A self-lubricating device and method for the cavity surface of a hexagonal complex precision forming die

Abstract

The application discloses a type cavity surface self-lubricating device and method of a hexagonal complex precision forming die, relates to the technical field of cold heading forming dies, and comprises a die base body, a type cavity is arranged in the top of the die base body and recessed downward, a one-way double grease storage groove is arranged in the inside of the die base body, the one-way double grease storage groove is communicated with the type cavity through a plurality of capillary micro-holes, a piston mechanism is movably arranged in the one-way double grease storage groove, and the piston mechanism is provided with a guide end. The application utilizes the reset action of the elastic ejection rod during the stamping return of the cold heading machine, converts linear motion into one-way rotary motion through the cooperation of the spiral groove and the one-way bearing, drives the piston pumping action triggered after the accumulated rotation of the inner tooth control disc and the inner tooth control disc, realizes the intermittent micro-grease supply to the type cavity wall, and the whole process does not need external electrical control or independent grease pump, and the functions of force accumulation during return and grease supply during multiple stamping are realized.

Description

Technical Field

[0001] This invention relates to the field of cold heading mold technology, and in particular to a self-lubricating device and method for the cavity surface of a plum blossom hexagonal composite precision forming mold. Background Technology

[0002] The Torx hexagonal composite precision forming mold is used for cold heading of screw heads. Its cavity has fine features such as Torx groove edges and hexagonal sharp edges. During the high pressure forming process, there is a great friction and contact stress between the cavity wall and the metal blank, which requires extremely high lubrication conditions on the cavity surface. Therefore, it is necessary to use a lubricating medium to continuously lubricate the inner wall of the cavity.

[0003] Existing mold cavity lubrication devices typically supply lubricating media through external spraying or pre-coating. The supply of lubricating media is separate from the molding action, which cannot achieve real-time and continuous lubrication of the cavity surface during the molding process. Furthermore, external spraying solutions require independent grease pumps, nozzles, and piping systems, resulting in complex structures and high manufacturing costs. Summary of the Invention

[0004] To improve the lubrication of the mold cavity lubrication device mentioned above, the lubricating medium is usually supplied by external spraying or pre-coating. The supply of lubricating medium is separated from the molding action, which cannot achieve real-time and continuous lubrication of the cavity surface during the molding process. In addition, the external spraying solution requires the configuration of an independent grease pump, nozzle and pipeline system, which is complex in structure and has high manufacturing cost.

[0005] This invention provides a self-lubricating device and method for the cavity surface of a plum blossom hexagonal composite precision molding die, employing the following technical solution: A self-lubricating device for the cavity surface of a plum blossom hexagonal composite precision molding die includes a mold base. The top of the mold base is recessed to form a cavity. A one-way double grease reservoir is formed inside the mold base. The one-way double grease reservoir is connected to the cavity through a number of capillary micropores. A piston mechanism is movably arranged inside the one-way double grease reservoir. The piston mechanism has a guide end that extends downward out of the one-way double grease reservoir. The bottom of the mold base is provided with an installation groove. A one-way transmission mechanism is rotatably installed in the installation groove, and an internal gear control disc is rotatably installed on the inner wall of the installation groove. The internal gear control disc meshes with the one-way transmission mechanism. The top surface of the internal gear control disc is recessed downward and provided with an annular guide groove. The guide end of the piston mechanism passes downward through the one-way double grease reservoir and is inserted into the annular guide groove. The guide end slides in cooperation with the inner wall of the annular guide groove. An elastic ejector rod is movably inserted into the inner bottom wall of the cavity. The lower end of the elastic ejector rod passes downward through the one-way transmission mechanism and extends out of the mold base. The elastic ejector rod has a guide structure, which slides in conjunction with the one-way transmission mechanism.

[0006] Optionally, in the above-mentioned self-lubricating device for the cavity surface of a plum blossom hexagonal composite precision molding die, the unidirectional dual grease reservoir includes a first grease reservoir and a second grease reservoir. The first grease reservoir and the second grease reservoir are both annular in shape and are both opened inside the mold base and surround the outer periphery of the cavity. The second grease reservoir is located above the first grease reservoir and is connected to the inner wall of the cavity through capillary micropores. The first grease reservoir and the second grease reservoir are connected by a one-way liquid guide pipe. A one-way valve is installed in the one-way liquid guide pipe. The one-way valve only allows graphite grease to flow from the first grease reservoir to the second grease reservoir. The piston mechanism is movably disposed in the first grease reservoir. The piston mechanism is used to pump the graphite grease in the first grease reservoir to the second grease reservoir through the one-way liquid guide pipe. The first grease reservoir is connected to an external graphite grease storage device via a one-way grease supply pipeline. The external graphite grease storage device is used to continuously replenish the first grease reservoir with graphite grease.

[0007] Optionally, in the above-mentioned self-lubricating device for the cavity surface of a plum blossom hexagonal composite precision molding die, the piston mechanism includes an annular piston disc, the annular piston disc is movably disposed in a first grease reservoir, and the outer circumferential surface of the annular piston disc is sealed and fitted with the inner wall of the first grease reservoir. Two guide rods are fixedly connected to the bottom surface of the annular piston disk. The two guide rods are symmetrically arranged along the circumference of the annular piston disk, and the two guide rods together form the guide end.

[0008] Optionally, in the above-mentioned self-lubricating device for the cavity surface of a plum blossom hexagonal composite precision molding die, the guide rod includes a vertical rod and a round rod. The upper end of the vertical rod is fixedly connected to the bottom surface of the annular piston disc, and the lower end of the vertical rod passes downward through the bottom wall of the first grease reservoir and is inserted into the annular guide groove. The round rod is fixedly connected to the lower end of the vertical rod, and the round rod extends in a direction perpendicular to the vertical rod. The end of the round rod slides in fit with the inner wall of the annular guide groove.

[0009] Optionally, in the above-mentioned self-lubricating device for the cavity surface of a plum blossom hexagonal composite precision molding die, the one-way transmission mechanism includes a one-way bearing, a first gear and a second gear, and the one-way bearing and the second gear are both vertically rotatably arranged in the mounting groove; The first gear is fixedly sleeved on the outer ring of the one-way bearing, and the second gear is located between the internal gear control disc and the first gear. The second gear meshes with the internal teeth of the internal gear control disc and the first gear respectively. The inner ring of the one-way bearing is fixedly connected to a guide block, and the elastic ejector rod is movably inserted into the inner ring of the one-way bearing. The guide structure on the elastic ejector rod is in sliding fit with the guide block.

[0010] Optionally, in the above-mentioned self-lubricating device for the cavity surface of a plum blossom hexagonal composite precision molding die, the annular guide groove includes an annular vertical groove and an annular sliding groove. The annular vertical groove is a circular annular groove opened on the top surface of the internal gear control disc, and the groove width of the annular vertical groove is adapted to the diameter of the vertical rod. The annular groove is formed on the inner bottom wall of the annular vertical groove. The annular groove extends circumferentially along the internal gear control disc, and the width of the annular groove is greater than the width of the annular vertical groove. The bottom depth of the annular groove is non-uniformly set along the circumferential direction, and the annular groove has at least two protrusions with shallow bottom depths.

[0011] Optionally, in the above-mentioned self-lubricating device for the cavity surface of a hexagonal composite precision molding die, the lower end of the vertical rod passes through the bottom wall of the first grease reservoir and is inserted into the annular vertical groove. The outer wall of the vertical rod is in sliding fit with the inner wall of the annular vertical groove. The two ends of the round rod extend out of the outer wall of the vertical rod and are located in the annular sliding groove. The end of the round rod is in sliding fit with the inner wall of the annular sliding groove.

[0012] Optionally, in the above-mentioned self-lubricating device for the cavity surface of a plum blossom hexagonal composite precision molding die, the elastic ejector rod includes a push plate and an ejector rod, the push plate is movably disposed on the inner bottom wall of the cavity, and the upper surface of the push plate is used to directly contact the workpiece; The upper end of the push rod is fixedly connected to the center of the bottom surface of the push plate. The rod body of the push rod passes through the bottom wall of the cavity and the inner ring of the one-way bearing in sequence and then extends out of the mold base. The lower end of the push rod is fixedly connected to a fixing plate. A return spring is fixedly connected between the upper surface of the fixed plate and the bottom surface of the mold base. The return spring is used to push the fixed plate and the ejector rod upward to reset after the stamping pressure is released. The outer wall of the top rod is provided with a spiral groove, and the guide block is slidably embedded in the spiral groove. The cooperation between the spiral groove and the guide block constitutes a guide structure. Several striking rods are fixedly connected to the side of the fixed plate facing the mold base. The upper ends of the striking rods alternately contact and detach from the bottom surface of the mold base when the fixed plate moves up and down with the elastic ejector rod, so as to generate intermittent striking vibrations on the mold base.

[0013] Optionally, in the above-mentioned self-lubricating device for the cavity surface of a plum blossom hexagonal composite precision molding die, a sealing cover is fixedly connected to the bottom surface of the die base. The sealing cover is coaxially arranged with the fixed plate and the sealing cover is placed outside the fixed plate and the striking rod. The outer peripheral surface of the fixed plate slides against the inner wall of the sealing cover. The sealing cover is used to prevent external debris from entering the connection part between the one-way transmission mechanism and the elastic ejection rod.

[0014] Another technical solution proposed in this invention: a method for self-lubricating the cavity surface of a hexagonal composite precision molding die, comprising the following steps: S1. Filling the lubricating medium: Graphite grease is replenished to the first grease tank in one direction through an external graphite grease storage device. Under the action of the initial pressure difference, the graphite grease in the graphite grease storage device enters the second grease tank through the one-way grease supply pipeline and one-way valve. Under the action of pressure, some graphite grease seeps out through the capillary micropores to the inner wall surface of the cavity, completing the initial pre-filling of the lubricating medium. S2. Workpiece Placement and Stamping: The workpiece to be formed is placed into the cavity, with the bottom of the workpiece contacting the upper surface of the push plate; the punch of the external stamping equipment moves downward to stamp the workpiece in the cavity. Under the stamping pressure, the workpiece pushes the push plate and the ejector rod downward. The ejector rod drives the one-way bearing to rotate in the free rotation direction through the spiral groove. The internal gear control plate remains stationary, and the piston mechanism is in a low-position standby state in the first grease reservoir; during the stamping process, the return spring is compressed and accumulates elastic potential energy. S3, Return stroke and grease supply trigger: The punch of the external stamping equipment returns upward, the pressure of the workpiece on the push plate is released, and the elastic restoring force of the return spring pushes the fixed plate, the push rod and the push plate to return upward. The push plate pushes the formed workpiece upward from the cavity; at the same time, when the push rod returns upward, it drives the one-way bearing to rotate in the locking direction through the spiral groove. The one-way bearing drives the internal gear control disc to rotate by a preset angle through the first gear and the second gear. S4. Intermittent Grease Supply: Repeat steps S2 to S3 multiple times. After the internal gear control disc has rotated a certain angle, the protrusion of the annular groove rotates to the position where it coincides with the round rod. The shallow bottom of the protrusion pushes the round rod upward, which in turn drives the annular piston disc to move upward through the vertical rod. This pumps the graphite grease in the first grease reservoir to the second grease reservoir through the one-way guide tube, and then it seeps out through the capillary micropores to the inner wall surface of the cavity, completing one pulse supply of graphite grease. After the protrusion continues to rotate away from the coincident position with the internal gear control disc, the annular piston disc returns to its original position and waits for the next pumping. S5. Vibration promotes seepage: When the elastic ejector rod moves up and down in steps S2 and S3, the striking rod moves together with the fixed plate, intermittently striking the bottom surface of the mold base to generate mechanical vibration. The vibration energy is transmitted to the cavity and the unidirectional double grease reservoir, promoting the flow of graphite grease in the capillary micropores, so that the graphite grease is evenly covered on the inner wall surface of the cavity. S6. Cyclic operation: Repeat steps S2 to S5 to achieve automatic intermittent supply and continuous lubrication of graphite grease on the cavity surface during cold heading. The device achieves a pulse supply of graphite grease through multiple consecutive stamping actions to reduce waste caused by continuous supply of graphite grease.

[0015] In summary, the present invention has at least one of the following beneficial effects: By utilizing the reset action of the elastic ejector rod during the return stroke of the cold heading machine, the linear motion is converted into unidirectional rotational motion through the cooperation of the spiral groove and the one-way bearing. This drives the internal gear control plate and the piston pumping action triggered by the cumulative rotation of the internal gear control plate, realizing intermittent micro-grease supply to the cavity wall. The entire process does not require external electrical control or an independent grease pump, and realizes the function of accumulating power during the return stroke and supplying grease after multiple stampings. By periodically cooperating with the protrusions on the internal gear control disc and the guide rod, a pulsed supply of graphite grease is achieved, which is triggered only once after multiple stampings. The amount of graphite grease supplied at one time is extremely small and is precisely controlled by the single stroke of the annular piston disc, forming a uniform film on the cavity surface without excessive accumulation, thus avoiding the waste of the traditional continuous supply method. When the elastic ejector rod moves up and down, it drives the striking rod to intermittently strike the mold base. The resulting mechanical vibration can have a disturbance effect on the graphite grease, promoting the flow and uniform spread of the graphite grease in the capillary micropores. This solves the problem of insufficient flow in traditional static grease supply under low temperature or high viscosity conditions, so that all the fine features of the cavity wall can be effectively lubricated. A one-way valve is installed between the first and second grease reservoirs, allowing graphite grease to flow upwards in only one direction, preventing backflow of grease in case of excessive pressure in the second reservoir. This dual-reservoir structure ensures stable transmission of grease supply pressure and a continuous, effective, micro-supply of lubricating medium to the cavity surface. 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 mold base of the present invention; Figure 3 This is a partial three-dimensional unfolded cross-sectional view of the unidirectional transmission mechanism of the present invention; Figure 4 This is a partial three-dimensional cross-sectional view of the internal gear control disc of the present invention.

[0017] In the diagram: 1. Mold base; 11. Cavity; 12. Micropores; 13. Mounting groove; 14. Sealing cover; 2. One-way double grease reservoir; 21. First grease reservoir; 22. Second grease reservoir; 23. One-way liquid guide pipe; 24. One-way valve; 3. Piston mechanism; 32. Annular piston disc; 33. Guide rod; 331. Vertical rod; 332. Round rod; 4. One-way transmission mechanism; 41. One-way bearing; 42. First gear; 43. Second gear; 44. Guide block; 5. Internal gear control disc; 6. Annular guide groove; 61. Annular vertical groove; 62. Annular sliding groove; 63. Protrusion; 7. Elastic ejector rod; 72. Push plate; 73. Ejector rod; 74. Fixing plate; 75. Return spring; 76. Spiral groove; 77. Striking rod. Detailed Implementation

[0018] The following is in conjunction with the appendix Figures 1-4 The present invention will be described in further detail below.

[0019] Please refer to the attached diagram in the instruction manual. Figures 1-4 The present invention provides an embodiment of a self-lubricating device for the cavity surface of a plum blossom hexagonal composite precision molding die, comprising a mold base 1, a cavity 11 recessed at the top of the mold base 1, a unidirectional double grease reservoir 2 inside the mold base 1, the unidirectional double grease reservoir 2 and the cavity 11 being connected by a plurality of capillary micropores 12, a piston mechanism 3 being movably disposed in the unidirectional double grease reservoir 2, the piston mechanism 3 having a guide end extending downward out of the unidirectional double grease reservoir 2.

[0020] The unidirectional double grease reservoir 2 includes a first grease reservoir 21 and a second grease reservoir 22. Both the first grease reservoir 21 and the second grease reservoir 22 are annular in shape and are opened inside the mold base 1 and surround the outer periphery of the cavity 11. The second grease reservoir 22 is located above the first grease reservoir 21 and is connected to the inner wall of the cavity 11 through capillary micropores 12. The first grease reservoir 21 and the second grease reservoir 22 are connected by a one-way liquid guide pipe 23. A one-way valve 24 is installed in the one-way liquid guide pipe 23. The one-way valve 24 only allows graphite grease to flow from the first grease reservoir 21 to the second grease reservoir 22. The piston mechanism 3 is movably disposed in the first grease reservoir 21. The piston mechanism 3 is used to pump the graphite grease in the first grease reservoir 21 to the second grease reservoir 22 through the one-way liquid guide pipe 23. The first grease reservoir 21 is connected to an external graphite grease storage device via a one-way grease supply pipeline. The external graphite grease storage device is used to continuously replenish graphite grease into the first grease reservoir 21.

[0021] The unidirectional double grease reservoir 2 consists of a first grease reservoir 21 and a second grease reservoir 22. Both are annular cavities that are opened inside the mold base 1 around the outer periphery of the cavity 11. The second grease reservoir 22 is located above the first grease reservoir 21, that is, the second grease reservoir 22 is closer to the cavity 11, while the first grease reservoir 21 is closer to the bottom of the mold base 1.

[0022] The second grease reservoir 22 is directly connected to the inner wall of the cavity 11 through capillary micropores 12. Graphite grease seeps from the second grease reservoir 22 through the capillary micropores 12 to the surface of the cavity 11. The first grease reservoir 21 and the second grease reservoir 22 are connected by a one-way liquid guide tube 23. The one-way valve 24 installed in the one-way liquid guide tube 23 only allows graphite grease to flow from the first grease reservoir 21 to the second grease reservoir 22 and does not allow backflow. The piston mechanism 3 is movably disposed in the first grease reservoir 21. When the piston mechanism 3 moves upward, the pressure in the first grease reservoir 21 increases. Under the action of pressure, the graphite grease is pumped into the second grease reservoir 22 through the one-way liquid guide tube 23 and the one-way valve 24. After the pressure in the second grease reservoir 22 increases, the graphite grease seeps out to the surface of the inner wall of the cavity 11 through the capillary micropores 12 under pressure.

[0023] The first grease reservoir 21 is connected to an external graphite grease storage device via a one-way grease supply pipeline. The external graphite grease storage device continuously replenishes the first grease reservoir 21 with graphite grease, ensuring that there is always sufficient lubricating medium in the first grease reservoir 21. During the reciprocating motion, the piston mechanism 3 continuously transports the graphite grease in the first grease reservoir 21 to the second grease reservoir 22, while simultaneously drawing the graphite grease in the external graphite grease storage device into the first grease reservoir 21 in a one-way manner, forming a continuous grease supply cycle.

[0024] The bottom of the mold base 1 is provided with an installation groove 13. A one-way transmission mechanism 4 is rotatably installed in the installation groove 13, and an internal gear control disc 5 is rotatably installed on the inner wall of the installation groove 13. The internal gear control disc 5 meshes with the one-way transmission mechanism 4. The top surface of the internal gear control disc 5 is recessed downward and provided with an annular guide groove 6. The guide end of the piston mechanism 3 passes downward through the one-way double grease reservoir 2 and is inserted into the annular guide groove 6. The guide end slides with the inner wall of the annular guide groove 6.

[0025] The piston mechanism 3 includes an annular piston disk 32, which is movably disposed in the first grease reservoir 21, and the outer peripheral surface of the annular piston disk 32 is sealed and fitted with the inner wall of the first grease reservoir 21. Two guide rods 33 are fixedly connected to the bottom surface of the annular piston disk 32. The two guide rods 33 are symmetrically arranged along the circumference of the annular piston disk 32, and the two guide rods 33 together form the guide end.

[0026] The annular piston disk 32 of the piston mechanism 3 is movably disposed in the first grease reservoir 21. Its annular shape is adapted to the annular shape of the first grease reservoir 21. The outer circumferential surface of the annular piston disk 32 is sealed and fitted with the inner wall of the first grease reservoir 21, ensuring that the graphite grease in the first grease reservoir 21 is effectively compressed when the annular piston disk 32 moves upward, generating sufficient pumping pressure and preventing leakage from the gap between the annular piston disk 32 and the cavity wall.

[0027] Two guide rods 33 are symmetrically arranged around the circumference of the annular piston disc 32 and are fixedly connected to the bottom surface of the annular piston disc 32. The guide rods 33 serve as guide ends, passing downward through the bottom wall of the first grease reservoir 21 and then inserting into the annular guide groove 6. When the bottom contour of the annular guide groove 6 pushes the guide rods 33, the guide rods 33 transmit the up and down driving force to the annular piston disc 32, causing the annular piston disc 32 to reciprocate within the first grease reservoir 21. The symmetrical arrangement of the two guide rods 33 ensures that the annular piston disc 32 is subjected to balanced force during movement, preventing skewness and jamming.

[0028] The guide rod 33 includes a vertical rod 331 and a round rod 332. The upper end of the vertical rod 331 is fixedly connected to the bottom surface of the annular piston disc 32, and the lower end of the vertical rod 331 passes downward through the bottom wall of the first grease reservoir 21 and is inserted into the annular guide groove 6. The round rod 332 is fixedly connected to the lower end of the vertical rod 331. The round rod 332 extends in a direction perpendicular to the vertical rod 331, and the end of the round rod 332 slides in fit with the inner wall of the annular guide groove 6.

[0029] When the internal gear control disc 5 rotates, the annular guide groove 6 rotates together with the internal gear control disc 5. The end of the round rod 332 slides along the groove wall in the annular guide groove 6. The depth of the bottom of the annular guide groove 6 changes circumferentially. When the shallow bottom of the protrusion 63 coincides with the round rod 332, the shallow bottom of the protrusion 63 pushes the round rod 332 upward. The round rod 332 transmits the upward thrust to the annular piston disc 32 through the vertical rod 331, driving the annular piston disc 32 to move upward. When the protrusion 63 rotates away from the position of coincidence with the round rod 332 with the internal gear control disc 5, the round rod 332 enters the deeper area of ​​the groove bottom. The annular piston disc 32 moves downward and resets under the action of gravity or the reverse pressure from above.

[0030] An elastic ejector rod 7 is movably inserted into the inner bottom wall of the cavity 11. The lower end of the elastic ejector rod 7 passes downward through the one-way transmission mechanism 4 and extends out of the mold base 1. The elastic ejector rod 7 has a guide structure, which slides in cooperation with the one-way transmission mechanism 4.

[0031] One-way transmission mechanism 4 includes one-way bearing 41, first gear 42 and second gear 43, both of which are vertically rotatably mounted in mounting groove 13; The first gear 42 is fixedly sleeved on the outer ring of the one-way bearing 41, and the second gear 43 is located between the internal gear control disk 5 and the first gear 42. The second gear 43 meshes with the internal teeth of the internal gear control disk 5 and the first gear 42 respectively. A guide block 44 is fixedly connected to the inner ring of the one-way bearing 41, and an elastic ejector rod 7 is movably inserted into the inner ring of the one-way bearing 41. The guide structure on the elastic ejector rod 7 is in sliding fit with the guide block 44.

[0032] The one-way bearing 41 of the one-way transmission mechanism 4 is vertically rotatably mounted in the mounting groove 13. Its outer ring can only rotate relative to the inner ring in one direction. The first gear 42 is fixedly mounted on the outer ring of the one-way bearing 41 and rotates together with the outer ring. The second gear 43 is vertically rotatably mounted in the mounting groove 13 and is located between the inner gear control disk 5 and the first gear 42, respectively meshing with the inner teeth of the inner gear control disk 5 and the first gear 42.

[0033] The guide block 44, which is fixedly connected to the inner ring of the one-way bearing 41, is a block that protrudes towards the center. The elastic ejector rod 7 is movably inserted into the inner ring of the one-way bearing 41, and the guide structure on the elastic ejector rod 7 is in sliding fit with the guide block 44.

[0034] When the elastic ejector rod 7 moves vertically under the action of external force, the guide structure pushes the guide block 44 to generate a circumferential component force, driving the guide block 44 to drive the inner ring of the one-way bearing 41 to rotate around the axis; when the elastic ejector rod 7 moves downward, the guide structure drives the inner ring to rotate in the free-spinning direction, the one-way bearing 41 slips, the outer ring and the first gear 42 do not rotate with it, and the second gear 43 and the internal gear control disk 5 remain stationary; when the elastic ejector rod 7 moves upward, the guide structure drives the inner ring to rotate in the locking direction, the one-way bearing 41 locks, and the rotation of the inner ring is transmitted to the outer ring through the locking of the one-way bearing 41. The outer ring drives the first gear 42 to rotate synchronously, the first gear 42 drives the second gear 43, and the second gear 43 drives the internal gear control disk 5 to rotate by a preset angle.

[0035] The annular guide groove 6 includes an annular vertical groove 61 and an annular sliding groove 62. The annular vertical groove 61 is a circular groove opened on the top surface of the internal gear control disk 5. The width of the annular vertical groove 61 is adapted to the diameter of the vertical rod 331. An annular groove 62 is formed on the inner bottom wall of the annular vertical groove 61. The annular groove 62 extends circumferentially along the inner tooth control disk 5, and the width of the annular groove 62 is greater than the width of the annular vertical groove 61. The bottom depth of the annular groove 62 is non-uniformly set along the circumferential direction. The annular groove 62 has at least two protrusions 63 with shallow bottom depths.

[0036] The annular vertical groove 61 of the annular guide groove 6 is a circular groove opened on the top surface of the internal gear control disk 5. Its groove width is adapted to the diameter of the vertical rod 331. The vertical rod 331 can slide in the annular vertical groove 61 along the extension direction of the groove. The annular vertical groove 61 restricts the vertical rod 331 to only follow the circumference of the internal gear control disk 5 and cannot produce radial offset.

[0037] An annular groove 62 is formed on the inner bottom wall of the annular vertical groove 61 and extends circumferentially along the internal gear control disc 5. The width of the annular groove 62 is greater than the width of the annular vertical groove 61. It is used to accommodate the two ends of the round rod 332 and allow the round rod 332 to slide circumferentially within it. The bottom depth of the annular groove 62 is non-uniformly set circumferentially. Most sections have a deeper bottom, while some sections have a shallower bottom, forming protrusions 63. The annular groove 62 has at least two protrusions 63 with shallow bottom depths. The protrusions 63 are symmetrically arranged circumferentially along the annular groove 62.

[0038] The lower end of the vertical rod 331 passes through the bottom wall of the first grease reservoir 21 and is inserted into the annular vertical groove 61. The outer wall of the vertical rod 331 is in sliding fit with the inner wall of the annular vertical groove 61. The two ends of the round rod 332 extend out of the outer wall of the vertical rod 331 and are located in the annular sliding groove 62. The end of the round rod 332 is in sliding fit with the inner wall of the annular sliding groove 62.

[0039] The lower end of the vertical rod 331 passes through the bottom wall of the first grease reservoir 21 and is inserted into the annular vertical groove 61. The outer wall of the vertical rod 331 slides in conjunction with the inner wall of the annular vertical groove 61, guiding the vertical movement of the vertical rod 331. The two ends of the round rod 332 extend out of the outer wall of the vertical rod 331 and are located in the annular sliding groove 62. The end of the round rod 332 slides in conjunction with the inner wall of the annular sliding groove 62.

[0040] When the internal gear control disc 5 rotates, the annular vertical groove 61 and the annular sliding groove 62 rotate together with the internal gear control disc 5. The end of the round rod 332 slides along the groove wall in the annular sliding groove 62. For most of the time, the round rod 332 is located in the deeper bottom section of the annular sliding groove 62. The annular piston disc 32 is in a low position and does not move. The internal gear control disc 5 rotates, but the piston mechanism 3 does not produce a pumping action. The graphite grease is not consumed during this period, and the grease supply system is in a "standby" state.

[0041] When the internal gear control disc 5 continues to rotate and the protrusion 63 of the annular groove 62 rotates to the position where it coincides with the round rod 332, the shallower bottom of the protrusion 63 pushes the round rod 332 upward. The round rod 332 drives the annular piston disc 32 to move upward in the first grease reservoir 21 through the vertical rod 331, compressing the graphite grease in the first grease reservoir 21. The high-pressure graphite grease is pumped into the second grease reservoir 22 through the one-way guide pipe 23 and the one-way valve 24, and seeps out into the inner wall of the cavity 11 through the capillary micropores 12. When the protrusion 63 continues to rotate with the internal gear control disc 5 and leaves the position where it coincides with the round rod 332, the round rod 332 re-enters the deeper bottom section of the groove. The annular piston disc 32 returns to the lower position under the pulling force of the round rod 332 and the vertical rod 331. The round rod 332 will only be subjected to an upward pushing force at the protrusion 63, producing a reciprocating pumping motion.

[0042] The annular groove 62 has two symmetrically arranged protrusions 63. Each time the internal gear control disc 5 rotates, the round rod 332 overlaps with the protrusion 63 twice, and the piston mechanism 3 completes two upward pumping strokes. The internal gear control disc 5 only rotates a preset small angle during each stamping return stroke. It takes multiple stamping cycles to complete one rotation. The device achieves one supply of graphite grease through multiple consecutive stamping actions. The grease supply speed is much lower than the stamping frequency, realizing intermittent micro-supply and avoiding waste caused by continuous supply.

[0043] The elastic ejector rod 7 includes a push plate 72 and an ejector rod 73. The push plate 72 is movably disposed on the inner bottom wall of the cavity 11, and the upper surface of the push plate 72 is used to directly contact the workpiece. The upper end of the ejector rod 73 is fixedly connected to the center of the bottom surface of the push plate 72. The rod body of the ejector rod 73 passes through the bottom wall of the cavity 11 and the inner ring of the one-way bearing 41 in sequence and then extends out of the mold base 1. The lower end of the ejector rod 73 is fixedly connected to the fixing plate 74. A return spring 75 is fixedly connected between the upper surface of the fixed plate 74 and the bottom surface of the mold base 1. The return spring 75 is used to push the fixed plate 74 and the ejector rod 73 upward to reset after the stamping pressure is released. The outer wall of the top rod 73 is provided with a spiral groove 76, and the guide block 44 is slidably embedded in the spiral groove 76. The cooperation between the spiral groove 76 and the guide block 44 constitutes a guide structure. A number of striking rods 77 are fixedly connected to the side of the fixed plate 74 facing the mold base 1. The upper ends of the striking rods 77 alternately contact and detach from the bottom surface of the mold base 1 when the fixed plate 74 moves up and down with the elastic ejector rod 7, so as to generate intermittent striking vibration on the mold base 1.

[0044] The push plate 72 of the elastic ejector rod 7 is movably disposed on the inner bottom wall of the cavity 11. The upper surface of the push plate 72 is used to directly contact the workpiece to be formed placed in the cavity 11. The upper end of the ejector rod 73 is fixedly connected to the center of the bottom surface of the push plate 72. The rod body of the ejector rod 73 passes downward through the bottom wall of the cavity 11 and the inner ring of the one-way bearing 41 and then extends out of the mold base 1. The fixing plate 74 fixedly connected to the lower end of the ejector rod 73 is used to support the elastic force of the return spring 75.

[0045] When the punch of the external stamping equipment stamps the workpiece in the cavity 11, the workpiece pushes the push plate 72 downward under the action of huge stamping force. The push plate 72 drives the ejector rod 73 to move downward. When the ejector rod 73 moves downward, the fixed plate 74 moves downward with the ejector rod 73, compressing the return spring 75 to accumulate elastic potential energy. After the stamping is completed and the punch returns, the pressure of the workpiece on the push plate 72 is released. The elastic restoring force of the return spring 75 pushes the fixed plate 74 to return upward. The fixed plate 74 drives the ejector rod 73 and the push plate 72 to return upward together. The push plate 72 pushes the formed workpiece upward from the cavity 11, completing the automatic unloading.

[0046] The spiral groove 76 on the outer wall of the push rod 73 extends spirally along the circumference of the push rod 73. The guide block 44 is embedded in the spiral groove 76 and slides with it. When the push rod 73 moves up and down in the vertical direction under the drive of external force, the guide block 44 slides along the spiral trajectory of the spiral groove 76. Since the extension direction of the spiral groove 76 is at an angle to the axial direction of the push rod 73, the spiral sidewall of the spiral groove 76 applies a circumferential pushing force to the guide block 44, driving the guide block 44 to drive the inner ring of the one-way bearing 41 to rotate around its own axis.

[0047] When the push rod 73 moves downward, the spiral groove 76 drives the inner ring of the guide block 44 and the one-way bearing 41 to rotate in the free-spinning direction. The one-way bearing 41 slips and does not drive the outer ring to rotate. When the push rod 73 returns to its original position, the spiral groove 76 drives the inner ring of the guide block 44 and the one-way bearing 41 to rotate in the locking direction. The one-way bearing 41 locks, and the rotation of the inner ring drives the outer ring to rotate. In turn, the first gear 42 and the second gear 43 drive the internal gear control disk 5 to rotate. This structure transforms the vertical linear reciprocating motion of the elastic push rod 7 into the unidirectional intermittent rotational motion of the internal gear control disk 5, realizing the mechanical linkage between the push action and the grease supply action.

[0048] A number of striking rods 77 are fixedly connected to the side of the fixed plate 74 facing the mold base 1, with their upper ends facing the bottom surface of the mold base 1. When the elastic ejector rod 7 moves up and down during the stamping and resetting process, the fixed plate 74 moves up and down together with the ejector rod 73, causing the striking rods 77 to move together. When the fixed plate 74 is close to the mold base 1, the upper end of the striking rod 77 contacts and collides with the bottom surface of the mold base 1, generating a striking vibration. When the fixed plate 74 is away from the mold base 1, the upper end of the striking rod 77 is separated from the bottom surface of the mold base 1. The continuous up and down movement of the elastic ejector rod 7 causes the striking rods 77 to continuously strike the mold base 1 intermittently.

[0049] The mechanical vibration generated by the striking rod 77 is transmitted through the mold base 1 to the cavity 11, the unidirectional double grease reservoir 2 and the graphite grease inside. The vibration has a disturbance effect on the graphite grease, promoting the flow of graphite grease in the unidirectional double grease reservoir 2 and the capillary micropores 12. This helps the graphite grease to be evenly covered on the inner wall surface of the cavity 11, improving the uniformity and coverage of lubrication.

[0050] A sealing cover 14 is fixedly connected to the bottom surface of the mold base 1. The sealing cover 14 is coaxially arranged with the fixed plate 74. The sealing cover 14 covers the outside of the fixed plate 74 and the striking rod 77. The outer peripheral surface of the fixed plate 74 slides against the inner wall of the sealing cover 14. The sealing cover 14 is used to prevent external debris from entering the connection part between the one-way transmission mechanism 4 and the elastic ejection rod 7.

[0051] The sealing cover 14, which is fixedly connected to the bottom surface of the mold base 1, is coaxially arranged with the fixed plate 74 and has a cylindrical structure. It covers the outside of the fixed plate 74 and the striking rod 77. The outer circumferential surface of the fixed plate 74 slides against the inner wall of the sealing cover 14 to form a closed cavity. The sealing cover 14 encloses the connection between the one-way transmission mechanism 4 and the elastic ejector rod 7, as well as the return spring 75 and the striking rod 77, inside. This prevents metal chips, dust and external coolant generated during the cold heading process from entering these precision-fitted parts, causing jamming, wear or corrosion damage. The sealing cover 14 forms a relatively closed protective space, which significantly extends the service life of the one-way transmission mechanism 4 and the elastic ejector rod 7 and ensures the long-term stable operation of the device.

[0052] In summary: The mold base 1 is fixedly installed on the cold heading machine workbench. The cavity 11 is a hexagonal composite cavity for forming screw heads. The unidirectional double grease reservoir 2 is opened inside the mold base 1 around the outer periphery of the cavity 11 to store graphite grease. The capillary micropores 12 connect the unidirectional double grease reservoir 2 to the inner wall of the cavity 11. Graphite grease can seep out from the unidirectional double grease reservoir 2 through the capillary micropores 12 to the inner wall surface of the cavity 11. The piston mechanism 3 is movably set in the unidirectional double grease reservoir 2. Its guide end extends downward out of the unidirectional double grease reservoir 2 and is used to reciprocate in the unidirectional double grease reservoir 2 under the action of external driving force to pump the graphite grease in the reservoir out.

[0053] The mounting groove 13 is located at the bottom of the mold base 1 and is used to accommodate the one-way transmission mechanism 4 and the internal gear control disc 5. The one-way transmission mechanism 4 is rotatably mounted in the mounting groove 13. Its one-way transmission characteristic determines that it can transmit power to the internal gear control disc 5 only in one rotational direction. When rotating in the opposite direction, it slips and spins freely. The internal gear control disc 5 is rotatably mounted on the inner wall of the mounting groove 13 and meshes with the one-way transmission mechanism 4 to receive the one-way rotational power from the one-way transmission mechanism 4. The annular guide groove 6 is located on the top surface of the internal gear control disc 5. The guide end of the piston mechanism 3 passes downward through the one-way double grease reservoir 2 and is inserted into the annular guide groove 6 and slides with it. When the internal gear control disc 5 rotates, the bottom contour of the annular guide groove 6 changes and pushes the guide end, driving the piston mechanism 3 to reciprocate in the one-way double grease reservoir 2.

[0054] The elastic ejector rod 7 is movably inserted into the inner bottom wall of the cavity 11. Its lower end passes downward through the one-way transmission mechanism 4 and extends out of the mold base 1. The upper end of the elastic ejector rod 7 is used to directly contact the workpiece in the cavity 11. During the stamping process, it moves downward under the pressure transmitted by the workpiece. During the stamping return stroke, it is reset upward under the action of the reset force. The elastic ejector rod 7 has a guide structure, which slides in cooperation with the one-way transmission mechanism 4.

[0055] When the punch of the external stamping equipment stamps the workpiece in the cavity 11, the workpiece pushes the elastic ejector rod 7 downward under the stamping pressure. The elastic ejector rod 7 moves downward. During the downward movement of the elastic ejector rod 7, the guide structure drives the one-way transmission mechanism 4 to rotate in the idling direction. The one-way transmission mechanism 4 slips and does not transmit the rotational power to the internal gear control plate 5. The internal gear control plate 5 remains stationary during this stage.

[0056] When the punch of the external stamping equipment completes the stamping and returns upward, the pressure of the workpiece on the elastic ejector rod 7 is released. The elastic ejector rod 7 is reset upward under the action of the internal reset mechanism. When the elastic ejector rod 7 moves upward, the guide structure drives the one-way transmission mechanism 4 to rotate in the locking direction. The one-way transmission mechanism 4 transmits the rotational power to the internal gear control disk 5, causing the internal gear control disk 5 to rotate by a preset angle. When the internal gear control disk 5 rotates, the annular guide groove 6 on its top surface rotates together with the internal gear control disk 5. Through the change of the groove bottom contour, it pushes the guide end of the piston mechanism 3, driving the piston mechanism 3 to reciprocate in the one-way double grease reservoir 2. When the piston mechanism 3 moves, it pumps the graphite grease in the one-way double grease reservoir 2 to the inner wall of the cavity 11 through the capillary micropores 12.

[0057] To better demonstrate a self-lubricating device for the cavity surface of a hexagonal composite precision molding die, this embodiment proposes a method for self-lubricating the cavity surface of a hexagonal composite precision molding die, comprising the following steps: S1. Filling the lubricating medium: Graphite grease is replenished unidirectionally into the first grease tank 21 through an external graphite grease storage device. Under the action of the initial pressure difference, the graphite grease in the graphite grease storage device enters the second grease tank 22 through the unidirectional grease supply pipeline and the unidirectional valve 24. Under the action of pressure, some graphite grease seeps out through the capillary micropores 12 to the inner wall surface of the cavity 11, completing the initial pre-filling of the lubricating medium. S2. Placing the workpiece and stamping: The workpiece to be formed is placed into the cavity 11, with the bottom of the workpiece contacting the upper surface of the push plate 72; the punch of the external stamping equipment moves downward to stamp the workpiece in the cavity 11. Under the action of stamping pressure, the workpiece pushes the push plate 72 and the push rod 73 downward. The push rod 73 drives the one-way bearing 41 to rotate in the free rotation direction through the spiral groove 76. The internal gear control plate 5 remains stationary, and the piston mechanism 3 is in a low-position standby state in the first grease reservoir 21; during the stamping process, the return spring 75 is compressed and stores elastic potential energy. S3, Return stroke and grease supply trigger: The punch of the external stamping equipment returns upward, the pressure of the workpiece on the push plate 72 is released, and the elastic restoring force of the return spring 75 pushes the fixed plate 74, the push rod 73 and the push plate 72 to return upward. The push plate 72 pushes the formed workpiece upward from the cavity 11. At the same time, when the push rod 73 returns upward, it drives the one-way bearing 41 to rotate in the locking direction through the spiral groove 76. The one-way bearing 41 drives the internal gear control disk 5 to rotate by a preset angle through the first gear 42 and the second gear 43. S4. Intermittent Grease Supply: Repeat steps S2 to S3 multiple times. After the internal gear control disc 5 has rotated a certain angle, the protrusion 63 of the annular groove 62 rotates to the position where it coincides with the round rod 332. The shallow bottom of the protrusion 63 pushes the round rod 332 upward, which drives the annular piston disc 32 to move upward through the vertical rod 331. The graphite grease in the first grease reservoir 21 is pumped to the second grease reservoir 22 through the one-way guide tube 23, and then seeps out through the capillary micropores 12 to the inner wall surface of the cavity 11, completing one pulse supply of graphite grease. After the protrusion 63 continues to rotate away from the coincident position with the internal gear control disc 5, the annular piston disc 32 returns to its original position and waits for the next pumping. S5. Vibration promotes seepage: When the elastic ejector rod 7 moves up and down in steps S2 and S3, the striking rod 77 moves together with the fixed plate 74, intermittently striking the bottom surface of the mold base 1 to generate mechanical vibration. The vibration energy is transmitted to the cavity 11 and the unidirectional double grease reservoir 2, promoting the flow of graphite grease in the capillary micropores 12, so that the graphite grease is evenly covered on the inner wall surface of the cavity 11. S6. Cyclic operation: Repeat steps S2 to S5 to achieve automatic intermittent supply and continuous lubrication of graphite grease on the cavity surface during cold heading. The device achieves a pulse supply of graphite grease through multiple consecutive stamping actions to reduce waste caused by continuous supply of graphite grease.

[0058] 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 self-lubricating device for the cavity surface of a plum blossom hexagonal composite precision molding die, comprising a die base (1), characterized in that: The top of the mold base (1) is recessed downward to form a cavity (11). The interior of the mold base (1) is provided with a unidirectional double grease reservoir (2). The unidirectional double grease reservoir (2) and the cavity (11) are connected by a number of capillary micropores (12). A piston mechanism (3) is movably arranged in the unidirectional double grease reservoir (2). The piston mechanism (3) has a guide end that extends downward out of the unidirectional double grease reservoir (2). The bottom of the mold base (1) is provided with an installation groove (13). A one-way transmission mechanism (4) is rotatably provided in the installation groove (13), and an internal gear control disc (5) is rotatably provided on the inner wall of the installation groove (13). The internal gear control disc (5) meshes with the one-way transmission mechanism (4). The top surface of the internal gear control disc (5) is recessed downward and provided with an annular guide groove (6). The guide end of the piston mechanism (3) passes downward through the one-way double grease reservoir (2) and is inserted into the annular guide groove (6). The guide end slides with the inner wall of the annular guide groove (6). An elastic ejector rod (7) is movably inserted into the inner bottom wall of the cavity (11). The lower end of the elastic ejector rod (7) passes downward through the one-way transmission mechanism (4) and extends out of the mold base (1). The elastic ejector rod (7) has a guide structure, which slides in cooperation with the one-way transmission mechanism (4).

2. The self-lubricating device for the cavity surface of the plum blossom hexagonal composite precision molding die according to claim 1, characterized in that: The unidirectional double grease reservoir (2) includes a first grease reservoir (21) and a second grease reservoir (22). The first grease reservoir (21) and the second grease reservoir (22) are both annular in shape and are both opened inside the mold base (1) and surround the outer periphery of the cavity (11). The second grease reservoir (22) is located above the first grease reservoir (21). The second grease reservoir (22) is connected to the inner wall of the cavity (11) through capillary micropores (12). The first grease reservoir (21) and the second grease reservoir (22) are connected by a one-way liquid guide pipe (23). A one-way valve (24) is installed in the one-way liquid guide pipe (23). The one-way valve (24) only allows graphite grease to flow from the first grease reservoir (21) to the second grease reservoir (22). The piston mechanism (3) is movably disposed in the first grease reservoir (21). The piston mechanism (3) is used to pump the graphite grease in the first grease reservoir (21) to the second grease reservoir (22) through the one-way liquid guide pipe (23). The first grease reservoir (21) is connected to an external graphite grease storage device through a one-way grease supply pipeline. The external graphite grease storage device is used to continuously replenish graphite grease into the first grease reservoir (21).

3. The self-lubricating device for the cavity surface of the plum blossom hexagonal composite precision molding die according to claim 2, characterized in that: The piston mechanism (3) includes an annular piston disk (32), which is movably disposed in the first grease reservoir (21), and the outer circumferential surface of the annular piston disk (32) is sealed and fitted with the inner wall of the first grease reservoir (21); Two guide rods (33) are fixedly connected to the bottom surface of the annular piston disk (32). The two guide rods (33) are arranged symmetrically along the circumference of the annular piston disk (32), and the two guide rods (33) together form the guide end.

4. The self-lubricating device for the cavity surface of the plum blossom hexagonal composite precision molding die according to claim 3, characterized in that: The guide rod (33) includes a vertical rod (331) and a round rod (332). The upper end of the vertical rod (331) is fixedly connected to the bottom surface of the annular piston disc (32), and the lower end of the vertical rod (331) passes downward through the bottom wall of the first grease reservoir (21) and is inserted into the annular guide groove (6). The round rod (332) is fixedly connected to the lower end of the vertical rod (331). The round rod (332) extends in a direction perpendicular to the vertical rod (331). The end of the round rod (332) slides in fit with the inner wall of the annular guide groove (6).

5. The self-lubricating device for the cavity surface of the plum blossom hexagonal composite precision molding die according to claim 1, characterized in that: The one-way transmission mechanism (4) includes a one-way bearing (41), a first gear (42) and a second gear (43), and the one-way bearing (41) and the second gear (43) are both vertically rotatably arranged in the mounting groove (13); The first gear (42) is fixedly sleeved on the outer ring of the one-way bearing (41), and the second gear (43) is located between the internal gear control disk (5) and the first gear (42). The second gear (43) meshes with the internal teeth of the internal gear control disk (5) and the first gear (42) respectively. The inner ring of the one-way bearing (41) is fixedly connected to a guide block (44), and the elastic ejector rod (7) is movably inserted into the inner ring of the one-way bearing (41). The guide structure on the elastic ejector rod (7) is in sliding fit with the guide block (44).

6. The self-lubricating device for the cavity surface of the plum blossom hexagonal composite precision molding die according to claim 1, characterized in that: The annular guide groove (6) includes an annular vertical groove (61) and an annular sliding groove (62). The annular vertical groove (61) is a circular groove opened on the top surface of the internal gear control disk (5). The width of the annular vertical groove (61) is adapted to the diameter of the vertical rod (331). The annular groove (62) is formed on the inner bottom wall of the annular vertical groove (61). The annular groove (62) extends circumferentially along the internal gear control disc (5), and the width of the annular groove (62) is greater than the width of the annular vertical groove (61). The bottom depth of the annular groove (62) is non-uniformly set along the circumferential direction. The annular groove (62) has at least two protrusions (63) with shallow bottom depths.

7. The self-lubricating device for the cavity surface of the plum blossom hexagonal composite precision molding die according to claim 6, characterized in that: The lower end of the vertical rod (331) passes through the bottom wall of the first grease reservoir (21) and is inserted into the annular vertical groove (61). The outer wall of the vertical rod (331) is in sliding fit with the inner wall of the annular vertical groove (61). The two ends of the round rod (332) extend out of the outer wall of the vertical rod (331) and are located in the annular sliding groove (62). The end of the round rod (332) is in sliding fit with the inner wall of the annular sliding groove (62).

8. The self-lubricating device for the cavity surface of the plum blossom hexagonal composite precision molding die according to claim 1, characterized in that: The elastic ejector rod (7) includes a push plate (72) and an ejector rod (73). The push plate (72) is movably disposed on the inner bottom wall of the cavity (11), and the upper surface of the push plate (72) is used to directly contact the workpiece. The upper end of the push rod (73) is fixedly connected to the center of the bottom surface of the push plate (72). The rod body of the push rod (73) passes through the bottom wall of the cavity (11) and the inner ring of the one-way bearing (41) in sequence and then extends out of the mold base (1). The lower end of the push rod (73) is fixedly connected to a fixing plate (74). A reset spring (75) is fixedly connected between the upper surface of the fixed plate (74) and the bottom surface of the mold base (1). The reset spring (75) is used to push the fixed plate (74) and the push rod (73) upward to reset after the stamping pressure is released. The outer wall of the top rod (73) is provided with a spiral groove (76), and the guide block (44) is slidably embedded in the spiral groove (76). The cooperation between the spiral groove (76) and the guide block (44) constitutes a guide structure. The fixed plate (74) is fixedly connected to a number of striking rods (77) on the side facing the mold base (1). The upper end of the striking rods (77) alternately contacts and disengages from the bottom surface of the mold base (1) when the fixed plate (74) moves up and down with the elastic ejector rod (7) to generate intermittent striking vibrations on the mold base (1).

9. The self-lubricating device for the cavity surface of the plum blossom hexagonal composite precision molding die according to claim 1, characterized in that: A sealing cover (14) is fixedly connected to the bottom surface of the mold base (1). The sealing cover (14) is coaxially arranged with the fixing plate (74). The sealing cover (14) covers the outside of the fixing plate (74) and the striking rod (77). The outer peripheral surface of the fixing plate (74) slides against the inner wall of the sealing cover (14). The sealing cover (14) is used to prevent external debris from entering the connection part between the one-way transmission mechanism (4) and the elastic ejector rod (7).

10. A method for self-lubricating the cavity surface of a hexagonal composite precision molding die, comprising the self-lubricating device for the cavity surface of the hexagonal composite precision molding die as described in any one of claims 1-9, characterized in that, It also includes the following steps: S1. Filling the lubricating medium: Graphite grease is added to the first grease tank (21) in one direction through the external graphite grease storage device. Under the action of the initial pressure difference, the graphite grease in the graphite grease storage device enters the second grease tank (22) through the one-way grease supply pipeline and the one-way valve (24). Under the action of pressure, some graphite grease seeps out through the capillary micropores (12) to the inner wall surface of the cavity (11) to complete the initial lubricating medium prefilling. S2. Placing the workpiece and stamping: The workpiece to be formed is placed into the cavity (11), and the bottom of the workpiece contacts the upper surface of the push plate (72); the punch of the external stamping equipment moves downward to stamp the workpiece in the cavity (11). Under the action of the stamping pressure, the workpiece pushes the push plate (72) and the push rod (73) downward. The push rod (73) drives the one-way bearing (41) to rotate in the idling direction through the spiral groove (76). The internal gear control plate (5) remains stationary, and the piston mechanism (3) is in a low-position standby state in the first grease reservoir (21). During the stamping process, the return spring (75) is compressed and stores elastic potential energy. S3, Return and Grease Supply Trigger: The punch of the external stamping equipment returns upward, the pressure of the workpiece on the push plate (72) is released, and the elastic restoring force of the return spring (75) pushes the fixed plate (74), the push rod (73) and the push plate (72) to return upward. The push plate (72) pushes the formed workpiece upward from the cavity (11). At the same time, when the push rod (73) returns upward, it drives the one-way bearing (41) to rotate in the locking direction through the spiral groove (76). The one-way bearing (41) drives the internal gear control plate (5) to rotate by a preset angle through the first gear (42) and the second gear (43). S4. Intermittent grease supply: Repeat steps S2 to S3 multiple times. After the internal gear control disc (5) rotates a certain angle, the protrusion (63) of the annular groove (62) rotates to the position of overlapping with the round rod (332). The shallow groove bottom of the protrusion (63) pushes the round rod (332) upward. Through the vertical rod (331), it drives the annular piston disc (32) to move upward, pumping the graphite grease in the first grease reservoir (21) to the second grease reservoir (22) through the one-way guide tube (23). Then, it seeps out through the capillary micropores (12) to the inner wall surface of the cavity (11), completing one pulse supply of graphite grease. After the protrusion (63) continues to rotate away from the overlapping position with the internal gear control disc (5), the annular piston disc (32) returns to its original position and waits for the next pumping. S5. Vibration promotes seepage: When the elastic ejector rod (7) moves up and down in steps S2 and S3, the striking rod (77) moves together with the fixed plate (74) and intermittently strikes the bottom surface of the mold base (1) to generate mechanical vibration. The vibration energy is transmitted to the cavity (11) and the unidirectional double grease reservoir (2), promoting the flow of graphite grease in the capillary micropores (12) and making the graphite grease evenly cover the inner wall surface of the cavity (11). S6. Cyclic operation: Repeat steps S2 to S5 to achieve automatic intermittent supply and continuous lubrication of graphite grease on the cavity surface during cold heading. The device achieves a pulse supply of graphite grease through multiple consecutive stamping actions to reduce waste caused by continuous supply of graphite grease.

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