 As shown, the hook tongue forging is mainly composed of a traction platform 12, a hook tongue body 13 and a hook head 14.

[0036] A multi-directional die forging die for a railway locomotive coupler tongue forging mainly consists of an upper die assembly, a lower die assembly and two left and right horizontal punches 5.

[0037] The upper die assembly is mainly composed of an upper die 1, an upper punch 3 and a side punch 4. The lower end of the upper punch 3 is set as an arc-shaped protrusion 10 that is compatible with the traction curved surface 16 of the hook tongue. The bottom surface of the upper die 1 is provided with a cavity 7 that is compatible with the upper punch 3; a groove structure 8 is set in the middle position of the bottom of the upper die 1 corresponding to the traction platform 12 of the hook tongue. The groove structure 8 is connected with the cavity 7, and the side punch 4 is placed in the groove structure 8.

[0038] The lower die assembly includes a lower die 2, the upper surface of which is provided with an arc groove 9 (such as Fig.10 As shown), the hook tongue body 13 corresponding to the hook head 14 connected to the traction platform 12 is provided with a matching groove structure 2 18 in the arc groove 9, and the positions of the two groove structures 3 16 on the front face 17 of the hook tongue inside the arc groove 9 are respectively provided with a matching convex structure 1 (due to Figure 6 Angle problem, not shown).

[0039] The two horizontal punches 5 are respectively provided with protruding structures 11 adapted thereto on the two sides of the hook tongue.

[0040] like Figure 1 , 2 As shown in FIG. 3 , the upper die 1, the upper punch 3, the side punch 4, the lower die 2 and the two horizontal punches 5 are combined to form a cavity in the shape of a hook tongue.

[0041] The molding process using the above mold is as follows:

[0042] S1. Blank cutting: Blank 6 is made of round bar material, the diameter of the round bar material is φ150mm~φ180mm, and the length is about 300mm~430mm.

[0043] S2. Die installation: Install the lower die assembly and the upper die assembly on the forging platform respectively to ensure the positioning accuracy of the die during installation and the centering accuracy of the upper and lower die assemblies.

[0044] S3. Billet heating: Billet 6 heating: Use a gas furnace, medium frequency furnace or resistance furnace to heat the billet to the initial forging temperature of 1200℃±20℃. When using a gas furnace and a resistance furnace for heating, the holding time is 0.5h; when using a medium frequency furnace for heating, there is no holding time, and continuous production can be achieved.

[0045] S4, placing the blank into the mold cavity: placing the heated blank 6 into the arc groove 9 of the lower concave mold 2.

[0046] S5. Clamping of the upper and lower dies: The upper die 1 moves downward by adopting the control method of "displacement first, pressure later". Displacement control is adopted before contacting the lower die 2 until contacting the lower die 2. During this process, the blank 6 and the upper die 1 are not in contact and no deformation occurs; after contact, pressure control is adopted to provide the clamping load required for the forming stage.

[0047] S6, the upper punch extrude downward: the upper punch 3 moves downward, passes through the hole 7 in the middle of the upper die 1, and performs upsetting and extrusion on the blank 6.

[0048] S7, horizontal punches extrusion towards each other: the two horizontal punches 5 move toward each other along their horizontal axes to extrude the blank 6. During the extrusion process, the metal first fills the horizontal end surface of the hook tongue forging. At this time, the two horizontal punches 5 have not reached the set end position, so they continue to extrude, and then press the excess metal into the traction table 12 position corresponding to the upper die 1 and the lower die 2 until the horizontal punch 5 reaches the set end point and stops extrusion.

[0049] S8, side punch back pressure: the side punch squeezes the excess metal at the position of the traction table 12 in step S7, presses it into the shape of the traction table 12, and completes the forging.

[0050] S9, die return: After the hook tongue forging is formed, the two horizontal punches 5 return first, and then the upper punch 3 and the upper die 1 return in sequence. At this time, the forging will be left in the cavity 7 of the upper die 1.

[0051] S10, taking out the forging: the upper punch 3 moves downward to eject the hook tongue forging from the upper die 1.

[0052] The present invention adopts a multi-directional die forging process to form a hook tongue forging. The upper punch directly extrude the blank to form the traction curved surface (S surface) of the hook tongue, so that the metal structure of this part is more compact, the wear resistance and impact resistance are improved, and the problem of frequent cracks on the S-shaped surface of the hook tongue is improved; the blank is under a four-directional compressive stress state of an upper punch, two horizontal punches and a side punch, which is conducive to grain refinement, the overall mechanical properties are improved, and a continuous metal streamline is formed in the closed die cavity, which greatly improves the quality of the hook tongue forging and extends its service life.

[0053] The above are only specific implementations of the present invention, but the protection of the present invention is not limited to this. All equivalent changes or substitutions to the technical features of the technical solution that can be thought of by technicians in this technical field are included in the protection scope of the present invention.

Claims

1. A multi-directional die forging process for a railway locomotive coupler tongue forging, characterized in that: Follow these steps: S1. Blank cutting: The blank is made of round bar; S2. Mold installation: including an upper mold assembly, a lower mold assembly and two horizontal punches. The upper mold assembly includes an upper die, an upper punch and a side punch; the lower mold assembly includes a lower die, and the upper die, an upper punch, a side punch, a lower die and two horizontal punches are combined to form a cavity in the shape of a hook tongue; The lower end of the upper punch is arranged as an arc-shaped protrusion adapted to the traction curved surface of the hook tongue, and the bottom surface of the upper die is provided with a cavity adapted to the upper punch; a groove structure 1 is arranged at the middle position of the bottom of the upper die corresponding to the traction platform of the hook tongue, and the side punch is placed in the groove structure 1; The upper surface of the lower concave die is provided with an arc-shaped groove matched with the front face of the hook tongue, and a matching groove structure 2 is provided in the arc-shaped groove corresponding to the hook tongue body connected with the hook head and the traction platform, and a matching convex structure 1 is provided in the position of the arc-shaped groove corresponding to the groove structure 3 on the front face of the hook tongue; Two horizontal punches are respectively provided with protruding structures 2 adapted thereto on two sides of the hook tongue; Install the lower die assembly and the upper die assembly on the forging platform respectively to ensure the positioning accuracy of the die during installation and the centering accuracy of the upper and lower die assemblies; S3. Billet heating: Use gas furnace, medium frequency furnace or resistance furnace to heat the billet to the initial forging temperature of 1200℃±20℃. When using gas furnace and resistance furnace for heating, the holding time is 0.5h; when using medium frequency furnace for heating, there is no holding time, which can realize continuous production; S4, placing the blank into the mold cavity: placing the heated blank into the arc groove of the lower concave mold; S5. Clamping of upper and lower dies: The upper die moves downward using the control method of "displacement first, pressure later". Displacement control is used before contacting the lower die, and pressure control is used after contact to provide the clamping load required for the forming stage. S6, the upper punch extrude downward: the upper punch moves downward and passes through the hole in the middle of the upper die to upset the blank; S7, horizontal punches extrusion: two horizontal punches move toward each other along their horizontal axes to extrude the blank until the horizontal punches reach the set end point and stop extruding. During the extrusion process, the metal first fills the horizontal end surface of the hook tongue forging, and the excess metal enters the upper traction table position of the upper die and the lower die; S8, side punch back pressure: the side punch squeezes the excess metal at the traction table position in step S7 to complete the forging; S9, die return: first the two horizontal punches return, then the upper punch and upper die return in sequence; S10. Take out the forging: the upper punch moves downward to eject the hook tongue forging from the upper die.

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