Manufacturing process of precise planetary lead screw nut

Abstract

The invention belongs to the technical field of lead screw nut manufacturing, and discloses a precise planetary lead screw nut manufacturing process which comprises the following steps that S1, a grinding machine is adopted for manufacturing a lead screw matched with an internal thread of a target nut, the precision of the lead screw is higher than that of a target planetary lead screw, and the lead screw is made of a high-temperature-resistant material such as silicon carbide, silicon carbide and silicon carbide; and S2, the manufactured lead screw is inserted into a mold assembly, and the mold assembly comprises a lower mold and an upper mold. According to the method, the tedious operation that in the prior art, three-dimensional model data of the workpiece needs to be input into a control system in advance or physical model information obtained through scanning equipment is needed, the bent contour of the workpiece is accurately recognized, and in the machining process, a mechanical arm drives a polishing tool to conduct track movement along the bent surface of the workpiece according to a preset program is omitted; and the product can be processed only by heating the product, so that the requirement on equipment precision and the manufacturing cost are reduced.

Description

Technical Field

[0001] This invention relates to the field of lead screw and nut manufacturing technology, and in particular to a manufacturing process for a precision planetary lead screw and nut. Background Technology

[0002] A planetary roller screw is a transmission device whose core function is to convert rotary motion into linear motion (or vice versa). It uses a planetary layout to achieve motion conversion and consists of core components such as a screw, nut, and rollers. The specific structure includes a main screw, nut, planetary roller assembly, internal gear ring, and cage. Typically, 6-8 threaded rollers surround the main screw to form a planetary motion layout.

[0003] Current processing mainly relies on bending rod grinding. Its core working principle is to accurately identify the bending contour of the workpiece by inputting the three-dimensional model data of the workpiece into the control system in advance or by using the physical model information obtained by scanning equipment. During the processing, the robotic arm drives the grinding tool to move along the curved surface of the workpiece according to the preset program, and gradually and continuously grinds the inner wall of the nut material. On the one hand, this processing requires high precision of the machine tool, and most of it relies on imported equipment, which is costly. On the other hand, the single-piece processing cycle time is long (generally four hours), and only a single product can be processed at a time, which is not suitable for mass production. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a manufacturing process for a precision planetary screw nut.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a manufacturing process for a precision planetary screw nut, comprising the following steps: S1. A lead screw that matches the internal thread of the target nut is manufactured using a grinding machine. The precision of the lead screw is higher than that of the target planetary lead screw. The lead screw is made of high-temperature resistant materials, such as silicon carbide. S2. Insert the manufactured lead screw into the mold assembly, which includes a lower mold and an upper mold; S3. Place the nut material between the lower mold and the upper mold and clamp it in place; S4. A heating mechanism is used to heat the clamped mold assembly, and a temperature controller is used to precisely control the heating temperature between 1500-1600℃. Cold isostatic pressing, hot isostatic pressing or dry pressing is used to sinter the inner wall of the nut into a thread that matches the surface of the lead screw. S5. After sintering, demolding is performed to obtain the target nut.

[0006] By adopting the above technical solution, firstly, a lead screw with a precision higher than that of the target planetary lead screw and compatible with the internal thread of the target nut is manufactured using an existing grinding machine. The lead screw is then inserted into the nut material and placed between the lower and upper molds for clamping and positioning. Subsequently, a heating mechanism heats the clamped mold assembly, and a temperature controller precisely controls the heating temperature between 1500-1600℃. The sintering time is generally controlled at 30-40 minutes. Through the principle of hot isostatic pressing, the inner wall of the nut is sintered to form a thread that matches the surface of the lead screw. After sintering, the demolding area... The method of obtaining the target nut eliminates the need for prior input of the workpiece's three-dimensional model data into the control system or the acquisition of physical model information using scanning equipment, which is required in the prior art. It accurately identifies the workpiece's curved contour. During the processing, the robotic arm drives the grinding tool to move along the curved surface of the workpiece according to a preset program. In addition, the product can be processed simply by heating it, which reduces the requirements for equipment precision and manufacturing costs. The processing time for a single piece is shorter, shortening the processing time. At the same time, the number of lead screws and mold components can be increased according to needs to achieve mass production.

[0007] Furthermore, in step S5, the heating mechanism, in conjunction with the processing equipment, heats the mold assembly. The processing equipment includes a sintering furnace, a protective door, a moving component, a forming mold mechanism, and a limiting component. The sintering furnace has a sintering cavity extending to one side of the sintering furnace. The protective door is fitted against the side wall of the sintering furnace located on the side of the opening of the sintering cavity. The moving component is mounted on the sintering furnace and is used to drive the protective door to move. The forming mold mechanism is used to fix and clamp the lead screw and nut material blanks. The heating mechanism is used to heat the sintering cavity.

[0008] By adopting the above technical solution, the protective door can be moved by operating the moving component, so that the protective door can be attached to or separated from the sintering furnace, so that the staff can take out the product or place it in the sintering chamber.

[0009] Furthermore, the mold assembly includes a placement rack slidably disposed within the sintering chamber and connected to a protective door. Multiple lower and upper molds are provided, with their positions corresponding one-to-one. Multiple lower molds are fixed to the placement rack, and multiple upper molds are slidably disposed on the placement rack. The bottom of each upper mold is in close contact with the top of the corresponding lower mold. The sidewalls of the lower and upper molds that are close to each other are provided with a first cavity and a second cavity. The two first cavities are used to place and clamp the nut material, and the two second cavities are used to clamp the end of the lead screw exposed outside the nut material. The forming mold mechanism also includes a lifting assembly for driving the multiple upper molds to rise and fall.

[0010] By adopting the above technical solution, the lifting assembly is operated to drive the upper mold to rise until the upper mold separates from the lower mold. Then, the lead screw and nut material assembly can be placed in the first cavity and the second cavity of the lower mold. The lifting assembly is operated to drive the upper mold to descend until the upper mold and the lower mold are pressed together again. The two first cavities will wrap and clamp the nut surface, and the two second cavities will wrap and clamp the lead screw to ensure the stability of the assembly during processing.

[0011] Furthermore, the side walls on both sides of the placement frame are provided with through holes. The lifting assembly includes a connecting frame fixed to the top of multiple upper molds. The two ends of the connecting frame are respectively inserted into two through holes and slidably engaged. The lifting assembly also includes a threaded rod that is inserted through the top wall of the through hole and rotatably connected to the placement frame, and a vertical rod that is fixed in the through hole and slidably engaged with the connecting frame. The threaded rods are inserted through the connecting frame and threadedly connected. The number of threaded rods is equal to the number of through holes and their positions correspond one-to-one. The forming mold mechanism also includes a rotating assembly for driving the two threaded rods to rotate synchronously.

[0012] By adopting the above technical solution, the rotating component drives the two threaded rods to rotate synchronously. With the vertical rod in a good limiting position, the connecting frame threaded to the threaded rod and the upper mold fixed to the connecting frame both rise or fall, so as to ensure the normal separation or close contact of the upper mold and the lower mold.

[0013] Furthermore, the rotating assembly includes a rack fixed to the top wall of the sintering chamber, a gear fixedly sleeved on a threaded rod away from the protective door, two sprockets respectively sleeved on the two threaded rods, and a chain that meshes with both sprockets, wherein the gear meshes with the rack.

[0014] By adopting the above technical solution, as the placement frame moves towards the outside of the sintering furnace, it drives the threaded rod connected to the placement frame and the gear connected to the threaded rod to move. Since the gear meshes with the rack, it drives the gear and the threaded rod fixed to the gear to rotate. The cooperation of the two sprockets and the chain causes the two threaded rods to rotate synchronously, thereby causing the connecting frame and the upper mold to rise, thus achieving the automatic separation of the lower mold and the upper mold. Similarly, as the placement frame moves towards the inside of the sintering furnace, it drives the threaded rod connected to the placement frame and the gear connected to the threaded rod to move in the opposite direction. Since the gear meshes with the rack, it drives the gear and the threaded rod fixed to the gear to rotate in the opposite direction. The cooperation of the two sprockets and the chain causes the two threaded rods to rotate synchronously, thereby causing the connecting frame and the upper mold to descend, thus achieving the automatic clamping of the lower mold and the upper mold.

[0015] Furthermore, both the lower and upper molds are provided with heating chambers. The heating mechanism includes a heating assembly, which includes an electric heating wire fixed in the sintering chamber, an oil return pipe fixed and connected to the heating chamber of one of the lower molds, an oil supply pipe fixed and connected to the heating chamber of one of the upper molds, a telescopic pipe fixed and connected to the heating chamber of the upper mold, and a connecting pipe fixed and connected between the heating chambers of two adjacent upper molds. The other end of the telescopic pipe is connected to the heating chamber of the lower mold. The number of telescopic pipes is equal to the number of lower molds and their positions correspond one-to-one. The heating mechanism also includes an oil supply assembly for supplying hot oil to the oil supply pipe.

[0016] By adopting the above technical solution, the electric heating wire heats the sintering chamber to ensure normal production operation. At the same time, the oil supply component supplies hot oil to the oil supply pipe. First, the hot oil in the oil supply pipe flows into the heating chamber of one of the upper molds, then is discharged to the heating chamber of the lower mold through the telescopic pipe, and finally is discharged to the return oil pipe from the heating chamber of the lower mold. Through the dual action of electric heating wire and hot oil heating, the heating speed of the device is improved, and the processing speed of the device is increased.

[0017] Furthermore, the oil supply assembly includes an oil storage tank fixed to the protective door, an electric heating plate fixed inside the oil storage tank, an oil pump fixed to the oil storage tank, and a delivery pipe fixed and connected to the oil outlet of the oil pump. The oil storage tank is filled with heat-conducting oil, the oil inlet of the oil pump is connected to the inside of the oil storage tank, the delivery pipe is fixed and connected to the oil supply pipe, and the return pipe is connected to the inside of the oil storage tank.

[0018] By adopting the above technical solution, the electric heating plate heats the oil in the oil storage tank, the oil pump extracts the hot oil from the oil storage tank and discharges it into the oil supply pipe through the delivery pipe, and finally the hot oil is discharged back into the oil storage tank through the return pipe, thus realizing the recycling of hot oil.

[0019] Furthermore, the limiting components are jointly disposed on the sintering furnace and the placement rack. Multiple sets of the limiting components are disposed and located on the top and bottom of the placement rack respectively. The limiting components include a mounting bracket fixed on the placement rack, a pulley rotatably mounted on the mounting bracket, and a guide rail fixed in the sintering chamber. The guide rail passes through the groove on the surface of the corresponding pulley and engages with it.

[0020] By adopting the above technical solution, the placement rack drives the mounting rack to move when it is working, which in turn drives the pulleys connected to the mounting rack to move. Since the guide rail passes through the grooves on the surface of the corresponding pulley and cooperates, the stability of the placement rack during movement is improved, while the friction between the placement rack and the side wall of the sintering cavity is reduced during movement.

[0021] Furthermore, the moving assembly is provided in two sets and symmetrically arranged about the middle of the sintering furnace. The moving assembly includes a hydraulic push rod fixed on the sintering furnace and a fixing block fixed on the protective door. The push rod end of the hydraulic push rod is fixed to the fixing block.

[0022] By adopting the above technical solution, the hydraulic push rod works to extend or retract its end, which drives the fixed block connected to the end of the hydraulic push rod and the protective door fixed to the fixed block to move, thereby realizing the operation of separating or attaching the protective door to the sintering furnace.

[0023] Furthermore, a heat insulation block that is inserted into the sintering chamber is fixed on the protective door, the placement rack is fixed on the heat insulation block, and the oil return pipe and oil supply pipe pass through the heat insulation block and the protective door in sequence and are fixedly connected to the heat insulation block and the protective door.

[0024] By adopting the above technical solution, the installation of the heat insulation block reduces the probability that heat inside the sintering cavity will be transferred out of the sintering cavity through the protective door.

[0025] In summary, the present invention has the following beneficial effects: In this application, by improving the prior art, the cumbersome operation of inputting the three-dimensional model data of the workpiece into the control system in advance or using the physical model information obtained by scanning equipment to accurately identify the bending contour of the workpiece is eliminated. During the processing, the robotic arm drives the grinding tool to move along the curved surface of the workpiece according to the preset program. In addition, the product can be processed by heating only, which reduces the requirements for equipment precision and manufacturing costs. The single-piece time is shorter, which shortens the processing time. At the same time, the number of lead screws and mold components can be increased according to the needs to achieve mass production. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 This is a cross-sectional structural schematic diagram of an embodiment of the present invention; Figure 3 This is a cross-sectional schematic diagram of an embodiment of the present invention used to highlight the internal structure of the sintering cavity; Figure 4 This is a schematic diagram illustrating the connection structure between the placement rack and the sintering furnace in an embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the internal structure of the placement rack in an embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the connection structure between the connecting frame and the upper mold in an embodiment of the present invention; Figure 7 This is an exploded view of an embodiment of the present invention used to highlight the connection structure between the upper and lower molds; Figure 8 yes Figure 6 Enlarged view of point A in the middle; Figure 9 This is an exploded view of the internal structure of the upper and lower molds, taken from a different nut material state.

[0027] In the diagram: 1. Sintering furnace; 2. Protective door; 3. Moving component; 31. Hydraulic push rod; 32. Fixing block; 4. Sintering chamber; 5. Molding mold mechanism; 51. Mold assembly; 511. Placement rack; 512. Lower mold; 513. Upper mold; 52. Lifting component; 521. Connecting frame; 522. Threaded rod; 523. Vertical rod; 53. Rotating component; 531. Rack; 532. Gear; 533. Sprocket; 534. Chain; 6. Heating mechanism; 61. Heating component; 611. Electric heating wire; 612. Oil return pipe; 613. Oil supply pipe; 614. Telescopic pipe; 615. Connecting pipe; 62. Oil supply component; 621. Oil storage tank; 622. Electric heating plate; 623. Oil pump; 624. Delivery pipe; 7. First cavity; 8. Second cavity; 9. Through hole; 10. Limiting component; 101. Mounting bracket; 102. Pulley; 103. Guide rail; 11. Heat insulation block. Detailed Implementation

[0028] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0029] like Figure 1-9 As shown in the embodiment of this application, a manufacturing process for a precision planetary screw nut is disclosed, including the following steps: S1, a screw adapted to the internal thread of the target nut is manufactured using a grinding machine. The precision of the screw is higher than that of the target planetary screw. The screw is made of a high-temperature resistant material, such as silicon carbide. S2. Insert the manufactured lead screw into the mold assembly 51, which includes a lower mold 512 and an upper mold 513. S3. Place the nut material between the lower mold 512 and the upper mold 513 and clamp and position it. S4. The heating mechanism 6 is used to heat the clamped mold assembly 51, and the temperature is precisely controlled by the temperature controller. The temperature is controlled between 1500-1600℃. The inner wall of the nut is sintered into a thread that matches the surface of the lead screw by cold isostatic pressing, hot isostatic pressing or dry pressing. S5. After sintering, demolding is performed to obtain the target nut.

[0030] By adopting the above technical solution, firstly, a lead screw with a precision higher than that of the target planetary lead screw and compatible with the internal thread of the target nut is manufactured using an existing grinding machine. The lead screw is then inserted into the nut material and placed between the lower mold 512 and the upper mold 513 for clamping and positioning. Subsequently, a heating mechanism heats the clamped mold assembly 51, and a temperature controller precisely controls the heating temperature between 1500-1600℃. The sintering time is generally controlled at 30-40 minutes. Through the principle of hot isostatic pressing, the inner wall of the nut is sintered to form a thread that matches the surface of the lead screw. After sintering is complete... The demolding process obtains the target nut, eliminating the need for prior input of the workpiece's three-dimensional model data into the control system or the acquisition of physical model information using scanning equipment, which is required in the prior art. This allows for precise identification of the workpiece's curved contour. During processing, the robotic arm drives the grinding tool to move along the curved surface of the workpiece according to a preset program, a cumbersome operation. Furthermore, the product only needs to be heated to achieve processing, reducing the requirements for equipment precision and manufacturing costs. The single-piece processing time is shorter, shortening the processing time. At the same time, the number of lead screws and mold components 51 can be increased according to needs to achieve mass production.

[0031] In step S5, the heating mechanism 6, in conjunction with the processing equipment, heats the mold assembly 51. The processing equipment includes a sintering furnace 1, a protective door 2, a moving assembly 3, a forming mold mechanism 5, and a limiting assembly 10. The sintering furnace 1 has a sintering cavity 4 extending to one side of the sintering furnace 1. The protective door 2 is fitted against the side wall of the sintering furnace 1 located on the opening side of the sintering cavity 4. The moving assembly 3 is mounted on the sintering furnace 1 and is used to drive the protective door 2 to move. The forming mold mechanism 5 is used to fix and clamp the lead screw and nut material blanks. The heating mechanism 6 is used to heat the sintering cavity 4. By operating the moving assembly 3 to drive the protective door 2 to move, the protective door 2 can be fitted or separated from the sintering furnace 1, so that the operator can take out the product or place it in the sintering cavity 4.

[0032] The molding die mechanism 5 includes a die assembly 51, a lifting assembly 52, and a rotating assembly 53. The die assembly 51 includes a placement frame 511, a lower die 512, and an upper die 513. The placement frame 511 is slidably disposed within the sintering chamber 4 and connected to the protective door 2. Multiple lower dies 512 are fixed on the placement frame 511. Through holes 9 are provided on both sides of the side walls of the placement frame 511. Heating chambers are provided inside both the lower die 512 and the upper die 513. Multiple upper dies 513 are slidably disposed on the placement frame 511. The bottom of the upper die 513 is in close contact with the top of the corresponding lower die 512. The side walls of the lower die 512 and the upper die 513 that are close to each other are provided with a first cavity 7 and a second cavity 8. The two first cavities 7 are used to place and clamp the nut material, and the two second cavities 8 are used to clamp the end of the lead screw exposed outside the nut material. The lifting assembly 52 drives the upper mold 513 to rise until it separates from the lower mold 512. Then, the lead screw and nut material assembly can be placed in the first cavity 7 and the second cavity 8 on the lower mold 512. The lifting assembly 52 drives the upper mold 513 to fall until it is pressed against the lower mold 512 again. The two first cavities 7 will wrap and clamp the nut surface, and the two second cavities 8 will wrap and clamp the lead screw to ensure the stability of the assembly during processing.

[0033] The lifting assembly 52 includes a connecting frame 521, threaded rods 522, and a vertical rod 523. The lifting assembly 52 is used to drive the lifting of multiple upper molds 513. The connecting frame 521 is fixed to the top of the multiple upper molds 513, and its two ends are respectively inserted into two through holes 9 and slidably engaged. The threaded rods 522 pass through the connecting frame 521 and are threadedly connected. The number of threaded rods 522 is equal to the number of through holes 9, and their positions correspond one-to-one. The threaded rods 522 are inserted into the top wall of the through holes 9 and rotatably connected to the placement frame 511. The vertical rod 523 is fixed in the through holes 9 and slidably engaged with the connecting frame 521. Operating the rotating assembly 53 drives the two threaded rods 522 to rotate synchronously. With the vertical rod 523 effectively limiting the movement, the connecting frame 521 threadedly connected to the threaded rods 522 and the upper molds 513 fixed to the connecting frame 521 both rise or fall, ensuring the normal separation or contact of the upper molds 513 and the lower molds 512.

[0034] The rotating assembly 53 drives the two threaded rods 522 to rotate synchronously. The rotating assembly 53 includes a rack 531, a gear 532, a sprocket 533, and a chain 534. The rack 531 is fixed to the inner top wall of the sintering chamber 4, and the gear 532 is fixedly sleeved on the threaded rod 522 on the side away from the protective door 2. The gear 532 meshes with the rack 531, and there are two sprockets 533. The two sprockets 533 are respectively sleeved on the two threaded rods 522, and the chain 534 meshes with both sprockets 533. As the placement frame 511 moves toward the outside of the sintering furnace 1, it drives the threaded rod 522 connected to the placement frame 511 and the gear 532 connected to the threaded rod 522 to move. Since the gear 532 meshes with the rack 531, it drives the gear 532 and the threaded rod 522 fixed to the gear 532 to rotate. With the cooperation of the two sprockets 533 and the chain 534, the two threaded rods 522 rotate synchronously, thereby causing the connecting frame 521 and the upper mold 513 to rise, thus realizing the automatic separation of the lower mold 512 and the upper mold 513. Similarly, as the placement frame 511 moves toward the side closer to the sintering furnace 1, it drives the threaded rod 522 connected to the placement frame 511 and the gear 532 connected to the threaded rod 522 to move in opposite directions. Since the gear 532 meshes with the rack 531, it can drive the gear 532 and the threaded rod 522 fixed to the gear 532 to rotate in opposite directions. With the cooperation of the two sprockets 533 and the chain 534, the two threaded rods 522 rotate synchronously, thereby causing the connecting frame 521 and the upper mold 513 to descend, thus realizing the operation of the lower mold 512 and the upper mold 513 automatically fitting together.

[0035] A heating mechanism 6 is mounted on the sintering furnace 1 and is used to heat the sintering chamber 4. The heating mechanism 6 includes a heating assembly 61 and an oil supply assembly 62. The heating assembly 61 includes an electric heating wire 611, an oil return pipe 612, an oil supply pipe 613, a telescopic pipe 614, and a connecting pipe 615. The electric heating wire 611 is fixed inside the sintering chamber 4. The oil return pipe 612 is fixed and connected to the heating chamber of one of the lower molds 512. The oil supply pipe 613 is fixed and connected to the heating chamber of one of the upper molds 513. The telescopic pipe 614 is fixed and connected to the heating chamber of the upper mold 513. The other end of the telescopic pipe 614 is connected to the heating chamber of the lower mold 512. The number of telescopic pipes 614 is equal to the number of lower molds 512, and their positions correspond one-to-one. The connecting pipe 615 is fixed and connected between the heating chambers of two adjacent upper molds 513. The electric heating wire 611 heats the sintering chamber 4 to ensure normal production operations. At the same time, the oil supply assembly 62 supplies hot oil to the oil supply pipe 613. First, the hot oil in the oil supply pipe 613 flows into the heating chamber of one of the upper molds 513, then is discharged through the telescopic pipe 614 to the heating chamber of the lower mold 512, and finally discharged from the heating chamber of the lower mold 512 to the return oil pipe 612. Through the dual action of electric heating wire 611 and hot oil heating, the heating speed of the device is improved, and the processing speed of the device is increased.

[0036] The oil supply assembly 62 is used to supply hot oil to the oil supply pipe 613. The oil supply assembly 62 includes an oil storage tank 621, an electric heating plate 622, an oil pump 623, and a delivery pipe 624. The oil storage tank 621 is fixed to the protective door 2 and contains heat transfer oil. The return oil pipe 612 is connected to the inside of the oil storage tank 621, and the electric heating plate 622 is fixed inside the oil storage tank 621. The oil pump 623 is fixed to the oil storage tank 621. The oil inlet end of the oil pump 623 is connected to the inside of the oil storage tank 621, and the delivery pipe 624 is fixed to and connected to the oil supply pipe 613, and is also fixed to and connected to the oil outlet end of the oil pump 623. The electric heating plate 622 heats the oil in the oil storage tank 621. The oil pump 623 extracts the hot oil from the oil storage tank 621 and discharges it to the oil supply pipe 613 through the delivery pipe 624. Finally, the hot oil is discharged back to the oil storage tank 621 through the return pipe 612, thus realizing the recycling of hot oil.

[0037] Limiting components 10 are jointly disposed on the sintering furnace 1 and the placement rack 511. Multiple sets of limiting components 10 are disposed on the top and bottom of the placement rack 511. Each limiting component 10 includes a mounting frame 101, pulleys 102, and guide rails 103. The mounting frame 101 is fixed to the placement rack 511. The pulleys 102 are rotatably mounted on the mounting frame 101, and the guide rails 103 are fixed inside the sintering chamber 4. The guide rails 103 pass through and engage with the grooves on the surfaces of the corresponding pulleys 102. When the placement rack 511 is in operation, it drives the mounting frame 101 to move, which in turn drives the pulleys 102 connected to the mounting frame 101 to move. Because the guide rails 103 pass through and engage with the grooves on the surfaces of the corresponding pulleys 102, the stability of the placement rack 511 during movement is improved, while the friction between the placement rack 511 and the side wall of the sintering chamber 4 is reduced.

[0038] Two sets of moving components 3 are symmetrically arranged about the center of the sintering furnace 1. Each moving component 3 includes a hydraulic push rod 31 and a fixing block 32. The hydraulic push rod 31 is fixed to the sintering furnace 1, and the fixing block 32 is fixed to the protective door 2. The push rod end of the hydraulic push rod 31 is fixed to the fixing block 32. When the hydraulic push rod 31 operates, its push rod end extends or retracts, driving the fixing block 32 connected to the push rod end of the hydraulic push rod 31 and the protective door 2 fixed to the fixing block 32 to move, thus enabling the protective door 2 to separate from or be attached to the sintering furnace 1.

[0039] A heat insulation block 11, which is inserted into the sintering chamber 4, is fixed on the protective door 2. A placement rack 511 is fixed on the heat insulation block 11. The oil return pipe 612 and the oil supply pipe 613 pass through the heat insulation block 11 and the protective door 2 in sequence and are both fixedly connected to the heat insulation block 11 and the protective door 2. The setting of the heat insulation block 11 reduces the probability that the heat in the sintering chamber 4 will be transferred out of the sintering chamber 4 through the protective door 2.

[0040] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A manufacturing process for a precision planetary screw nut, characterized in that, Includes the following steps: S1. A lead screw that is compatible with the internal thread of the target nut is manufactured using a grinding machine; S2. Insert the manufactured lead screw into the mold assembly (51). The mold assembly (51) includes a lower mold (512) and an upper mold (513). S3. Place the nut material between the lower mold (512) and the upper mold (513) and clamp and position it. S4. The clamped mold assembly (51) is heated by a heating mechanism (6); S5. After sintering, demolding is performed to obtain the target nut.

2. The manufacturing process of a precision planetary screw nut according to claim 1, characterized in that: In step S5, the heating mechanism (6) works with the processing equipment to heat the mold assembly (51). The processing equipment includes a sintering furnace (1), a protective door (2), a moving component (3), a forming mold mechanism (5), and a limiting component (10). The sintering furnace (1) has a sintering cavity (4) extending to one side of the sintering furnace (1). The protective door (2) is attached to the side wall of the sintering furnace (1) located on the side of the opening of the sintering cavity (4). The moving component (3) is set on the sintering furnace (1) and is used to drive the protective door (2) to move. The forming mold mechanism (5) is used to fix and clamp the blanks of the lead screw and nut materials. The heating mechanism (6) is used to heat the sintering cavity (4).

3. The manufacturing process of a precision planetary screw nut according to claim 2, characterized in that: The mold assembly (51) includes a placement rack (511) that is slidably disposed in the sintering chamber (4) and connected to the protective door (2). The lower mold (512) and the upper mold (513) are provided in multiple pieces and their positions correspond one to one. The multiple lower molds (512) are fixed on the placement rack (511), and the multiple upper molds (513) are slidably disposed on the placement rack (511). The bottom of the upper mold (513) is close to the top of the corresponding lower mold (512). The side walls of the lower mold (512) and the upper mold (513) that are close to each other are provided with a first cavity (7) and a second cavity (8). The two first cavities (7) are used to place and clamp the nut material, and the two second cavities (8) are used to clamp the end of the lead screw exposed outside the nut material. The forming mold mechanism (5) also includes a lifting assembly (52) for driving the multiple upper molds (513) to rise and fall.

4. The manufacturing process of a precision planetary screw nut according to claim 3, characterized in that: The side walls on both sides of the placement frame (511) are provided with through holes (9). The lifting assembly (52) includes a connecting frame (521) fixed to the top of multiple upper molds (513). The two ends of the connecting frame (521) are respectively inserted into two through holes (9) and slidably engaged. The lifting assembly (52) also includes a threaded rod (522) that is provided through the top wall of the through hole (9) and rotatably connected to the placement frame (511) and a vertical rod (523) that is fixed in the through hole (9) and slidably engaged with the connecting frame (521). The threaded rod (522) passes through the connecting frame (521) and is threadedly connected. The number of threaded rods (522) is equal to the number of through holes (9) and their positions correspond one-to-one. The forming mold mechanism (5) also includes a rotating assembly (53) for driving the two threaded rods (522) to rotate synchronously.

5. The manufacturing process of a precision planetary screw nut according to claim 4, characterized in that: The rotating assembly (53) includes a rack (531) fixed to the top wall of the sintering chamber (4), a gear (532) fixedly sleeved on a threaded rod (522) away from the protective door (2), two sprockets (533) respectively sleeved on the two threaded rods (522), and a chain (534) meshing with the two sprockets (533). The gear (532) meshes with the rack (531).

6. The manufacturing process of a precision planetary screw nut according to claim 3, characterized in that: Heating chambers are provided in both the lower mold (512) and the upper mold (513). The heating mechanism (6) includes a heating component (61). The heating component (61) includes an electric heating wire (611) fixed in the sintering chamber (4), an oil return pipe (612) fixed and connected to the heating chamber of one of the lower molds (512), an oil supply pipe (613) fixed and connected to the heating chamber of one of the upper molds (513), a telescopic pipe (614) fixed and connected to the heating chamber of the upper mold (513), and a connecting pipe (615) fixed and connected between the heating chambers of two adjacent upper molds (513). The other end of the telescopic pipe (614) is connected to the heating chamber of the lower mold (512). The number of telescopic pipes (614) is equal to the number of lower molds (512) and their positions correspond one-to-one. The heating mechanism (6) also includes an oil supply component (62) for supplying hot oil to the oil supply pipe (613).

7. The manufacturing process of a precision planetary screw nut according to claim 6, characterized in that: The oil supply assembly (62) includes an oil storage tank (621) fixed to the protective door (2), an electric heating plate (622) fixed inside the oil storage tank (621), an oil pump (623) fixed to the oil storage tank (621), and a delivery pipe (624) fixed and connected to the oil outlet of the oil pump (623). The oil inlet of the oil pump (623) is connected to the inside of the oil storage tank (621), the delivery pipe (624) is fixed and connected to the oil supply pipe (613), and the return pipe (612) is connected to the inside of the oil storage tank (621).

8. The manufacturing process of a precision planetary screw nut according to claim 2, characterized in that: The limiting components (10) are jointly disposed on the sintering furnace (1) and the placement rack (511). Multiple sets of the limiting components (10) are disposed on the top and bottom of the placement rack (511). The limiting components (10) include a mounting frame (101) fixed on the placement rack (511), a pulley (102) rotatably mounted on the mounting frame (101), and a guide rail (103) fixed in the sintering chamber (4). The guide rail (103) passes through the groove on the surface of the corresponding pulley (102) and engages with it.

9. The manufacturing process of a precision planetary screw nut according to claim 2, characterized in that: The moving component (3) is provided in two sets and is symmetrically arranged about the middle of the sintering furnace (1). The moving component (3) includes a hydraulic push rod (31) fixed on the sintering furnace (1) and a fixing block (32) fixed on the protective door (2). The push rod end of the hydraulic push rod (31) is fixed to the fixing block (32).

10. The manufacturing process of a precision planetary screw nut according to claim 6, characterized in that: The protective door (2) is fixed with a heat insulation block (11) that is inserted into the sintering chamber (4). The placement rack (511) is fixed on the heat insulation block (11). The oil return pipe (612) and the oil supply pipe (613) pass through the heat insulation block 11 and the protective door 2 in sequence and are fixedly connected to the heat insulation block 11 and the protective door 2.

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