A double-notch synchronous stamping die for automotive electric drive front axle bushings

Abstract

This utility model discloses a double-notch synchronous stamping die for an automotive electric drive front axle bushing. The synchronous stamping die is divided into an upper part and a lower part. The upper part includes a die shank, an upper template, an upper limit rod, and an upper pressure block. The lower part includes a lower limit rod, a movable punch, a punching die, a stripper spring, a lower pad, a lower template, a pressure spring, a stop plate, and a support plate. This utility model uses bosses and grooves for automatically correcting die clearance. The punch is designed to be movable and placed in the punching die cavity, and elastic positioning devices are added. The traditional two-step process (punch 1 and punch 2) is optimized into a single step, increasing production efficiency by 87%, saving the development cost of a complete set of dies, and extending die life by 5.7 times, thereby reducing production costs and ensuring stable product quality.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical equipment and relates to a mold for manufacturing sleeves, and particularly to a double-notch synchronous stamping mold for automotive electric drive front axle sleeves. Background Technology

[0002] The bushing is a crucial component of the automotive electric drive front axle assembly. Its ends are typically connected to flanges and ferrules, so the quality of the bushing directly affects the fatigue strength of the entire front axle and the vehicle's ride comfort, handling, and reliability. Traditionally, bushings are processed in five steps: blanking → necking → precision machining → punching notch 1 (punching a notch on one side) → punching notch 2 (punching a notch on the other side) to meet product design requirements. This process requires a large number of molds, is time-consuming, and involves multiple material transfers between various machines, resulting in low production efficiency. Furthermore, the traditional notching die design typically places the notching die in the lower die, making it prone to cracking due to its suspended position and the cutting edge (as the product needs to be inserted into the notching die for loading and unloading), thus affecting the die's lifespan. This utility model is based on the optimization consideration of the existing production process. It designs a sleeve punching die that enables the product to simultaneously perform two different stamping combination operations, punching notch 1 and punching notch 2, in the same die set, and makes the punching process of the product stable. Therefore, it is very necessary to design a die that can simultaneously punch two notches in the production of automotive electric drive front axle sleeves to improve production efficiency and ensure product quality. Utility Model Content

[0003] One objective of this invention is to provide a double-notch synchronous stamping die for automotive electric drive front axle bushings. The die employs bosses and grooves for automatically correcting die clearance. The punching punch is designed to be movable and placed within the punching die cavity. Additional structures, such as an elastic positioning device, are added to improve die accuracy, lifespan, and product quality. This die is mounted on a press to perform the punching process on the bushing.

[0004] The second objective of this utility model is to design a die that uses a sleeve to punch two notches at the same time, in order to replace the traditional process of two combined steps (i.e., punching notch 1 and punching notch 2).

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A double-notch synchronous stamping die for an electric drive front axle sleeve of an automobile is provided. The die is divided into an upper part and a lower part. The upper part of the die includes a die shank, an upper template, an upper limit rod, and an upper pressure block. The lower part of the die includes a lower limit rod, a movable punch, a punch die, an unloading spring, a lower pad, a lower template, a pressure spring, a stop plate, and a support plate. The die shank is installed in the die shank hole of the upper die plate by interference fit. Two upper limit rods are fixed to the two sides of the upper die plate by bolts from the upper end face. The upper die plate is connected to the upper pressure block by bolts. Two lower limit rods are fixed to the two sides of the lower die plate by bolts from the lower end face. The lower die plate and the lower backing plate are connected to the punching die by bolts. Three stripper springs are pre-compressed and installed in the spring holes of the lower backing plate. The movable punch is placed directly in the cavity of the punching die by clearance fit. It is then movably connected to the stripper spring, the lower backing plate, and the lower die plate by stripper bolts. Two support plates are fixed to the front and rear ends of the lower die plate by bolts from the upper end face. Two stop plates are movably connected to the pressure spring and the support plates from the side by pressure bolts.

[0006] Furthermore, the movable punch has a boss at each of its left and right ends that automatically corrects the die clearance, and the punch also has a groove at each of its left and right ends that automatically corrects the die clearance. The double-sided clearance between the two is 0.10 to 0.12 mm.

[0007] Furthermore, both the movable punch and the punching die are designed in the lower die section, and the movable punch is designed to be movable and freely placed in the cavity of the punching die.

[0008] Furthermore, the movable punch has a first notch cutting edge and a second notch cutting edge on each side, which are integrated with the correction boss of the movable punch. The first notch cutting edge is made into an arc shape at the top and bottom so that the inner hole of the product can be placed on its inner surface. The second notch cutting edge is made into an arc shape at the bottom so that the lower arc of the inner hole of the product and the notch already punched in the first cut can be placed on its inner surface. The upper cutting edge is made into a flat shape and extends all the way to the upper plane.

[0009] Furthermore, upper and lower limit rods are added to the upper and lower parts of the mold respectively to limit the depth of the moving punch entering the punching die.

[0010] Furthermore, both the active punch and the punch die are made of die steel Cr12MoV1 with a quenching hardness of HRC56-58 to improve the impact toughness of the cutting edge. Moreover, the non-cutting edge areas are all rounded to reduce internal stress.

[0011] Furthermore, the lower part of the mold is equipped with a pressure spring, a baffle plate, and a support plate to improve the product positioning accuracy. Specifically, the baffle plate presses the end face of the large circle of the product under the pressure of the pressure spring to prevent the product from moving outward when punching the notch, while the support plate is used to support the outer circle of the product to improve the stability of the product positioning.

[0012] Furthermore, the first cutting edge is used to accommodate the inner hole of the product, and the second cutting edge is used to accommodate the lower arc of the inner hole of the product and the punched notch.

[0013] Furthermore, the unloading spring is pre-compressed and installed, and the unloading bolt enables the elastic unloading function of the movable punch.

[0014] Another technical solution of this utility model is as follows: The process of punching notches in the bushings of automotive electric drive front axle using a double-notch synchronous stamping die includes the following steps: Step 1: Rotate the mold 90° and install it on the 100T pneumatic press; Step 2: Place the pre-made sleeve after blanking, necking, and precision machining on the side of the movable punch near the first notch cutting edge, and place the inner hole of the necked end of the product in the first notch cutting edge of the movable punch. Use the small boss on the movable punch to fix the small round end face of the product, while the stop plate presses the large round end face of the product under the pressure of the pressure spring. Use the punching die and the support plate to support the outer round face of the small round and the outer round face of the large round respectively. The small round is the necked end. Step 3: Start the press. The upper template moves downward along the worktable on the bed. The upper pressure block presses the movable punch downward until the lower surface of the upper limit rod contacts the upper surface of the lower limit rod. The movable punch and the punch die complete the first notch punching process of the product. Step 4: After the product is punched, the upper slide of the press drives the upper part of the mold to return to its original position. The movable punching punch unloads the product under the force of the unloading spring, while the punching waste leaks out from the lower mold and the lower worktable of the machine tool. The workpiece can then be removed directly by hand. Step 5: Place the sleeve with the first notch punched in Step 4 on the side of the movable punching punch that is close to the cutting edge of the second notch, and insert the notch on the product into the cutting edge of the second notch of the movable punch to fix it. Use the small boss on the movable punch to fix the small round end face of the product, while the baffle plate presses the large round end face of the product under the pressure of the pressure spring. Use the punching die and the support plate to support the outer round face of the small round face and the outer round face of the large round face of the product respectively. Then place another pre-made sleeve after blanking, necking, and precision machining on the side of the movable punch with the cutting edge of the first notch to fix it, as in Step 2. Step 6: Start the press. The upper template moves downward along the worktable on the bed. The upper pressure block presses the movable punch downward until the lower surface of the upper limit rod contacts the upper surface of the lower limit rod. The movable punch completes the first notch punching process with the punching die by cutting the first notch. The movable punch completes the second notch punching process with the punching die by cutting the second notch. Step 7: After the product is punched, the upper slide of the press drives the upper part of the mold to return to its original position. The movable punching punch unloads the product under the force of the unloading spring, while the punching waste leaks out from the lower mold and the lower worktable of the machine tool. Then, the two products are taken out directly by hand, and a product with notches punched on both the upper and lower parts is placed into the material box. Step 8: Repeat steps 5 to 7 to produce the next workpiece.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: The mold of this utility model adopts a boss and groove that automatically corrects the mold gap, the punching punch is designed to be movable and placed in the punching die cavity, and the elastic positioning device and other structures are added. The traditional two processes (i.e., punching 1 and punching 2) are optimized and combined into one process, which improves the production efficiency by 87%, saves the mold development cost of a set of processes, and increases the mold life by 5.7 times, thereby reducing the production cost and ensuring stable product quality. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the main structure of the first notch mold in Embodiment 1 of this utility model.

[0018] Figure 2 This is a top view of the lower mold portion of Embodiment 1 of this utility model.

[0019] Figure 3 This is a schematic diagram of the main structure of the mold for cutting the second notch in Embodiment 1 of this utility model.

[0020] Figure 4 This is a schematic diagram of the movable punching punch structure of the mold in Embodiment 1 of this utility model.

[0021] Figure 5 This is a schematic diagram of the punching die structure of the mold in Embodiment 1 of this utility model.

[0022] Figure 6 This is a schematic diagram of the sleeve structure of Embodiment 1 of this utility model.

[0023] In the diagram: 1. Die handle; 2. Upper template; 3. Upper limit rod; 4. Upper pressure block; 5. Lower limit rod; 6. Movable punch; 7. Punch; 8. Unloading spring; 9. Lower pad; 10. Lower template; 11. Pressure spring; 12. Stop plate; 13. Material support plate. Detailed Implementation

[0024] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0025] Example 1: Taking the machining of the front axle sleeve of a Jiangling EV electric light truck as an example: The die structure for punching two notches simultaneously on the front axle sleeve of the Jiangling EV electric light truck is like " Figures 1 to 6 As shown: The mold is divided into an upper part and a lower part.

[0026] The mold employs bosses and grooves for automatic mold clearance correction. The punching punch is designed to be movable and placed within the punching die cavity. Elastic positioning devices and other structures are added to improve mold accuracy, lifespan, and product quality. The mold is divided into an upper and lower section. The upper section includes: mold shank 1, upper template 2, upper limit rod 3, and upper pressure block 4. The lower section includes: lower limit rod 5, movable punching punch 6, punching die 7, stripper spring 8, lower pad 9, lower template 10, pressure spring 11, stop plate 12, and support plate 13. Its features are as follows: the mold shank 1 is installed in the mold shank hole of the upper mold plate 2 by interference fit; two upper limit rods 3 are fixed to the two sides of the upper mold plate 2 from the upper end face by bolts; the upper mold plate 2 is connected to the upper pressure block 4 by bolts; two lower limit rods 5 are fixed to the two sides of the lower mold plate 10 from the lower end face by bolts; the lower mold plate 10 and the lower pad 9 are connected to the punching die 7 by bolts; three unloading springs 8 are pre-compressed and installed in the spring holes of the lower pad 9; the movable punching punch 6 is placed directly in the cavity of the punching die 7 by clearance fit, and is then movably connected to the unloading spring 8, the lower pad 9, and the lower mold plate 10 by unloading bolts; two material support plates 13 are fixed to the front and rear ends of the lower mold plate 10 from the upper end face by bolts; and two baffle plates 12 are movably connected to the pressure spring 11 and the material support plate 13 from the side by pressure bolts.

[0027] The active punch 6 has a boss at each of its left and right ends that automatically corrects the die clearance, and the punch die 7 also has a groove at each of its left and right ends that automatically corrects the die clearance. The double-sided clearance between the two is 0.10 to 0.12 mm. In this way, the uniformity of the die clearance is not controlled by the manual skills of the fitter, but is ensured by the machining accuracy of the machine tool, thereby improving the die manufacturing accuracy. Moreover, it also plays a guiding role when the die is working, thereby improving the die strength and life.

[0028] Both the movable punch 6 and the punch die 7 are designed in the lower die part. Moreover, the movable punch 6 is designed to be movable and freely placed in the cavity of the punch die 7, instead of the traditional fixed structure in which the punch and die are fixed in the upper and lower parts of the mold respectively. This makes the product positioning accurate and quick (that is, the inner hole of the product is defined by the notch on the movable punch 6, and the outer circle of the product is supported by the punch die 7 and the support plate 13), thereby ensuring product quality.

[0029] The movable punching punch 6 has a first notch cutting edge and a second notch cutting edge on both sides, which are integrated with the correction boss of the punching punch 6. The first notch cutting edge is rounded at the top and bottom to allow the inner hole of the product to be placed on its inner surface. The second notch cutting edge is rounded at the bottom to allow the lower arc of the inner hole of the product and the notch already punched in the first cut to be placed on its inner surface, while the upper cutting edge is flat and extends to the upper plane. This improves the strength of the punching notch cutting edges on both sides of the movable punching punch 6 (because the sleeve wall thickness is 4.5mm, which is a thick plate, the punching force is large, and the punching notch cutting edge is prone to cracking), thereby improving the die life.

[0030] The upper and lower parts of the mold are respectively equipped with upper limit rod 3 and lower limit rod 5 to limit the depth of the movable punch 6 into the punch die 7, thereby improving the mold life (because the deeper the movable punch 6 enters the punch die 7, the greater the punching force, and the easier it is for the punching edge on the movable punch 6 to break).

[0031] Both the active punch 6 and the punch die 7 are made of die steel Cr12MoV1 with a quenching hardness of HRC56~58 to improve the impact toughness of the cutting edge. In addition, the non-cutting edge parts are all rounded to reduce internal stress, thereby improving the die life.

[0032] The lower part of the mold is equipped with a pressure spring 11, a baffle plate 12, and a support plate 13 to improve the product positioning accuracy. Specifically, the baffle plate 12 presses the end face of the large circle of the product under the pressure of the pressure spring 11 to prevent the product from moving outward when punching the notch, while the support plate 13 is used to support the outer circle of the product to improve the stability of the product positioning, thereby improving the product quality.

[0033] The second technical solution of this utility model is implemented as follows: Step 1: Simultaneously punch two notch dies for the electric drive front axle sleeve of the car and rotate them 90° to install them on a 100T pneumatic press. Step 2: Place the pre-made sleeve after blanking, necking, and precision machining on the side of the movable punch 6 near the first notch cutting edge, and place the inner hole of the necked end of the product in the first notch cutting edge of the movable punch 6. Use the small boss surface on the movable punch 6 to fix the end face of the small circle (i.e., the necked end) of the product, while the baffle plate 12 presses the end face of the large circle of the product under the pressure of the pressure spring 11 (i.e., to prevent the product from moving outward when punching the notch), and use the punch die 7 and the support plate 13 to support the outer circle surface of the small circle (i.e., the necked end) and the outer circle surface of the large circle of the product, respectively.

[0034] Step 3: Start the press. The upper template 2 moves downward along the worktable on the press. The upper pressure block 4 presses the movable punch 6 downward until the lower surface of the upper limit rod 3 contacts the upper surface of the lower limit rod 5. The movable punch 6 and the punch die 7 complete the first notch punching process of the product (i.e., the product punches out a notch on one side first). Step 4: After the product is punched, the upper slide of the press drives the upper part of the mold to return to its original position. The movable punching punch 6 unloads the product under the force of the unloading spring 8, and the punching waste leaks out from the lower mold and the lower worktable of the machine tool. The workpiece can then be taken out directly by hand. Step 5: Place the sleeve with the first notch punched in Step 4 on the side of the movable punching punch 6 that is close to the cutting edge of the second notch, and position the notch on the product into the cutting edge of the second notch of the movable punching punch 6 (that is, to ensure that the upper and lower notches of the product are concentric). Use the small boss surface on the movable punching punch 6 to position the end face of the small circle (i.e., the narrowing) of the product, while the baffle plate 12 presses the end face of the large circle of the product under the pressure of the pressure spring 11 (that is, to prevent the product from moving outward when punching the notch), and use the punching die 7 and the support plate 13 to support the outer circle surface of the small circle (i.e., the narrowing) and the outer circle surface of the large circle of the product respectively. Then place another pre-made sleeve after blanking, narrowing, and precision machining in Step 2 on the side of the movable punching punch 6 that is close to the cutting edge of the first notch. Step 6: Start the press. The upper template 2 moves downward along the worktable on the press. The upper pressure block 4 presses the movable punch 6 downward until the lower surface of the upper limit rod 3 contacts the upper surface of the lower limit rod 5. The movable punch 6, with the cutting edge of the first notch, completes the first notch punching process with the punch die 7. The movable punch 6, with the cutting edge of the second notch, completes the second notch punching process with the punch die 7 (that is, at this time, the upper and lower notches of the product are punched out on the side of the movable punch 6 with the cutting edge of the second notch). Step 7: After the product is punched, the upper slide of the press drives the upper part of the mold to return to its original position. The movable punching punch 6 unloads the product under the force of the unloading spring 8, while the punching waste leaks out from the lower mold and the lower worktable of the machine tool. Then, the two products are directly taken out by hand, and a product with notches punched on both the upper and lower sides (i.e. the product on the side of the movable punching punch 6 near the cutting edge of the second notch) is placed into the material box. Step 8: Repeat steps 5 to 7 to produce the next workpiece.

[0035] This utility model mold adopts a boss and groove for automatically correcting mold gaps. The punching punch is designed to be movable and placed in the punching die cavity. It also adds a structure such as an elastic positioning device. The traditional two processes (i.e., punching 1 and punching 2) are optimized into one process, which improves production efficiency by 87%, saves the mold development cost of a set of processes, and increases the mold life by 5.7 times, thereby reducing production costs and ensuring stable product quality.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A double-notch synchronous stamping die for a front axle sleeve of an electric drive vehicle, the die being divided into an upper part and a lower part, wherein, The upper part of the mold includes: mold handle, upper template, upper limit rod and upper pressure block; the lower part of the mold includes: lower limit rod, movable punch, punch die, stripper spring, lower pad, lower template, pressure spring, stop plate and support plate. The feature is that the die shank is installed in the die shank hole of the upper die plate by interference fit; two upper limit rods are fixed to the two sides of the upper die plate by bolts from the upper end face; the upper die plate is connected to the upper pressure block by bolts; two lower limit rods are fixed to the two sides of the lower die plate by bolts from the lower end face; the lower die plate and the lower backing plate are connected to the punching die by bolts; three unloading springs are pre-compressed and installed in the spring holes of the lower backing plate; the movable punch is placed directly in the cavity of the punching die by clearance fit; and is then movably connected to the unloading spring, the lower backing plate, and the lower die plate by unloading bolts; two support plates are fixed to the front and rear ends of the lower die plate by bolts from the upper end face; and two stop plates are movably connected to the pressure spring and the support plates from the side by pressure bolts.

2. The mold according to claim 1, characterized in that, The movable punch has a boss at each of its left and right ends for automatically correcting the die clearance, and the punch also has a groove at each of its left and right ends for automatically correcting the die clearance. The double-sided clearance between the two is 0.10 to 0.12 mm.

3. The mold according to claim 1 or 2, characterized in that, Both the movable punch and the punch die are designed in the lower die part, and the movable punch is designed to be movable and freely placed in the cavity of the punch die.

4. The mold according to claim 1 or 2, characterized in that, The movable punching punch has a first notch cutting edge and a second notch cutting edge on each side, which are integrated with the correction boss of the movable punching punch. The first notch cutting edge is made into an arc shape at the top and bottom so that the inner hole of the product can be placed on its inner surface. The second notch cutting edge is made into an arc shape at the bottom so that the lower arc of the inner hole of the product and the notch already punched in the first cut can be placed on its inner surface. The upper cutting edge is made into a flat shape and extends all the way to the upper plane.

5. The mold according to claim 1 or 2, characterized in that, The upper and lower parts of the mold are respectively equipped with an upper limit rod and a lower limit rod to limit the depth of the movable punch entering the punch die.

6. The mold according to claim 1 or 2, characterized in that, Both the active punch and punch die are made of die steel Cr12MoV1 with a quenching hardness of HRC56-58 to improve the impact toughness of the cutting edge. In addition, the non-cutting edge areas are all rounded to reduce internal stress.

7. The mold according to claim 1 or 2, characterized in that, The lower part of the mold is equipped with a pressure spring, a baffle plate, and a support plate to improve the product positioning accuracy. Specifically, the baffle plate presses the end face of the large circle of the product under the pressure of the pressure spring to prevent the product from moving outward when punching the notch, while the support plate is used to support the outer circle of the product to improve the stability of the product positioning.

8. The mold according to claim 4, characterized in that, The first cutting edge is used to accommodate the inner hole of the product, and the second cutting edge is used to accommodate the lower arc of the inner hole of the product and the punched notch.

9. The mold according to claim 1, characterized in that, The unloading spring is pre-compressed and the unloading bolt enables the elastic unloading function of the movable punch.

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