Flange welding spot cold forging die and cold forging method
By designing cold forging dies for flange weld points and implementing annealing treatment, the problem of poor material flowability was solved, achieving efficient weld point forming and cost reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUANGZHOU KOIDE KOKAN
- Filing Date
- 2023-12-21
- Publication Date
- 2026-07-03
AI Technical Summary
In the current cold forging process, when processing flange welds, the increased material hardness leads to poor fluidity, which can easily cause problems such as material shortage and root breakage, thus increasing production costs.
Design a cold forging die for flange weld points. The first inner chamfer in the upper die guides the material to the extrusion pit, and air is discharged through the venting channel. Combined with annealing and phosphating treatment, the material hardness is reduced and the fluidity is improved.
It improves the fullness of weld joint formation, reduces material shortage and root breakage, and lowers production costs.
Smart Images
Figure CN117733051B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of cold extrusion technology, and in particular to a cold forging die and cold forging method for flange weld points. Background Technology
[0002] Flanges with welded joints are a common connecting component in automotive chassis, with high market demand. These flanges typically consist of a stem and a flange. Multiple raised weld points are located on the flange surface. These weld points are used to weld the flange to other components. The weld points serve two purposes: firstly, they guide the welding position, facilitating subsequent welding; secondly, the weld points themselves are integral to the flange body, preventing them from easily detaching and thus enhancing the weld's strength and reducing the risk of weld failure.
[0003] Currently, similar products on the market use cold forging technology to form the rod and flange sections during processing. Then, a CNC machining center is used to cut the flange surface, creating multiple raised weld points. However, CNC cutting is time-consuming and results in high material consumption, making it difficult to achieve the expected production efficiency in mass production. To address this, a process using cold forging technology to form the weld points has emerged. By creating multiple recesses on a mold, when the mold is pressed against the flange surface, the flange surface deforms and fills the recesses, thus obtaining the weld point structure.
[0004] However, when using cold forging to process weld joints, it was found that because weld joint processing is generally in the latter half of the production process, the flange parts undergo multiple cold forgings, increasing their hardness. This results in a high surface hardness and poor flowability of the flange material during cold forging. Furthermore, the cold forging die for weld joints has multiple recesses, and to maximize the outward protrusion of the weld joint, these recesses are designed to be narrow and deep, creating significant resistance to material flow. This leads to weld joints prone to problems such as material shortages and root breakage, requiring rework and repair, which ultimately increases production costs. Summary of the Invention
[0005] The purpose of this application is to at least solve one of the technical problems existing in the prior art, and to provide a cold forging die and cold forging method for flange weld points, which can improve the welding point processing efficiency and make the generated weld points full.
[0006] According to a first aspect of this application, a cold forging die for a flange weld joint is provided, comprising:
[0007] The lower die is used to abut against the bottom of the flange portion in the flange component;
[0008] The upper die is used to abut against the top of the flange portion in the flange part. The upper die has an extrusion pit and a plurality of weld point forming pits disposed in the extrusion pit. The edge of the extrusion pit is provided with a first inner chamfer. The inner diameter of the weld point forming pit gradually decreases from bottom to top. The top of the weld point forming pit is provided with an exhaust channel, which penetrates the upper die.
[0009] The upper and lower dies are close to each other to compress the flange portion of the flange. The material on the surface of the flange portion flows into the extrusion pit and fills each of the weld point forming pits. The air in the extrusion pit is discharged from the exhaust channel.
[0010] According to a first aspect of the present application, the roughness of the extrusion pit and the weld point forming pit is less than or equal to Ra0.05.
[0011] According to a first aspect embodiment of this application, the angle between the first inner chamfer and the bottom plane of the upper mold is further 30°±20'.
[0012] According to a first aspect embodiment of this application, the lower mold is further provided with a first inner chamfer, and the first inner chamfer of the upper mold is disposed opposite to the first inner chamfer of the lower mold.
[0013] According to a first aspect of the present application, the extrusion pit is further provided with a guide pit, and the weld point forming pit is disposed in the middle of the guide pit. The guide pit is used to guide the material on the surface of the flange to flow into the weld point forming pit.
[0014] According to a first aspect of the present application, the edge of the guide pit is further provided with a second inner chamfer.
[0015] According to a first aspect of the present application, the junction between the solder joint forming pit and the guide pit is further rounded.
[0016] According to a first aspect embodiment of this application, the depth of the guide pit ranges from 0.04 to 0.06 mm.
[0017] According to a second aspect of this application, a cold forging method for flange weld joints is provided, based on the aforementioned cold forging die for flange weld joints, comprising the following steps:
[0018] Annealing and phosphating are performed on the flange parts with the processed rod and flange parts to reduce the hardness and surface roughness of the flange parts.
[0019] The flange is placed into the lower die, and the upper die is driven to approach the flange for cold forging.
[0020] The material on the flange surface flows into the extrusion pit along the first inner chamfer;
[0021] The upper and lower molds further compress the material, and the material on the surface of the flange enters the weld point forming pit. The air in the weld point forming pit is discharged through the exhaust channel.
[0022] The upper mold separates from the lower mold, and the flange is removed from it;
[0023] The weld points on the flange are trimmed and burrs are removed using a CNC machining center.
[0024] According to the second aspect of the embodiment of this application, after the processing of the solder joint is completed, the following work is performed:
[0025] The outer surface and internal pre-formed holes of the flange are trimmed using a CNC machining center;
[0026] The inner hole is obtained by punching along the pre-formed hole of the flange using cold forging equipment.
[0027] The inner hole of the flange is tapped to obtain an internal thread.
[0028] The beneficial effects of this application embodiment include at least the following: the material on the flange surface is guided to the extrusion pit by the first inner chamfer in the upper mold, and then filled into the weld point forming pit; the weld point forming pit is connected to the exhaust channel, which allows the gas in the pit to be discharged from the exhaust channel, making the material forming more full; the flange is annealed and phosphated before weld point forming, thereby reducing hardness and surface roughness and improving the fluidity of the material. Attached Figure Description
[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly explained below. Obviously, the described drawings are only a part of the embodiments of this application, and not all of them. Those skilled in the art can obtain other design schemes and drawings based on these drawings without creative effort.
[0030] Figure 1 This is a sectional view of flange part 300;
[0031] Figure 2 This is a comparison diagram of a traditional solder joint and this solder joint 321;
[0032] Figure 3 This is a cross-sectional view of the cold forging die for the flange weld joint according to the first aspect of this application;
[0033] Figure 4 This is a cross-sectional view of the upper die 200 in the cold forging die for the flange weld point according to the first aspect embodiment of this application;
[0034] Figure 5 yes Figure 4 A magnified view of a section at point A in the middle;
[0035] Figure 6 This is a schematic diagram of steps a and b in the cold forging method of flange weld joints according to the second aspect embodiment of this application;
[0036] Figure 7 This is a schematic diagram of steps c to e in the cold forging method of flange weld joints according to the second aspect embodiment of this application.
[0037] Reference numerals: 100-lower die, 110-punch, 200-upper die, 210-extrusion pit, 211-first inner chamfer, 220-weld point forming pit, 230-venting channel, 240-guide pit, 300-flange, 310-rod, 320-flange, 321-weld point, 3211-weld point recess, 400-pre-forming hole, 500-inner hole, 600-internal threaded hole. Detailed Implementation
[0038] This section will describe in detail the specific embodiments of this application. Preferred embodiments of this application are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of this application, but they should not be construed as limiting the scope of protection of this application.
[0039] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0040] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0041] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.
[0042] Reference Figure 1The flange 300 referred to in this application includes a stem 310 and a flange 320, which are integrally formed. Multiple protruding weld points 321 are provided on the surface of the flange 320, which can be dot-shaped, ring-shaped, strip-shaped, or other outwardly protruding shapes. These weld points 321 can be used to complete the welding work when the flange 300 is subsequently welded to the surface of other components. The weld points 321 serve two purposes: firstly, they guide the welding position, facilitating subsequent welding work; secondly, the weld points 321 are themselves part of the flange 300, making them less likely to detach from the flange 300 body, thus improving the strength of the weld and preventing detachment.
[0043] Currently, flange parts 300 on the market are manufactured using cold forging technology to form the rod 310 and flange 320. Then, a CNC machining center is used to cut the surface of the flange 320, creating multiple raised weld points 321. However, the CNC cutting process is time-consuming and results in high material consumption, making it difficult to achieve the expected production efficiency in mass production. To address this, a process using cold forging technology to form the weld points has emerged. By setting multiple recesses on a mold, when the mold is pressed against the surface of the flange 320, the surface of the flange 320 deforms and fills the recesses, thus obtaining the weld points 321.
[0044] However, when cold forging weld point 321 was used, it was found that because the processing of weld point 321 generally occurs in the latter half of the production process, the flange part 300 undergoes multiple cold forgings, resulting in increased hardness. Therefore, the surface material of the flange part 320 has high hardness and poor fluidity during the cold forging of weld point 321. The cold forging die for weld point 321 has multiple recesses, and to ensure the formed weld point 321 protrudes outwards as much as possible, the corresponding recesses are designed to be narrow in width and deep in depth. (Refer to...) Figure 2 , Figure 2 'a' represents the weld point structure of a traditional flange. Figure 2 In this application, b represents solder joint 321. To increase the height T of solder joint 321 while keeping the width H constant, it is necessary to deeply extrude the solder joint 321 on both sides to form solder joint pits 3211, thereby allowing more material to be formed into the towering shape of solder joint 321. Undoubtedly, a more complex solder joint 321 will cause greater resistance to material flow during forming. The resulting solder joint 321 is prone to problems such as material shortage and root breakage, thus requiring rework and increasing production costs.
[0045] In response, this application proposes a cold forging die and cold forging method for flange weld points. The material on the surface of the flange portion 320 is guided to the extrusion pit 210 through the first inner chamfer 211 in the upper die 200, and then filled into the weld point forming pit 220. The weld point forming pit 220 is connected to the venting channel 230, which allows the gas in the pit to be discharged from the venting channel 230, making the material forming more complete. Before the weld point forming, the flange part 300 is annealed and phosphated to reduce the hardness and surface roughness and improve the fluidity of the material.
[0046] Reference Figure 3 The cold forging die for the flange weld point in the first embodiment of this application includes a lower die 100 and an upper die 200. The weld point is formed by extruding the flange 300 through the lower die 100 and the upper die 200. Specifically, one of the lower die 100 and the upper die 200 is a fixed structure, and a power drive device drives the other die to move. In this embodiment, the lower die 100 is fixed and the upper die 200 is a movable die. The lower die 100 is provided with a limiting hole that matches the rod portion 310 of the flange 300, thereby limiting the position of the flange 300. The top of the lower die 100 abuts against the bottom of the flange portion 320, and the lower die 100 is also provided with a punch 110, which abuts against the bottom of the rod portion 310. During the forming of the weld point, the lower die 100 and the punch 110 can suppress the deformation of the main body of the flange 300.
[0047] Reference Figure 4 The upper die 200 is used to abut against the top of the flange portion 320 in the flange part 300. The upper die 200 has an extrusion pit 210 and multiple weld point forming pits 220 disposed in the extrusion pit 210. (Refer to...) Figure 5 The extrusion pit 210 has a first inner chamfer 211 at its edge to guide material into the extrusion pit 210 and reduce material overflow. The inner diameter of the solder joint forming pit 220 gradually decreases from bottom to top to guide material from the extrusion pit 210 into the solder joint forming pit 220. The top of the solder joint forming pit 220 has an exhaust channel 230 that penetrates the upper mold 200 to promptly expel internal air when material enters the solder joint forming pit 220, reducing the air pressure inside the solder joint forming pit 220 and preventing air bubbles from forming in the finished product.
[0048] The working principle of the cold forging die for this flange weld point is as follows: the upper die 200 and the lower die 100 approach each other to compress the flange part 320 in the flange part 300. The material on the surface of the flange part 320 flows into the extrusion pit 210 and fills each weld point forming pit 220. The air in the extrusion pit 210 is discharged from the exhaust channel 230 to prevent it from affecting the forming process.
[0049] Furthermore, by using processes such as grinding and polishing, the roughness of the extrusion pit 210 and the solder joint forming pit 220 is limited to less than or equal to Ra0.05, thereby reducing the resistance of the material flowing over the surfaces of the extrusion pit 210 and the solder joint forming pit 220.
[0050] Furthermore, the angle between the first inner chamfer 211 and the bottom plane of the upper die 200 is 30°±20', which makes it easier for the material on the surface of the flange 320 to slide into the extrusion pit 210.
[0051] Furthermore, the lower die 100 is also provided with a first inner chamfer 211. The first inner chamfer 211 of the upper die 200 is provided opposite to the first inner chamfer 211 of the lower die 100. This is also to reduce material overflow and control the material of the flange portion 320 within the outer contour range of the extrusion pit 210.
[0052] Furthermore, a guide pit 240 is also provided within the extrusion pit 210, with a depth ranging from 0.04 to 0.06 mm. A weld point forming pit 220 is located in the middle of the guide pit 240, which guides the material from the surface of the flange portion 320 into the weld point forming pit 220. Moreover, the flange portion 320 requires high flatness. Due to the poor material flow near the weld point 321, this flat area is prone to springback after demolding, resulting in substandard flatness in the produced product. Therefore, the guide pit 240 is designed to make the material near the weld point 321 thicker, reducing the amount of material springback after demolding, thereby meeting the flatness requirements of the flange portion 320.
[0053] The edge of the guide pit 240 is provided with a second inner chamfer to guide the material into the guide pit 240. In order to reduce the resistance when the material in the guide pit 240 enters the solder joint forming pit 220, the junction between the solder joint forming pit 220 and the guide pit 240 is rounded.
[0054] A cold forging method for a flange weld joint, as described in a second aspect embodiment of this application, is based on the aforementioned cold forging die for the flange weld joint and includes the following steps:
[0055] S100. Reference Figure 6 In step a, the flange 300 is pre-cooled to produce a prototype flange 320, the upper and lower surfaces of which are inclined at 30°±30°; and the flange 300 with the processed rod 310 and flange 320 is annealed and phosphated to reduce the hardness and surface roughness of the flange 300. At the same time, the annealing reduces the material hardness and also reduces the stamping pressure requirements of the stamping equipment.
[0056] S200. Place the flange 300 into the lower die 100 and drive the upper die 200 close to the flange 300 for cold forging;
[0057] S300. The material on the surface of the flange 320 flows into the extrusion pit 210 along the first inner chamfer 211;
[0058] S400. The upper die 200 and the lower die 100 further extrude, and the material on the surface of the flange 320 enters the weld point forming pit 220. The air in the weld point forming pit 220 is discharged through the exhaust channel 230.
[0059] S500. The upper die 200 separates from the lower die 100, and the flange 300 is removed from it, resulting in the following: Figure 6 The workpiece in section b;
[0060] S600. The weld points 321 of the flange 320 are trimmed and deburred using a CNC machining center to obtain shaped weld points 321.
[0061] Furthermore, after completing the machining of weld point 321, the following work is performed on flange part 300:
[0062] S700. Reference Figure 7 c. Using a CNC machining center, the outer surface of the flange 300 and the pre-formed holes 400 inside are trimmed. The pre-formed holes 400 are prepared for subsequent punching.
[0063] S800. Reference Figure 7 The inner hole 500 is obtained by punching along the pre-formed hole 400 of the flange 300 using cold forging equipment; the inner hole is obtained by cold forging punching, which is more efficient and saves more raw materials compared with CNC machining.
[0064] S900. Reference Figure 7 e, tap the inner hole 500 of flange 300 to obtain an internal threaded hole 600.
[0065] The above is a detailed description of the preferred embodiments of this application. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.
Claims
1. A cold forging die for a flange weld, characterized by, include: The lower mold (100) is used to abut against the bottom of the flange portion (320) in the flange (300); The upper mold (200) is used to abut against the top of the flange portion (320) in the flange part (300). The upper mold (200) has an extrusion pit (210) and a plurality of weld point forming pits (220) provided in the extrusion pit (210). The edge of the extrusion pit (210) is provided with a first inner chamfer (211). The inner diameter of the weld point forming pit (220) gradually decreases from bottom to top. The top of the weld point forming pit (220) is provided with an exhaust channel (230), which penetrates the upper mold (200). The upper die (200) and the lower die (100) are close to each other to compress the flange portion (320) in the flange part (300). The material on the surface of the flange portion (320) flows into the extrusion pit (210) and fills each of the weld point forming pits (220). The air in the extrusion pit (210) is discharged from the exhaust channel (230). The extrusion pit (210) is also provided with a guide pit (240), and the weld point forming pit (220) is provided in the middle of the guide pit (240). The guide pit (240) is used to guide the material on the surface of the flange (320) into the weld point forming pit (220). The edge of the guide pit (240) is provided with a second inner chamfer.
2. The flange weld cold-swaging die of claim 1, wherein: The roughness of the extrusion pit (210) and the weld point forming pit (220) is less than or equal to Ra0.
05.
3. The flange weld cold-forging die according to claim 1, characterized in that: The angle between the first inner chamfer (211) and the bottom plane of the upper mold (200) is 30°±20'.
4. The flange weld cold-forging die according to claim 1, characterized in that: The lower mold (100) is also provided with a first inner chamfer (211), and the first inner chamfer (211) of the upper mold (200) is provided opposite to the first inner chamfer (211) of the lower mold (100).
5. The flange weld cold-forging die according to claim 1, characterized in that: The junction of the weld point forming pit (220) and the guide pit (240) is rounded.
6. The cold forging die for flange weld points according to claim 1, characterized in that: The depth of the guide pit (240) ranges from 0.04 to 0.06 mm.
7. A cold forging method for flange weld joints, based on a cold forging die for flange weld joints according to any one of claims 1 to 6, characterized in that: The flange (300) with the processed rod (310) and flange (320) is annealed and phosphated to reduce the hardness and surface roughness of the flange (300). The flange (300) is placed into the lower die (100), and the upper die (200) is driven to approach the flange (300) for cold forging; The material on the surface of the flange (320) flows into the extrusion pit (210) along the first inner chamfer (211); The upper mold (200) and the lower mold (100) further compress the material on the surface of the flange (320) into the weld point forming pit (220), and the air in the weld point forming pit (220) is discharged through the exhaust channel (230); The upper mold (200) moves away from the lower mold (100) to remove the flange (300); The weld points (321) of the flange (320) are trimmed and deburred using a CNC machining center.
8. The method of cold forging a flange weld according to claim 7, characterized in that: After completing the machining of the solder joint (321), the following work is performed: The outer surface of the flange (300) and the pre-formed holes (400) inside are finished using a CNC machining center; The inner hole (500) is obtained by punching along the pre-formed hole (400) of the flange (300) using a cold forging equipment. The inner hole (500) of the flange (300) is tapped to obtain an internal threaded hole (600).