A shoe bolt manufacturing mold and a manufacturing process thereof

Abstract

This invention discloses a brake shoe pin manufacturing mold and its manufacturing process, belonging to the technical field of brake shoe pin manufacturing processes. The key features are: the blanking mold includes an upper blanking template and a lower blanking template; the upper blanking template includes an upper blanking base plate, a cutter, and a pressing block; the lower blanking template includes a lower blanking base plate, a supporting block, and a positioning mechanism; the forming mold includes an upper forming template and a lower forming template; the upper forming template includes an upper forming base plate, an upper die stretching punch, and a corrugated upper module; the lower forming template includes a lower forming base plate, a lower die concave block, and a corrugated lower template; the bending mold includes an upper bending template and a lower bending template; the upper bending template includes a lower bending base plate, a lower bending module, and an upper die floating pre-pressing block; the lower bending template includes a lower bending base plate, a lower bending module, and a lower die floating pre-pressing block. Compared with existing technologies, this invention features the ability to form multiple curved shapes in a single bending operation.

Description

Technical Field

[0001] This invention relates to the field of brake shoe pin manufacturing technology, and in particular to a brake shoe pin manufacturing mold and its manufacturing process. Background Technology

[0002] Brake shoe pins, as an indispensable and crucial component and consumable part in train braking systems, play a vital role. Their ingenious design, utilizing pre-set grooves, significantly increases the friction between the brake shoe and the wheel contact surface, which is fundamental to effective braking. Furthermore, the carefully designed anti-slip grooves on the pin surface ensure a tight and stable engagement between the brake shoe and the wheel during emergency braking. This design greatly reduces the risk of brake shoe detachment due to uneven force, thus guaranteeing a significant increase in the engagement force between the brake shoe and the wheel at the moment of train braking. This results in faster braking action, more significant braking effect, and ensures the safety of train operation.

[0003] Given the crucial role of brake shoe pins in the braking process and the complex mechanical environment they face, they must possess a considerable degree of hardness and toughness to withstand the enormous frictional and impact forces generated during braking, while maintaining structural integrity and stability. To achieve these performance requirements, brake shoe pins are typically manufactured using high-quality spring steel, a material renowned for its excellent elastic recovery and good mechanical strength, making it an ideal choice for manufacturing components subjected to dynamic loads.

[0004] However, manufacturing the brake shoe pin is no easy task. Its forging design is unique, with chamfered ends, resulting in a relatively long and thin piece with a complex and varied shape, including multiple curved sections, wavy patterns, and raised grooves on the surface. While these design features enhance the pin's functionality and durability, they also present machining challenges. Due to its complex shape and slender dimensions, the brake shoe pin is highly susceptible to bending deformation during forging, which undoubtedly increases production difficulty.

[0005] Traditional direct forging methods not only result in low material utilization and resource waste, but also often cannot be formed in one step due to the complexity of the shape, requiring multiple processing and adjustments. This not only prolongs the production cycle and reduces production efficiency, but also increases manufacturing costs. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the prior art by providing a brake shoe pin preparation mold and its preparation process, achieving the goal of forming a multi-curved appearance in a single bending operation.

[0007] This invention provides a mold for manufacturing brake shoe pins, comprising a blanking mold, a forming mold, and a bending mold; characterized in that: the blanking mold includes an upper blanking template and a lower blanking template; the upper blanking template includes an upper blanking base plate, a cutter, and a pressing block; a pressing block is installed at the middle position of the lower end face of the upper base plate, and cutters are respectively installed at both ends of the pressing block, with the upper ends of the cutters fixedly connected to the upper base plate; the lower blanking template includes a lower blanking base plate, a supporting block, and a positioning mechanism; a supporting block is installed on the upper end face of the lower blanking base plate, supporting the material... The block is provided with a limiting cavity; the forming die includes an upper forming template and a lower forming template. The upper forming template includes an upper forming base plate, an upper die stretching punch, and a corrugated upper template. The upper die stretching punch and the corrugated upper template are fixedly installed on the lower end face of the upper forming base plate. The corrugated upper template has a corrugated cavity. The lower forming template includes a lower forming base plate, a lower die recess, and a corrugated lower template. The lower die recess corresponds to the stretching groove of the upper die stretching punch. The corrugated lower template has a corrugated cavity, and the cavities of the corrugated lower template and the corrugated upper template are connected. Correspondingly, the bending die includes an upper bending template and a lower bending template. The upper bending template includes a lower bending die base plate, an upper bending module, and an upper die floating preload block. The lower end face of the upper bending die base plate is fixedly connected to the upper bending module. The lower end face of the upper bending module is the bending surface. The rear end of the upper bending module has a guide cavity with an opening at the lower end. The upper die floating preload block is placed in the guide cavity of the upper bending module. The lower end of the upper die floating preload block has a corrugated cavity. The corrugated cavity of the upper die floating preload block corresponds to the corrugated cavity of the corrugated upper template. Correspondingly, the bending lower template includes a bending lower mold base plate, a bending lower module, and a lower mold floating pre-compression block. The upper end face of the bending lower mold base plate is fixedly connected to the bending lower module. The front end of the bending lower module is provided with a guide cavity with an upper opening. The lower mold floating pre-compression block is placed in the guide cavity of the bending upper module. The upper end of the lower mold floating pre-compression block is rotatably connected to a roller. The front end of the upper end face of the bending lower module is a bending surface, and the rear end is a corrugated cavity. The corrugated cavity of the bending lower module corresponds to the corrugated cavity of the corrugated lower template.

[0008] Furthermore, the upper bottom plate for material discharge is connected to the pressure block via a pressure plate, and the upper bottom plate for material discharge and the pressure plate are connected by bolts. A spring is sleeved on the outside of the bolt, with the upper end of the spring connected to the upper bottom plate for material discharge and the lower end connected to the pressure plate.

[0009] Furthermore, the positioning mechanism is located at one end of the slot in the material receiving block. The positioning mechanism includes a floating positioning block, a spring, and a guide pin. A guide pin is fixedly installed on the bottom plate of the material discharge. The floating positioning block has a guide through hole. The guide through hole of the floating positioning block slides up and down with the guide pin. A spring is sleeved on the outside of the guide pin. The upper end of the spring is connected to the floating positioning block, and the lower end of the floating positioning block is connected to the bottom plate of the material discharge.

[0010] Furthermore, the upper die stretching punch is stepped, and its boss is mounted on the forming upper base plate.

[0011] Furthermore, the lower end of the forming upper base plate is connected to the upper die block by bolts. A spring is sleeved on the outside of the bolt. The upper end of the spring is fixedly connected to the forming upper base plate, and the lower end is fixedly connected to the upper die block. The upper die block is provided with a through hole, and the upper die stretching punch passes through the through hole of the upper die block.

[0012] Furthermore, a lower mold positioning block is installed at one end of the corrugated lower mold plate.

[0013] Furthermore, the lower end of the forming bottom plate is connected to the lower die block by bolts. A spring is sleeved on the outside of the bolt. The upper end of the spring is fixedly connected to the lower die block, and the lower end is fixedly connected to the forming bottom plate. The lower die block is provided with through holes, and the lower die concave block and the corrugated lower die plate pass through the through holes of the lower die block respectively.

[0014] A manufacturing process for brake shoe pins based on the above-mentioned mold, characterized by the following steps:

[0015] ① Heating the material;

[0016] The long bar stock is heated in a segmented manner, passing through four stages in sequence: preheating, heating, uniform heating, and heat preservation.

[0017] ② Phosphorus removal treatment;

[0018] Using a descaling machine to remove the oxide scale from the surface of long bars helps maintain the surface quality of subsequent processing;

[0019] ③ Rolled billet;

[0020] During rolling, the long bar is rough rolled to a thickness of 6±0.25mm and a width of 18 mm±0.5mm, then fine rolled to a thickness of 5.2±0.15mm and a width of 21.8 mm±0.1mm, and finally shaped into a long billet with a thickness of 5±0.1mm and a width of 22 mm±0.1mm.

[0021] ④Blanking;

[0022] Cut a single long billet and chamfer both ends of the billet to C8. Place the long billet into the limiting cavity of the support block and position it using the floating positioning block at the front end. Place the long billet in the limiting cavity of the support block and position it using the initial positioning surface of the floating positioning block at the front end to complete the initial positioning. The upper blanking template moves downward, the pressure block holds the long billet down, and the cutter cuts off the first small billet from both ends of the support block. The upper blanking template moves upward, driving the pressure block and the cutter upward to remove the first small billet. The long billet with the small billet removed is placed in the limiting cavity of the support block and positioned using the subsequent positioning surface of the floating positioning block to complete the secondary positioning. The upper blanking template moves downward, the pressure block holds the long billet down, and the cutter cuts off the second small billet from both ends of the support block. The upper blanking template moves upward, driving the pressure block and the cutter upward to remove the second small billet. Subsequent blanks are cut off sequentially according to the positioning method of the second small billet until all blanks are cut off.

[0023] ⑤ Pressing;

[0024] The small blank is placed between the stretching groove of the lower die concave block and the lower die positioning block to complete the initial positioning; the upper forming die moves downward, the upper die stretching punch presses down on the long blank, and the upper die stretching punch cooperates with the stretching groove of the lower die concave block to stretch out the workpiece boss and extrude the raised mark; at the same time, the corrugated upper die and corrugated lower die extrude the corrugated pattern of the workpiece; the upper forming die moves upward and takes out the formed workpiece;

[0025] ⑥ Bending;

[0026] The formed blank is positioned at the corrugated end and placed on the limiting groove of the lower bending module. The blank is horizontally lifted by the rollers of the lower die floating pre-pressure block. The upper bending template moves downward, and the upper die floating pre-pressure block first pre-presses the corrugated surface of the blank, while the lower die floating pre-pressure block begins to move downward. The upper bending template continues to move downward, and the upper bending module and the lower bending module come into contact and gradually compact the blank. At the same time, the lower die floating pre-pressure block continues to move downward, and the blank is pulled by the rollers of the lower die floating pre-pressure block and bent downward until the upper bending module and the lower bending module are relatively closed, and finally the blank is formed. The upper bending template moves upward, and the lower die floating pre-pressure block removes the formed workpiece from the mold.

[0027] ⑦ After the forming process is completed, the temperature is automatically sorted. If the temperature is greater than or equal to 860℃, it enters the heating and holding line; otherwise, it enters the heating and holding line and enters the tracked quenching and tempering line after reaching the design temperature. The tempering temperature is 460℃±5℃ and the tempering time is 120±15 min. The hardness after heat treatment reaches HRC44~52 and the metallographic structure is better than grade 4.

[0028] ⑧ Shot blasting;

[0029] Use shot blasting with sand or fine steel wire cut into shot;

[0030] 9. Flaw Detection

[0031] Perform magnetic particle testing on the workpiece, remove surface microcracks no deeper than 0.2 mm, remove tin and scrap workpieces with deep cracks;

[0032] ⑩ Cold plastic surgery;

[0033] The workpiece is cold-formed to ensure that the dimensional angular tolerance does not exceed ±0.5° and the length tolerance does not exceed ±0.76 mm.

[0034] ⑪ Surface treatment;

[0035] The surface of the workpiece is treated with rust prevention.

[0036] Compared with the prior art, the present invention has the following outstanding advantages:

[0037] 1. This invention can form multiple curved shapes in one bending process using a bending die, with high reliability in forming dimensions;

[0038] 2. This invention can make the long bar material drop into the blanking die so that the front and back of the material are connected, resulting in less waste and higher material utilization. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the blanking die of the present invention;

[0040] Figure 2 yes Figure 1 A magnified view of part A in the middle;

[0041] Figure 3 This is a schematic diagram of the forming mold of the present invention;

[0042] Figure 4 This is a schematic diagram of the bending die of the present invention;

[0043] The components include: 1. Upper blanking template; 11. Pressure block; 12. Cutting knife; 13. Upper blanking base plate; 2. Lower blanking template; 21. Lower blanking base plate; 22. Material support block; 23. Positioning mechanism; 231. Floating positioning block; 232. Guide pin; 233. Initial positioning surface; 234. Subsequent positioning surface; 3. Upper forming template; 31. Upper forming base plate; 32. Upper die stretching punch; 33. Upper die pressure block; 34. Corrugated upper die. 4. Forming lower template; 41. Forming lower base plate; 42. Lower die concave block; 43. Lower die positioning block; 44. Corrugated lower template; 45. Lower die positioning block; 5. Bending upper template; 51. Bending upper die base plate; 52. Bending upper module; 53. Upper die floating pre-compression block; 6. Bending lower template; 61. Bending lower module; 62. Lower die floating pre-compression block; 63. Bending lower die base plate; 64. Roller; 65. Bending lower positioning block. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0045] The present invention includes a blanking die, a forming die, and a bending die.

[0046] like Figure 1 As shown, the blanking mold includes a blanking upper template 1 and a blanking lower template 2. The blanking upper template 1 includes a blanking upper base plate 13, a cutter 12 and a pressing block 11. The pressing block 11 is installed at the middle position of the lower end face of the upper base plate. The cutter 12 is installed at both ends of the pressing block 11. The upper end of the cutter 12 is fixedly connected to the upper base plate.

[0047] In the optimized scheme, the upper bottom plate 13 for unloading is connected to the pressure block 11 via a pressure plate. The upper bottom plate 13 for unloading is connected to the pressure plate via bolts. A spring is sleeved on the outside of the bolt. The upper end of the spring is connected to the upper bottom plate 13 for unloading, and the lower end is connected to the pressure plate.

[0048] The blanking template 2 includes a blanking base plate 21, a material receiving block 22, and a positioning mechanism 23. The material receiving block 22 is installed on the upper end face of the blanking base plate 21. The material receiving block 22 is provided with a limiting cavity with a groove width of 22.1 mm ± 0.05 mm and a depth of 2.5 mm ± 0.05 mm, which is used to position the blank in the width direction to prevent it from tilting. The positioning mechanism 23 is set at one end of the groove of the material receiving block 22. The positioning mechanism 23 includes a floating positioning block 231, a spring, and a guide pin 232.

[0049] like Figure 2 As shown, a guide pin 232 is fixedly installed on the lower base plate 21 for material discharge, and a guide through hole is provided on the floating positioning block 231. The guide through hole of the floating positioning block 231 and the guide pin 232 slide together vertically. A spring is sleeved on the outside of the guide pin 232. The upper end of the spring is connected to the floating positioning block 231, and the lower end of the floating positioning block 231 is connected to the lower base plate 21 for material discharge.

[0050] The floating positioning block 231 is in the shape of an inverted L and has two levels of positioning. The upper level is the initial positioning surface 233, which is used for the initial punching positioning of long blanks, and the lower level is the subsequent positioning surface 234, which is used for subsequent material feeding positioning.

[0051] like Figure 3 As shown, the forming die includes an upper forming template 3 and a lower forming template 4. The upper forming template 3 includes an upper forming base plate 31, an upper die stretching punch 32, and a corrugated upper template 34. The upper die stretching punch 32 and the corrugated upper template are fixedly installed on the lower end surface of the upper forming base plate 31. The corrugated upper template has a corrugated cavity, and the upper die stretching punch 32 and the surface of the corrugated upper template 34 maintain a certain height difference.

[0052] The upper die stretching punch 32 is made with reverse concave characters.

[0053] In the optimized design, the upper die stretching punch 32 is stepped, and its boss is mounted on the forming upper base plate 31.

[0054] The lower end of the forming upper base plate 31 is connected to the upper die pressing block 33 by bolts. A spring is sleeved on the outside of the bolt. The upper end of the spring is fixedly connected to the forming upper base plate 31, and the lower end is fixedly connected to the upper die pressing block 33. The upper die pressing block 33 is provided with a through hole, and the upper die stretching punch 32 passes through the through hole of the upper die pressing block 33.

[0055] The forming lower template 4 includes a forming lower base plate 41, a lower die recess 42, and a corrugated lower template 44. The lower die recess 42 has a stretching groove corresponding to the upper die stretching punch 32. The corrugated lower template 44 has a wave-shaped cavity, and the corrugated lower template 44 corresponds to the cavity of the corrugated upper template.

[0056] The lower die concave block 42 has a stretching groove with a width of 22.25 mm ± 0.05 mm and a depth of 2.5 mm ± 0.05 mm, which is used to position long blanks in the width direction to prevent them from tilting.

[0057] One end of the corrugated lower template is equipped with a lower mold positioning block to limit the length direction of the small blank.

[0058] In the optimized scheme, the lower end of the forming bottom plate 41 is connected to the lower die pressing block by bolts. A spring is sleeved on the outside of the bolt. The upper end of the spring is fixedly connected to the lower die pressing block, and the lower end is fixedly connected to the forming bottom plate 41. The lower die pressing block is provided with through holes. The lower die concave block 42 and the corrugated lower template 44 pass through the through holes of the lower die pressing block respectively.

[0059] like Figure 4 As shown, the bending die includes an upper bending template 5 and a lower bending template 6. The upper bending template 5 includes an upper bending die base plate 51, an upper bending module 52, and an upper bending die floating pre-pressure block 53. The lower end face of the upper bending die base plate 51 is fixedly connected to the upper bending module 52. The lower end face of the upper bending module 52 is a bending surface. The rear end of the upper bending module 52 is provided with a guide cavity with a lower opening. The upper bending die floating pre-pressure block 53 is placed in the guide cavity of the upper bending module 52. The lower end of the upper bending die floating pre-pressure block 53 is a corrugated cavity. The corrugated cavity of the upper bending die floating pre-pressure block 53 corresponds to the corrugated cavity of the corrugated upper template.

[0060] In the optimized scheme, bolts are fixedly installed on the top wall of the guide cavity of the bending upper module 52, and the upper end of the upper mold floating preload block 53 is provided with a threaded blind hole. The bolts are threadedly engaged with the threaded blind hole of the upper mold floating preload block 53. A spring is sleeved on the outside of the bolts. The upper end of the spring is fixedly connected to the bending upper module 52, and the lower end is fixedly connected to the upper mold floating preload block 53.

[0061] The bending lower template 6 includes a bending lower template base plate 63, a bending lower module 61, and a lower template floating pre-compression block 62. The upper end face of the bending lower template base plate 63 is fixedly connected to the bending lower module 61. The front end of the bending lower module 61 is provided with a guide cavity with an upper opening. The lower template floating pre-compression block 62 is placed in the guide cavity of the bending upper module 52. The upper end of the lower template floating pre-compression block 62 is rotatably connected to the roller 64. The front end of the upper end face of the bending lower module 61 is a bending surface, and the rear end is a corrugated cavity. The corrugated cavity of the bending lower module 61 corresponds to the corrugated cavity of the corrugated lower template 44.

[0062] The bending lower module 61 has a limiting groove with a depth of about 3mm and a width that is about 0.5mm larger than that of the blank in the length direction.

[0063] In the optimized scheme, bolts are fixedly installed on the bottom wall of the guide cavity of the bending lower module 61, and a blind hole is provided at the lower end of the lower mold floating preload block 62. The bolts are inserted into the blind hole of the lower mold floating preload block 62, and a spring is sleeved on the outside of the bolts. The lower end of the spring is fixedly connected to the bending lower module 61, and the lower end is fixedly connected to the lower mold floating preload block 62.

[0064] A bending positioning block 65 is fixedly installed on the rear wall of the bending lower module 61.

[0065] A process for manufacturing brake shoe pins using the above-mentioned mold specifically includes the following steps:

[0066] 1. Material heating;

[0067] The long bar stock is heated in a segmented manner, passing through four stages: preheating, heating, uniform heating, and heat preservation. The temperatures are 0~250℃±10℃, 250℃±10℃~1200℃±15℃, 1200℃±5℃, and 1200℃±5℃, respectively. The total heating time for each bar stock is 10s~12s to ensure that the material is fully heated and to reduce oxidation.

[0068] 2. Phosphorus removal treatment;

[0069] Using a descaling machine to remove more than 90% of the oxide scale from the surface of long bars helps maintain the surface quality of subsequent processing; the descaling time is 8s to 10s.

[0070] 3. Rolling the billet;

[0071] During rolling, the long bar is rough rolled to a thickness of 6±0.25mm and a width of 18 mm±0.5mm, then finish rolled to a thickness of 5.2±0.15mm and a width of 21.8 mm±0.1mm, and finally shaped into a long billet with a thickness of 5±0.1mm and a width of 22 mm±0.1mm; the total rolling time is 610s.

[0072] 4. Blanking;

[0073] Cut a single long blank and chamfer both ends of the long blank with C8; place the long blank into the limiting cavity of the material receiving block 22 and position it with the floating positioning block 231 at the front end; the stamping time cycle is 1s to 2s;

[0074] The long billet is placed in the limiting cavity of the receiving block 22 and positioned by the initial positioning surface 233 of the floating positioning block 231 at the front end, completing the initial positioning; the upper blanking template 1 moves downward, the pressure block 11 presses down on the long billet, and the cutter 12 cuts off the first small billet from both ends of the receiving block 22; the upper blanking template 1 moves upward, driving the pressure block 11 and the cutter 12 upward, and removing the first small billet; the long billet with the small billet cut off is placed in the limiting cavity of the receiving block 22 and positioned by the subsequent positioning surface 234 of the floating positioning block 231, completing the secondary positioning; the upper blanking template 1 moves downward, the pressure block 11 presses down on the long billet, and the cutter 12 cuts off the second small billet from both ends of the receiving block 22; the upper blanking template 1 moves upward, driving the pressure block 11 and the cutter 12 upward, and removing the second small billet; the subsequent blanks are cut off sequentially according to the positioning method of the second small billet, until the blanking is completed.

[0075] 5. Pressing;

[0076] The small blank is placed between the stretching groove of the lower die concave block 42 and the lower die positioning block to complete the initial positioning; the upper forming die 3 moves downward, the upper die stretching punch 32 presses the long blank, the upper die stretching punch 32 cooperates with the stretching groove of the lower die concave block 42 to stretch out the workpiece boss and extrude the raised mark; at the same time, the corrugated upper die 34 and the corrugated lower die extrude the corrugated pattern of the workpiece; the upper forming die 3 moves upward, and the formed workpiece is taken out. The stamping time cycle is 2s to 3s.

[0077] 6. Bending;

[0078] The formed blank is positioned at the corrugated end and placed on the limiting groove of the lower bending module 61. The blank is horizontally lifted by the rollers 64 of the lower die floating pre-pressure block 62. The upper bending template 5 moves downward, and the upper die floating pre-pressure block 53 first pre-presses the corrugated surface of the blank. At the same time, the lower die floating pre-pressure block 62 begins to move downward. The upper bending template 5 continues to move downward, and the upper bending module 52 and the lower bending module 61 come into contact and gradually compact the blank. At the same time, the lower die floating pre-pressure block 62 continues to move downward. The blank is pulled by the rollers 64 of the lower die floating pre-pressure block 62 and bends downward until the upper bending module 52 and the lower bending module 61 are relatively closed, and the blank is finally formed. The upper bending template 5 moves upward, and the lower die floating pre-pressure block 62 removes the formed workpiece from the mold. The stamping cycle time is 2s to 3s.

[0079] 7. After the forming process is completed, the temperature is automatically sorted. If the temperature is greater than or equal to 860℃, it enters the heating and holding line; otherwise, it enters the heating and holding line and enters the tracked quenching and tempering line after reaching the design temperature. The tempering temperature is 460℃±5℃ and the tempering time is 120±15 min. The hardness after heat treatment reaches HRC44~52 and the metallographic structure is better than grade 4.

[0080] 8. Shot blasting;

[0081] Use blasting shot made of sand or fine steel wire (0.6-0.8 mm) and set the time to 8-10 minutes per 0.5t shot, based on the loading amount.

[0082] 9. Flaw detection

[0083] Perform magnetic particle testing on the workpiece, remove surface microcracks no deeper than 0.2 mm, remove tin and scrap workpieces with deep cracks.

[0084] 10. Cold plastic surgery;

[0085] The workpiece is cold-formed to ensure that the dimensional angular tolerance does not exceed ±0.5° and the length tolerance does not exceed ±0.76 mm.

[0086] 11. Surface treatment;

[0087] The surface of the workpiece is treated with rust prevention.

[0088] It should be noted that the specific embodiments of the present invention have been described in detail. For those skilled in the art, various obvious changes made to it without departing from the spirit and scope of the present invention are within the protection scope of the present invention.

Claims

1. A mold for preparing brake shoe pins, comprising a blanking mold, a forming mold, and a bending mold; characterized in that: The blanking mold includes a blanking upper template (1) and a blanking lower template (2). The blanking upper template (1) includes a blanking upper base plate (13), a cutter (12), and a pressing block (11). The pressing block (11) is installed at the middle position of the lower end face of the upper base plate. The cutter (12) is installed at both ends of the pressing block (11). The upper end of the cutter (12) is fixedly connected to the upper base plate. The blanking lower template (2) includes a blanking lower base plate (21), a supporting block (22), and a positioning mechanism (23). The supporting block (22) is installed on the upper end face of the blanking lower base plate (21). The supporting block (22) is provided with a limiting cavity. The forming mold includes a forming upper template (3). The forming lower template (4) and the forming upper template (3) include a forming upper base plate (31), an upper die stretching punch (32) and a corrugated upper template (34). The upper die stretching punch (32) and the corrugated upper template are fixedly installed on the lower end face of the forming upper base plate (31). The corrugated upper template has a corrugated cavity. The forming lower template (4) includes a forming lower base plate (41), a lower die recess (42) and a corrugated lower template (44). The lower die recess (42) has a stretching groove corresponding to the upper die stretching punch (32). The corrugated lower template (44) has a corrugated cavity, and the corrugated lower template (44) corresponds to the cavity of the corrugated upper template. The bending die includes a bending lower template (44) and a corrugated upper template (44). The upper bending template (5) and the lower bending template (6) are provided. The upper bending template (5) includes an upper bending mold base plate (51), an upper bending module (52), and an upper mold floating pre-pressure block (53). The lower end face of the upper bending mold base plate (51) is fixedly connected to the upper bending module (52). The lower end face of the upper bending module (52) is a bending surface. The rear end of the upper bending module (52) is provided with a guide cavity with an opening at the lower end. The upper mold floating pre-pressure block (53) is placed in the guide cavity of the upper bending module (52). The lower end of the upper mold floating pre-pressure block (53) is a corrugated cavity. The corrugated cavity of the upper mold floating pre-pressure block (53) corresponds to the corrugated cavity of the corrugated upper template. The bending lower template (6) includes a bending lower mold base plate (63), a bending lower module (61), and a lower mold floating pre-pressure block (62). The upper end face of the bending lower mold base plate (63) is fixedly connected to the bending lower module (61). The front end of the bending lower module (61) is provided with a guide cavity with an upper opening. The lower mold floating pre-pressure block (62) is placed in the guide cavity of the bending upper module (52). The upper end of the lower mold floating pre-pressure block (62) is rotatably connected to the roller (64). The front end of the upper end face of the bending lower module (61) is a bending surface, and the rear end is a corrugated cavity. The corrugated cavity of the bending lower module (61) corresponds to the corrugated cavity of the corrugated lower template (44).

2. The brake shoe pin manufacturing mold according to claim 1, characterized in that: The material dropping upper base plate (13) is connected to the material pressing block (11) through a pressure plate. The material dropping upper base plate (13) and the pressure plate are connected by bolts. A spring is sleeved on the outside of the bolt. The upper end of the spring is connected to the material dropping upper base plate (13), and the lower end is connected to the pressure plate.

3. The brake shoe pin manufacturing mold according to claim 1, characterized in that: The positioning mechanism (23) is located at one end of the slot of the material receiving block (22). The positioning mechanism (23) includes a floating positioning block (231), a spring and a guide pin (232). The guide pin (232) is fixedly installed on the material dropping bottom plate (21). The floating positioning block (231) is provided with a guide through hole. The guide through hole of the floating positioning block (231) slides up and down with the guide pin (232). The outer side of the guide pin (232) is fitted with a spring. The upper end of the spring is connected to the floating positioning block (231), and the lower end of the floating positioning block (231) is connected to the material dropping bottom plate (21).

4. The brake shoe pin manufacturing mold according to claim 1, characterized in that: The upper die stretching punch (32) is stepped, and its boss is mounted on the forming upper base plate (31).

5. The brake shoe pin manufacturing mold according to claim 1, characterized in that: The lower end of the forming upper base plate (31) is connected to the upper die block (33) by bolts. A spring is sleeved on the outside of the bolt. The upper end of the spring is fixedly connected to the forming upper base plate (31), and the lower end is fixedly connected to the upper die block (33). The upper die block (33) is provided with a through hole, and the upper die stretching punch (32) passes through the through hole of the upper die block (33).

6. The brake shoe pin manufacturing mold according to claim 1, characterized in that: A lower mold positioning block is installed at one end of the corrugated lower mold plate.

7. The brake shoe pin manufacturing mold according to claim 1, characterized in that: The lower end of the forming bottom plate (41) is connected to the lower die pressing block by bolts. A spring is sleeved on the outside of the bolt. The upper end of the spring is fixedly connected to the lower die pressing block, and the lower end is fixedly connected to the forming bottom plate (41). The lower die pressing block is provided with through holes. The lower die concave block (42) and the corrugated lower template (44) pass through the through holes of the lower die pressing block respectively.

8. A brake shoe pin manufacturing process based on the brake shoe pin manufacturing mold as described in any one of claims 1 to 7, characterized in that: Includes the following steps, ① Heating the material; The long bar stock is heated in a segmented manner, passing through four stages in sequence: preheating, heating, uniform heating, and heat preservation. ② Phosphorus removal treatment; Using a descaling machine to remove the oxide scale from the surface of long bars helps maintain the surface quality of subsequent processing; ③ Rolled billet; During rolling, the long bar is rough rolled to a thickness of 6±0.25mm and a width of 18 mm±0.5mm, then fine rolled to a thickness of 5.2±0.15mm and a width of 21.8 mm±0.1mm, and finally shaped into a long billet with a thickness of 5±0.1mm and a width of 22 mm±0.1mm. ④Blanking; The long blank is cut into pieces, and the two ends of the long blank are chamfered to C8. The long blank is placed into the limiting cavity of the supporting block (22) and positioned by the floating positioning block (231) at the front end. The long blank is placed in the limiting cavity of the supporting block (22) and positioned by the initial positioning surface (233) of the floating positioning block (231) at the front end, thus completing the initial positioning. The upper blanking template (1) moves down, the pressure block (11) presses down the long blank, and the cutter (12) cuts off the first small blank from both ends of the supporting block (22). The upper blanking template (1) moves up, driving the pressure block (11) and the cutter (12) to move up. 12) Move upwards and remove the first small blank; place the long blank cut from the small blank into the limiting cavity of the support block (22) and the subsequent positioning surface (234) of the floating positioning block (231) to complete the secondary positioning; the upper blanking template (1) moves downwards, the pressure block (11) presses down the long blank, and the cutter (12) cuts off the second small blank from both ends of the support block (22); the upper blanking template (1) moves upwards, driving the pressure block (11) and the cutter (12) upwards to remove the second small blank; the subsequent blanks are cut off in sequence according to the positioning method of the second small blank until the blanking is completed; ⑤ Pressing; The small blank is placed between the stretching groove of the lower die concave block (42) and the lower die positioning block to complete the initial positioning; the upper forming template (3) moves down, the upper die stretching punch (32) presses the long blank, the upper die stretching punch (32) cooperates with the stretching groove of the lower die concave block (42) to stretch out the workpiece boss and extrude the raised mark; at the same time, the corrugated upper template (34) and the corrugated lower template extrude the corrugated pattern of the workpiece; the upper forming template (3) moves up and takes out the workpiece after forming; ⑥ Bending; The small blank after pressing is positioned at the corrugated end and placed on the limiting groove of the lower bending module (61); the small blank is horizontally lifted by the roller (64) of the lower die floating pre-pressing block (62); the upper bending template (5) moves down, the upper die floating pre-pressing block (53) first pre-presses the corrugated surface of the small blank, and at the same time the lower die floating pre-pressing block (62) begins to move down; the upper bending template (5) continues to move down, the upper bending module (52) and the lower bending module (61) come into contact and gradually press the small blank, while the lower die floating pre-pressing block (62) continues to move down, the small blank is pulled from the roller (64) of the lower die floating pre-pressing block (62) and bent downward until the upper bending module (52) and the lower bending module (61) are relatively closed, and finally the blank is formed, the upper bending template (5) moves up, and the lower die floating pre-pressing block (62) removes the formed workpiece from the mold; ⑦ After the forming process is completed, the temperature is automatically sorted. If the temperature is greater than or equal to 860℃, it will enter the heating and heat preservation line. Otherwise, after entering the heating and holding line to reach the design temperature, it enters the tracked quenching and tempering line; the tempering temperature is 460℃±5℃ and the tempering time is 120±15 min; the hardness after heat treatment reaches HRC44~52; the metallographic structure is better than grade 4. ⑧ Shot blasting; Use shot blasting with sand or fine steel wire cut into shot; 9. Flaw Detection Perform magnetic particle testing on the workpiece, remove surface microcracks no deeper than 0.2 mm, remove tin and scrap workpieces with deep cracks; ⑩ Cold plastic surgery; The workpiece is cold-formed to ensure that the dimensional angular tolerance does not exceed ±0.5° and the length tolerance does not exceed ±0.76mm. ⑪ Surface treatment; The surface of the workpiece is treated with rust prevention.

Images