A screw cold heading processing forming die

Abstract

The utility model discloses a screw cold heading processing forming die relates to cold heading die technical field, the utility model discloses a first cold heading die and second cold heading die, the first cold heading die bottom is fixed with first fixed plate, and first fixed plate one side is passed through with the positioning pin, and first fixed plate bottom is passed through with first bolt, the second cold heading die bottom is fixed with second fixed plate, and second fixed plate one side is passed through with linear bearing, and linear bearing one side is connected with the positioning sleeve, and positioning sleeve one side is passed through with second bolt. The utility model discloses the setting of positioning pin, positioning sleeve and linear bearing, and the one end of positioning pin is set as the circular truncated cone, and the circular truncated cone end face can directly participate in the guidance correction through its inclined plane, when the positioning pin exists the deviation, and the circular truncated cone end face cooperates with the circular truncated cone inner hole inclined plane of positioning sleeve, and the lateral force produced by the inclined plane contact initiatively guides the positioning pin to return to the original position, realizes the accurate positioning guidance when cold heading die closes.

Description

Technical Field

[0001] This utility model relates to the field of cold heading mold technology, specifically a screw cold heading forming mold. Background Technology

[0002] Automotive bolts are key basic connecting parts in automobile manufacturing. They are widely used in the assembly of core components such as engines, chassis, body frames, and suspension systems. Their connection strength and precision directly affect the overall safety, stability, and service life of automobiles. They are important fasteners that ensure the coordinated operation of various automotive components.

[0003] The processing of automotive bolt blanks mostly adopts the cold heading process, which is completed in collaboration with multiple sets of cold heading dies: after the metal bar is fed into the cold heading equipment, multiple sets of cold heading dies sequentially perform upsetting, forming and other processing on the bar. Through progressive plastic deformation, the original bar is gradually processed into bolt blanks that meet the size requirements. These cold heading dies are usually installed on the same die frame and continuous processing is achieved through equipment linkage.

[0004] When processing automotive bolt blanks with existing cold heading dies, the guide structure is mostly set on the die holder rather than the die itself. Under the influence of factors such as impact and vibration during cold heading and assembly accuracy deviation, the die is prone to offset from the preset processing position, resulting in inaccurate positioning when the die is closed. This leads to defects such as dimensional deviation, deformation, and flash in the head of the processed bolt blank, affecting the subsequent processing accuracy and the quality of the finished bolt. Utility Model Content

[0005] Therefore, the purpose of this utility model is to provide a cold heading forming mold for screws to solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a cold heading forming mold for screws, comprising a first cold heading mold and a second cold heading mold, wherein a first fixing plate is fixed to the bottom of the first cold heading mold, and a positioning pin passes through one side of the first fixing plate, and a first bolt passes through the bottom of the first fixing plate; a second fixing plate is fixed to the bottom of the second cold heading mold, and a linear bearing passes through one side of the second fixing plate, a positioning sleeve is connected to one side of the linear bearing, and a second bolt passes through one side of the positioning sleeve.

[0007] By adopting the above technical solution, and by setting mutually cooperating positioning pins, linear bearings, and positioning sleeves at the bottom of the first and second cold heading dies respectively, and fixing them with fixing plates and bolts, the die itself integrates a positioning and guiding structure, thereby reducing die offset caused by vibration and assembly accuracy deviation from the source, and improving the processing accuracy and quality of automotive bolt blanks.

[0008] Furthermore, one end of the positioning pin is frustum-shaped, and the outer ring of the positioning pin is provided with a conical protrusion.

[0009] By adopting the above technical solution, the frustum-shaped end face of the positioning pin can form a beveled fit with the frustum-shaped inner hole of the positioning sleeve, providing a contact basis for offset correction; the conical protrusion of the outer ring increases the contact area with the first fixing plate, significantly enhancing the bending resistance of the positioning pin, ensuring that it is not easily bent when subjected to correction force and impact, and ensuring long-term stability of positioning accuracy.

[0010] Furthermore, the positioning pin is detachably connected to the first fixing plate via the first bolt.

[0011] By adopting the above technical solution, the positioning pin and the first fixing plate can be detachably fixed. When the positioning pin wears down due to long-term high-frequency contact and the accuracy of the inclined surface decreases, it can be quickly replaced by disassembling the first bolt without replacing the entire mold, thus reducing maintenance costs and improving equipment utilization.

[0012] Furthermore, the inner hole of the positioning sleeve is frustum-shaped, and the positioning pin abuts against the inner hole of the positioning sleeve.

[0013] By adopting the above technical solution, the frustum-shaped inner hole of the positioning sleeve and the frustum-shaped end face of the positioning pin are precisely matched. When the positioning pin is offset, the inclined contact between the two will generate a lateral corrective force, which actively guides the positioning pin back into place, ensuring that the linear bearing can be accurately inserted in the future and avoiding structural damage caused by hard collision.

[0014] Furthermore, the locating pin is slidably connected to the linear bearing.

[0015] By adopting the above technical solution, the locating pin is inserted into the linear bearing to form a stable sliding fit, which can not only provide precise guidance for mold closure, but also reduce the wear between the locating pin and the bearing through the low friction characteristics of the linear bearing, extend the service life of both, and ensure positioning accuracy in long-term use.

[0016] Furthermore, the positioning sleeve is detachably connected to the linear bearing via the second bolt, and the linear bearing is detachably connected to the second fixing plate via the second bolt.

[0017] By adopting the above technical solution, the positioning sleeve, linear bearing and second fixed plate are synchronously and detachably connected by the second bolt. When the positioning sleeve or linear bearing wears and fails, it can be disassembled and replaced at one time, simplifying the maintenance process and ensuring the overall fit accuracy of the positioning structure.

[0018] Furthermore, the contact surface between the first bolt and the locating pin is not threaded, and the contact surface between the second bolt and the linear bearing and the locating sleeve is not threaded.

[0019] By adopting the above technical solution, the threadless design between the bolt and the contact surface can avoid wear caused by thread stress, while increasing the bolt's shear resistance and reducing the radial force generated by cold forging impact that could cause bolt bending or thread damage, thus ensuring the stability and durability of the connection.

[0020] Furthermore, both the first and second bolts are provided with toothed anti-loosening washers or double-layered self-locking washers on their exteriors.

[0021] By adopting the above technical solutions, toothed anti-loosening washers or double-layered self-locking washers can resist high-frequency vibrations during cold heading through mechanical locking or continuous pre-tightening force, prevent bolts from loosening, ensure the stable installation position of components such as locating pins and linear bearings, and avoid a decrease in positioning accuracy due to bolt loosening.

[0022] Furthermore, there are two of each of the first fixing plate, the second fixing plate, the positioning pin, the first bolt, the linear bearing, and the positioning sleeve, and there are two sets of the second bolts. The two first fixing plates, the second fixing plates, the positioning pin, the first bolt, the linear bearing, the positioning sleeve, and the two sets of second bolts are all mirror images of each other.

[0023] By adopting the above technical solution, the dual-set mirror-distributed positioning structure can simultaneously play a positioning and guiding role from both sides of the mold, making the mold more uniformly stressed, dispersing the impact force to reduce damage to the positioning structure, and extending its service life.

[0024] Furthermore, both the locating pin and the locating sleeve are made of GCr15 bearing steel, and the surfaces of both the locating pin and the locating sleeve have undergone ion nitriding treatment.

[0025] By adopting the above technical solutions, GCr15 bearing steel itself has excellent wear resistance and rigidity. Combined with the high-hardness nitrided layer formed by ion nitriding treatment, it can significantly improve the wear resistance of the contact surface between the locating pin and the locating sleeve, and avoid the failure of the inclined structure caused by long-term high-frequency contact. At the same time, the nitrided layer and the substrate are metallurgically bonded, eliminating the risk of coating peeling, and can withstand cold heading impact vibration, extending the component replacement cycle and reducing maintenance costs.

[0026] In summary, the present invention has the following main advantages:

[0027] 1. This utility model utilizes a positioning pin, a positioning sleeve, and a linear bearing. One end of the positioning pin is shaped like a frustum, and its frustum end face can directly participate in guiding and correcting through its own inclined surface. When the positioning pin is offset, the frustum end face engages with the inclined surface of the frustum inner hole of the positioning sleeve, and the lateral force generated by the inclined surface contact actively guides the positioning pin back to its original position. At the same time, the conical protrusion on the outer ring of the positioning pin increases the contact area with the first fixed plate, enhancing bending resistance and ensuring stable transmission of the correcting force. Since the positioning pin and the first cold heading die, and the positioning sleeve and the second cold heading die are rigidly connected, the guiding and correcting force can directly drive the two dies to align synchronously, fundamentally reducing offset. The linear bearing, in conjunction with the sliding of the positioning pin, reduces friction and wear, effectively solving the problem of screw head defects caused by die offset in the prior art, and improving processing accuracy. It achieves precise positioning and guidance when the cold heading die is closed.

[0028] 2. By setting up a first cold heading mold, a first fixing plate, a second cold heading mold, and a second fixing plate, this utility model integrates positioning structures such as positioning pins into the bottom of the mold, avoiding the movement path of the clamping and transfer structure inside the cold heading machine, and preventing the positioning structure from colliding with the transfer structure above the cold heading mold; while ensuring the stable operation of the positioning and guiding function, it improves the safety and continuity of equipment operation.

[0029] 3. This utility model, through the arrangement of a first fixing plate, a first bolt, a second fixing plate, and a second bolt, allows for the removal and replacement of worn locating pins with the first bolt, and the simultaneous removal and replacement of worn linear bearings and locating sleeves with the second bolt. Furthermore, the bolts have a threadless contact surface with the locating pins, locating sleeves, and linear bearings, increasing the bolts' shear resistance and reducing thread wear caused by bending or radial forces. Simultaneously, anti-loosening washers ensure the stability of the connection, improve seismic resistance, and reduce the occurrence of loosening and detachment of the first and second bolts due to impact vibrations. This achieves convenient disassembly and assembly and stable connection of key components. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model;

[0031] Figure 2 This is a cross-sectional structural diagram of Embodiment 1 of the present utility model;

[0032] Figure 3 This is Embodiment 1 of the present utility model. Figure 2 Enlarged view of the structure at point A in the image;

[0033] Figure 4 This is a schematic diagram of the exploded structure of the first cold heading die according to Embodiment 1 of this utility model;

[0034] Figure 5 This is a schematic diagram of the exploded structure of the second cold heading die according to Embodiment 1 of this utility model;

[0035] Figure 6 This is a schematic diagram of the side structure of the first cold heading mold in Embodiment 2 of this utility model.

[0036] In the diagram: 1. First cold heading mold; 2. Second cold heading mold; 3. First fixing plate; 4. Second fixing plate; 5. Positioning pin; 6. First bolt; 7. Linear bearing; 8. Positioning sleeve; 9. Second bolt. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0038] The embodiments of this utility model will be described below based on its overall structure.

[0039] Example 1:

[0040] A screw cold heading forming die, such as Figures 1-6 As shown, the assembly includes a first cold heading mold 1 and a second cold heading mold 2. A first fixing plate 3 is fixed to the bottom of the first cold heading mold 1, and a positioning pin 5 passes through one side of the first fixing plate 3. One end of the positioning pin 5 is frustum-shaped, and its outer ring has a conical protrusion. A second fixing plate 4 is fixed to the bottom of the second cold heading mold 2, and a linear bearing 7 passes through one side of the second fixing plate 4. The positioning pin 5 is slidably connected to the linear bearing 7. A positioning sleeve 8 is connected to one side of the linear bearing 7. The inner hole of the positioning sleeve 8 is frustum-shaped, and the positioning pin 5 abuts against the inner hole of the positioning sleeve 8. When the first cold heading mold 1 and the second cold heading mold 2 are closed, the positioning pin 5 moves with the first cold heading mold. 1. When moving synchronously, the frustum-shaped end face of the positioning pin 5 first contacts the frustum-shaped inner hole of the positioning sleeve 8. If there is any offset, the inclined surface of the positioning sleeve 8 will apply a lateral corrective force to the frustum-shaped end face of the positioning pin 5. Since the positioning pin 5 and the first cold heading mold 1, and the positioning sleeve 8 and the second cold heading mold 2 are all rigidly connected, the corrective force is directly transmitted to the two molds, causing the molds to align synchronously. Subsequently, the positioning pin 5 is precisely inserted into the linear bearing 7. The sliding fit of the linear bearing 7 further stabilizes the guide, reduces friction and wear when the mold is closed, and ensures that the mold can still maintain accurate alignment under high-frequency impact and vibration, thereby avoiding defects in the head of the bolt blank.

[0041] See Figures 2-6In the above embodiment, a first bolt 6 passes through the bottom of the first fixing plate 3. The contact surface between the first bolt 6 and the positioning pin 5 is not threaded. The positioning pin 5 is detachably connected to the first fixing plate 3 through the first bolt 6. A second bolt 9 passes through one side of the positioning sleeve 8. The contact surface between the second bolt 9 and the linear bearing 7 and the positioning sleeve 8 is not threaded. The positioning sleeve 8 and the linear bearing 7 are detachably connected to the second fixing plate 4 through the second bolt 9. Toothed anti-loosening washers are fitted on the outside of both the first bolt 6 and the second bolt 9. When the positioning pin 5, the linear bearing 7, or the positioning sleeve 8 wears out due to long-term use, the operator can quickly replace the positioning pin 5 by removing the first bolt 6. The operator can simultaneously replace the linear bearing 7 and the positioning sleeve 8 by removing the second bolt 9. The anti-loosening washers ensure a stable connection and maintain the long-term processing accuracy of the mold.

[0042] Example 2:

[0043] Based on the above embodiment one, in order to further improve positioning stability, the following settings are now implemented.

[0044] See Figures 1-6 In the above embodiment, there are two of each of the first fixing plate 3, the second fixing plate 4, the positioning pin 5, the first bolt 6, the linear bearing 7, and the positioning sleeve 8, and two sets of the second bolt 9. The two first fixing plates 3, the second fixing plates 4, the positioning pin 5, the first bolt 6, the linear bearing 7, the positioning sleeve 8, and the two sets of second bolt 9 are all mirror images of each other. In this embodiment, the two sets of positioning structures can simultaneously play a positioning and guiding role from both sides of the mold, disperse the impact force, reduce the damage to the positioning structure, and thus extend the service life.

[0045] Example 3:

[0046] Based on the above embodiment one, in order to enhance the wear resistance and service life of the positioning component, the following settings are now implemented.

[0047] See Figure 6 In the above embodiments, both the positioning pin 5 and the positioning sleeve 8 are made of GCr15 bearing steel, and the surfaces of both the positioning pin 5 and the positioning sleeve 8 are ion nitrided. The implementation of the positioning pin 5 and the positioning sleeve 8 being made of GCr15 bearing steel and having their surfaces ion nitrided gives GCr15 bearing steel excellent rigidity and wear resistance. Combined with the high-hardness nitrided layer formed by ion nitriding, it can significantly improve the wear resistance of the frustum end face of the positioning pin 5 and the inclined surface of the inner hole of the positioning sleeve 8, reduce the failure of the inclined surface structure caused by long-term high-frequency contact, and the coating is not easy to peel off. It can better adapt to the impact and vibration during the cold heading process, extend the component replacement cycle, and reduce maintenance costs.

[0048] The implementation principle of this utility model is as follows: First, during the cold heading process of automotive bolt blanks, after the metal bar enters the cold heading equipment, multiple sets of molds sequentially perform step-by-step plastic deformation processing on the bar; when the first cold heading mold 1 and the second cold heading mold 2 of this utility model are closed, the positioning pin 5 moves synchronously with the first cold heading mold 1, and its frustum-shaped end face first contacts the frustum-shaped inner hole of the positioning sleeve 8; if there is a misalignment, the inclined surface of the positioning sleeve 8 will apply a lateral corrective force to the frustum-shaped end face of the positioning pin 5. Since the positioning pin 5 and the first cold heading mold 1, and the positioning sleeve 8 and the second cold heading mold 2 are all rigidly connected... The corrective force is directly transmitted to the two molds, causing them to align synchronously. Subsequently, the positioning pin 5 is precisely inserted into the linear bearing 7. The sliding fit of the linear bearing 7 further stabilizes the guide, reduces friction and wear when the mold is closed, and ensures that the mold can maintain accurate alignment under high-frequency impact and vibration, thereby avoiding defects in the head of the bolt blank. At the same time, the contact surfaces of the first bolt 6 and the positioning pin 5, and the second bolt 9 and the linear bearing 7 and the positioning sleeve 8 are not threaded, which can increase the shear resistance of the bolts, reduce thread wear or bolt bending caused by radial force, and further improve the connection stability.

[0049] The implementation method, which includes two first fixing plates 3, second fixing plates 4, positioning pins 5, first bolts 6, linear bearings 7, and positioning sleeves 8 arranged in a mirror image, allows the dual positioning structure to simultaneously provide positioning and guidance from both sides of the mold, dispersing impact forces and reducing damage to the positioning structure, thereby extending its service life. Furthermore, the implementation method, which uses GCr15 bearing steel with ion nitriding treatment for the positioning pins 5 and positioning sleeves 8, leverages the excellent rigidity and wear resistance of GCr15 bearing steel. Combined with the high-hardness nitriding layer formed by ion nitriding, this significantly improves the wear resistance of the frustum end face of the positioning pin 5 and the inclined surface of the inner hole of the positioning sleeve 8, reducing the failure of the inclined surface structure caused by long-term high-frequency contact. The coating is also less prone to peeling off, better adapting to the impact and vibration during cold heading, extending component replacement cycles, and reducing maintenance costs.

[0050] Meanwhile, the positioning structure is integrated into the bottom of the mold, which can avoid the clamping and transfer structure in the cold heading machine during the opening and closing of the mold and the transfer of the bar stock, ensuring the continuous and stable operation of the equipment. When the positioning pin 5, linear bearing 7 or positioning sleeve 8 wears out due to long-term use, the operator can quickly replace the positioning pin 5 by removing the first bolt 6. The operator can simultaneously replace the linear bearing 7 and positioning sleeve 8 by removing the second bolt 9. With the help of anti-loosening shims, the connection is ensured to be firm and the long-term processing accuracy of the mold is maintained.

[0051] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the present invention and are not intended to limit the invention. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the present invention, provided that such modifications, substitutions, and variations are within the scope of the claims of the present invention and are protected by patent law.

Claims

1. A cold heading forming die for screws, comprising a first cold heading die (1) and a second cold heading die (2), characterized in that: The first cold heading mold (1) has a first fixing plate (3) fixed at the bottom, and a positioning pin (5) passes through one side of the first fixing plate (3), and a first bolt (6) passes through the bottom of the first fixing plate (3); the second cold heading mold (2) has a second fixing plate (4) fixed at the bottom, and a linear bearing (7) passes through one side of the second fixing plate (4), a positioning sleeve (8) is connected to one side of the linear bearing (7), and a second bolt (9) passes through one side of the positioning sleeve (8).

2. The screw cold heading forming mold according to claim 1, characterized in that: One end of the positioning pin (5) is truncated cone-shaped, and the outer ring of the positioning pin (5) is provided with a conical protrusion.

3. The screw cold heading forming mold according to claim 2, characterized in that: The positioning pin (5) is detachably connected to the first fixing plate (3) by the first bolt (6).

4. The screw cold heading forming mold according to claim 1, characterized in that: The inner hole of the positioning sleeve (8) is frustum-shaped, and the positioning pin (5) abuts against the inner hole of the positioning sleeve (8).

5. The screw cold heading forming mold according to claim 1, characterized in that: The locating pin (5) is slidably connected to the linear bearing (7).

6. The screw cold heading forming die according to claim 5, characterized in that: The positioning sleeve (8) is detached from the linear bearing (7) by the second bolt (9), and the linear bearing (7) is detached from the second fixing plate (4) by the second bolt (9).

7. The screw cold heading forming die according to claim 6, characterized in that: The contact surface between the first bolt (6) and the locating pin (5) is not threaded, and the contact surface between the second bolt (9) and the linear bearing (7) and the locating sleeve (8) is not threaded.

8. The screw cold heading forming die according to claim 7, characterized in that: Both the first bolt (6) and the second bolt (9) are provided with toothed anti-loosening washers or double-layered self-locking washers on the outside.

9. The screw cold heading forming die according to claim 1, characterized in that: The first fixing plate (3), the second fixing plate (4), the positioning pin (5), the first bolt (6), the linear bearing (7) and the positioning sleeve (8) are all provided in twos, and the second bolt (9) is provided in two sets. The two first fixing plates (3), the second fixing plates (4), the positioning pin (5), the first bolt (6), the linear bearing (7), the positioning sleeve (8) and the two sets of second bolts (9) are all mirror images.

10. The screw cold heading forming die according to claim 9, characterized in that: The positioning pin (5) and the positioning sleeve (8) are both made of GCr15 bearing steel, and the surfaces of the positioning pin (5) and the positioning sleeve (8) are both ion nitrided.

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