High-precision machining tool for special-shaped shell part with male end

Abstract

According to the high-precision machining tool for the special-shaped shell part with the male end, a boring and milling hole is formed in the plane B of the shell part, and a male end boss concentric with the boring and milling hole is formed; the flatness of the plane B is not greater than 0.015 mm, and the perpendicularity of the plane B and the plane A is not greater than 0.01 mm; the roughness of the plane A and the plane B does not exceed Ra1.6 mu m; the tool is composed of a positioning tool shaft, a gland, a spring gasket and a fine thread nut. The positioning tool shaft penetrates through the boring and milling hole to concentrically position and clamp the male end boss; a gland is arranged on the opposite inner side surface of the plane B; the spring gasket and the fine thread nut sequentially penetrate through the front end of the positioning tool shaft, and the fine thread nut is screwed with the threads at the front end of the positioning tool shaft, so that the shell part and the positioning tool shaft are concentrically pressed and fixedly connected into a whole. According to the utility model, through the tool design and the adoption of turning processing instead of a numerical control boring and milling processing center processing mode, the planeness and perpendicularity of the plane B of the special-shaped shell part with the male end meet the requirements of customers.

Description

Technical Field

[0001] This utility model belongs to the technical field of workpiece processing tooling on machine tools, specifically relating to a high-precision machining tooling for irregularly shaped shell parts with an outer stop. Background Technology

[0002] In the harmonic reducer industry, such as Figure 1 The irregularly shaped housing part with an external stop shown is a structural component in a reducer that supports the internal structure and mounts the motor. The conventional design uses a boss for the motor stop, with a small clearance fit between the boss and the reducer's groove to ensure minimal cumulative error after assembly. However, due to the unique design of this reducer and its connected motor structure, an annular sealing groove needs to be designed at the motor stop, and space is required at the connection point with the reducer to install a sealing ring. This means the structure where the motor and reducer mate needs to be designed as a recessed hole, while the reducer housing is designed as a boss. This results in a large area for plane B, requiring high flatness and geometric tolerances. The conventional method is to mill plane B and the boss on a CNC machining center. However, during milling, the uneven thickness of plane B leads to insufficient flatness and perpendicularity. Therefore, to meet customer requirements, the following technical solution is proposed. Utility Model Content

[0003] The technical problem solved by this utility model is to provide a high-precision machining fixture for irregularly shaped shell parts with external stops. By designing the fixture and using turning to replace CNC boring and milling machining center machining, the flatness and perpendicularity of plane B of the irregularly shaped shell parts with external stops meet customer requirements.

[0004] The technical solution adopted in this utility model is as follows: A high-precision machining fixture for irregularly shaped shell parts with an external stop. The shell part has a ФD4H7 boring and milling hole on plane B, and an external stop boss is made concentrically with the boring and milling hole ФD4H7. The flatness of plane B is not greater than 0.015mm, and the perpendicularity of plane B to the reference plane A is not greater than 0.01mm. The surface roughness of plane B and the reference plane A does not exceed Ra1.6μm. The fixture consists of a positioning fixture shaft, a pressure cap, a spring washer, and a fine-pitch nut. The middle part of the positioning fixture shaft passes through the boring and milling hole and concentrically positions and clamps the external stop boss of the shell part. A pressure cap is provided on the inner side opposite to plane B of the shell part. The pressure cap is used to press the shell part, and the pressure cap passes through the front end of the positioning fixture shaft to increase the pressing area of ​​the pressure cap pressing the shell part. The spring washer and the fine-pitch nut pass through the front end of the positioning fixture shaft one after the other, and the fine-pitch nut engages with the front thread of the positioning fixture shaft to concentrically press and fasten the shell part and the positioning fixture shaft into one piece.

[0005] In the above technical solution: the outer diameter of the outer stop boss completed by turning is ФD2h7, the perpendicularity of the outer stop boss to the A datum plane is not greater than 0.01mm, and the surface roughness of the outer stop boss does not exceed Ra1.6μm.

[0006] In the above technical solution, the preferred embodiment is that the positioning tool shaft is made of alloy structural steel that has undergone tempering treatment.

[0007] In the above technical solution, the preferred embodiment is as follows: the positioning fixture shaft is composed of three concentrically formed optical shaft bodies I (ФD6h7), II (Ф33), and III (ФD5h6), with diameters decreasing sequentially, and a fine-pitch threaded portion; the front end of the optical shaft body II is used for a concentrically fitted external stop boss that fits the positioning and clamping housing part; the transition between the rear end of the optical shaft body II and the optical shaft body I provides clearance space for turning the external stop boss; the optical shaft body III is used for a concentrically fitted ФD4H7 boring and milling hole for the positioning and clamping housing part; the left end positioning surface of the axial length L5 formed by the aforementioned optical shaft body III and the fine-pitch threaded portion concentrically meets the form and position tolerance requirements of plane B; the fine-pitch threaded portion is used to fit the pressure cap, spring washer, and fine-pitch nut, wherein the fine-pitch nut is screwed to fit the fine-pitch threaded portion.

[0008] In the above technical solution, preferably: the axial length of the optical shaft body III is less than the axial length of the boring and milling hole of the housing part ФD4H7; the inner side of the pressure cap presses against the inner side of the opposite side of the plane B of the housing part, and the pressure cap center through hole D4 is adapted to the fine thread part clearance fitting.

[0009] In the above technical solution, the preferred option is an M8×1 fine-thread nut.

[0010] In the above technical solution, the preferred embodiment is that the surface roughness of the positioning tool shaft does not exceed Ra1.6μm, the circumferential runout tolerance is not greater than 0.015mm, and the coaxiality error between the shafts does not exceed 0.015mm.

[0011] Advantages of this utility model compared to the prior art:

[0012] 1. This utility model has a simplified number of tooling components, simple and convenient assembly operation, accurate machining positioning, good self-locking and anti-loosening effect of M8 fine thread, excellent mechanical properties of alloy structural steel, effectively improving the machining qualification rate, and the tooling can be reused repeatedly, reducing costs.

[0013] 2. After clamping the parts, the tooling of this utility model replaces the boring and milling process with turning, ensuring that the high precision and flatness of the outer stop boss of the parts meet the customer requirements. The technical solution is stable and has good processability in the mass production of parts. Attached Figure Description

[0014] Figure 1This is a front view of a non-circular housing part with an external stop, related to this utility model.

[0015] Figure 2 for Figure 1 AA process requires a cross-sectional view;

[0016] Figure 3 for Figure 1 Three-dimensional view of the housing parts;

[0017] Figure 4 For the tooling clamping of this utility model Figure 1 Schematic diagram of the assembly structure of the shell parts;

[0018] Figure 5 This utility model Figure 4 A schematic diagram showing the structure, dimensions, and manufacturing process of the positioning tooling shaft.

[0019] Figure 6 This utility model Figure 4 Schematic diagram of the medium pressure cover structure;

[0020] Figure 7 This utility model Figure 4 Front view of a medium-fine thread nut;

[0021] Figure 8 for Figure 7 Side view;

[0022] In the diagram: 1-Housing part, 2-Positioning fixture shaft, 201-Optical shaft body I, 202-Optical shaft body II, 203-Optical shaft body III, 204-Fine thread part, 3-Gap cap, 4-Spring washer, 5-Fine thread nut. Detailed Implementation

[0023] The following will refer to the appendix in the embodiments of this utility model. Figure 1-8 The technical solutions in the embodiments of this utility model are clearly and completely described herein. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] This utility model claims protection for a high-precision machining fixture for irregularly shaped shell parts with external stops (such as...). Figure 1-3As shown, regarding the form and position tolerance requirements of housing part 1, the housing part 1 has a ФD4H7 boring and milling hole on plane B. It should be noted that ФD4H7 should be understood as having a diameter of D4 and a tolerance grade of H7. An external stop boss is concentrically formed with the boring and milling hole ФD4H7; the flatness of plane B is not greater than 0.015mm, the perpendicularity of plane B to datum plane A is not greater than 0.01mm, and the surface roughness of plane B and datum plane A does not exceed Ra1.6μm. That is, this utility model is applicable to the processing of irregularly shaped housing parts with external stops that meet the above-mentioned process requirements.

[0025] Due to the high-precision structure of the outer stop boss of housing part 1, this location is the motor mounting surface, characterized by high dimensional accuracy and strict geometric tolerances. The commonly used machining method is milling. However, milling this structure is prone to deformation and cannot meet the requirements. Therefore, the following tooling design is proposed:

[0026] (like Figure 4-5 The tooling shown consists of a positioning tooling shaft 2, a pressure cap 3, a spring washer 4, and a fine-thread nut 5. The tooling structure of this invention has a reduced number of components, simplifying operation and lowering costs.

[0027] Furthermore, the positioning fixture shaft 2 passes through the boring and milling hole in the middle and concentrically positions and clamps the outer stop boss of the housing part 1. A pressure cap 3 is provided on the inner side opposite plane B of the housing part 1. The pressure cap 3 is used to press the housing part 1, and it passes through the front end of the positioning fixture shaft 2 to increase the pressing area of ​​the pressure cap 3 on the housing part 1, improving the firmness and reliability of the pressing. The spring washer 4 and the fine-thread nut 5 pass through the front end of the positioning fixture shaft 2 one after the other, and the fine-thread nut 5 engages with the front thread of the positioning fixture shaft 2, thereby concentrically pressing and fixing the housing part 1 and the positioning fixture shaft 2 into one unit, ensuring precise positioning and easy assembly. Therefore, the tooling design of this utility model is simple in structure, convenient for loading, unloading, and positioning, has good manufacturability, improves the processing qualification rate, reduces costs, and the tooling can be reused repeatedly.

[0028] In the above embodiments, preferably, the outer diameter of the external stop boss, which is machined by turning, is ФD2h7, that is, the outer diameter of the external stop boss is D2, and the tolerance zone is h7. (e.g.) Figure 2 As shown, the perpendicularity of the outer stop boss to the A reference plane is not greater than 0.01 mm, and the surface roughness of the outer stop boss does not exceed Ra1.6 μm.

[0029] In the above embodiments, preferably, the positioning tooling shaft 2 is made of tempered alloy structural steel. Because alloy structural steel contains a certain amount of alloying elements, its microstructure is generally more complex than that of carbon steel. After appropriate heat treatment, alloy structural steel can obtain a uniform sorbite, bainite, or extremely fine pearlite structure, thus possessing excellent mechanical properties. Therefore, the positioning tooling shaft 2 has a certain hardness and is wear-resistant for repeated use.

[0030] In the above embodiments, preferably, the positioning tooling shaft 2 is composed of three concentrically formed optical shaft bodies: ФD6h7 optical shaft body I 201, Ф33 optical shaft body II 202, ФD5h6 optical shaft body III 203, and a fine thread portion 204, all with diameters decreasing sequentially. Specifically, optical shaft body I 201 has a diameter of D6 and a tolerance zone of h7; optical shaft body II 202 has a diameter of 33mm; and optical shaft body III 203 has a diameter of D5 and a tolerance zone of h6.

[0031] This utility model features a one-piece molding of the positioning tooling shaft 2, reducing the need for detailed machining and splicing of multiple components, saving production time, improving overall production efficiency, and lowering production costs. The sequentially decreasing diameter shaft design allows for easier and more precise positioning of the tooling shaft during assembly, reducing assembly errors and improving product accuracy and consistency. The sequentially decreasing diameter design also facilitates a smoother assembly process, reducing resistance and friction, increasing assembly speed, and lowering assembly costs. Despite the gradually decreasing diameter, the overall structure remains compact and robust, capable of withstanding significant loads and impacts, thus improving product durability. The fine-pitch thread has a small pitch, resulting in high precision and stability.

[0032] The front end of the optical axis shaft body II 202 is used to concentrically fit and position the outer stop boss of the housing part 1. The transition between the rear end of the optical axis shaft body II 202 and the optical axis shaft body I 201 is used to provide clearance space when turning the outer stop boss.

[0033] (like Figure 2 , Figure 4 , Figure 5 The optical shaft body Ⅲ203 shown is used for concentric and adapted positioning and clamping of the ФD4H7 boring and milling hole (D4=D5) of the housing part 1. This fit serves as the positioning reference for the fit between the tooling and the housing part 1. The small clearance fit ensures centering during assembly and ensures that the tooling and the housing part 1 are coaxial.

[0034] The left end positioning surface of the axial length L5 formed by the aforementioned optical shaft body Ⅲ203 and the fine thread part 204 concentrically meets the form and position tolerance requirements of plane B (the form and position tolerance requirements are described above) to ensure that this end face of the tooling fits snugly with the mating end face of the housing part 1, ensuring that this position does not move and improving positioning accuracy.

[0035] The fine-threaded portion 204 is used to fit the pressure cap 3, spring washer 4, and fine-threaded nut 5, wherein the fine-threaded nut 5 is screwed into the fine-threaded portion 204. This ensures that the tooling is pressed tightly against the housing part 1, preventing displacement of the part 1 due to machining during processing.

[0036] (like Figure 7 , 8 (As shown) In the above embodiment, preferably, the fine-pitch nut 5 is an M8×1 fine-pitch nut. The internal thread diameter of the M8×1 fine-pitch nut is 8 mm, and the pitch is 1 mm. This specification allows the nut to maintain sufficient connection strength while having a small size and weight, making it suitable for applications with strict space and weight requirements. The fine-pitch nut is characterized by its smaller pitch, which gives it a better anti-loosening effect after locking or backing. In addition, the fine-pitch design also allows the nut to provide a more uniform stress distribution during connection, thereby improving the reliability and durability of the connection. Due to the smaller helix angle of the fine-pitch nut, its self-locking and anti-loosening effect is better than that of a coarse-pitch nut when the nut is locked or backed. This makes the M8×1 fine-pitch nut perform excellently in the connection of high-speed rotating or moving parts, effectively preventing loosening caused by vibration or impact.

[0037] In the above embodiments, preferably: the axial length of the optical axis shaft body Ⅲ203 is less than the axial length of the boring and milling hole of the housing part 1ФD4H7; the inner side of the pressure cap 3 presses against the inner side of the opposite side of plane B of the housing part 1, (in conjunction with) Figure 6 (As shown) and the pressure cap 3 has a central through hole D4 that is fitted with the fine thread part 204 with a clearance fitting, which facilitates the quick assembly of the pressure cap 3.

[0038] Preferably, the surface roughness of the positioning fixture shaft 1 does not exceed Ra 1.6 μm, the circumferential runout tolerance is not greater than 0.015 mm, and the coaxiality error between shafts does not exceed 0.015 mm. The smaller the surface roughness, the smaller the clearance between parts, thus improving the fitting accuracy. This helps reduce errors and deviations during assembly, ensuring a tight fit between parts. A smooth surface reduces friction and wear, extending the service life of parts. The smaller the circumferential runout tolerance, the better the stability of the parts during rotation. This helps reduce vibration and noise, improving the operating efficiency of the machinery. The smaller the coaxiality error, the higher the assembly accuracy between shafts, helping to ensure the overall performance and stability of the mechanical system. A shaft system with good coaxiality can reduce vibration and noise, improving the smoothness of machinery operation.

[0039] This utility model relates to a high-precision machining method for irregularly shaped shell parts with external stops, comprising the following steps:

[0040] Step S1: Boring and milling the ФD4H7 hole in plane B of housing part 1.

[0041] Step S2: Boring and milling the outer stop boss and plane B of the housing part 1, and leaving machining allowances of 0.015mm and 0.1mm for the outer stop boss and plane B respectively.

[0042] Step S3: After clamping the housing part 1 with any of the toolings described above, turn the outer stop boss of plane B of the housing part 1 so that plane B and the outer stop boss meet the process accuracy requirements.

[0043] The design principle of the relevant method of this utility model is as follows: First, rough mill the outer stop boss and plane B on the machining center machine tool, and make appropriate allowances for the outer stop boss and plane B respectively, so as to allow the part to deform as much as possible; second, clamp the shell part 1 on the lathe through the designed tooling to complete the deformation repair of the shell part 1 and the fine machining of the process requirements.

[0044] Step S3 involves the following steps for clamping the housing part 1 with the tooling:

[0045] S301. Fixture clamping on the lathe: Mount the positioning fixture shaft 2 on the lathe, that is, clamp the ФD6h7 optical shaft body Ⅰ201 of the positioning fixture shaft 2.

[0046] S302. Alignment of the tooling on the lathe: Alignment ensures that the outer diameter of the ФD5h6 optical shaft body Ⅲ203 in the positioning tooling shaft 2 is within 0.005mm.

[0047] S303, Clamping the housing part: Install the housing part 1 on the positioning fixture shaft 2 and manually rotate the housing part 1 slowly so that the ФD4H7 boring and milling hole of the housing part 1 is concentric with the ФD6h7 optical shaft body I201 of the positioning fixture shaft 2.

[0048] S303, clamping the housing parts: install the pressure cover 3, spring washer 4, and fine-thread nut 5 in sequence on the front end of the positioning fixture shaft 2, and tighten the fine-thread nut 5 to complete the clamping of the housing parts 1 in the fixture.

[0049] The positioning fixture shaft 2 is reusable. When a second clamping is required after processing a batch of shell parts 1, the left end face of the axial length L5 dimension formed by the concentric optical shaft body Ⅲ203 and the fine thread part 204 in the positioning fixture shaft 2 can be machined to ensure the form and position tolerance requirements of the clamping reference plane B of the positioning fixture shaft 2 and eliminate the wear of the end face during previous use.

[0050] As can be seen from the above description, this utility model has a simplified number of tooling components, simple and convenient assembly operation, accurate machining positioning, good self-locking and anti-loosening effect of M8 fine thread, excellent mechanical properties of alloy structural steel, effectively improves the machining qualification rate, and the tooling can be reused repeatedly, reducing costs.

[0051] This utility model replaces the boring and milling process with turning, ensuring that the high precision and flatness of the outer stop boss meet customer requirements. The technical solution is stable and has good processability in the mass production of parts.

[0052] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0053] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model. Any modifications and equivalent substitutions made within the spirit and principles of the present utility model are included within the scope of protection of the present utility model.

Claims

1. A high-precision machining fixture for irregularly shaped shell parts with external stops, characterized in that: The shell part (1) is provided with a ФD4H7 boring and milling hole on the plane B, and an external stop boss is provided concentrically on the boring and milling hole ФD4H7; the flatness of the plane B is not greater than 0.015mm, the perpendicularity of the plane B and the reference plane A is not greater than 0.01mm; the surface roughness of the plane B and the reference plane A is not more than Ra1.6μm; The tooling is composed of a positioning tooling shaft (2), a gland (3), a spring washer (4) and a fine tooth nut (5); the positioning tooling shaft (2) passes through the boring and milling hole and is concentrically positioned and clamped to the external stop boss of the shell part (1); the opposite side of the plane B of the shell part (1) is provided with the gland (3) on the inner side surface, the gland (3) is used for pressing the shell part (1), and the gland (3) passes through the front end of the positioning tooling shaft (2) to increase the pressing area of the gland (3) for pressing the shell part (1); the spring washer (4) and the fine tooth nut (5) pass through the front end of the positioning tooling shaft (2) in sequence, and the fine tooth nut (5) is screwed to the front end thread of the positioning tooling shaft (2) to integrally connect the shell part (1) and the positioning tooling shaft (2) concentrically and press tightly.

2. The tooling of claim 1, wherein: The external diameter of the external stop boss completed by turning is ФD2h7, the perpendicularity of the external stop boss and the reference plane A is not greater than 0.01mm, and the surface roughness of the external stop boss is not more than Ra1.6μm.

3. The tooling of claim 1, wherein: The positioning tooling shaft (2) is made of modulated alloy structural steel.

4. The tooling of claim 1 or 3, wherein: The positioning tooling shaft (2) is composed of a ФD6h7 optical shaft body I (201), a Ф33 optical shaft body II (202), a ФD5h6 optical shaft body III (203) and a fine tooth thread part (204) which are concentrically and integrally formed and sequentially decrease in diameter; the front end of the optical shaft body II (202) is used for concentrically and adaptively positioning and clamping the external stop boss of the shell part (1); the rear end of the optical shaft body II (202) and the transition of the optical shaft body I (201) are used for providing a space for turning the external stop boss; the optical shaft body III (203) is used for concentrically and adaptively positioning and clamping the ФD4H7 boring and milling hole of the shell part (1); the left end positioning surface of the axial length L5 composed of the aforementioned optical shaft body III (203) and the fine tooth thread part (204) meets the shape and position tolerance requirements of the plane B; the fine tooth thread part (204) is used for sleeving the gland (3), the spring washer (4) and the fine tooth nut (5), and the fine tooth nut (5) is screwed to the fine tooth thread part (204).

5. The tooling of claim 4, wherein: The axial length of the optical shaft body III (203) is smaller than the axial length of the ФD4H7 boring and milling hole of the shell part (1); the inner side surface of the gland (3) presses the opposite side inner side surface of the plane B of the shell part (1), and the gland center through hole D4 of the gland (3) is gap-fitted to the fine tooth thread part (204).

6. The tooling of claim 5, wherein: The fine tooth nut (5) is an M8×1 fine tooth nut.

7. The tooling of claim 4 wherein: The surface roughness of the positioning tooling shaft (2) is not more than Ra1.6μm, the circumferential runout tolerance is not greater than 0.015mm, and the coaxiality error between the shafts is not more than 0.015mm.

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