Machining process for through flat type special-shaped shaft

Abstract

The invention belongs to the field of shaft machining, and particularly relates to a through flat type special-shaped shaft machining technology. The invention discloses a through-flat special-shaped shaft machining process which comprises the following steps: preparing materials; roughly turning the outer diameter, finely machining an eccentric hole and roughly machining a semi-through flat, namely roughly machining the outer diameter and the eccentric hole on the outer circle of the bar, roughly machining the semi-through flat as a positioning reference of a subsequent finished through flat, and enabling the thickness of the positioning flat to be smaller than that of the finished through flat; the outer diameter of the workpiece is subjected to through type grinding through a centerless grinding machine tool; and the workpiece is put into flat grinding equipment to be subjected to through flat grinding finish machining. The production process is easy, convenient and rapid to operate and high in machining efficiency, the machining quality of the through-flat special-shaped shaft is greatly improved, the requirement for the precision of production equipment is not high, and investment is small; the production cost is low.

Description

Technical Field

[0001] The invention belongs to the field of shaft processing, and in particular relates to a processing technology for a flat special-shaped shaft. Background Art

[0002] The through-flat type special-shaped shaft has a short structure, and a through-flat is provided on the shaft body. There is a positional relationship between the through-flat, the outer circle of the shaft body and the inner hole.

[0003] The existing through-flat special-shaped shaft processing technology uses a turning process to complete the positional relationship of the special-shaped shaft body in one process. Because the shaft body is through-flat, the subsequent process can only use a double-top external cylindrical grinding process to fine-process the external cylindrical surface. The existing through-flat processing technology can meet the size requirements of this special-shaped shaft, but the processing cost is high, the efficiency is low, and the product processing quality is unstable. Summary of the invention

[0004] The present invention aims to solve the problems of low processing efficiency, unsuitability for mass production, high cost, unstable product processing quality, etc. in the conventional flat-shaped special-shaped shaft processing technology. A flat-shaped special-shaped shaft processing technology is proposed, which includes the following steps:

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

[0006] S2: Rough turning of the outer diameter, finishing of the eccentric hole in the core, and rough machining of the semi-through flat;

[0007] Roughly process the outer diameter and the eccentric hole of the core on the outer circle of the bar, and roughly process the semi-through flat as the positioning reference for the subsequent finished product through flat. The thickness of the positioning flat is smaller than the finished product through flat.

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

[0009] S4: Fine grinding: put the workpiece into the flat grinding equipment for fine grinding;

[0010] First, put the product into the flattening tooling and clamp it;

[0011] When the workpiece is placed in the flattening fixture, the semi-through flattened workpiece processed in step S2 is used as the positioning reference and is placed in the flattening fixture one by one for fixing. The flattened part is placed upward and a through gauge is set, and the flattened workpiece is finely ground once by a flat grinding machine.

[0012] According to the above-mentioned through-flat special-shaped shaft processing technology, in step S1, the diameter of the bar material is 0.4 mm larger than the outer diameter of the finished through-flat special-shaped shaft.

[0013] According to the above-mentioned through-flat special-shaped shaft processing technology, in step S2, a Swiss-type lathe turning process is adopted to roughly turn the outer diameter of the workpiece, finely machine the eccentric hole of the core, and roughly machine the semi-through-flattening.

[0014] According to the above-mentioned through-flat special-shaped shaft processing technology, in step S2, a grinding allowance of 0.1 mm is left after the outer diameter is roughly turned.

[0015] According to the above-mentioned through-flat special-shaped shaft processing technology, the half-through flat length is 3-5mm, and the half-through flat thickness has a grinding allowance of 0.03-0.08mm.

[0016] According to the above-mentioned through-flat special-shaped shaft processing technology, in step S3, the outer diameter tolerance of the processed workpiece is within 0.003mm, the roundness tolerance of the outer diameter of the workpiece is within 0.002mm, and the roughness is within RZ2.

[0017] According to the above-mentioned through-flat special-shaped shaft processing technology, in step S4, the relative position angle accuracy of the through-flat special-shaped shaft and the outer diameter and the core eccentric hole is between ±3 degrees, and the through-flat thickness accuracy is within the tolerance of 0.03mm.

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

[0019] 1. The present invention rough-machines the outer diameter and the eccentric hole of the core on the outer circle of the bar stock, and rough-machines the semi-through flat as the positioning reference of the subsequent finished product through flat, so that the outer diameter can be ground and finished by a universal centerless grinding machine for through-type grinding, without the need to use a double-top external cylindrical grinding process to fine-machine the outer circle. The production process is simple and quick to operate, thereby achieving low-cost production of the outer diameter of through-type special-shaped shafts with high processing efficiency. This grinding method has stable quality, high efficiency and low cost for processing through-type special-shaped outer diameters. The outer diameter tolerance of the processed workpiece is within 0.003mm, the roundness tolerance of the workpiece outer diameter is within 0.002mm, the roughness is within RZ2, and the processing efficiency can reach within 1 second.

[0020] 2. The present invention adopts a clamping and positioning method with the flat part facing upward and a through gauge to grind and fine-process the flat part in one time on a flat grinding machine. The phase relationship between the flat part and the outer circle is achieved by positioning the flattening positioning tool, and the through gauge is used to detect the semi-through flattening thickness, thereby ensuring the phase relationship between the flat part of the ground through-flattened special-shaped shaft and the outer diameter of the through-flattened special-shaped shaft, greatly improving the processing quality of the eccentric shaft.

[0021] 3. The length of the half-through flat of the present invention is 3-5mm, which plays a role in positioning the flat part. The thickness of the half-through flat leaves a grinding allowance of 0.03-0.08mm for the fine grinding process of the through flat; it further ensures the positional relationship between the outer diameter of the through flat special-shaped shaft, the eccentric hole of the core, and the through flat. In the turning process, the half-through flat milled on the Swiss machine and other processed parts are processed in one clamping and positioning, with high overall accuracy. Using this half-through flat as the basis for subsequent grinding processing can reduce positioning errors, thereby ensuring the dimensional accuracy of the eccentric shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the processing steps of the present invention.

[0023] Figure 2 It is a schematic diagram of the structure of the rod material in step S1 of the present invention.

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

[0025] Figure 4 A is a front view of the structural schematic diagram of the workpiece after processing in step S2 of the present invention. 1 -A 1 Cross-sectional view.

[0026] Figure 5 B is a front view of the structural schematic diagram of the workpiece after processing in step S2 of the present invention. 1 Towards view.

[0027] Figure 6 It is a three-dimensional diagram of the structural schematic diagram of the workpiece after being processed 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 state of the workpiece after clamping and waiting to be processed in step S4 of the present invention.

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

[0031] Fig.10 This is a front view of the schematic diagram of the flat-shaped special-shaped shaft structure after processing in step S4 of the present invention.

[0032] Fig.11 A is a front view of the schematic diagram of the flat-shaped special-shaped shaft structure after processing in step S4 of the present invention. 2 -A 2 Cross-sectional view.

[0033] Fig.12B is a front view of the schematic diagram of the flat-shaped special-shaped shaft structure after processing in step S4 of the present invention. 2 Towards view. DETAILED DESCRIPTION

[0034] Preferred Embodiments

[0035] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

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

[0037] Step 1: Material preparation: prepare 3m long bar stock and prepare the stock according to the length of the through-flat special-shaped shaft. The bar stock diameter is 0.4mm larger than the outer diameter of the finished through-flat special-shaped shaft.

[0038] Step 2: Rough turning of the outer diameter, finishing of the core eccentric hole 11 and rough machining of the half-through flat 13:

[0039] The bar material is processed by a Swiss-type lathe to obtain the outer diameter of the workpiece 2. The diameter of the bar material after rough turning is 0.1 mm larger than the outer diameter of the finished flat-shaped special-shaped shaft.

[0040] Here, the bar diameter is 0.4mm larger than the outer diameter of the finished flat special-shaped shaft, and 0.3mm is removed by turning, leaving an outer diameter of 0.1mm for the final grinding.

[0041] Rough-machine the outer diameter and the eccentric hole 11 in the core on the outer circle of the bar, and rough-machine the half-through flat 12 as the positioning reference for the finished product through flat 12 in the subsequent sequence. The size design of the half-through flat 12 should take into account the positioning function of the fine grinding through flat 12 and not affect the subsequent centerless grinding. The thickness of the half-through flat 13 is less than that of the finished product through flat 12, leaving a grinding amount of 0.06-0.10mm for the subsequent fine grinding of the through flat 12. This can improve the grinding processing efficiency and positioning accuracy. 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 times. If the half-through flat 13 is too long, it cannot be ground with a centerless grinder. Products ground by centerless grinding equipment cannot have too long flats or keyways. In order to use a high-efficiency and low-cost centerless grinding process to grind the outer diameter in the subsequent sequence, the length of the half-through flat is designed to be as short as possible, as long as it can play a positioning role. In this process, the relative position relationship between the outer diameter of the workpiece 2, the core eccentric hole 11, and the half-through flat 13 is preliminarily determined;

[0042] Step 3: Grinding and finishing the outer diameter: Use a centerless grinding machine to perform through-type grinding on workpiece 2. This grinding method has stable processing quality, high efficiency and low cost. The tolerance of the processed outer diameter can be stabilized within 0.003mm, the roundness tolerance can be stabilized within 0.002, the roughness can be stabilized within RZ2, and the processing efficiency can be within 1 second. This processing method has loose requirements on grinding equipment, and can be produced by one person with multiple machines. Compared with the cylindrical grinding method, it is very efficient;

[0043] Step 4: Fine grinding of flat surface 12: Put the workpiece 2 into the flat grinding equipment for fine grinding of flat surface 12;

[0044] First, the workpiece 2 is placed in the flattening fixture 100 and clamped and fixed by tightening the hexagon socket screw 104;

[0045] When the workpiece 2 is placed in the flattening fixture 100, the half-through flattened part 13 processed in step 2 is used as the positioning reference and is placed in the flattening fixture 100 one by one for fixing. See the assembly drawing. Figure 7 As shown. The relative position relationship between the half-through flattening 13 and the outer diameter of the workpiece is achieved by positioning the flattening fixture 100, so that the relative position relationship between the flattening 13 and the outer diameter of the flattened special-shaped shaft meets the processing requirements. The flattening fixture adopts the method of setting a through gauge with the flat part facing upward. The workpiece 2 is placed in the flattening fixture 100. The first side surface T1 of the through gauge and the half-through flattening 13 of the clamped workpiece are located at the same horizontal plane, indicating that the product is placed correctly.

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

[0047] In step three, the outer diameter of the product is ground with a through-type centerless grinder, which has high precision, stable quality, high efficiency and low cost. The tolerance of the outer diameter is within 0.003mm, the roundness is within 0.002, the roughness is within RZ2, and the processing cycle is within 1 second. This processing method has low requirements for grinding equipment. Compared with the external cylindrical grinding method, it is particularly superior and is the first choice for batch grinding technology. Because step two processes half-through flat 13 instead of through flat 12, and the flat length of half-through flat 13 is 3-5mm, centerless grinding can be used. This is the key to the processing technology.

[0048] In step 4, the relative position angle accuracy of the flattened part 12 and the outer diameter and the core eccentric hole 11 of the processed flattened special-shaped shaft is within ±3 degrees, and the flattened part thickness accuracy is within a tolerance of 0.03 mm.

[0049] The processing technology of the present invention can realize high-efficiency, high-quality, and low-cost centerless grinding to grind the outer diameter of the through-flat special-shaped shaft, and can realize the positional relationship between the through-flat and the outer diameter and the eccentric hole of the core. By adopting this technology, the production efficiency of such processed products is high, the quality is high, and the production cost is low.

[0050] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for processing a flat special-shaped shaft, characterized in that: The following steps are involved: S1: Material preparation: Cutting according to the outer diameter and shaft length of the flat special-shaped shaft; S2: Rough turning of outer diameter, finishing of eccentric hole, and rough machining of half-through flat; Roughly process the outer diameter and eccentric hole on the outer circle of the bar, and roughly process the semi-through flat as the positioning reference for the subsequent finished product through flat. The thickness of the positioning flat is smaller than the finished product through flat. S3: Grinding finishing outer diameter: The outer diameter of the workpiece is through-grinded using a centerless grinding machine; S4: Fine grinding: put the workpiece into the flat grinding equipment for fine grinding; First, put the product into the flattening tooling and clamp it; When the workpiece is placed in the flattening fixture, the semi-through flattened workpiece processed in step S2 is used as the positioning reference and is placed in the flattening fixture one by one for fixing. The flattened part is placed upward and a through gauge is set, and the flattened workpiece is finely ground once by a flat grinding machine.

2. A process for processing a flat-shaped special-shaped shaft according to claim 1, characterized in that: In step S1, the diameter of the bar material is 0.4 mm larger than the outer diameter of the finished flat-shaped special-shaped shaft.

3. A process for processing a flat-shaped special-shaped shaft according to claim 2, characterized in that: In step S2, a Swiss-type lathe turning process is used to roughly turn the outer diameter of the workpiece, finely machine the eccentric hole, and roughly machine the half-through flat.

4. A process for processing a flat-shaped special-shaped shaft according to claim 3, characterized in that: In step S2, a grinding allowance of 0.1 mm is left after the outer diameter is roughly turned.

5. A process for processing a flat-shaped special-shaped shaft according to claim 4, characterized in that: The length of the half-through flat is 3-5 mm, and the thickness of the half-through flat is left with a grinding allowance of 0.03-0.08 mm.

6. A process for processing a flat-shaped special-shaped 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 of the workpiece is within 0.002 mm, and the roughness is within RZ2.

7. A process for processing a flat-shaped special-shaped shaft according to claim 6, characterized in that: In step S4, the relative position angle accuracy of the flattened special-shaped shaft processed, the outer diameter and the eccentric hole is within ±3 degrees, and the flattened thickness accuracy is within a tolerance of 0.03 mm.

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