Cold heading equipment for self-tapping screw machining

Abstract

The utility model relates to the technical field of cold heading equipment, in particular to cold heading equipment for self-tapping screw machining, which comprises a machining table, a lower die and an upper die, a hydraulic cylinder is arranged on the machining table, a hydraulic rod is connected with a movable plate, and a cold heading head is arranged on the movable plate; a motor for driving the upper die to move downwards is arranged on the supporting frame, a bearing base is arranged at the end, away from the hydraulic cylinder, of the machining table, an abutting rod body is slidably connected to the bearing base, and a limiting mechanism is arranged between the bearing base and the abutting rod body; the limiting mechanism comprises a first limiting insertion hole formed in the bearing base and a plurality of second limiting insertion holes formed in the abutting rod body at equal intervals. When the first limiting insertion hole and the second limiting insertion hole coincide, the limiting insertion rod is inserted to limit the position of the abutting rod body. By means of the adjustable abutting rod body, the applicable product range is widened.

Description

Technical Field

[0001] This utility model relates to the field of cold heading equipment technology, specifically to a cold heading equipment for processing self-tapping screws. Background Technology

[0002] Cold heading, also known as cold extrusion, is a process that uses dies to forge metal at room temperature to achieve plastic deformation and meet specified geometric shapes, dimensions, and quality requirements. However, existing cold heading equipment has some problems. Primarily, it applies pressure to both the top and bottom of the workpiece vertically simultaneously, resulting in a relatively high overall equipment height and a large footprint. Furthermore, the high placement of the workpiece makes operation less convenient.

[0003] Chinese patent CN222519877U discloses a cold heading device for hexagonal double-threaded bolts. In operation, the unprocessed workpiece is first placed in the lower forming cavity of the lower mold. Then, an electric push rod is energized, causing a moving plate to move downwards. The moving plate, in turn, moves the upper mold above the lower mold downwards, merging with it. Subsequently, a hydraulic cylinder, under the action of an external hydraulic source, moves a sliding block to the right. The sliding block then moves the cold heading head to the right, applying pressure to the workpiece. Because the right side of the workpiece is blocked by the abutment block, the workpiece is compressed, thus forming an external hexagon. After compression, the electric push rod resets, moving the upper mold upwards. The hydraulic cylinder also resets, moving the cold heading head to the left. At this point, the processed workpiece can be removed from the lower mold, completing the cold heading process. The entire process utilizes a hydraulic cylinder, sliding rail, and sliding block to apply pressure to one side of the workpiece. The design of the upper and lower molds also facilitates the placement and removal of the workpiece, making the operation simpler. However, the abutment block of the device cannot be moved, resulting in a limited number of bolt types that the device can be used with.

[0004] Therefore, this application provides a cold heading apparatus for self-tapping screw processing to solve the above-mentioned problems. Utility Model Content

[0005] To address the aforementioned issues, a cold heading device for self-tapping screw processing is provided. This device features a receiving base on the processing table, with a sliding abutment rod connected to the base. The abutment rod has several equally spaced second limiting holes, while the receiving base has a first limiting hole. By aligning different second limiting holes with the first limiting hole and inserting the limiting rod, the abutment rod is positioned to limit its movement. This solves the problem of limited applicability due to the immobility of the abutment block.

[0006] To address the problems of existing technologies, this utility model provides a cold heading device for processing self-tapping screws, comprising a processing table, a lower mold on the processing table, support frames at both ends of the lower mold, an upper mold on the support frames, a hydraulic cylinder at one end of the processing table, a moving plate connected to the output shaft of the hydraulic rod, and a cold heading head on the moving plate; a lower forming cavity is formed in the lower mold, and a lower external hexagonal cavity is formed in the lower forming cavity; an upper forming cavity is formed in the upper forming cavity, and an upper external hexagonal cavity is formed in the upper forming cavity; a motor for driving the upper mold to move downwards is provided on the support frame; a receiving base is provided at the end of the processing table away from the hydraulic cylinder, and an abutment rod is slidably connected to the receiving base; a limiting mechanism is provided between the receiving base and the abutment rod, the limiting mechanism including a first limiting insertion hole on the receiving base and a plurality of second limiting insertion holes equally spaced on the abutment rod; when the first limiting insertion hole and the second limiting insertion hole coincide, the limiting insertion rod is inserted to limit the position of the abutment rod.

[0007] Preferably, the cold heading head includes an abutment part and a fixing part, the fixing part is fixedly connected to the moving plate, the abutment part is slidably connected to the fixing part, and a return spring is provided between the abutment part and the fixing part.

[0008] Preferably, the abutting part is provided with a guide block, and the fixing part is provided with a guide groove adapted to the guide block, and the guide block is inserted into the guide groove.

[0009] Preferably, the fixing part is provided with an anti-detachment block to prevent the abutment part from falling off.

[0010] Preferably, the processing table is provided with a plurality of guide rails, and the bottom of the movable plate is provided with a plurality of movable grooves that are adapted to the guide rails.

[0011] Preferably, the lower mold is mounted on the processing table by bolts.

[0012] Preferably, a guiding mechanism is provided between the upper mold and the processing table, the guiding mechanism including a guide rod; through slots are provided on the upper mold, the lower mold and the processing table, and the guide rod passes through the through slots on the upper mold, the lower mold and the processing table.

[0013] Preferably, the guide rod has threads at both ends, and the guide rod is installed on the processing table by nuts.

[0014] The advantages of this utility model compared to the prior art are:

[0015] 1. By adjusting the sliding position of the abutment rod on the receiving base and locking the position with the limiting mechanism, this utility model can adapt to blanks of different lengths, realize the processing of self-tapping screws of multiple specifications, significantly improve the versatility and flexibility of the equipment, and solve the problem that cold heading equipment in the prior art can only process bolts of fixed size.

[0016] 2. The abutment part and the fixing part in this utility model adopt a sliding connection and are equipped with a return spring. This structure allows the abutment part to buffer the impact force if the resistance of the workpiece suddenly increases during the pressure process, avoiding rigid collision damage to the cold heading head or mold, enhancing the equipment's adaptability to workpiece deformation resistance, and improving the stability and durability of the equipment.

[0017] 3. In this utility model, the precise fit between the guide rail and the moving groove, along with the forced constraint of the guide rod on the movement trajectory of the upper mold, ensures the linear movement of the cold heading head during the pressure application process, eliminating the risk of lateral offset or torsion and improving the thread forming accuracy. Simultaneously, the rigid support provided by the guide rod and bolts effectively suppresses vibration during the cold heading process, further improving the processing accuracy and service life of the equipment. Attached Figure Description

[0018] Figure 1 This is a three-dimensional schematic diagram of a cold heading device for processing self-tapping screws according to this utility model.

[0019] Figure 2 This is a front view of a cold heading device for processing self-tapping screws according to this utility model.

[0020] Figure 3 This is an exploded view of the limiting mechanism of a cold heading equipment for self-tapping screw processing according to the present invention.

[0021] Figure 4 This is a three-dimensional schematic diagram of the moving plate of a cold heading equipment for processing self-tapping screws according to this utility model.

[0022] Figure 5 This is a three-dimensional schematic diagram of the upper mold of a cold heading equipment for processing self-tapping screws according to this utility model.

[0023] Figure 6 This is a partial sectional view of the cold heading head of a cold heading device for processing self-tapping screws, according to this utility model.

[0024] Figure 7 This is an exploded view of the cold heading head of a cold heading equipment for processing self-tapping screws, according to this utility model.

[0025] The following are the labels in the diagram: 1. Processing table; 11. Receiving base; 12. Hydraulic cylinder; 13. Moving plate; 14. Cold heading head; 141. Abutting part; 142. Fixing part; 143. Anti-detachment block; 15. Guide rail; 16. Moving groove; 2. Lower mold; 21. Lower forming cavity; 22. Lower external hexagonal cavity; 3. Upper mold; 31. Upper forming cavity; 32. Upper external hexagonal cavity; 4. Abutting rod; 5. Limiting mechanism; 51. First limiting insertion hole; 52. Limiting insertion rod; 53. Second limiting insertion hole; 6. Guiding mechanism; 61. Guide rod. Detailed Implementation

[0026] To further understand the features, technical means, and specific objectives and functions achieved by this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments.

[0027] Reference Figures 1-7 As shown: A cold heading device for processing self-tapping screws includes a processing table 1, a lower mold 2 on the processing table 1, support frames at both ends of the lower mold 2, an upper mold 3 on the support frames, a hydraulic cylinder 12 at one end of the processing table 1, a moving plate 13 connected to the output shaft of the hydraulic cylinder, and a cold heading head 14 on the moving plate 13; a lower forming cavity 21 is formed in the lower mold 2, and a lower external hexagonal cavity 22 is formed in the lower forming cavity 21; an upper forming cavity 31 is formed in the upper mold 3, and an upper external hexagonal cavity 32 is formed in the upper forming cavity 31. The support frame is equipped with a motor that drives the upper mold 3 to move downward. The end of the processing table 1 away from the hydraulic cylinder 12 is equipped with a receiving base 11. The receiving base 11 is slidably connected to an abutment rod 4. A limiting mechanism 5 is provided between the receiving base 11 and the abutment rod 4. The limiting mechanism 5 includes a first limiting insertion hole 51 opened on the receiving base 11 and a plurality of second limiting insertion holes 53 opened at equal intervals on the abutment rod 4. When the first limiting insertion hole 51 and the second limiting insertion hole 53 overlap, a limiting rod 52 is inserted to limit the position of the abutment rod 4.

[0028] In the prior art, cold heading equipment can only operate on bolts of fixed size, and the applicable bolt types are limited. To solve this problem, this application provides a cold heading device for processing self-tapping screws. The working principle of this cold heading device is as follows:

[0029] During processing, the self-tapping screw blank is first placed in the lower forming cavity 21 of the lower mold 2. The motor on the support frame is started, driving the upper mold 3 to move vertically downward, so that the upper forming cavity 31 and the lower forming cavity 21 close together, clamping the blank. At the same time, the upper external hexagonal cavity 32 and the lower external hexagonal cavity 22 are aligned to form a complete hexagonal cavity, which is used to form the head contour of the self-tapping screw. Subsequently, the hydraulic cylinder 12 pushes the moving plate 13 to move horizontally, driving the cold heading head 14 to pressurize towards the blank. Under the extrusion of the cold heading head 14, the blank undergoes plastic deformation, filling the hexagonal cavity and forming a threaded structure. At this time, the other end of the blank provides reverse support through the abutment rod 4 to prevent workpiece displacement. By adjusting the sliding position of the abutment rod 4 on the receiving base 11, blanks of different lengths can be accurately positioned. When the first limiting hole 51 coincides with a certain second limiting hole 53, inserting the limiting rod 52 locks the position of the abutment rod 4, ensuring workpiece stability during pressure application. After cold heading, the hydraulic cylinder 12 retracts, the motor drives the upper mold 3 to rise, and the self-tapping screw is removed, completing the processing cycle.

[0030] Reference Figure 6 and Figure 7 As shown: The cold heading head 14 includes an abutment part 141 and a fixing part 142. The fixing part 142 is fixedly connected to the moving plate 13, and the abutment part 141 and the fixing part 142 are slidably connected. A return spring is provided between the abutment part 141 and the fixing part 142.

[0031] When the hydraulic cylinder 12 drives the moving plate 13 to advance horizontally, the fixed part 142 moves synchronously with the moving plate 13, and the abutment part 141 contacts the workpiece and applies pressure under the sliding guide of the fixed part 142. During the pressure application process, if the workpiece resistance suddenly increases (such as uneven material hardness), the abutment part 141 can slide backward along the fixed part 142, compressing the return spring to buffer the impact force and avoid rigid collision damage to the cold heading head 14 or the mold; when the pressure is released (the hydraulic cylinder 12 retracts), the return spring elastically recovers, pushing the abutment part 141 back to the initial position, ensuring the consistency of the stroke for the next pressure application. Through the synergistic effect of the sliding connection and the spring, both the stability of pressure transmission and the adaptive capability of the equipment to the deformation resistance of the workpiece are achieved.

[0032] Reference Figure 6 and Figure 7 As shown: The abutting part 141 is provided with a guide block, and the fixing part 142 is provided with a guide groove that matches the guide block, and the guide block is inserted into the guide groove.

[0033] When the hydraulic cylinder 12 pushes the moving plate 13 to move horizontally, the fixed part 142 drives the guide groove to move forward synchronously, and the guide block inside the abutment part 141 slides straight along the guide groove, forcibly limiting the movement direction of the abutment part 141, and preventing deviation or tilting caused by lateral force during the pressure application process.

[0034] Reference Figure 6 and Figure 7 As shown: The fixing part 142 is provided with an anti-detachment block 143 to prevent the abutment part 141 from falling off.

[0035] The anti-detachment block 143 limits the maximum sliding stroke of the abutment portion 141 through its protruding structure.

[0036] Reference Figures 1-4 As shown: The processing table 1 is provided with several guide rails 15, and the bottom of the moving plate 13 is provided with several moving grooves 16 that are adapted to the guide rails 15.

[0037] The guide rail 15 on the processing table 1 and the sliding groove 16 at the bottom of the moving plate 13 form a sliding pair. When the hydraulic cylinder 12 drives the moving plate 13 to move horizontally, the sliding groove 16 slides along the straight trajectory of the guide rail 15. Through the lateral constraint of the guide rail 15 on the sliding groove 16, the moving plate 13 is forced to move only in a single direction (i.e., the direction of pressure applied by the cold heading head 14), eliminating the risk of lateral deviation or torsion. The precise fit between the guide rail 15 and the sliding groove 16 ensures the movement stability of the moving plate 13 when carrying the cold heading head 14, and also shares the axial pressure transmitted by the hydraulic cylinder 12 through the sliding surface, reducing the frictional loss between the moving plate 13 and the processing table 1. At the same time, the rigid support of the guide rail 15 can suppress the vibration when the cold heading head 14 applies pressure, ensuring that the pressure is evenly transmitted to the workpiece, thereby improving the thread forming accuracy and the service life of the equipment.

[0038] Reference Figures 1-3 As shown: The lower mold 2 is mounted on the processing table 1 by bolts.

[0039] The lower mold 2 is fastened to the pre-threaded hole of the processing table 1 by bolts. The axial preload of the bolts presses the mold against the surface of the processing table 1 to form a rigid fixation.

[0040] Reference Figures 1-4 As shown: A guide mechanism 6 is provided between the upper mold 3 and the processing table 1. The guide mechanism 6 includes a guide rod 61. Through slots are provided on the upper mold 3, the lower mold 2 and the processing table 1. The guide rod 61 passes through the through slots on the upper mold 3, the lower mold 2 and the processing table 1.

[0041] The guide rod 61 vertically passes through the through slots of the upper mold 3, lower mold 2, and processing table 1. When the upper mold 3 moves downward driven by the motor, the guide rod 61 constrains the movement trajectory of the upper mold 3 through the through slot, forcing it to align and close with the lower mold 2 along a straight path, ensuring that the upper forming cavity 31 and the lower forming cavity 21 match, and avoiding workpiece forming errors caused by skewness. During the cold heading process, the guide rod 61 simultaneously bears the vertical pressure transmitted by the upper mold 3 and the horizontal impact force applied by the cold heading head 14. The rigid rod body disperses part of the load to the processing table 1, reducing the risk of deformation of the mold and support frame. In addition, the clearance fit between the through slot and the guide rod 61 allows for minor adjustments, ensuring strict alignment when the mold closes and avoiding jamming problems caused by thermal expansion or vibration, thereby improving the thread forming accuracy and equipment operation stability.

[0042] Reference Figure 1 and Figure 2 As shown: The guide rod 61 has threads at both ends, and the guide rod 61 is installed on the processing table 1 by nuts.

[0043] The threads at both ends of the guide rod 61 are engaged with nuts. By tightening the nuts, the guide rod 61 is vertically fixed on the processing table 1, so that the guide rod 61 and the mold through groove form a rigid connection.

[0044] Working principle: During processing, the self-tapping screw blank is placed in the lower forming cavity 21 of the lower mold 2. The motor on the support frame drives the upper mold 3 to move vertically downward, closing the upper forming cavity 31 and the lower forming cavity 21 to clamp the blank. At the same time, the upper external hexagonal cavity 32 and the lower external hexagonal cavity 22 are aligned to form a complete hexagonal cavity, which is used to form the contour of the self-tapping screw head. The hydraulic cylinder 12 pushes the moving plate 13 to move horizontally along the guide rail 15 of the processing table 1. The moving groove 16 at the bottom of the moving plate 13 is precisely matched with the guide rail 15, restricting the moving plate 13 to move only in the cold heading pressure direction, driving the cold heading head 14 to pressurize the blank. The fixed part 142 of the cold heading head 14 advances synchronously with the moving plate 13. The abutment part 141 inside the cold heading head 14 contacts the workpiece through the linear sliding contact between the guide block and the guide groove. If the resistance suddenly increases during the pressure application, the abutment part 141 compresses the reset spring to buffer the impact and avoid rigid damage. The anti-detachment block 143 limits the maximum stroke of the guide block to prevent the abutment part 141 from detaching from the fixed part 142. The other end of the blank is provided with reverse support through the abutment rod 4. The position of the abutment rod 4 on the receiving base 11 can be adjusted by sliding to accommodate blanks of different lengths. When the first limiting insertion hole 51 coincides with the second limiting insertion hole 53, the limiting insertion rod 52 is inserted to lock the position and ensure stable pressure application.

[0045] Guide rod 61 vertically penetrates the through slots of upper mold 3, lower mold 2, and processing table 1, forcibly constraining the linear motion trajectory of upper mold 3 as it moves downwards, ensuring precise alignment of the upper and lower mold cavities. Both ends of guide rod 61 are fixed to processing table 1 by threads and nuts, utilizing thread preload to enhance rigidity and distribute impact loads during cold heading. Lower mold 2 is bolted to processing table 1; the symmetrical distribution of bolts ensures even load transfer to processing table 1, preventing misalignment. Upper mold 3 is also bolted to moving plate 13 for easy and quick replacement. After cold heading, hydraulic cylinder 12 retracts, and motor drives upper mold 3 to rise, removing the formed self-tapping screw and completing the processing cycle. Through the mechanical linkage and structural optimization of each component, the equipment achieves high-precision cold heading of self-tapping screws, while also possessing comprehensive advantages such as impact resistance, ease of maintenance, and adaptability to various workpiece specifications.

[0046] The above embodiments only illustrate one or more implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the appended claims.

Claims

1. A cold heading device for processing self-tapping screws, comprising a processing table (1), a lower mold (2) provided on the processing table (1), support frames provided at both ends of the lower mold (2), and an upper mold (3) provided on the support frames, characterized in that, One end of the processing table (1) is provided with a hydraulic cylinder (12), and the output shaft of the hydraulic rod is connected to a moving plate (13), and a cold heading head (14) is provided on the moving plate (13). The lower mold (2) has a lower forming cavity (21) and a lower outer hexagonal cavity (22) is formed inside the lower forming cavity (21). The upper mold (3) has an upper forming cavity (31) and an upper outer hexagonal cavity (32) is formed inside the upper forming cavity (31). The support frame is equipped with a motor that drives the upper mold (3) to move down. The processing table (1) is equipped with a receiving base (11) at one end away from the hydraulic cylinder (12). The receiving base (11) is slidably connected with an abutment rod (4). A limiting mechanism (5) is provided between the receiving base (11) and the abutment rod (4). The limiting mechanism (5) includes a first limiting hole (51) opened on the receiving base (11) and a plurality of second limiting holes (53) opened at equal intervals on the abutment rod (4). When the first limiting socket (51) and the second limiting socket (53) coincide, the limiting plug (52) is inserted to limit the position of the abutment rod (4).

2. The cold heading equipment for self-tapping screw processing according to claim 1, characterized in that, The cold heading head (14) includes an abutting part (141) and a fixing part (142). The fixed part (142) is fixedly connected to the movable plate (13), the abutting part (141) is slidably connected to the fixed part (142), and a return spring is provided between the abutting part (141) and the fixed part (142).

3. A cold heading device for self-tapping screw processing according to claim 2, characterized in that, The abutting part (141) is provided with a guide block, and the fixing part (142) is provided with a guide groove that is adapted to the guide block, and the guide block is inserted into the guide groove.

4. A cold heading device for self-tapping screw processing according to claim 2, characterized in that, The fixing part (142) is provided with an anti-detachment block (143) to prevent the abutment part (141) from falling off.

5. A cold heading device for self-tapping screw processing according to claim 1, characterized in that, The processing table (1) is provided with several guide rails (15), and the bottom of the moving plate (13) is provided with several moving grooves (16) that are adapted to the guide rails (15).

6. A cold heading device for self-tapping screw processing according to claim 1, characterized in that, The lower mold (2) is mounted on the processing table (1) by bolts.

7. A cold heading device for self-tapping screw processing according to claim 1, characterized in that, A guide mechanism (6) is provided between the upper mold (3) and the processing table (1), and the guide mechanism (6) includes a guide rod (61). The upper mold (3), lower mold (2) and processing table (1) are provided with through slots, and the guide rod (61) passes through the through slots on the upper mold (3), lower mold (2) and processing table (1).

8. A cold heading device for self-tapping screw processing according to claim 7, characterized in that, The guide rod (61) has threads at both ends, and the guide rod (61) is installed on the processing table (1) by nuts.

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