Processing technology of a through-flat special-shaped shaft

Abstract

This invention belongs to the field of shaft machining, and specifically relates to a machining process for a through-flat irregular shaft. The machining process for a through-flat irregular shaft includes the following steps: material preparation; rough turning of the outer diameter, finish machining of the eccentric hole, and rough machining of a semi-through flattened section: rough machining of the outer diameter and eccentric hole on the outer circle of the bar stock, and rough machining of a semi-through flattened section as a positioning reference for the subsequent finished through-flattened section, the thickness of the positioning flattened section being smaller than that of the finished through-flattened section; grinding and finish machining of the outer diameter: through-grinding of the workpiece's outer diameter using a centerless grinder; finish grinding and flattening: placing the workpiece in a surface grinder for through-flattening and finish machining. This invention's production process is simple and quick to operate, has high processing efficiency, greatly improves the machining quality of the through-flat irregular shaft, has low requirements for the precision of production equipment, requires little investment, and has low production costs.

Description

Technical Field

[0001] This invention belongs to the field of shaft processing, and specifically relates to a processing technology for a flat, irregularly shaped shaft. Background Technology

[0002] The through-flat type irregular shaft structure is short and compact, with a through flat part on the shaft body. The through flat part has a positional relationship with the outer circle of the shaft body and the inner hole.

[0003] Existing machining processes for through-flat irregular shafts employ turning to complete the positional relationships of the shaft body in a single operation. Because the shaft body is through-flat, subsequent finishing can only be done using a double-headed external cylindrical grinding process for external diameter finishing. While existing through-flat machining processes can meet the dimensional requirements of such irregular shafts, they are costly, inefficient, and result in inconsistent product quality. Summary of the Invention

[0004] To address the problems of low processing efficiency, unsuitability for mass production, high cost, and unstable product quality in existing flat irregular shaft processing technologies, this invention proposes a flat irregular shaft processing technology, comprising the following steps:

[0005] S1: Material preparation: Prepare materials according to the outer diameter and length of the flat, irregularly shaped shaft;

[0006] S2: Rough turn the outer diameter, finish machine the eccentric hole in the core, and rough machine the semi-flat core.

[0007] The outer diameter and the eccentric hole in the core are rough machined on the outer circle of the bar stock, and a semi-flat bar is rough machined as the positioning reference for the finished flat bar in the subsequent process. The thickness of the positioning flat bar is smaller than that of the finished flat bar.

[0008] S3: Grinding and finishing of outer diameter: The outer diameter of the workpiece is ground using a centerless grinding machine;

[0009] S4: Precision flattening: The workpiece is placed in a surface grinding machine for fine flattening.

[0010] First, place the product into the flattening fixture and clamp it in place;

[0011] When the workpiece is placed into the grinding fixture, it is placed into the grinding fixture one by one with the semi-flat part processed in step S2 as the positioning reference. The flat part is facing upward and a gauge is set. The flat part is then precision ground in one pass by a surface grinder.

[0012] According to the above-described processing technology for a flat profiled shaft, in step S1, the diameter of the bar stock is 0.4 mm larger than the outer diameter of the finished flat profiled shaft.

[0013] According to the above-described machining process for a through-flat irregular shaft, in step S2, a Swiss-type lathe is used to rough turn the outer diameter of the workpiece, finish machine the eccentric hole in the core, and rough machine the semi-through flat shaft.

[0014] According to the above-described machining process for a flat, irregularly shaped shaft, in step S2, after rough turning the outer diameter, a grinding allowance of 0.1 mm is left.

[0015] According to the above-described machining process for a flat, irregularly shaped shaft, the semi-flat shaft has a length of 3-5mm and a thickness of 0.03-0.08mm with a grinding allowance.

[0016] According to the above-described machining process for a flat, irregularly shaped shaft, in step S3, the outer diameter tolerance of the machined workpiece is within 0.003 mm, the roundness tolerance of the outer diameter is within 0.002 mm, and the surface roughness is within RZ2.

[0017] According to the above-described processing technology for a through-flat irregular shaft, in step S4, the relative positional angle accuracy of the through-flatness, outer diameter, and core eccentric hole of the processed through-flat irregular shaft is within ±3 degrees, and the through-flatness thickness accuracy is within 0.03mm tolerance.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. This invention utilizes rough machining of the outer diameter and eccentric hole in the core of the bar stock, along with rough machining of the semi-flat section as the positioning reference for the subsequent finished flat section. This allows for the grinding and finishing of the outer diameter using a general-purpose centerless grinder for through-feature grinding, eliminating the need for a double-top cylindrical grinder. The production process is simple and quick, achieving low-cost production of flat, irregularly shaped shaft outer diameters with high processing efficiency. This grinding method produces flat, irregularly shaped outer diameters with stable quality, high efficiency, and low cost. The machined workpiece outer diameter tolerance is within 0.003mm, the outer diameter roundness tolerance is within 0.002mm, the surface roughness is within RZ2, and the processing efficiency can reach less than 1 second.

[0020] 2. This invention adopts a clamping and positioning method with the flat side facing upward and a go gauge set. The flat side is precision ground in one pass on a surface grinder. The phase relationship between the flat side and the outer circle is achieved by positioning the flat side using a grinding positioning fixture. The thickness of the half-flat side is detected by the go gauge, thereby ensuring the phase relationship between the flat side of the ground through-flat shaped shaft and the outer diameter of the through-flat shaped shaft, which greatly improves the machining quality of the eccentric shaft.

[0021] 3. The semi-flat section of this invention has a length of 3-5mm, which serves as a positioning element for the flat section. The thickness of the semi-flat section allows for a grinding allowance of 0.03-0.08mm for the fine grinding process. This further ensures the positional relationship between the outer diameter of the flat-shaped shaft, the eccentric hole in the core, and the flat section. During the turning process, the semi-flat section milled on a Swiss-type lathe is machined in one clamping and positioning process with other machining parts, resulting in high overall precision. Using this semi-flat section as a reference for subsequent grinding processes can reduce positioning errors and thus ensure the dimensional accuracy of the eccentric shaft. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the processing steps of the present invention.

[0023] Figure 2 This is a schematic diagram of the bar stock in step S1 of the present invention.

[0024] Figure 3 This is a front view of the structural schematic diagram of the workpiece after processing in step S2 of the present invention.

[0025] Figure 4 The A1-A1 section view is a schematic diagram of the structure of the workpiece after processing in step S2 of the present invention.

[0026] Figure 5 The front view of the structural schematic diagram of the workpiece after processing in step S2 of the present invention is shown from direction B1.

[0027] Figure 6 This is a perspective view of the structure of the workpiece after processing in step S2 of the present invention.

[0028] Figure 7 This is a schematic diagram of workpiece clamping in step S4 of the present invention.

[0029] Figure 8 This is a schematic diagram of the workpiece after clamping and awaiting processing in step S4 of the present invention.

[0030] Figure 9 This is a schematic diagram of the workpiece state after processing in step S4 of the present invention.

[0031] Figure 10 This is a front view of the through-flat irregular shaft structure after processing in step S4 of the present invention.

[0032] Figure 11 The A2-A2 section view is a front view of the schematic diagram of the through-flat irregular shaft structure after processing in step S4 of the present invention.

[0033] Figure 12 This is the B2 view of the front view of the schematic diagram of the through-flat irregular shaft structure after processing in step S4 of the present invention. Detailed Implementation

[0034] Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. 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.

[0036] like Figures 1 to 5 As shown: In this embodiment, a machining process for a flat, irregularly shaped shaft includes the following steps:

[0037] Step 1: Material preparation: Prepare 3m long bar stock, and prepare the material according to the length of the flat profile shaft. The diameter of the bar stock should be 0.4mm larger than the outer diameter of the finished flat profile shaft.

[0038] Step 2: Rough turning of the outer diameter, finish machining of the eccentric hole 11 in the core, and rough machining of the semi-flat section 13.

[0039] The outer diameter of the workpiece 2 is machined using a Swiss-type lathe. The diameter of the bar after rough machining is 0.1 mm larger than the outer diameter of the finished flat profile shaft.

[0040] Here, the allowance of 0.3mm, which is 0.4mm larger than the outer diameter of the finished flat profile shaft, is removed by turning, leaving an outer diameter of 0.1mm for final grinding.

[0041] The outer diameter and the eccentric hole 11 in the core are rough-machined on the outer circle of the bar stock, and a semi-flat section 13 is rough-machined as the positioning reference for the subsequent finished flat section. The size design of the semi-flat section 13 should take into account the positioning function of the fine-grinding flat section 12 and not affect the subsequent centerless grinding. The thickness of the semi-flat section 13 is less than the thickness of the finished flat section 12, leaving a grinding allowance of 0.06-0.10mm for the subsequent fine grinding of the flat section 12. This can improve the processing efficiency and positioning accuracy of the flat section. Because this is a short shaft, with a length of 13mm and a diameter of 25mm, the diameter-to-length ratio is close to 2. If the semi-flat section 13 is too long, it cannot be ground by a centerless grinder. Products ground by centerless grinding equipment cannot have too long flat sections or keyways. In order to use a high-efficiency and low-cost centerless grinding process to grind the outer diameter in the subsequent process, the length of the semi-flat section should be as short as possible, just enough to serve a positioning function. In this process, the relative positional relationship of the outer diameter of workpiece 2, the eccentric hole 11 in the core, and the semi-flat section 13 is initially determined.

[0042] Step 3: Grinding and finishing the outer diameter: Workpiece 2 is ground using a centerless grinder in a through-feed process. This grinding method offers stable machining quality, high efficiency, and low cost. The outer diameter tolerance can be consistently within 0.003mm, the roundness tolerance within 0.002mm, and the surface roughness within RZ2. The machining efficiency can reach less than 1 second. This machining method has less demanding requirements on grinding equipment, allowing one person to operate multiple machines simultaneously. Compared to external cylindrical grinding, its efficiency is extremely high.

[0043] Step 4: Precision grinding of flattened parts 12: Place workpiece 2 into a surface grinding machine for precision grinding of flattened parts 12;

[0044] First, place workpiece 2 into the flattening fixture 100 and clamp it in place by tightening the internal hex screws 104;

[0045] When placing workpiece 2 into the grinding fixture 100, it should be placed into the grinding fixture 100 one by one, using the semi-flattened part 13 processed in step 2 as the positioning reference, for fixation. See the assembly drawing. Figure 7 As shown. The relative positional relationship between the semi-flattened part 13 and the outer diameter of the workpiece is achieved by positioning the flattening fixture 100, thereby ensuring that the relative positional relationship between the flattened part 12 and the outer diameter of the flattened irregular shaft meets the processing requirements. The flattening fixture adopts a method of flattening with the flat part facing upward and setting the go gauge. When the workpiece 2 is placed in the flattening fixture 100, if the first side T1 of the go gauge and the semi-flattened part 13 of the clamped workpiece are on the same horizontal plane, it indicates that the product is placed correctly.

[0046] In this embodiment, workpieces 2 are placed in a group of 5 into the flattening fixture 100.

[0047] In step three, a through-type centerless grinder is used to grind the outer diameter of the product. This method offers high precision, stable quality, high efficiency, and low cost. The outer diameter tolerance is within 0.003mm, roundness within 0.002, and surface roughness within RZ2, with a processing cycle of less than 1 second. This processing method has low requirements for grinding equipment and is significantly superior to external cylindrical grinding, making it the preferred choice for batch grinding. Because step two processes a semi-through flat 13 (not a through flat 12), and the length of the semi-through flat 13 is 3-5mm, a centerless grinder can be used. This is a crucial aspect of the processing technology.

[0048] In step four, the relative positional angular accuracy of the through flat 12 of the machined through flat irregular shaft with its outer diameter and the eccentric hole 11 in the core is within ±3 degrees, and the through flat thickness accuracy is within 0.03mm tolerance.

[0049] The processing technology of this invention enables high-efficiency, high-quality, and low-cost centerless grinding of the outer diameter of a through-type profiled shaft, and can achieve the positional relationship between the through-type profile, the outer diameter, and the eccentric hole in the core. Using this technology, the production efficiency and quality of this type of machined product are high, while the production cost is low.

[0050] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A process for machining a profiled shaft of the type with a flat, characterized in that: Includes the following steps: S1: Material preparation: Cut the material according to the outer diameter and length of the flat irregular shaft; S2: Rough turn the outer diameter, finish machine the eccentric hole, and rough machine the semi-through flat hole; The outer diameter and eccentric hole are rough machined on the outer circle of the bar stock, and a semi-flat bar is rough machined as the positioning reference for the finished flat bar in the subsequent process. The thickness of the semi-flat bar is smaller than that of the finished flat bar. S3: Grinding and finishing of outer diameter: The outer diameter of the workpiece is ground using a centerless grinding machine; S4: Precision flattening: The workpiece is placed in a surface grinding machine for fine flattening. First, place the product into the flattening fixture and clamp it in place; When the workpiece is placed into the grinding fixture, it is placed into the grinding fixture one by one with the semi-flat part processed in step S2 as the positioning reference. The flat part is facing upward and a gauge is set. The flat part is then precision ground in one pass by a surface grinder.

2. A process for machining a profiled shaft of the type according to claim 1, characterized in that: In step S1, the diameter of the bar stock is 0.4 mm larger than the outer diameter of the finished flat profile shaft.

3. The machining process for a through-type flat irregular shaft according to claim 2, characterized in that: In step S2, a Swiss-type lathe is used to rough turn the outer diameter of the workpiece, finish machine the eccentric hole, and rough machine the semi-flat section.

4. The machining process for a through-type flat irregular shaft according to claim 3, characterized in that: In step S2, after rough turning the outer diameter, a grinding allowance of 0.1 mm is left.

5. The machining process for a through-type flat irregular shaft according to claim 4, characterized in that: The semi-flat section has a length of 3-5mm and a thickness of 0.03-0.08mm for grinding.

6. The machining process for a through-type flat irregular shaft according to claim 5, characterized in that: In step S3, the outer diameter tolerance of the machined workpiece is within 0.003 mm, the roundness tolerance of the outer diameter is within 0.002 mm, and the surface roughness is within RZ2.

7. The machining process for a through-type flat irregular shaft according to claim 6, characterized in that: In step S4, the relative positional angular accuracy of the through flatness, outer diameter, and eccentric hole of the machined through flat irregular shaft is within ±3 degrees, and the through flatness thickness accuracy is within 0.03mm tolerance.

Images