Rotary bending die for automobile electric drive rear axle oil pipe support with negative angle and round shape and machining technology of rotary bending die for automobile electric drive rear axle oil pipe support with negative angle and round shape

Abstract

The invention discloses a rotary bending die for an automobile electric drive rear axle oil pipe support with a negative angle and a circle and a machining technology of the rotary bending die, and the rotary bending die for the oil pipe support comprises an upper die structure and a lower die structure; the upper die structure comprises a die handle, an upper die plate, a guide sleeve, an upper base plate, a pressing spring, an upper fixing plate, a fixed bending upper die, a pressing block, a tension spring bayonet lock, a tension spring, a rotating shaft, a rotary bending upper die and a rotating shaft pressing ring. The lower die structure comprises a guide column, a lower bending die, a lower base plate, a lower die plate and a stop pin. According to the die, the upper bending die is designed to be rotatable, and the lower bending die is additionally provided with a groove and other structures (the groove and other structures play a role in guiding die gaps and positioning products), so that the die precision and the product quality are improved. The rotary bending die for the oil pipe support is installed on a press machine to conduct bending process machining on the oil pipe support.

Description

Technical Field

[0001] This invention belongs to the field of mechanical equipment and relates to a manufacturing mold for oil pipe supports, particularly to a rotary bending mold for an oil pipe support with negative angle and circular shape for an electric drive rear axle of an automobile and its processing technology, especially a rotary process that simultaneously bends negative angle and circular shape. Background Technology

[0002] The automotive electric drive rear axle oil pipe bracket is welded to the rear axle housing and primarily serves to install and secure the oil pipes. It ensures the oil pipes are fixed in the most suitable way, preventing interference with surrounding components, and limits the oil pipe routing. This protects the oil pipes, improves their appearance, enhances connection reliability, simplifies assembly processes, and increases assembly efficiency. Traditionally, the oil pipe bracket is manufactured through five processes: blanking, bending, bending one side at a negative angle, and bending the other side at a negative angle to meet product design requirements. This process requires a large number of molds, is time-consuming, and involves multiple material transfers between multiple machines, resulting in low production efficiency. This invention is based on the optimization considerations of the existing production process. It designs a rotary bending die for oil pipe supports, which enables the product to simultaneously perform three different stamping operations in the same die: bending into a circle, bending one side at a negative angle, and bending the other side at a negative angle. In other words, it optimizes three processes into one process. Therefore, it is essential to design a rotary bending die that can meet the requirements of producing oil pipe supports with negative angles and circles for electric drive rear axles of automobiles, and can also complete the processing of two workpieces at the same time to improve product quality and production efficiency. Summary of the Invention

[0003] One objective of this invention is to provide a rotary bending die for an automotive electric drive rear axle with a negative angle and a circular shape for oil pipe supports. The die improves precision and product quality by designing a rotatable upper bending die and adding grooves and other structures to the lower bending die (which both guide the die gap and position the product). This rotary bending die for oil pipe supports is mounted on a press to perform the bending process on the oil pipe supports.

[0004] The second objective of this invention is to design a rotary bending mold for oil pipe supports to replace the traditional three-step process (i.e., bending into a circle, bending one side at a negative angle, and bending the other side at a negative angle), and to bend two products at the same time, especially the rotary bending process.

[0005] One of the objectives of this invention is achieved as follows: A rotary bending die for an electric drive rear axle oil pipe bracket with negative angle and circular shape, comprising an upper die structure and a lower die structure; The upper die structure includes a die handle, an upper template, a guide sleeve, an upper pad, a pressure spring, an upper fixing plate, a fixed bending upper die, a pressure block, a tension spring pin, a tension spring, a rotating shaft, a rotating bending upper die, and a rotating shaft pressure ring; The lower mold structure includes guide pillars, a bending lower mold, a lower backing plate, a lower template, and a stop pin; The fixed bending upper die is installed in the fixed cavity of the upper fixed plate by interference fit and is connected to the upper pad plate by bolts; The mold shank is installed in the mold shank hole of the upper mold plate by interference fit; the guide sleeve is installed in the guide sleeve holes on both sides of the upper mold plate by interference fit. The pressure block is fitted into the cavity of the pressure block of the fixed bending upper die with clearance fit; the pressure spring is pre-compressed and installed in the corresponding spring holes of the fixed bending upper die, the upper pad plate and the die handle; The upper template and upper pad are connected to the upper fixed plate by bolts and locating pins; Two rotating bending upper dies are fitted with clearance in the guide cavities on the left and right sides of the fixed bending upper die, and are connected to the upper fixed plate through a rotating shaft; The rotating shaft is interference-fitted with the upper bending die and clearance-fitted with the upper fixed plate; four rotating shaft pressure rings are connected to the rotating shaft by bolts. Four tension spring clips are installed in the tension spring clip holes on the front and rear sides of the upper rotating bending die by interference fit, and another four are installed in the tension spring clip holes on the front and rear sides of the upper fixed plate by interference fit. Four tension springs are connected at one end to the tension spring retainer on the upper fixed plate and at the other end to the tension spring retainer on the upper bending die; the guide pillars are installed in the guide pillar holes on both sides of the lower template through an interference fit; the stop pins are installed in the stop pin holes of the lower bending die through an interference fit; the lower template and the lower pad are connected to the lower bending die through bolts and positioning pins.

[0006] Furthermore, the rotary bending upper die can rotate left and right around the pivot.

[0007] Furthermore, tension springs are provided on both the front and rear sides of the upper rotating bending die.

[0008] Furthermore, the lower bending die is provided with a groove with a height of 10mm, which is in clearance fit with the upper bending die in the length direction, with a single-sided clearance of 0.10–0.12mm.

[0009] Furthermore, the fixed bending upper die has an inlaid structure, and the upper fixing plate has an integral structure; the fixed bending upper die has guide arcs on the left and right sides, which are fitted with the rotation arcs of the rotary bending upper die with a clearance of 0.12–0.15 mm on each side.

[0010] Furthermore, the upper mold section is equipped with a pressure block and a pressure spring.

[0011] Furthermore, the die handle is provided with a hole for accommodating the pressure spring.

[0012] Furthermore, a stop pin is set at the feed end of the bending lower die to limit the feeding position of the product blank.

[0013] Furthermore, the length of the groove on the lower bending die is 0.3 mm longer than the length of the product bending blank.

[0014] The second technical solution of the present invention is implemented as follows: Step 1: Install the rotating bending mold of the electric drive rear axle of the car with negative angle and circular oil pipe bracket on the 100T pneumatic press; Step 2: Place the two prefabricated oil pipe brackets, after the blanking and unloading processes, side by side and flat in the positioning groove of the bending lower mold to fix the two sides of the workpiece, and use the stop pin to fix the front end of the workpiece. Step 3: Start the press. The upper template moves downward along the worktable on the press bed. Under the pressure of the pressure spring, the pressure block and the lower bending die first press the product together. Under the tension of the tension spring, the upper bending die presses against the vertical limiting surface of the fixed bending die to keep it in a vertical state. Then, as the upper template continues to move downward, the upper bending die presses the product downward while rotating around the pivot and sliding into the bending cavity of the lower bending die until the lower surface of the fixed bending die is pressed against the upper surface of the product. The fixed bending die, the upper bending die, and the lower bending die complete the bending and rounding process of the product. Step 4: After the workpiece is bent and rounded, the slide block on the press drives the upper die structure to return to its original position. The rotating bending upper die moves upward under the tension of the tension spring and rotates around the pivot while sliding out of the bending cavity of the lower bending die. Then, the workpiece is taken out from the bending cavity of the lower bending die and placed into the material box using an auxiliary tool. Step 5: Repeat steps 2 to 4 to produce the next two products.

[0015] The beneficial effects of this invention are as follows: By designing the upper bending die to be rotatable, and adding structures such as grooves to the lower bending die (which both guide the die gap and position the product), the mold's precision and product quality are improved. This rotary bending mold for oil pipe supports is installed on a press to perform the bending process on oil pipe supports. Attached Figure Description

[0016] Figure 1 This is a bottom view of the upper mold portion in an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the main structure of the mold in an embodiment of the present invention.

[0018] Figure 3 This is a top view of the lower mold portion in an embodiment of the present invention.

[0019] Figure 4 This is a schematic diagram of the main view structure of the product placed at the dead point on the mold in an embodiment of the present invention.

[0020] Figure 5 This is a schematic diagram of the tubing support structure in an embodiment of the present invention.

[0021] In the diagram: 1. Die handle; 2. Upper template; 3. Guide sleeve; 4. Upper pad; 5. Pressure spring; 6. Upper fixing plate; 7. Fixed bending upper die; 8. Pressure block; 9. Tension spring pin; 10. Tension spring; 11. Rotating shaft; 12. Rotating bending upper die; 13. Rotating shaft pressure ring; 14. Guide post; 15. Bending lower die; 16. Lower pad; 17. Lower template; 18. Stop pin. Detailed Implementation

[0022] The present invention can be implemented through specific technical solutions. The present invention can be further described through the following embodiments. However, the scope of the present invention is not limited to the following embodiments.

[0023] Taking the processing of the rear axle oil pipe bracket for Jiangling EV electric light truck as an example: The rear axle of the Jiangling EV electric light truck features a negative angle and a circular oil pipe bracket, with a rotary bending die structure resembling " Figures 1 to 5 As shown: The mold is divided into an upper mold structure and a lower mold structure.

[0024] The upper mold structure includes: mold handle 1, upper template 2, guide sleeve 3, upper pad 4, pressure spring 5, upper fixing plate 6, fixed bending upper mold 7, pressure block 8, tension spring pin 9, tension spring 10, rotating shaft 11, rotating bending upper mold 12, and rotating shaft pressure ring 13; The lower die structure includes: guide post 14, bending lower die 15, lower pad plate 16, lower template 17, and stop pin 18. Its features are: the fixed bending upper die 7 is installed in the fixed cavity of the upper fixed plate 6 via an interference fit, and is connected to the upper pad plate 4 from the upper end face via bolts; the die handle 1 is installed in the die handle hole of the upper template 2 via an interference fit; the guide sleeve 3 is installed in the guide sleeve holes on both sides of the upper template 2 via an interference fit; the pressure block 8 is placed directly in the pressure block cavity of the fixed bending upper die 7 via a clearance fit; the pressure spring 5 is pre-compressed and installed in the corresponding spring holes of the fixed bending upper die 7, the upper pad plate 4, and the die handle 1; the upper template 2 and the upper pad plate 4 are connected to the upper fixed plate 6 via bolts and positioning pins; two rotating bending upper dies 12 are placed directly in the guide cavities on the left and right sides of the fixed bending upper die 7 via a clearance fit, and are connected to the upper fixed plate 6 via a rotating shaft 11. The shaft 11 and the upper rotary bending die 12 are interference-fitted, while the shaft 11 and the upper fixed plate 6 are clearance-fitted. This allows the upper rotary bending die 12 to rotate freely left and right around the shaft 11. Four shaft pressure rings 13 are connected to the shaft 11 from the side by bolts, which prevents the shaft 11 from moving forward and backward. Four tension spring clips 9 pass through the clearance groove on the upper fixed plate 6 and are installed in the tension spring clip holes on the front and rear sides of the upper rotary bending die 12 through interference fit. Another four tension spring clips 9 are installed in the tension spring clip holes on the front and rear sides of the upper fixed plate 6 through interference fit. One end of the four tension springs 10 is pre-stretched and installed on the tension spring clips 9 on the upper fixed plate 6, and the other end is installed on the tension spring clips 9 on the upper rotary bending die 12. The guide post 14 is installed in the guide post holes on both sides of the lower template 17 by interference fit, and the stop pin 18 is installed in the stop pin hole of the bending lower die 15 by interference fit. The lower template 17 and the lower pad 16 are connected to the bending lower die 15 by bolts and positioning pins.

[0025] The upper die section is equipped with a rotatable bending upper die 12 (which can rotate left and right around the pivot 11), which allows the oil pipe bracket to bend at a negative angle and bend into a circle simultaneously in one operation. If designed with a traditional bending die structure (i.e., the bending upper die is fixed and cannot rotate), it would require three processes to bend the product shape (i.e., first pre-bending the two sides of the product into a 90° U-shape and two circles on both sides, then bending one side of the product at a 90° angle into a 70° negative angle, and finally bending the other side of the product at a 90° angle into a 70° negative angle).

[0026] Tension springs 10 are added to both the front and rear sides of the upper rotary bending die 12. This ensures that the upper rotary bending die 12 remains in a vertical state before contacting the product blank. This guarantees that the upper rotary bending die 12 can smoothly slide into the bending cavity of the lower rotary bending die 15 after contacting the product blank. When the die returns to its original position, the upper rotary bending die 12 can smoothly slide out of the bending cavity of the lower rotary bending die 15, thereby reducing bending marks on the product and improving product quality.

[0027] The lower bending die 15 has a 10mm high groove. The groove is in clearance fit with the fixed upper bending die 7 in the length direction. The single-sided clearance is 0.10 to 0.12mm, which ensures the uniformity of the die clearance, thereby improving the die accuracy and life. In addition, the groove also plays the role of positioning the product to ensure the bending quality of the product (because the length of the groove on the lower bending die 15 is 0.3mm longer than the length of the product bending blank).

[0028] The fixed bending upper die 7 is an insert type, and the upper fixing plate 6 is an integral type. The fixed bending upper die 7 is fixed in the upper fixing plate 6 by interference fit, which can improve the strength of the fixed bending upper die 7. The left and right sides of the fixed bending upper die 7 are provided with guide arcs that are clearance fit with the rotation arc of the rotary bending upper die 12. The clearance on one side is 0.12 to 0.15 mm. This can ensure that the rotary bending upper die 12 rotates smoothly in the guide arc of the fixed bending upper die 7 without getting stuck, and can also improve the strength of the rotary bending upper die 12, thereby improving the die life.

[0029] The upper mold is equipped with a pressing block 8 and a pressing spring 5, etc., so that the pressing block 8 will press the product blank before bending, preventing the product from moving left or right during the bending process, thereby ensuring the bending quality of the product.

[0030] The mold handle 1 is provided with a hole for placing the pressure spring 5. This ensures that the pressure spring 5 has sufficient pressure force and reduces the closing height of the mold, so that the mold can be installed on a 100T press.

[0031] This type of Jiangling EV electric light truck rear axle oil pipe bracket is made of 2.0mm thick ST12 cold-rolled sheet through stamping. After the blanking and unblanking processes, it can be directly used for bending processing with rotary bending dies. Step 1: Install the rotating bending mold of the electric drive rear axle of the car with negative angle and circular oil pipe bracket on the 100T pneumatic press; Step 2: Place the two prefabricated oil pipe brackets after the blanking and unloading processes side by side in the positioning groove of the bending lower mold 15 to fix the two sides of the workpiece, and fix the front end face of the workpiece 1 with the stop pin 18. Step 3: Start the press. The upper template 2 moves downward along the worktable on the press. Under the pressure of the pressure spring 5, the pressure block 8 and the lower bending die 15 first press the product together. Meanwhile, the upper bending die 12, under the tension of the tension spring 10, presses against the vertical limiting surface of the fixed upper bending die 7 to keep it in a vertical state. Then, as the upper template 2 continues to move downward, the upper bending die 12 presses the product downward while rotating around the pivot 11 and sliding into the bending cavity of the lower bending die 15 until the lower surface of the fixed bending die 7 is pressed against the upper surface of the product. The fixed bending die 7, the upper bending die 12, and the lower bending die 15 complete the product bending and rounding process. Step 4: After the workpiece is bent and rounded, the slide block on the press drives the upper die structure to return to its original position. Meanwhile, the rotating bending upper die 12 moves upward under the tension of the tension spring 10 and rotates around the rotating shaft 11, sliding out of the bending cavity of the lower bending die 15. Then, the workpiece is taken out from the bending cavity of the lower bending die 15 and placed into the material box using an auxiliary tool. Step 5: Repeat steps 2 to 4 to produce the next two products.

[0032] After adopting a rotary bending die and processing technology, the bending-related dimensions of the Jiangling EV electric light truck rear axle oil pipe bracket are all within tolerance. The traditional three-step process (bending to a circle, bending one side at a negative angle, and bending the other side at a negative angle) has been optimized into a single step, allowing for the simultaneous bending of two products. This increases production efficiency by 5.3 times and saves on the development cost of a separate die set. The upper part of the die is rotatable, and the addition of grooves to the lower bending die increases the die life by 2.6 times, ensuring stable product quality and reducing production costs. This ensures that the Jiangling EV electric light truck rear axle oil pipe bracket consistently meets the product design requirements.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention 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 the present invention.

Claims

1. A rotary bending die for an oil pipe bracket with a negative angle and a circular shape for an electric drive rear axle of an automobile, comprising an upper die structure and a lower die structure, characterized in that: The upper mold structure includes a mold handle (1), an upper template (2), a guide sleeve (3), an upper pad (4), a pressure spring (5), an upper fixing plate (6), a fixed bending upper mold (7), a pressure block (8), a tension spring pin (9), a tension spring (10), a rotating shaft (11), a rotating bending upper mold (12), and a rotating shaft pressure ring (13). The lower mold structure includes a guide post (14), a bent lower mold (15), a lower pad (16), a lower template (17), and a stop pin (18). The fixed bending upper die (7) is installed in the fixed cavity of the upper fixed plate (6) by interference fit and is connected to the upper pad plate (4) by bolts; The mold handle (1) is installed in the mold handle hole of the upper template (2) by interference fit; The guide sleeve (3) is installed in the guide sleeve holes on both sides of the upper template (2) by interference fit; The pressure block (8) is fitted into the pressure block cavity of the fixed bending upper die (7) with a clearance fit; The pressure spring (5) is pre-compressed and installed in the corresponding spring holes of the fixed bending upper die (7), upper pad (4) and die handle (1); The upper template (2) and the upper pad (4) are connected to the upper fixing plate (6) by bolts and positioning pins; The two rotating bending upper dies (12) are set in the guide cavities on the left and right sides of the fixed bending upper die (7) through clearance fit, and are connected to the upper fixed plate (6) through the rotating shaft (11); The rotating shaft (11) is interference-fitted with the upper rotating bending die (12) and clearance-fitted with the upper fixed plate (6); the four rotating shaft pressure rings (13) are connected to the rotating shaft (11) by bolts; Four of the aforementioned tension spring clips (9) are installed in the tension spring clip holes on the front and rear sides of the rotary bending upper die (12) by interference fit, and the other four are installed in the tension spring clip holes on the front and rear sides of the upper fixing plate (6) by interference fit. One end of the four tension springs (10) is connected to the tension spring pin (9) on the upper fixed plate (6), and the other end is connected to the tension spring pin (9) on the rotating bending upper mold (12). The guide post (14) is installed in the guide post holes on both sides of the lower template (17) by interference fit; The stop pin (18) is installed in the stop pin hole of the bending lower die (15) by interference fit; The lower template (17) and the lower pad (16) are connected to the bending lower mold (15) by bolts and positioning pins.

2. The mold according to claim 1, characterized in that: The rotating bending upper die (12) can rotate left and right around the rotating shaft (11).

3. The mold according to claim 1 or 2, characterized in that: The upper rotating bending die (12) is provided with tension springs (10) on both the front and rear sides.

4. The mold according to claim 1 or 2, characterized in that: The lower bending die (15) is provided with a groove with a height of 10mm. The groove is in clearance fit with the upper bending die (7) in the length direction, with a single-sided clearance of 0.10–0.12mm.

5. The mold according to claim 1 or 2, characterized in that: The fixed bending upper die (7) is an inlaid structure, and the upper fixing plate (6) is an integral structure; the fixed bending upper die (7) has guide arcs on the left and right sides, which are matched with the rotation arcs of the rotating bending upper die (12) with a clearance of 0.12–0.15 mm on each side.

6. The mold according to claim 1 or 2, characterized in that: The upper mold part is provided with a pressure block (8) and a pressure spring (5).

7. The mold according to claim 1 or 2, characterized in that: The die handle (1) is provided with a hole for accommodating the pressure spring (5).

8. The mold according to claim 1 or 2, characterized in that: The stop pin (18) is set at the feeding end of the bending lower die (15) to limit the feeding position of the product blank.

9. The mold according to claim 4, characterized in that: The length of the groove on the lower bending die (15) is 0.3 mm longer than the length of the product bending blank.

10. A processing method for using the rotary bending die for the oil pipe bracket with negative angle and circular shape of the automotive electric drive rear axle as described in claim 1, characterized in that, Includes the following steps: Step 1: Install the rotary bending mold for the oil pipe bracket with negative angle and circular shape of the electric drive rear axle of the car onto a 100T pneumatic press; Step 2: Place the two prefabricated oil pipe brackets, which have undergone the blanking and unloading processes, side by side in the positioning groove of the bending lower mold (15) to position the two sides of the workpiece, and use the stop pin (18) to position the front end of the workpiece. Step 3: Start the press. The upper template (2) moves downward along the worktable on the press. The pressure block (8) presses the product against the lower bending die (15) under the pressure of the pressure spring (5). The rotating bending die (12) presses against the vertical limiting surface of the fixed bending die (7) and remains vertical under the tension of the tension spring (10). Then, as the upper template (2) continues to move downward, the rotating bending die (12) presses the product downward and rotates around the pivot (11) and slides into the bending cavity of the lower bending die (15) until the lower surface of the fixed bending die (7) presses against the upper surface of the product. At this time, the fixed bending die (7), the rotating bending die (12) and the lower bending die (15) together complete the bending and rounding of the product. Step 4: After the workpiece is processed, the upper slide of the press drives the upper die structure to return to its original position. The rotating bending upper die (12) moves upward under the tension of the tension spring (10), while rotating around the rotating shaft (11) and sliding out of the bending cavity of the bending lower die (15). Then, the workpiece is taken out from the bending cavity of the bending lower die (15) and placed into the material box using an auxiliary tool. Step 5: Repeat steps 2 through 4 to process the subsequent workpieces.

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