A stainless steel cross pipe machining method based on multi-axis machining

Abstract

The application discloses a stainless steel horizontal pipe machining method based on multi-axis machining, and comprises the following steps: step S1, machining clamping position and top surface reference; step S2, clamping to a five-axis numerical control machining center through the clamping position, and utilizing multi-axis linkage to complete preliminary machining of front side surface, rear side surface, bottom surface, convex block, two side arc curved surfaces and groove cavity in one clamping, and drilling a wire hole, reserving a process circular table coaxially arranged with the shaft hole; step S3, taking the process circular table as a reference to perform turning machining; step S4, removing the clamping position and the process circular table; and step S5, cutting the groove cavity from the wire hole as a starting line. The application eliminates error transmission chain from the root by one clamping and process circular table reference design of multi-axis linkage, greatly improves the part groove cavity symmetry and hole system coaxiality, simultaneously significantly shortens the machining cycle, and is suitable for batch production of stainless steel complex precision parts.

Description

Technical Field

[0001] This invention belongs to the field of machining technology, specifically relating to a method for machining stainless steel horizontal tubes based on multi-axis machining. Background Technology

[0002] like Figure 1 The diagram illustrates the structure of a finished stainless steel horizontal tube part. This part is a complex spatial structure integrating multiple features such as curved surfaces, high-precision grooves, precision hole systems, and external threads. It also demands extremely high dimensional and positional tolerances, including groove symmetry and hole system coaxiality. Traditional machining methods struggle to guarantee both accuracy and efficiency when dealing with such complex structures.

[0003] Currently, the traditional processing technology for this type of stainless steel horizontal tube typically employs an eight-step process: "conventional turning → conventional milling → CNC milling → CNC turning → conventional milling → wire cutting → CNC milling → deburring." However, in actual production, this traditional process has the following technical drawbacks: First, error accumulation is severe, involving multiple clamping and datum conversions, leading to the continuous transmission and accumulation of positioning and machining errors from each step, causing fluctuations in critical dimensions. Second, geometric tolerance control is difficult; positioning deviations caused by multiple clampings make it difficult to guarantee the coaxiality of the internal hole system and the symmetry of the internal groove cavity of the cylindrical protrusion on the front side of the part, frequently resulting in out-of-tolerance issues. Third, production efficiency is low; redundant processes lead to excessively high proportions of equipment changeover and clamping correction time, significantly extending the processing cycle of a single part. Therefore, there is an urgent need to develop a high-efficiency stainless steel horizontal tube processing technology that can eliminate error accumulation from the source, accurately control complex geometric tolerances, and eliminate the need for frequent switching of machining datums. Summary of the Invention

[0004] To address the shortcomings of the existing technology, the present invention aims to provide a method for machining stainless steel horizontal tubes based on multi-axis machining. This method utilizes the core advantage of multi-axis linkage technology, which allows for "machining multiple features in a single clamping," to solve the technical bottlenecks of traditional processes, such as long error accumulation chains, difficulty in controlling geometric tolerances, and low production efficiency caused by multiple clamping operations.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A method for machining stainless steel horizontal tubes based on multi-axis machining includes the following steps: Step S1. Blank pretreatment and datum machining: Select a bar blank and machine a clamping position and top surface datum for subsequent clamping on one side of the blank. Step S2. Multi-axis linkage milling: The blank obtained in step S1 is clamped through the clamping position, and multiple features are formed in one clamping by multi-axis linkage. A process frustum coaxial with the hole system of the part is reserved, and a wire threading hole is drilled at the same time. Step S3. Turning: Using the process frustum reserved in step S2 as the clamping reference, the part is turned. Step S4. Auxiliary structure removal: Remove the clamping position processed in step S1 and the process frustum reserved in step S2; Step S5. Wire EDM finishing: Starting from the wire threading hole drilled in step S2, perform wire EDM finishing.

[0006] Furthermore, in step S1, the material of the bar blank is stainless steel, and the clamping position is a straight clamping position extending along the axial direction of the bar. The top surface reference of the part is formed simultaneously by milling the clamping position.

[0007] Furthermore, in step S2, the multi-feature forming includes milling the front side and front cylindrical protrusion blank, rear side, bottom surface and bottom protrusion of the part, as well as performing preliminary processing on the arc-shaped curved surfaces on both sides of the part and the internal preset groove cavity.

[0008] Furthermore, the central axis of the process frustum reserved in step S2 coincides with the central axis of the shaft hole to be machined in step S3.

[0009] Furthermore, in step S2, the wire-threading hole extends along the left-right direction of the part, and its central axis coincides with the central axis of the bar stock blank.

[0010] Furthermore, in step S2, the multi-axis linkage machining specifically uses the linkage between the rotary axis and the linear axis to enable the tool to perform adaptive cutting along the arc-shaped surface contour, ensuring the surface forming accuracy.

[0011] Furthermore, in step S3, the turning process includes: drilling and finishing the shaft hole to a predetermined size, coaxially machining the enlarged hole, and machining a pre-defined standard external thread and a pre-defined relief groove on the outer side of the front cylindrical protrusion.

[0012] Furthermore, in step S3, the process frustum reserved in step S2 is clamped for turning, and the process frustum is used as a positioning reference to enhance turning rigidity and ensure machining accuracy.

[0013] Furthermore, in step S4, when removing the auxiliary structure, the clamping position processed in step S1 and the process frustum reserved in step S2 are cut off respectively, so that the part exposes the complete forming features.

[0014] Furthermore, in step S5, the specific sequence of the wire cutting precision machining is as follows: first, cut the arc-shaped curved surfaces and arc-shaped bosses at both ends of the part; then, cut the notch on the front cylindrical protrusion end face; and finally, cut the preset groove cavity inside the part with the wire threading hole as the starting point.

[0015] The present invention has the following beneficial effects: Significantly improved accuracy and geometric tolerances: Step S2 completes the forming of multiple features and reserves process frustum in one clamping, eliminating the datum conversion error caused by frequent clamping, significantly reducing the fluctuation range of key dimensions of parts, and completely solving the long-standing problem of excessive tolerance in hole system coaxiality and groove cavity symmetry, greatly enhancing product quality consistency.

[0016] Leapfrog improvement in production efficiency: By streamlining the process route, the traditional cumbersome process is reduced to 5 core processes, which significantly shortens the processing cycle of a single part; and the process table reserved in step S2 serves as the turning reference, which greatly reduces the correction time of turning clamping in step S3 and improves the efficiency of the turning process.

[0017] Effective reduction in overall costs: Thanks to the significant reduction in scrap rate and the shortening of single-piece processing cycle, coupled with the reduction in labor and equipment losses due to streamlined processes, the overall processing cost of a single part has been effectively controlled, creating significant economic benefits for the enterprise. Attached Figure Description

[0018] Figure 1 This is a structural schematic diagram of the stainless steel horizontal tube finished part according to the present invention; in the figure, a is the front view of the part, b is the top view of the part, c is the bottom view of the part (the cylindrical protrusion is cut along the bottom surface of the part), and d is the left view of the part.

[0019] Figure 2 This is a schematic diagram of the structure of the pre-reserved process frustum in the processing described in this invention.

[0020] As shown in the figure: 10-Main body, 11-Top surface reference, 12-Bottom surface, 13-Protrusion; 20-Left arc-shaped area, 21-Left arc-shaped inner curved surface, 22-Left arc-shaped outer curved surface, 23-Left arc-shaped boss; 30-Right arc-shaped area, 31-Right arc-shaped inner curved surface, 32-Right arc-shaped outer curved surface, 33-Right arc-shaped boss; 40-Groove cavity; 50-Cylindrical protrusion, 51-Shaft hole, 52-Enlarged hole, 53-Vertical groove, 54-Undrilled groove, 55-External thread; 60-Rear side; 70-Process frustum; 80-Clamping position; 81-Bar blank; 90-Threading hole; 100-Front side. Detailed Implementation

[0021] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figure 1 As shown, the main body 10 of the finished stainless steel horizontal tube part processed in this embodiment has a trapezoidal frame structure, with its width gradually increasing from top to bottom, and the contours of the left and right ends transitioning in an arc shape. For ease of explanation, the main body 10 is described in detail in terms of its top, bottom, left and right sides, front side, rear side, and internal features: Top and bottom structure: The top of the main body 10 is provided with a top surface reference 11; the bottom of the main body 10 is provided with a downward protruding protrusion 13 at the middle position. The front and rear end faces of the protrusion 13 are flush with the front and rear surfaces of the main body 10. The left and right width of the protrusion 13 is less than the top length of the main body 10, and the bottom surfaces 12 on the left and right sides of the protrusion 13 are located in the same plane.

[0023] Left and right side structures: The main body 10 has a symmetrical structure at its left and right ends, with a left arc-shaped area 20 and a right arc-shaped area 30 respectively. Each arc-shaped area includes a left arc-shaped inner curved surface 21 and a right arc-shaped inner curved surface 31 facing upwards, and a left arc-shaped outer curved surface 22 and a right arc-shaped outer curved surface 32 extending outwards from the arc-shaped inner curved surface. The radii of the left arc-shaped outer curved surface 22 and the right arc-shaped outer curved surface 32 are larger than those of the left arc-shaped inner curved surface 21 and the right arc-shaped inner curved surface 31, thus forming a left arc-shaped boss 23 and a right arc-shaped boss 33 with a certain arc length at the left and right ends of the part, respectively. Internal structure: The main body 10 has a groove 40 inside that runs through the arc-shaped inner curved surfaces (left arc-shaped inner curved surface 21 and right arc-shaped inner curved surface 31) at both ends along the left and right directions. The groove 40 has a square cross section.

[0024] Front structure: The front side of the main body 10 has a cylindrical protrusion 50 that is perpendicular to the front side and protrudes outward. The approximate center of the cylindrical protrusion 50 is located at the intersection of the protrusion 13 and the bottom surface 12. The cylindrical protrusion 50 has an axially extending shaft hole 51 that penetrates and extends deep into the interior of the main body 10. After extending into the main body, the shaft hole 51 communicates with the groove cavity 40. At one end of the cylindrical protrusion 50, the shaft hole 51 is located on the outside and has an enlarged hole 52 that is coaxial with the shaft hole and has a larger diameter than the shaft hole. Furthermore, the front end face of the front cylindrical protrusion 50 has a pre-set vertical groove 53, the outer wall of the cylindrical protrusion 50 has a standard external thread 55, and a necking / relief groove 54 is provided on the outer part of the cylindrical protrusion 50 near the main body.

[0025] Rear structure: The rear side 60 of the main body 10 is a flat plane, and the process frustum 70 reserved in the processing technology of the present invention is located on the rear side 60 and the rear side of the protrusion 13.

[0026] Based on the above structure, the stainless steel horizontal tube processing method of the present invention is implemented according to the following steps: Step S1. Blank pretreatment and datum machining: A stainless steel bar 81 of predetermined diameter and length is selected as the blank. Milling is performed on one side of the blank 81 to form a straight clamping position 80 extending axially (e.g., ...). Figure 2 (As shown). The clamping position 80 has a predetermined positioning surface and clamping thickness, mainly used for reliable clamping of multi-axis equipment in subsequent steps. While milling the clamping position 80, the top surface reference 11 of the part is machined simultaneously to provide a unified initial height reference for subsequent processes.

[0027] Step S2. Multi-axis simultaneous milling The blank 81, with the clamping position 80 machined in step S1, is clamped in a self-centering vise and mounted onto a five-axis CNC machining center. In this embodiment, the rotation axes of the five-axis CNC machining center's worktable are defined as the B-axis and C-axis (where the B-axis oscillates around the Y-axis and the C-axis rotates around the Z-axis). Utilizing the linkage technology of the five-axis CNC machining center and its rotatable worktable, a variety of complex features are formed in a single operation during this clamping process, specifically including the following four postures and process actions: First rotation posture: Adjust the worktable of the five-axis CNC machining center, rough machine the front side of the part, mill out the rough blank of the front cylindrical protrusion 50, and at the same time perform preliminary rough machining on the corresponding left arc inner curved surface 21 and left arc outer curved surface 22 in this direction.

[0028] Second rotation posture: Rotate the worktable to B90° and C0° posture, and drill the wire-passing hole 90 along the left and right directions of the part with the central axis of the bar blank 81 as the reference.

[0029] Third rotation posture: Rotate the worktable to B90° and C90° postures to rough mill the bottom surface 12 and bottom protrusion 13 of the part.

[0030] Fourth rotation posture: Rotate the worktable to B90°, C270° posture, rough mill the rear side 60 of the part, and at the same time perform preliminary rough machining on the right arc inner curved surface 31 and right arc outer curved surface 32 corresponding to this direction side. During the rough milling of the rear side 60 and the rear side of the protrusion 13, the process frustum 70 coaxially set with the shaft hole 51 to be machined later is reserved simultaneously.

[0031] It should be noted that the machining order of the third and fourth rotational postures can be interchanged (i.e., rough milling of the bottom surface first or rough milling of the side surface first), and both can be completed in one clamping, without affecting the final machining accuracy.

[0032] In this step, the five-axis CNC machining center uses the linkage between the rotary axis and the linear axis to enable the tool to perform adaptive cutting along the contours of the inner curved surfaces 21 and 31 and the outer curved surfaces 22 and 32, ensuring the surface forming accuracy and ensuring that the allowance of wire cutting in the subsequent step S5 is uniform.

[0033] Step S3. Turning The semi-finished product, after multi-axis milling in step S2, is transferred to the turning equipment. The key to this step is to use the process frustum 70 reserved in step S2 as a clamping datum. By clamping the process frustum 70 with a fixture, since the frustum has a coaxial positioning relationship with the shaft hole to be machined later, it can provide a precise positioning datum for turning, significantly reducing the difficulty of clamping and correction during turning, while also enhancing the rigidity of the turning process.

[0034] Under this reference, the turning process is performed in sequence: the shaft hole 51 is drilled and finished to a predetermined size, and the hole 52 is coaxially machined; a preset standard specification external thread 55 is machined on the outside of the front cylindrical protrusion 50, and a necking / relief groove 54 of a predetermined size is machined.

[0035] Step S4. Removal of auxiliary structures After the part is turned in step S3, remove the auxiliary process structures set up for machining. Specifically, cut off the clamping position 80 machined in step S1 and the process frustum 70 reserved in step S2. After the removal, the part will reveal all its complete final forming features.

[0036] Step S5. Wire EDM finishing Transfer the part, after removing the auxiliary structures, to the wire EDM machine. Perform wire EDM finishing in the following steps: Step 1: Use wire cutting to process the left arc-shaped inner curved surface 21, the right arc-shaped inner curved surface 31, the left arc-shaped outer curved surface 22, and the right arc-shaped outer curved surface 32 at both ends of the part, and form the left arc-shaped boss 23 and the right arc-shaped boss 33 on both sides.

[0037] Step 2: Use wire cutting to process the pre-set vertical groove 53 on the front end face of the front cylindrical protrusion 50.

[0038] Step 3: Using the wire-threading hole 90 drilled in step S2 as the starting point, wire cut through the grooves 40 at both ends of the part.

[0039] The processing method described in steps S1 to S5 was used for batch production verification. The results showed that the dimensional fluctuation range of the processed stainless steel horizontal tube body 10 was significantly reduced, the compliance rate of key dimensional and positional tolerances (such as the coaxiality between the shaft hole 51, the enlarged hole 52 and the front cylindrical protrusion 50, and the symmetry of the groove cavity 40) was significantly improved, the processing time of a single part was greatly shortened, and the overall processing cost of a single part was effectively controlled, thus effectively solving the technical bottleneck of the original process.

[0040] In summary, this invention provides an efficient, high-precision, and reproducible technical solution for the manufacturing of complex stainless steel parts through the organic combination of multi-axis linkage and benchmark optimization. Other aspects of the invention not detailed herein are conventional techniques well-known to those skilled in the art.

[0041] It should be noted that the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0042] The scope of protection of this invention is not limited to the technical solutions disclosed in the specific embodiments. Any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of this invention shall fall within the scope of protection of this invention.

Claims

1. A method for machining stainless steel horizontal tubes based on multi-axis machining, characterized in that, Includes the following steps: Step S1. Blank pretreatment and datum machining: Select a bar blank and machine a clamping position and top surface datum for subsequent clamping on one side of the blank. Step S2. Multi-axis linkage milling: The blank obtained in step S1 is clamped through the clamping position, and multiple features are formed in one clamping by multi-axis linkage. A process frustum coaxial with the hole system of the part is reserved, and a wire threading hole is drilled at the same time. Step S3. Turning: Using the process frustum reserved in step S2 as the clamping reference, the part is turned. Step S4. Auxiliary structure removal: Remove the clamping position processed in step S1 and the process frustum reserved in step S2; Step S5. Wire EDM finishing: Starting from the wire threading hole drilled in step S2, perform wire EDM finishing.

2. The method for machining stainless steel horizontal tubes based on multi-axis machining according to claim 1, characterized in that: In step S1, the material of the bar blank is stainless steel, and the clamping position is a straight clamping position extending along the axial direction of the bar. The top surface reference of the part is formed by milling the clamping position.

3. The method for machining stainless steel horizontal tubes based on multi-axis machining according to claim 1, characterized in that: In step S2, the multi-feature forming includes milling the front side and front cylindrical protrusion blank, rear side, bottom surface and bottom protrusion of the part, as well as performing preliminary processing on the arc-shaped curved surfaces on both sides of the part and the internal preset groove cavity.

4. The method for machining stainless steel horizontal tubes based on multi-axis machining according to claim 1, characterized in that: The central axis of the process frustum reserved in step S2 coincides with the central axis of the shaft hole to be machined in step S3.

5. The method for machining stainless steel horizontal tubes based on multi-axis machining according to claim 1, characterized in that: In step S2, the wire-threading hole extends along the left-right direction of the part, and its central axis coincides with the central axis of the bar stock blank.

6. The method for machining stainless steel horizontal tubes based on multi-axis machining according to claim 1, characterized in that: In step S2, the multi-axis linkage machining specifically uses the linkage between the rotary axis and the linear axis to enable the tool to perform adaptive cutting along the arc-shaped surface contour, ensuring the surface forming accuracy.

7. The method for machining stainless steel horizontal tubes based on multi-axis machining according to claim 1, characterized in that: In step S3, the turning process includes: drilling and finishing the shaft hole to a predetermined size, coaxially machining the enlarged hole, and machining a pre-defined standard external thread and a pre-defined relief groove on the outer side of the front cylindrical protrusion.

8. The method for machining stainless steel horizontal tubes based on multi-axis machining according to claim 1, characterized in that: In step S3, the process frustum reserved in step S2 is clamped for turning. The process frustum is used as a positioning reference to enhance turning rigidity and ensure machining accuracy.

9. The method for machining stainless steel horizontal tubes based on multi-axis machining according to claim 1, characterized in that: In step S4, when removing the auxiliary structure, the clamping position processed in step S1 and the process frustum reserved in step S2 are cut off respectively, so that the part exposes the complete forming features.

10. A method for machining stainless steel horizontal tubes based on multi-axis machining according to claim 1, characterized in that: In step S5, the specific sequence of wire EDM finishing is as follows: first, cut the arc-shaped curved surfaces and arc-shaped bosses at both ends of the part; then, cut the notch on the front cylindrical protrusion end face; and finally, cut the preset groove cavity inside the part with the wire threading hole as the starting point.

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