A precision forming die device for a quick-attack composite screw and a machining forming method thereof

Abstract

This invention discloses a precision forming mold device for fast-attach composite screws and its machining forming method, relating to the field of cold heading forming mold technology. It includes a cold heading machine frame, with a mold base fixedly connected to the bottom of the frame. A cylinder is fixedly installed on the upper part of the frame, and a punch seat is fixedly installed at the extended end of the cylinder. The punch seat can move vertically up and down under the drive of the cylinder. An ultrasonic vibration generating component is fixedly installed inside the punch seat. This invention applies longitudinal ultrasonic vibration to the hexagonal punch during the cold heading process using the ultrasonic vibration generating component. The "surface effect" of ultrasonic vibration reduces the friction coefficient between the blank and the punch cavity surface, and the "volume effect" of ultrasonic vibration reduces the flow stress of the blank metal, significantly improving the filling fullness and forming quality of the fine features of the hexagonal punch, while simultaneously reducing demolding friction and mold wear.

Description

Technical Field

[0001] This invention relates to the field of cold heading forming mold technology, and in particular to a precision forming mold device for fast-acting composite screws and its machining forming method. Background Technology

[0002] Quick-acting composite screws are a type of composite screw with a hexagonal drive groove on the head and a multi-faceted self-tapping structure on the tip. They are widely used in construction, furniture, automobiles and other fields. The hexagonal structure on the head has multiple micro-features such as the hexagonal groove. During the cold heading process, the metal blank needs to be squeezed into these micro-grooves under extremely high pressure, making the forming difficulty much higher than that of ordinary screws.

[0003] Existing cold heading dies for screws typically employ a fixed punch structure. During the forming process, the filling of the fine features of the hexagonal cavity requires a tremendous forming force, and the friction between the blank and the die cavity is extremely high. This can easily lead to increased die wear, resulting in a shorter die lifespan. Furthermore, defects such as incomplete filling and missing corners are prone to occur in the hexagonal groove contour. Summary of the Invention

[0004] To improve the aforementioned screw cold heading forming mold, a fixed punch structure is usually adopted. During the forming process, the filling of the fine features of the hexagonal cavity requires a great forming force, and the friction between the blank and the mold cavity is extremely high, which can easily lead to increased mold wear, resulting in a shorter mold life. In addition, the hexagonal groove contour is prone to defects such as incomplete filling and missing corners.

[0005] This invention provides a precision forming mold device for fast-acting composite screws and its machining forming method, adopting the following technical solution: A precision forming die device for fast-attach composite screws includes a cold heading machine frame, a die holder fixedly connected to the bottom of the cold heading machine frame, a cylinder fixedly mounted on the upper part of the cold heading machine frame, a punch holder fixedly mounted on the extended end of the cylinder, the punch holder being able to move up and down vertically under the drive of the cylinder, and an ultrasonic vibration generating component fixedly mounted inside the punch holder for generating longitudinal ultrasonic vibration. The inner bottom of the punch holder is detachably fitted with a hexagonal punch. The upper end of the hexagonal punch abuts against the lower end of the ultrasonic vibration generating component. The ultrasonic vibration generating component is used to transmit longitudinal ultrasonic vibration to the hexagonal punch. The lower end of the punch holder is provided with a double locking mechanism. The double locking mechanism has a first positioning end and a second positioning end. The first positioning end is threadedly inserted into the hexagonal punch, and the second positioning end is movably inserted into one end of the hexagonal punch that is inserted into the punch holder. The double locking mechanism is used to double lock the hexagonal punch in the punch holder and keep it in constant contact with the ultrasonic vibration generating component. The punch seat has a cooling chamber inside, and a piston mechanism is movably arranged in the cooling chamber. The piston mechanism is used to reciprocate in the cooling chamber to drive the coolant and gas to circulate. The piston mechanism has a movable end that extends upward out of the cooling chamber. An external gear control disc is rotatably mounted inside the punch seat. A guide structure is provided on the bottom surface of the external gear control disc. The movable end of the piston mechanism extends into the guide structure and slides in cooperation with the inner wall of the guide structure. Two transmission gears are symmetrically arranged on the outer wall of the punch seat. Both transmission gears extend into the punch seat and mesh with the external gear control disc. Each transmission gear has a guide rod movably inserted into its inner hole. The guide rod is used to drive the transmission gear to rotate when the punch seat moves up and down. The upper ends of the two guide rods are fixedly connected to the cold heading machine frame.

[0006] Optionally, in the above-mentioned fast-acting composite screw precision forming mold device, the bottom of the punch seat is recessed upward and provided with an installation groove, and the ultrasonic vibration generating component is fixedly installed in the installation groove; The inner sidewall at the upper end of the mounting groove is provided with a gear receiving groove, and the external gear control disk is rotatably disposed in the gear receiving groove. The inner wall at the lower end of the mounting groove is provided with several movable grooves, each movable groove extending radially along the punch seat, and the second positioning end of the double locking mechanism is movably disposed in the corresponding movable groove.

[0007] Optionally, in the above-mentioned fast-acting composite screw precision forming mold device, the ultrasonic vibration generating component includes an ultrasonic transducer and an amplitude transformer. The ultrasonic transducer is fixedly installed on the inner top wall of the mounting groove. The upper end of the amplitude transformer is threadedly connected to the radiation surface of the ultrasonic transducer. A flange is provided at the vibration node position of the amplitude transformer. The flange is fixedly installed on the inner side wall of the mounting groove. The flange is used to fix the amplitude transformer in the punch seat. The lower end of the amplitude transformer abuts against the upper end of the hexagonal punch. The amplitude transformer is used to amplify the longitudinal ultrasonic vibration generated by the ultrasonic transducer and transmit it to the hexagonal punch.

[0008] Optionally, in the above-mentioned fast-acting composite screw precision forming mold device, a punch position sensor is fixedly installed at the bottom of the punch seat. The punch position sensor is used to detect whether the Torx hexagonal punch enters or leaves the contact area with the blank. The punch position sensor is electrically connected to the ultrasonic transducer. The outer wall of the hexagonal punch is fixedly fitted with a retaining ring, which is used to be threaded into the first positioning end of the double locking mechanism. The outer wall of the end of the hexagonal punch inserted into the punch seat is provided with an annular wedge groove, which is used to be movably inserted into the second positioning end of the double locking mechanism.

[0009] Optionally, in the above-mentioned fast-acting composite screw precision forming mold device, the dual locking mechanism includes several round-headed screws and several wedge blocks. Several round-headed screws are vertically threaded into the punch seat, and the lower end of each round-headed screw passes through the punch seat and is threaded into the retaining ring. Several round-headed screws together constitute the first positioning end. The number of wedges corresponds to the number of movable slots. Each wedge is movably set in its corresponding movable slot. One end of the wedge extends out of the movable slot and is inserted into the annular wedge surface groove. The other end of the wedge is connected to the inner wall of the movable slot through a first spring, and the other end of the wedge abuts against the side wall of the round-headed screw. Several wedges together constitute the second positioning end.

[0010] Optionally, in the above-mentioned fast-acting composite screw precision forming mold device, the piston mechanism includes a piston disc and two round rods. The piston disc is movably disposed in the cooling chamber. The outer peripheral surface of the piston disc is sealed and fitted with the inner wall of the cooling chamber. The top surface of the piston disc is connected to the inner top wall of the cooling chamber by a compression spring. Two circular rods are symmetrically fixedly connected to the top surface of the piston disc. The circular rods extend upward into the cooling chamber. The upper end of the circular rods is inserted into the guide structure and slides in cooperation with the inner wall of the guide structure. The two circular rods together form the movable end. The cooling chamber is divided into a water-cooled chamber and an air-cooled chamber by a piston disc. The water-cooled chamber is used to contain circulating coolant, and the air-cooled chamber is used to contain circulating cooling gas.

[0011] Optionally, in the above-mentioned fast-acting composite screw precision forming mold device, two liquid flow hoses are symmetrically inserted into the outer wall of the punch seat. Both liquid flow hoses are connected to the water cooling chamber of the cooling chamber. One-way valves are provided in both liquid flow hoses. One liquid flow hose is an inlet pipe and the other liquid flow hose is an outlet pipe. The outer wall of the punch holder has two symmetrical air inlets, both of which are connected to the air-cooled chamber of the cooling chamber.

[0012] Optionally, in the above-mentioned quick-attack composite screw precision forming mold device, an external gear ring is provided on the upper outer wall of the external gear control disk, and the external gear ring meshes with the transmission gear; The guide structure is an annular wavy groove formed on the bottom surface of the external gear control disk. The annular wavy groove extends circumferentially along the external gear control disk, and the depth of the groove bottom varies in a wavy pattern along the circumferential direction. The upper end of the round rod is inserted into the annular wavy groove, and the upper end of the round rod slides in contact with the inner wall of the annular wavy groove.

[0013] Optionally, in the above-mentioned fast-acting composite screw precision forming mold device, two protective covers are symmetrically fixedly connected to the outer wall of the punch seat, and the two protective covers are installed outside the corresponding transmission gears; The transmission gear has a through hole in its center for the guide rod to pass through, and a guide block is fixedly connected to the inner wall of the through hole; The guide rod is movably inserted into the through hole, and a spiral groove is formed on the outer wall of the guide rod. The guide block is slidably embedded in the spiral groove and slides in cooperation with the inner wall of the spiral groove.

[0014] Another technical solution proposed in this invention: a machining method for precision forming of fast-acting composite screws, comprising the following steps: S1. Punch installation and locking: Insert the upper end of the hexagonal punch into the mounting groove at the bottom of the punch seat, so that the upper end face of the hexagonal punch abuts against the lower end of the ultrasonic vibration generating component; screw in each round-head screw, and achieve the first locking by the threaded connection between the round-head screw and the retaining ring. At the same time, the side wall of the round-head screw pushes the wedge block to move inward along the movable groove, and the end of the wedge block inserts into the annular wedge surface groove to achieve the second locking. Through the cooperation of the wedge surface, the hexagonal punch is pushed towards the top of the mounting groove, so that its upper end face is in close contact with the ultrasonic vibration generating component. S2. Blank conveying: When the cold heading machine starts its working cycle, the automatic feeding mechanism automatically picks up the screw blank to be processed and conveys it to the top of the mold base and releases it according to the working rhythm of the cold heading machine. S3. Cold Heading and Ultrasonic Assistance Linkage: The extended end of the cylinder drives the punch seat to move vertically downwards at high speed. The punch position sensor detects the end face position of the hexagonal punch in real time. When the punch position sensor detects that the hexagonal punch has entered the blank contact area, it sends a trigger signal to the control system. The ultrasonic generator automatically turns on, driving the ultrasonic transducer to generate longitudinal ultrasonic vibration. The amplitude is amplified by the amplitude transformer and transmitted to the hexagonal punch. The hexagonal punch performs cold heading on the blank with the assistance of longitudinal ultrasonic vibration. The "surface effect" of ultrasonic vibration reduces the friction coefficient between the blank and the punch cavity surface, and the "volume effect" of ultrasonic vibration reduces the flow stress of the blank metal and improves the filling fullness of the hexagonal micro-features. S4. Cooling Circulation Linkage: While the punch seat moves up and down vertically, the spiral groove on the guide rod pushes the guide block in the inner hole of the transmission gear to generate a circumferential force, driving the transmission gear to rotate around its own axis; the transmission gear drives the external gear control disk to rotate through meshing; the annular wave-shaped groove on the bottom surface of the external gear control disk rotates together with the external gear control disk, and pushes the upper end of the round rod through the undulation of the groove bottom, driving the piston disk to make vertical reciprocating motion in the cooling chamber, alternately compressing and sucking the coolant and gas in the water-cooled chamber and the air-cooled chamber, forming a continuous coolant circulation and air-cooling circulation inside the punch seat to cool the ultrasonic vibration generating component and the hexagonal punch; S5. Demolding and Ultrasonic Stop: After cold heading is completed, the extended end of the cylinder drives the punch seat to rise upward, and the hexagonal punch exits from the formed part; when the punch position sensor detects that the hexagonal punch has disengaged from the blank contact area, it sends a stop signal to the control system, and the ultrasonic generator automatically stops ultrasonic output. S6. Punch Disassembly and Replacement: When it is necessary to replace the hexagonal punch, turn each round-headed screw in the opposite direction to gradually unscrew it from the punch holder. The side wall of the round-headed screw will disengage from the wedge block. Under the elastic restoring force of the first spring, the wedge block will reset outward along the movable groove. The end of the wedge block will exit from the annular wedge groove, and the hexagonal punch will be unlocked. Remove the old punch from the punch holder and replace it with a new punch. Repeat step S1 to complete the installation and locking of the new punch.

[0015] In summary, the present invention has at least one of the following beneficial effects: By applying longitudinal ultrasonic vibration to the hexagonal punch during the cold heading process using an ultrasonic vibration generator, the friction coefficient between the blank and the punch cavity surface is reduced by utilizing the "surface effect" of ultrasonic vibration, and the flow stress of the blank metal is reduced by utilizing the "volume effect" of ultrasonic vibration. This significantly improves the filling fullness and forming quality of the fine features of the hexagonal punch, while reducing demolding friction and reducing mold wear. The first axial locking is achieved by the threaded connection between the round-headed screw and the retaining ring, and the second radial locking is achieved by the movable connection between the wedge block and the annular wedge groove. At the same time, the wedge-shaped inclined surface of the wedge block pushes the hexagonal punch towards the top of the mounting groove, so that its upper end face is always in close contact with the ultrasonic vibration generating component, eliminating the fit gap and ensuring the efficient transmission of ultrasonic vibration energy. By utilizing the up-and-down movement of the punch seat, the transmission gear is driven to rotate through the spiral groove on the guide rod. Then, the piston mechanism is driven to reciprocate within the cooling chamber through the annular wave-shaped groove on the bottom surface of the external gear control disc, thereby achieving the circulation of coolant and gas without the need for an external water pump or independent cooling power source. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a partial three-dimensional cross-sectional view of the punch holder of the present invention; Figure 3 This is a partial three-dimensional unfolded cross-sectional view of the punch holder of the present invention; Figure 4 This is a partial three-dimensional unfolded cross-sectional view of the transmission gear of the present invention; Figure 5 This is a partial three-dimensional cross-sectional view of the cooling cavity of the present invention; Figure 6 This is a partial three-dimensional structural diagram of the bottom surface of the external gear control disk of the present invention.

[0017] In the diagram: 1. Cold heading machine frame; 2. Die holder; 3. Cylinder; 4. Punch holder; 41. Cooling chamber; 411. Water-cooled chamber; 412. Air-cooled chamber; 42. Mounting slot; 43. Gear receiving slot; 44. Movable slot; 45. Fluid flow hose; 46. Air inlet; 47. Protective cover; 5. Ultrasonic vibration generating assembly; 51. Ultrasonic transducer; 52. Amplitude bar; 53. Flange; 6. Torx hexagonal punch; 61. 62. Punch position sensor; 63. Retaining ring; 7. Annular wedge groove; 8. Double locking mechanism; 93. Round head screw; 10. Wedge block; 11. First spring; 12. Piston mechanism; 13. Piston disc; 14. Round rod; 15. Compression spring; 16. External gear control disc; 17. Annular wave groove; 18. Transmission gear; 19. Through hole; 10. Guide block; 20. Guide rod; 21. Spiral groove. Detailed Implementation

[0018] The following is in conjunction with the appendix Figures 1-6 The present invention will be described in further detail below.

[0019] Please refer to the attached diagram in the instruction manual. Figures 1-6An embodiment of the present invention provides a precision forming mold device for fast-attach composite screws, including a cold heading machine frame 1, a mold base 2 fixedly connected to the bottom of the cold heading machine frame 1, a cylinder 3 fixedly installed on the upper part of the cold heading machine frame 1, a punch seat 4 fixedly installed at the extended end of the cylinder 3, the punch seat 4 can move up and down in the vertical direction under the drive of the cylinder 3, and an ultrasonic vibration generating component 5 is fixedly installed inside the punch seat 4, the ultrasonic vibration generating component 5 is used to generate longitudinal ultrasonic vibration; The inner bottom of the punch holder 4 is detachably fitted with a hexagonal punch 6. The upper end of the hexagonal punch 6 abuts against the lower end of the ultrasonic vibration generating component 5. The ultrasonic vibration generating component 5 is used to transmit longitudinal ultrasonic vibration to the hexagonal punch 6. The lower end of the punch seat 4 is provided with a double locking mechanism 7. The double locking mechanism 7 has a first positioning end and a second positioning end. The first positioning end is threaded into the hexagonal punch 6, and the second positioning end is movably inserted into one end of the hexagonal punch 6 that is inserted into the punch seat 4. The double locking mechanism 7 is used to double lock the hexagonal punch 6 in the punch seat 4 and keep it in constant contact with the ultrasonic vibration generating component 5. The punch seat 4 has a cooling chamber 41 inside, and a piston mechanism 8 is movably arranged in the cooling chamber 41. The piston mechanism 8 is used to reciprocate in the cooling chamber 41 to drive the coolant and gas to circulate. The piston mechanism 8 has a movable end that extends upward out of the cooling chamber 41. An external gear control disk 9 is rotatably installed inside the punch seat 4. A guide structure is provided on the bottom surface of the external gear control disk 9. The movable end of the piston mechanism 8 extends into the guide structure and slides in cooperation with the inner wall of the guide structure. Two transmission gears 10 are symmetrically arranged on the outer wall of the punch seat 4. Both transmission gears 10 extend into the punch seat 4 and mesh with the external gear control disk 9. Each transmission gear 10 has a guide rod 20 movably inserted into its inner hole. The guide rod 20 is used to drive the transmission gear 10 to rotate when the punch seat 4 moves up and down. The upper ends of the two guide rods 20 are fixedly connected to the cold heading machine frame 1.

[0020] The bottom of the punch seat 4 is recessed upward and has a mounting groove 42, in which the ultrasonic vibration generating component 5 is fixedly installed. A gear receiving groove 43 is provided on the inner side wall of the upper end of the mounting groove 42, and the external gear control disk 9 is rotatably disposed in the gear receiving groove 43. The inner sidewall at the lower end of the mounting groove 42 is provided with several movable grooves 44, each movable groove 44 extending radially along the punch seat 4, and the second positioning end of the double locking mechanism 7 is movably disposed in the corresponding movable groove 44.

[0021] The mounting groove 42, which is recessed upward at the bottom of the punch seat 4, provides mounting space for the ultrasonic vibration generating component 5 and the hexagonal punch 6. The ultrasonic vibration generating component 5 is fixedly installed on the inner top wall of the mounting groove 42, and the longitudinal ultrasonic vibration it generates is transmitted downward to the hexagonal punch 6.

[0022] The gear receiving groove 43, which is an annular groove, is opened on the inner side wall of the upper end of the mounting groove 42. It is used to accommodate the external gear control disk 9 and provide it with rotational space. The external gear control disk 9 is rotatably set in the gear receiving groove 43 and can rotate freely around the axis of the punch seat 4.

[0023] Several movable grooves 44 are opened on the inner side wall at the lower end of the mounting groove 42, extending radially along the punch seat 4, providing a radial sliding guide channel for the wedge block 74 of the double locking mechanism 7. Each wedge block 74 is movably set in the corresponding movable groove 44 and can move inward or outward along the radial direction of the movable groove 44. When the wedge block 74 moves inward, its end extends out of the movable groove 44 and inserts into the annular wedge surface groove 63 on the outer wall of the hexagonal pendant 6, thereby achieving radial locking of the hexagonal pendant 6. When the wedge block 74 moves outward, its end exits the annular wedge surface groove 63, releasing the radial locking of the hexagonal pendant 6.

[0024] The ultrasonic vibration generating assembly 5 includes an ultrasonic transducer 51 and an amplitude transformer 52. The ultrasonic transducer 51 is fixedly installed on the inner top wall of the mounting groove 42. The upper end of the amplitude transformer 52 is threadedly connected to the radiation surface of the ultrasonic transducer 51. A flange 53 is provided at the vibration node position of the amplitude transformer 52. The flange 53 is fixedly installed on the inner side wall of the mounting groove 42. The flange 53 is used to fix the amplitude transformer 52 in the punch seat 4. The lower end of the amplitude transformer 52 abuts against the upper end of the hexagonal punch 6. The amplitude transformer 52 is used to amplify the longitudinal ultrasonic vibration generated by the ultrasonic transducer 51 and transmit it to the hexagonal punch 6.

[0025] The ultrasonic transducer 51 is fixedly installed on the inner top wall of the mounting groove 42. Its interior is composed of a piezoelectric ceramic wafer and front and rear metal cover plates. When the ultrasonic generator sends a high-frequency electrical signal to the ultrasonic transducer 51, the piezoelectric ceramic wafer generates high-frequency mechanical vibration under the action of the inverse piezoelectric effect. The upper end of the amplitude transformer 52 is tightly connected to the radiation surface of the ultrasonic transducer 51 by threads. The mechanical vibration generated by the ultrasonic transducer 51 is transmitted to the amplitude transformer 52 through the contact surface.

[0026] The amplitude transformer 52 adopts a stepped structure that is thicker at the top and thinner at the bottom. According to the principle of vibration energy transmission, the amplitude is amplified when the vibration is transmitted from the large cross section to the small cross section. The amplitude amplification factor is equal to the ratio of the area of ​​the large end to the area of ​​the small end. The vibration node position of the amplitude transformer 52 is the cross section where the vibration displacement is zero, and this position does not participate in the vibration. The flange 53 is located at the vibration node position of the amplitude transformer 52 and is fixedly installed on the inner wall of the mounting groove 42. Since the amplitude at the node position is zero, the flange 53 will not loosen due to vibration, nor will it transmit the vibration energy to the punch seat 4, thus ensuring the effective transmission of ultrasonic vibration energy and the long-term reliable operation of the device.

[0027] The lower end of the amplitude transformer 52 is in close contact with the upper end of the hexagonal punch 6. The basic amplitude generated by the ultrasonic transducer 51 is amplified by the amplitude transformer 52 and transmitted to the hexagonal punch 6 with higher vibration energy, so that the hexagonal punch 6 generates strong longitudinal ultrasonic vibration during the cold heading process, which plays the role of reducing friction and load and promoting filling.

[0028] A punch position sensor is fixedly installed at the bottom of the punch holder 4. The punch position sensor is used to detect whether the hexagonal punch 6 enters or leaves the contact area with the blank. The punch position sensor is electrically connected to the ultrasonic transducer 51. A retaining ring 62 is fixedly fitted on the outer wall of the hexagonal pendant 6. The retaining ring 62 is used to be threaded into the first positioning end of the double locking mechanism 7. An annular wedge groove 63 is opened on the outer wall of the end of the hexagonal pendant 6 that is inserted into the pendant seat 4. The annular wedge groove 63 is used to be movably inserted into the second positioning end of the double locking mechanism 7.

[0029] The punch position sensor is fixedly installed at the bottom of the punch holder 4 to detect in real time whether the end face of the hexagonal punch 6 enters or leaves the contact area with the blank. The punch position sensor is electrically connected to the ultrasonic transducer 51 through the control system. When the punch position sensor detects that the hexagonal punch 6 enters the contact area with the blank, it sends a trigger signal to the control system. The control system controls the ultrasonic generator to turn on and drives the ultrasonic transducer 51 to generate longitudinal ultrasonic vibration. The ultrasonic vibration is only turned on during the forming stage when the mold is in contact with the blank, and automatically stops during the non-contact idle stroke. This realizes the on-demand supply of ultrasonic vibration, avoids energy waste caused by long-term idle operation, reduces energy consumption and noise, and at the same time reduces the continuous heating of the ultrasonic transducer 51 and the amplitude transformer 52, thus extending the service life of the ultrasonic system.

[0030] The retaining ring 62 is fixedly sleeved on the outer wall of the hexagonal punch 6 and has a circular flange structure. Multiple threaded holes are opened on the side of the retaining ring 62 for threaded insertion with the first positioning end of the double locking mechanism 7. When the lower end of the round-headed screw 73 is screwed into the threaded hole of the retaining ring 62, the retaining ring 62 is firmly locked on the punch seat 4, realizing the fixation of the hexagonal punch 6 in the axial direction.

[0031] An annular wedge groove 63 is formed on the outer wall of one end of the hexagonal punch 6 inserted into the punch seat 4. It is a wedge-shaped annular groove extending circumferentially along the hexagonal punch 6, and the bottom of the annular wedge groove 63 is an inclined surface. When the wedge block 74 of the double locking mechanism 7 is inserted into the annular wedge groove 63, the wedge end face of the wedge block 74 cooperates with the inclined bottom of the annular wedge groove 63 to generate an upward pushing force along the axial direction of the hexagonal punch 6, pushing the hexagonal punch 6 towards the top of the mounting groove 42, so that its upper end face tightly abuts against the lower end face of the amplitude transformer 52. This structure realizes the dual functions of radial locking and axial pushing, ensuring the efficient transmission of ultrasonic vibration energy between the hexagonal punch 6 and the amplitude transformer 52.

[0032] The double locking mechanism 7 includes several round-headed screws 73 and several wedge blocks 74. The several round-headed screws 73 are vertically threaded into the punch seat 4. The lower end of each round-headed screw 73 passes through the punch seat 4 and is threaded into the retaining ring 62. The several round-headed screws 73 together form the first positioning end. The number of wedge blocks 74 corresponds to the number of movable slots 44. Each wedge block 74 is movably disposed in the corresponding movable slot 44. One end of the wedge block 74 extends out of the movable slot 44 and is inserted into the annular wedge surface groove 63. The other end of the wedge block 74 is connected to the inner wall of the movable slot 44 through a first spring 75, and the other end of the wedge block 74 abuts against the side wall of the round head screw 73. Several wedge blocks 74 together constitute the second positioning end.

[0033] When the operator needs to install the hexagonal pendant 6, first insert the upper end of the hexagonal pendant 6 into the mounting groove 42 at the bottom of the punch seat 4, so that the upper end face of the hexagonal pendant 6 is aligned with and in contact with the lower end face of the amplitude rod 52. Then, each round-headed screw 73 is screwed into the corresponding threaded hole on the punch seat 4 in sequence. During the screwing process, the lower end of the round-headed screw 73 gradually moves downward to contact the retaining ring 62 and screws into the threaded hole of the retaining ring 62. The retaining ring 62 and the punch seat 4 are firmly locked through the threaded connection, realizing the first locking.

[0034] During the screwing of the round-headed screw 73, the sidewall of the round-headed screw 73 contacts and pushes the wedge-shaped block 74 located on the side of the outer end of the movable groove 44. Under the pushing of the round-headed screw 73, the wedge-shaped block 74 overcomes the elastic force of the first spring 75 and moves inward along the radial direction of the movable groove 44; the wedge-shaped end face of the wedge-shaped block 74 gradually extends out of the movable groove 44 and inserts into the annular wedge groove 63 on the outer wall of the hexagonal punch 6; since the bottom of the annular wedge groove 63 is inclined, the wedge-shaped block 74... During insertion, a wedge-tightening effect is generated, locking the hexagonal punch 6 radially and achieving a second locking. At the same time, as the wedge-shaped inclined surface of the wedge block 74 wedges into the annular wedge groove 63, it applies an upward axial thrust to the inclined bottom of the annular wedge groove 63. This thrust pushes the hexagonal punch 6 as a whole towards the top of the mounting groove 42, making the contact between the upper end face of the hexagonal punch 6 and the lower end face of the amplitude rod 52 tighter and eliminating the fit clearance.

[0035] When the operator needs to disassemble and replace the hexagonal pendant 6, they should reverse the rotation of each round-headed screw 73 to gradually remove it from the punch seat 4. As the round-headed screw 73 retracts upward, the pushing contact between its sidewall and the wedge block 74 gradually dissipates. The wedge block 74 loses the pushing force of the round-headed screw 73 and, under the elastic restoring force of the first spring 75, moves outward and resets itself along the radial direction of the movable groove 44. The wedge-shaped end face of the wedge block 74 exits from the annular wedge groove 63, releasing the radial locking and axial pushing of the hexagonal pendant 6. After the radial locking and axial pushing of the hexagonal pendant 6 are released, it returns to its free state, and the operator can easily pull the hexagonal pendant 6 downward from the punch seat 4 to complete the disassembly.

[0036] The piston mechanism 8 includes a piston disc 82 and two round rods 83. The piston disc 82 is movably disposed in the cooling chamber 41. The outer peripheral surface of the piston disc 82 is sealed and fitted with the inner wall of the cooling chamber 41. The top surface of the piston disc 82 is connected to the inner top wall of the cooling chamber by a compression spring 84. Two round rods 83 are symmetrically fixedly connected to the top surface of the piston disc 82. The round rods 83 extend upward into the cooling chamber 41. The upper end of the round rods 83 is inserted into the guide structure and slides in cooperation with the inner wall of the guide structure. The two round rods 83 together form the movable end. The cooling chamber 41 is divided into a water-cooled chamber 411 and an air-cooled chamber 412 by a piston disc 82. The water-cooled chamber 411 is used to contain circulating coolant, and the air-cooled chamber 412 is used to contain circulating cooling gas.

[0037] The piston disc 82 is movably disposed within the cooling chamber 41. Its outer circumference is sealed to the inner wall of the cooling chamber 41 by a sealing ring or precision fit, completely isolating the upper and lower spaces of the cooling chamber 41 so that they do not communicate with each other. The piston disc 82 divides the cooling chamber 41 into two independent chambers located above and below the piston disc 82. The chamber located above the piston disc 82 is the water-cooled chamber 411, which is used to contain circulating coolant; the chamber located below the piston disc 82 is the air-cooled chamber 412, which is used to contain circulating cooling gas, i.e., air.

[0038] Two round rods 83 are symmetrically fixed to the top surface of the piston disc 82. The rod body of the round rod 83 passes upward through the top wall of the cooling cavity 41. The upper end of the round rod 83 extends out of the cooling cavity 41 and is inserted into the guide structure on the bottom surface of the external gear control disc 9. The sliding cooperation between the round rod 83 and the guide structure converts the rotational motion of the external gear control disc 9 into the vertical reciprocating motion of the piston disc 82 in the cooling cavity 41. The two round rods 83 are symmetrically arranged to ensure that the piston disc 82 is subjected to balanced force during the movement and will not be tilted or jammed. The two round rods 83 together constitute the movable end.

[0039] Two liquid flow hoses 45 are symmetrically inserted into the outer wall of the punch seat 4. Both liquid flow hoses 45 are connected to the water cooling chamber 411 of the cooling chamber 41. Both liquid flow hoses 45 are equipped with a one-way valve. One of the liquid flow hoses 45 is the liquid inlet pipe and the other liquid flow hose 45 is the liquid outlet pipe. Two air inlets 46 are symmetrically opened on the outer wall of the punch seat 4, and both air inlets 46 are connected to the air-cooled cavity 412 of the cooling cavity 41.

[0040] Two fluid flow hoses 45 are symmetrically inserted into the outer wall of the punch seat 4, and are respectively connected to the upper and lower parts of the water-cooled cavity 411 of the cooling chamber 41, ensuring that the coolant can flow in from one side and out from the other side to form a complete circulation loop; each fluid flow hose 45 is equipped with a one-way valve. One fluid flow hose 45 is the outlet pipe, and its one-way valve only allows the coolant to flow out of the water-cooled cavity 411; the other fluid flow hose 45 is the inlet pipe, and its one-way valve only allows external coolant to flow into the water-cooled cavity 411. The one-way valve ensures that the coolant can only circulate in one direction and will not backflow.

[0041] Two air inlets 46 are symmetrically opened on the outer wall of the punch seat 4, and are connected to the upper and lower parts of the air-cooled cavity 412 of the cooling cavity 41, respectively, to ensure that external air can enter from one side and exit from the other side, forming a complete airflow circulation. The diameter of the air inlet 46 is smaller than the volume of the air-cooled cavity 412, and the gas has a higher flow rate when flowing in and out, which enhances the convective heat transfer effect.

[0042] When the piston disc 82 moves downward in the cooling chamber 41, the volume of the water-cooled chamber 411 is compressed, and the pressure of the coolant in the chamber increases. At this time, the coolant is discharged outward through the outlet pipe, and the high-temperature coolant that has absorbed heat in the water-cooled chamber 411 is transported to the external circulating cooling system for heat dissipation. At the same time, the volume of the air-cooled chamber 412 increases, and a negative pressure is formed in the chamber. Under the action of atmospheric pressure, external cold air is drawn into the air-cooled chamber 412 through the air inlet 46. During the contact process with the inner wall of the air-cooled chamber 412, the cold air absorbs the heat around the mounting groove 42, and stores the cold capacity for the next compression and exhaust.

[0043] When the piston disc 82 moves upward in the cooling chamber 41 under the action of the compression spring 84, the volume of the water-cooling chamber 411 increases, and a negative pressure is formed inside the chamber. At this time, the external low-temperature coolant is drawn into the water-cooling chamber 411 through the inlet pipe. When the low-temperature coolant flows through the water-cooling chamber 411, it absorbs the heat generated by the ultrasonic vibration generating component 5 and the molding process, and reserves the heat absorption capacity for the next compression and discharge. At the same time, the volume of the air-cooling chamber 412 is compressed, the gas pressure inside the chamber increases, and the gas is discharged out at high speed through the air inlet 46, carrying the heat absorbed earlier out of the air-cooling chamber 412, completing one air-cooling cycle.

[0044] An external gear ring is provided on the upper outer wall of the external gear control disk 9, and the external gear ring meshes with the transmission gear 10; The guide structure is an annular wave-shaped groove 92 opened on the bottom surface of the external gear control disk 9. The annular wave-shaped groove 92 extends along the circumference of the external gear control disk 9, and the bottom depth of the annular wave-shaped groove 92 varies in a wave-like manner along the circumference. The upper end of the round rod 83 is inserted into the annular wavy groove 92, and the upper end of the round rod 83 slides in contact with the inner wall of the annular wavy groove 92.

[0045] The external gear control disk 9 is an annular disk with an external gear ring on its upper outer wall. The external gear ring meshes with two transmission gears 10 simultaneously. The two transmission gears 10 are symmetrically arranged on both sides of the external gear control disk 9. When the transmission gears 10 rotate, they drive the external gear control disk 9 to rotate around its own axis through gear meshing. The symmetrical arrangement of the two transmission gears 10 ensures that the external gear control disk 9 will not generate an eccentric torque when subjected to force.

[0046] The guide structure is an annular wavy groove 92 opened on the bottom surface of the external gear control disk 9. The annular wavy groove 92 surrounds the circumference of the external gear control disk 9. The bottom depth of the annular wavy groove 92 varies in a wavy manner along the circumference, with alternating "peak" and "trough" sections. The upper end of the round rod 83 is inserted into the annular wavy groove 92, and the upper end face of the round rod 83 slides in contact with the inner wall of the annular wavy groove 92.

[0047] When the external gear control disk 9 rotates under the drive of the transmission gear 10, the annular wave groove 92 rotates together with the external gear control disk 9, and the "crest" and "trough" sections of the annular wave groove 92 alternately pass through the upper end of the round rod 83.

[0048] When the "crest" section rotates to align with the round rod 83, the shallower groove bottom of the "crest" section pushes the round rod 83 downward. The round rod 83 drives the piston disc 82 to move downward in the cooling chamber 41. When the piston disc 82 moves downward, the volume of the water-cooled chamber 411 is compressed, and the pressure of the coolant in the chamber increases, so as to cause the coolant to be discharged outward through the outlet pipe. At the same time, the volume of the air-cooled chamber 412 increases, and a negative pressure is formed in the chamber. External cold air is drawn into the air-cooled chamber 412 through the air inlet 46, completing the exhaust and intake.

[0049] When the "trough" section rotates to align with the round rod 83, the deeper groove bottom of the "trough" section allows the round rod 83 to move upward. Under the action of the compression spring 84, the piston disc 82 moves upward. When the piston disc 82 moves upward, the volume of the water-cooled cavity 411 increases, and a negative pressure is formed inside the cavity. At this time, the external low-temperature coolant is drawn into the water-cooled cavity 411 through the liquid inlet pipe, completing the liquid intake. At the same time, the volume of the air-cooled cavity 412 is compressed, the gas pressure inside the cavity increases, and the gas is discharged out at high speed through the air inlet 46, carrying heat out of the air-cooled cavity 412, completing the exhaust.

[0050] As the external gear control disc 9 continues to rotate, the piston disc 82 continues to reciprocate within the cooling chamber 41. The coolant and gas continuously circulate within the water-cooled chamber 411 and the air-cooled chamber 412, constantly carrying away the heat generated by the ultrasonic vibration generating component 5 and the hexagonal punch 6, thus achieving efficient cooling and protection for the ultrasonic system.

[0051] Two protective covers 47 are symmetrically fixed to the outer wall of the punch seat 4, and the two protective covers 47 are placed on the outside of the corresponding transmission gear 10. The transmission gear 10 has a through hole 101 through its center for the guide rod 20 to pass through, and a guide block 102 is fixedly connected to the inner wall of the through hole 101. The guide rod 20 is movably inserted into the through hole 101. The outer wall of the guide rod 20 is provided with a spiral groove 201. The guide block 102 is slidably embedded in the spiral groove 201 and slides in cooperation with the inner wall of the spiral groove 201.

[0052] Two protective covers 47 are symmetrically fixed to the outer wall of the punch seat 4, covering the corresponding transmission gears 10. The protective covers 47 isolate the transmission gears 10 from the external environment, preventing metal chips, dust and coolant generated during cold heading from entering the gear meshing area, causing jamming or wear, thus ensuring the smoothness and service life of the gear transmission. The protective covers 47 can be filled with grease to maintain good lubrication of the gear pair.

[0053] A through hole 101 is formed in the center of the transmission gear 10 to accommodate the guide rod 20. A guide block 102, which is fixedly connected to the inner wall of the through hole 101, is a cylindrical pin or rectangular block protruding towards the center of the through hole 101. The guide rod 20 is movably inserted into the through hole 101 and can generate relative vertical movement with the punch seat 4. A spiral groove 201 is formed on the outer wall of the guide rod 20 and extends spirally along the circumference of the guide rod 20. The guide block 102 is embedded in the spiral groove 201, and the outer peripheral surface of the guide block 102 slides with the inner wall of the spiral groove 201 to form a spiral transmission pair.

[0054] When the punch seat 4 moves up and down in the vertical direction with the cylinder 3, the punch seat 4 drives the transmission gear 10 to move together in the vertical direction. Since the upper end of the guide rod 20 is fixedly connected to the cold heading machine frame 1, the guide rod 20 remains stationary. The transmission gear 10 moves in the vertical direction with the punch seat 4 relative to the guide rod 20, and the guide rod 20 slides relative to the through hole 101 of the transmission gear 10.

[0055] The guide block 102 is fixed to the inner wall of the through hole 101 of the transmission gear 10 and moves vertically relative to the guide rod 20 along with the transmission gear 10. The guide block 102 slides relative to the guide rod 20 along a spiral trajectory in the spiral groove 201 on the outer wall of the guide rod 20. Since the extension direction of the spiral groove 201 is at an angle to the axial direction of the guide rod 20, the spiral sidewall of the spiral groove 201 applies a circumferential pushing force to the guide block 102. This circumferential force drives the transmission gear 10 to rotate around its own axis through the guide block 102.

[0056] When the punch seat 4 moves downward, the transmission gear 10 moves downward along the guide rod 20, and the spiral groove 201 drives the transmission gear 10 to rotate in one direction; when the punch seat 4 moves upward, the transmission gear 10 moves upward along the guide rod 20, and the spiral groove 201 drives the transmission gear 10 to rotate in the opposite direction. Each up and down movement of the punch seat 4 causes the transmission gear 10 to rotate in the corresponding direction and angle, converting the linear reciprocating motion of the cylinder 3 into the rotational motion of the transmission gear 10. The transmission gear 10 drives the external gear control disk 9 to rotate through meshing, and then drives the piston mechanism 8 to reciprocate in the cooling chamber 41 through the annular wave groove 92, realizing the pure mechanical linkage between the punching stroke and the cooling cycle of the punch seat 4.

[0057] In summary: The automatic feeding mechanism set on the front side of the cold heading machine frame 1, such as a rotary feeder or a clamp-type feeding arm, automatically picks up the screw blank to be processed according to the working rhythm of the cold heading machine and transports it to the top of the mold base 2 for release. Then, the extended end of the cylinder 3 drives the punch base 4 to move downward at high speed in the vertical direction.

[0058] An ultrasonic vibration generating component 5, fixedly installed inside the punch holder 4, generates longitudinal ultrasonic vibration. This vibration is transmitted through the amplitude transformer at the lower end to the hexagonal punch 6, which directly contacts the punch. This causes the punch to generate high-frequency longitudinal ultrasonic vibration when it contacts the blank. Due to the "surface effect" of ultrasonic vibration, the coefficient of friction between the blank and the surface of the punch cavity is reduced. At the same time, the "volume effect" of ultrasonic vibration reduces the flow stress of the metal material and improves the fluidity of the blank metal. Under the synergistic effect of these two effects, the blank metal can be more easily squeezed into the micro-grooves of the hexagonal cavity, significantly improving the filling fullness and forming quality of the micro-features and reducing the direct adhesion of the metal to the cavity surface.

[0059] The punch position sensor is used to detect in real time whether the hexagonal punch 6 enters or leaves the contact area with the billet, and is electrically connected to the ultrasonic transducer 51. When the punch position sensor detects that the hexagonal punch 6 enters the contact area with the billet, it automatically controls the ultrasonic vibration to start. When it detects that the punch has left the billet, it automatically stops the ultrasonic vibration, so as to achieve precise control of ultrasonic vibration and avoid energy waste caused by long-term operation of ultrasonic vibration.

[0060] The double locking mechanism 7 forms a first positioning end through the threaded connection between the round-headed screw 73 and the retaining ring 62, and forms a second positioning end through the movable connection between the wedge block 74 and the annular wedge groove 63. The first positioning end firmly locks the retaining ring 62 onto the punch seat 4, and the second positioning end radially locks the upper end of the hexagonal pendant 6. At the same time, as the wedge block 74 is pushed into the annular wedge groove 63, it uses the wedge-shaped inclined surface to push the hexagonal pendant 6 towards the top of the mounting groove 42, so that the upper end face of the hexagonal pendant 6 always closely contacts the lower end face of the amplitude transformer 52, ensuring the accurate transmission of ultrasonic vibration energy and eliminating vibration energy loss caused by the fit gap.

[0061] While the hexagonal punch 6 is cold heading the blank, the up-and-down movement of the punch seat 4 also drives the automatic operation of the cooling system. When the punch seat 4 moves up and down vertically with the cylinder 3, the upper end of the guide rod 20 is fixedly connected to the cold heading machine frame 1, so the guide rod 20 remains stationary. The punch seat 4 moves relative to the guide rod 20. The transmission gear 10 moves with the punch seat 4. The spiral groove 201 on the guide rod 20 pushes the guide block 102 in the inner hole of the transmission gear 10 to generate a circumferential force, driving the transmission gear 10 to rotate around its own axis. The transmission gear 10 drives the external gear control disk 9 to rotate through meshing. The annular wave groove 92 on the bottom surface of the external gear control disk 9 rotates with the external gear control disk 9. The undulation of the groove bottom pushes the upper end of the round rod 83, driving the piston mechanism 8 to make vertical reciprocating motion in the cooling chamber 41.

[0062] As the piston disc 82 moves up and down, the volumes of the water-cooled chamber 411 and the air-cooled chamber 412 change alternately. The negative pressure and high pressure generated are used to draw in and discharge the external coolant, as well as to draw in and discharge the external air. A continuous coolant circulation and air-cooling circulation are formed inside the punch seat 4. The coolant flows through the cooling chamber 41 around the mounting groove 42, continuously absorbing and carrying away the heat generated by the ultrasonic vibration generating component 5 and the hexagonal punch 6 during the forming process. The air-cooling circulation draws external cold air into the air-cooled chamber 412. After absorbing heat, the air is compressed and discharged, carrying away the heat generated by the ultrasonic transducer 51 and the high-frequency vibration component.

[0063] To better demonstrate a precision forming mold device for fast-acting composite screws, this embodiment proposes a machining method for precision forming of fast-acting composite screws, including the following steps: S1. Punch installation and locking: Insert the upper end of the hexagonal punch 6 into the mounting groove 42 at the bottom of the punch seat 4, so that the upper end face of the hexagonal punch 6 abuts against the lower end of the ultrasonic vibration generating component 5; screw in each round-headed screw 73, and achieve the first locking by the threaded connection between the round-headed screw 73 and the retaining ring 62. At the same time, the side wall of the round-headed screw 73 pushes the wedge block 74 to move inward along the movable groove 44. The end of the wedge block 74 is inserted into the annular wedge surface groove 63 to achieve the second locking. And through the cooperation of the wedge surface, push the hexagonal punch 6 towards the top of the mounting groove 42, so that its upper end face abuts tightly against the ultrasonic vibration generating component 5. S2. Blank conveying: When the cold heading machine starts its working cycle, the automatic feeding mechanism automatically picks up the screw blank to be processed and conveys it to the top of the mold base 2 and releases it according to the working rhythm of the cold heading machine. S3. Cold heading and ultrasonic-assisted linkage: The extended end of cylinder 3 drives punch seat 4 to move downward at high speed in the vertical direction. The punch position sensor detects the end face position of the hexagonal punch 6 in real time. When the punch position sensor detects that the hexagonal punch 6 has entered the blank contact area, it sends a trigger signal to the control system. The ultrasonic generator is automatically turned on, driving the ultrasonic transducer 51 to generate longitudinal ultrasonic vibration. The amplitude is amplified by the amplitude transformer 52 and then transmitted to the hexagonal punch 6. The hexagonal punch 6 performs cold heading on the blank with the assistance of longitudinal ultrasonic vibration. The "surface effect" of ultrasonic vibration reduces the friction coefficient between the blank and the surface of the punch cavity. The "volume effect" of ultrasonic vibration reduces the flow stress of the blank metal and improves the filling fullness of the fine features of the hexagonal punch. S4, Cooling Circulation Linkage: While the punch seat 4 moves up and down in the vertical direction, the spiral groove 201 on the guide rod 20 pushes the guide block 102 in the inner hole of the transmission gear 10 to generate a circumferential force, driving the transmission gear 10 to rotate around its own axis; the transmission gear 10 drives the external gear control disk 9 to rotate through meshing; the annular wave groove 92 on the bottom surface of the external gear control disk 9 rotates together with the external gear control disk 9, and pushes the upper end of the round rod 83 through the undulation of the groove bottom, driving the piston disk 82 to make vertical reciprocating motion in the cooling chamber 41, alternately compressing and sucking the coolant and gas in the water-cooled chamber 411 and the air-cooled chamber 412, forming a continuous coolant circulation and air-cooling circulation inside the punch seat 4 to cool the ultrasonic vibration generating component 5 and the hexagonal punch 6; S5. Demolding and Ultrasonic Stop: After cold heading is completed, the extended end of cylinder 3 drives punch seat 4 to rise upward, and the hexagonal punch 6 exits from the formed part; when the punch position sensor detects that the hexagonal punch 6 has left the blank contact area, it sends a stop signal to the control system, and the ultrasonic generator automatically stops ultrasonic output. S6. Punch Disassembly and Replacement: When it is necessary to replace the hexagonal punch 6, turn each round-headed screw 73 in the opposite direction to gradually unscrew it from the punch seat 4. The side wall of the round-headed screw 73 will disengage from the wedge block 74. Under the elastic restoring force of the first spring 75, the wedge block 74 will reset outward along the movable groove 44. The end of the wedge block 74 will exit from the annular wedge groove 63, and the hexagonal punch 6 will be unlocked. Remove the old punch from the punch seat 4 and replace it with a new punch. Repeat step S1 to complete the installation and locking of the new punch.

[0064] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A precision forming die device for fast-acting composite screws, comprising a cold heading machine frame (1), characterized in that: The bottom of the cold heading machine frame (1) is fixedly connected to a mold base (2), and a cylinder (3) is fixedly installed on the upper part of the cold heading machine frame (1). A punch seat (4) is fixedly installed on the extended end of the cylinder (3). The punch seat (4) can move up and down in the vertical direction under the drive of the cylinder (3). An ultrasonic vibration generating component (5) is fixedly installed inside the punch seat (4). The ultrasonic vibration generating component (5) is used to generate longitudinal ultrasonic vibration. The inner bottom of the punch seat (4) is detachably fitted with a hexagonal punch (6). The upper end of the hexagonal punch (6) abuts against the lower end of the ultrasonic vibration generating component (5). The ultrasonic vibration generating component (5) is used to transmit longitudinal ultrasonic vibration to the hexagonal punch (6). The lower end of the punch seat (4) is provided with a double locking mechanism (7). The double locking mechanism (7) has a first positioning end and a second positioning end. The first positioning end is threaded into the hexagonal punch (6), and the second positioning end is movably inserted into one end of the hexagonal punch (6) inserted into the punch seat (4). The double locking mechanism (7) is used to double lock the hexagonal punch (6) in the punch seat (4) and make it always in contact with the ultrasonic vibration generating component (5). The punch seat (4) has a cooling chamber (41) inside. A piston mechanism (8) is movably arranged in the cooling chamber (41). The piston mechanism (8) is used to reciprocate in the cooling chamber (41) to drive the coolant and gas to circulate. The piston mechanism (8) has a movable end that extends upward out of the cooling chamber (41). The punch seat (4) is rotatably equipped with an external gear control disk (9). The bottom surface of the external gear control disk (9) is provided with a guide structure. The movable end of the piston mechanism (8) extends into the guide structure and slides in cooperation with the inner wall of the guide structure. Two transmission gears (10) are symmetrically arranged on the outer wall of the punch seat (4). Both transmission gears (10) extend into the punch seat (4) and mesh with the external gear control disk (9). Each transmission gear (10) has a guide rod (20) movably inserted into its inner hole. The guide rod (20) is used to drive the transmission gear (10) to rotate when the punch seat (4) moves up and down. The upper ends of the two guide rods (20) are fixedly connected to the cold heading machine frame (1).

2. The precision forming die device for quick-acting composite screws according to claim 1, characterized in that: The bottom of the punch seat (4) is recessed upward and has an installation groove (42), and the ultrasonic vibration generating component (5) is fixedly installed in the installation groove (42); The inner sidewall of the upper end of the mounting groove (42) is provided with a gear receiving groove (43), and the external gear control disk (9) is rotatably disposed in the gear receiving groove (43); The inner wall of the lower end of the mounting groove (42) is provided with a number of movable grooves (44), each movable groove (44) extends radially along the punch seat (4), and the second positioning end of the double locking mechanism (7) is movably set in the corresponding movable groove (44).

3. The precision forming die device for fast-acting composite screws according to claim 2, characterized in that: The ultrasonic vibration generating assembly (5) includes an ultrasonic transducer (51) and an amplitude transformer (52). The ultrasonic transducer (51) is fixedly installed on the inner top wall of the mounting groove (42). The upper end of the amplitude transformer (52) is threadedly connected to the radiation surface of the ultrasonic transducer (51). A flange (53) is provided at the vibration node position of the amplitude transformer (52). The flange (53) is fixedly installed on the inner side wall of the mounting groove (42). The flange (53) is used to fix the amplitude transformer (52) in the punch seat (4). The lower end of the amplitude rod (52) abuts against the upper end of the hexagonal punch (6). The amplitude rod (52) is used to amplify the longitudinal ultrasonic vibration generated by the ultrasonic transducer (51) and transmit it to the hexagonal punch (6).

4. The precision forming die device for quick-acting composite screws according to claim 2, characterized in that: A punch position sensor is fixedly installed at the bottom of the punch holder (4). The punch position sensor is used to detect whether the hexagonal punch (6) enters or leaves the contact area with the blank. The punch position sensor is electrically connected to the ultrasonic transducer (51). The outer wall of the hexagonal punch (6) is fixedly fitted with a retaining ring (62), which is used to be threaded into the first positioning end of the double locking mechanism (7). The outer wall of the end of the hexagonal punch (6) inserted into the punch seat (4) is provided with an annular wedge groove (63), which is used to be movably inserted into the second positioning end of the double locking mechanism (7).

5. The precision forming die device for quick-acting composite screws according to claim 4, characterized in that: The dual locking mechanism (7) includes several round-headed screws (73) and several wedge blocks (74). Several round-headed screws (73) are vertically threaded into the punch seat (4). The lower end of each round-headed screw (73) passes through the punch seat (4) and is threaded into the retaining ring (62). Several round-headed screws (73) together form the first positioning end. The number of wedge blocks (74) corresponds to the number of movable slots (44). Each wedge block (74) is movably set in the corresponding movable slot (44). One end of the wedge block (74) extends out of the movable slot (44) and is inserted into the annular wedge surface groove (63). The other end of the wedge block (74) is connected to the inner wall of the movable slot (44) by a first spring (75), and the other end of the wedge block (74) abuts against the side wall of the round head screw (73). Several wedge blocks (74) together constitute the second positioning end.

6. The precision forming die device for fast-acting composite screws according to claim 2, characterized in that: The piston mechanism (8) includes a piston disc (82) and two round rods (83). The piston disc (82) is movably disposed in the cooling chamber (41). The outer circumferential surface of the piston disc (82) is sealed and fitted with the inner wall of the cooling chamber (41). The top surface of the piston disc (82) is connected to the inner top wall of the cooling chamber by a compression spring (84). Two round rods (83) are symmetrically fixed to the top surface of the piston disc (82). The round rods (83) extend upward into the cooling chamber (41). The upper end of the round rods (83) is inserted into the guide structure and slides in cooperation with the inner wall of the guide structure. The two round rods (83) together form the movable end. The cooling chamber (41) is divided into a water-cooled chamber (411) and an air-cooled chamber (412) by a piston disc (82). The water-cooled chamber (411) is used to contain circulating coolant, and the air-cooled chamber (412) is used to contain circulating cooling gas.

7. The precision forming die device for quick-acting composite screws according to claim 6, characterized in that: Two liquid flow hoses (45) are symmetrically inserted into the outer wall of the punch seat (4). Both liquid flow hoses (45) are connected to the water cooling chamber (411) of the cooling chamber (41). Both liquid flow hoses (45) are equipped with one-way valves. One liquid flow hose (45) is the liquid inlet pipe, and the other liquid flow hose (45) is the liquid outlet pipe. The outer wall of the punch seat (4) has two symmetrical air inlets (46), and both air inlets (46) are connected to the air-cooled cavity (412) of the cooling cavity (41).

8. The precision forming die device for quick-acting composite screws according to claim 6, characterized in that: An external gear ring is provided on the upper outer wall of the external gear control disk (9), and the external gear ring meshes with the transmission gear (10); The guide structure is an annular wave-shaped groove (92) opened on the bottom surface of the external gear control disk (9). The annular wave-shaped groove (92) extends along the circumference of the external gear control disk (9), and the bottom depth of the annular wave-shaped groove (92) varies in a wave-like manner along the circumference. The upper end of the round rod (83) is inserted into the annular wavy groove (92), and the upper end of the round rod (83) slides in contact with the inner wall of the annular wavy groove (92).

9. The precision forming die device for quick-acting composite screws according to claim 2, characterized in that: The outer wall of the punch seat (4) is symmetrically fixed with two protective covers (47), and the two protective covers (47) are placed on the outside of the corresponding transmission gear (10). The transmission gear (10) has a through hole (101) through its center for the guide rod (20) to pass through, and a guide block (102) is fixedly connected to the inner wall of the through hole (101). The guide rod (20) is movably inserted into the through hole (101). The outer wall of the guide rod (20) is provided with a spiral groove (201). The guide block (102) is slidably embedded in the spiral groove (201) and slides in cooperation with the inner wall of the spiral groove (201).

10. A machining method for precision forming of quick-acting composite screws, comprising the quick-acting composite screw precision forming mold apparatus as described in any one of claims 1-9, characterized in that, It also includes the following steps: S1. Punch installation and locking: Insert the upper end of the hexagonal punch (6) into the mounting groove (42) at the bottom of the punch seat (4), so that the upper end face of the hexagonal punch (6) abuts against the lower end of the ultrasonic vibration generating component (5); screw in each round head screw (73), and achieve the first locking by the threaded connection between the round head screw (73) and the retaining ring (62). At the same time, the side wall of the round head screw (73) pushes the wedge block (74) to move inward along the movable groove (44), and the end of the wedge block (74) is inserted into the annular wedge surface groove (63) to achieve the second locking. Through the cooperation of the wedge surface, the hexagonal punch (6) is pushed towards the top of the mounting groove (42), so that its upper end face abuts against the ultrasonic vibration generating component (5). S2, blank conveying: When the cold heading machine starts its working cycle, the automatic feeding mechanism automatically picks up the screw blank to be processed and conveys it to the top of the mold base (2) and releases it according to the working rhythm of the cold heading machine; S3, Cold heading and ultrasonic-assisted linkage: The extended end of the cylinder (3) drives the punch seat (4) to move downward at high speed in the vertical direction. The punch position sensor detects the end face position of the hexagonal punch (6) in real time. When the punch position sensor detects that the hexagonal punch (6) enters the blank contact area, it sends a trigger signal to the control system. The ultrasonic generator is automatically turned on and drives the ultrasonic transducer (51) to generate longitudinal ultrasonic vibration. After the amplitude is amplified by the amplitude transformer (52), it is transmitted to the hexagonal punch (6). The hexagonal punch (6) performs cold heading on the blank with the assistance of longitudinal ultrasonic vibration. The "surface effect" of ultrasonic vibration reduces the friction coefficient between the blank and the surface of the punch cavity. The "volume effect" of ultrasonic vibration reduces the flow stress of the blank metal and improves the filling fullness of the hexagonal micro-features. S4, Cooling Circulation Linkage: While the punch seat (4) moves up and down in the vertical direction, the spiral groove (201) on the guide rod (20) pushes the guide block (102) in the inner hole of the transmission gear (10) to generate a circumferential force, driving the transmission gear (10) to rotate around its own axis; the transmission gear (10) drives the external gear control disk (9) to rotate through meshing; the annular wave groove (92) on the bottom surface of the external gear control disk (9) rotates together with the external gear control disk (9), and pushes the upper end of the round rod (83) through the undulation of the bottom of the groove, driving the piston disk (82) to make vertical reciprocating motion in the cooling chamber (41), alternately compressing and sucking the coolant and gas in the water cooling chamber (411) and the air cooling chamber (412), forming a continuous coolant circulation and air cooling circulation inside the punch seat (4) to cool the ultrasonic vibration generating component (5) and the plum blossom hexagonal punch (6); S5, Demolding and Ultrasonic Stop: After the cold heading is completed, the extended end of the cylinder (3) drives the punch seat (4) to rise upward, and the hexagonal punch (6) exits from the formed part; when the punch position sensor detects that the hexagonal punch (6) has left the blank contact area, it sends a stop signal to the control system, and the ultrasonic generator automatically stops ultrasonic output; S6. Punch Disassembly and Replacement: When it is necessary to replace the hexagonal punch (6), turn each round-headed screw (73) in the opposite direction so that it gradually comes out of the punch seat (4). The side wall of the round-headed screw (73) is disengaged from the wedge block (74). Under the elastic restoring force of the first spring (75), the wedge block (74) is reset outward along the movable groove (44). The end of the wedge block (74) is removed from the annular wedge groove (63). The hexagonal punch (6) is unlocked. Remove the old punch from the punch seat (4) and replace it with a new punch. Repeat step S1 to complete the installation and locking of the new punch.

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