Method for integrated grinding of 3j01 alloy elastic element rotary workpiece

Abstract

The application belongs to the technical field of aviation machining and relates to an integrated grinding method for alloy 3J01 rotary workpieces for elastic elements. The method comprises the following steps: installing a bar material on a lathe by using a lathe spring chuck; clamping an outer circle of one end of the bar material, and respectively performing rough machining on the outer circle and two end faces of the workpiece to obtain a rough-turned workpiece; placing the rough-turned workpieces in a centerless grinding automatic feeding disc in batches; performing rough grinding on the rough-turned workpieces by using a centerless grinding device, and performing semi-finishing machining on the outer circle; performing fine grinding on the semi-finished workpieces by using the centerless grinding device to ensure the consistency of the outer circle size and the straightness of the outer circle; installing the fine-ground workpieces on a step grinding spring chuck of a step grinding device; aligning the workpieces to within 0.03, pressing the fine-ground workpieces by using a V-block support device, simultaneously grinding the outer circle and the end faces by using a coarse-fine grinding wheel, and finely grinding the outer circle and the end faces ground by the coarse grinding wheel by using a fine grinding wheel to obtain rotary workpieces.

Description

Technical Field

[0001] This invention belongs to the field of aerospace machining technology and relates to an integrated grinding method for rotary workpieces made of alloy 3J01 for elastic elements. Background Technology

[0002] The aerospace mechanical manufacturing field contains a large number of rotating structural components, with shaft parts serving as important components in linear displacement sensors and force motors. These parts have a length-to-diameter ratio greater than 20:1, are made of 3J01 material with poor machinability, and require a coaxiality of 0.02 mm on the same side of the outer diameter. Currently, these parts are rough-moved on small-scale lathes, straightened by fitter, ground manually, and then finished by CNC lathe to ensure dimensional accuracy. This process is inefficient, involves high tooling costs, and results in inconsistent part dimensions. Summary of the Invention

[0003] The purpose of this invention is to propose an integrated grinding method for rotary workpieces made of alloy 3J01 for elastic elements, which has high processing efficiency, stable and reliable processing quality, and can meet the requirements of mass production.

[0004] The technical solution of this invention is:

[0005] A method for integral grinding of rotary workpieces made of alloy 3J01 for elastic elements is provided, comprising the following steps:

[0006] The bar stock is mounted on the lathe using a lathe collet;

[0007] Clamp the outer circle of one end of the bar stock, and perform rough machining on the outer circle and both end faces of the workpiece to obtain the rough-machined workpiece.

[0008] After rough machining, the workpieces are placed in batches on the automatic feeding tray of the centerless mill;

[0009] The workpiece after rough turning is rough ground using a centerless grinding machine, and the outer diameter is semi-finished.

[0010] The semi-finished workpiece is precision ground using a centerless grinding machine to ensure the consistency of the outer diameter and the straightness of the outer diameter.

[0011] The workpiece after precision grinding is mounted on the step grinding equipment using step grinding spring chucks;

[0012] By aligning the workpiece to within 0.03, the V-block support device presses the workpiece after fine grinding. The coarse and fine grinding wheels grind the outer circle and end face simultaneously, and the fine grinding wheel finely grinds the outer circle and end face after the coarse grinding wheel, thus obtaining the rotating workpiece.

[0013] Furthermore, the hardness of the material for rotary workpieces after heat treatment is HRC36-42; the smallest diameter of rotary workpieces is φ2.3, the length-to-diameter ratio is 42:1, and the coaxiality between the outer circles is required to be less than or equal to 0.05mm.

[0014] Furthermore, the outer diameter of one end of the clamping bar is rough-machined, and the outer diameter and both end faces of the workpiece are rough-machined to obtain the rough-machined workpiece, including:

[0015] Clamp the outer circle with the spring collet, extend 20-30mm to the right as the part to be machined, flatten both ends of the workpiece, remove the excess 0.5mm, and machine the center holes A1 / 2.12 at both ends;

[0016] The spring collet clamps the outer circle, extending 130-140mm to the right as the part to be machined. The right end is supported by the center. The outer circle of the part to be machined is rough-machined, and the excess 1mm is removed.

[0017] Turn the machine around and clamp it, extending 130-140mm to the right as the part to be machined. Support the right end with the center, rough turn the outer diameter of the part to be machined, remove the excess material of 1mm, and connect it to the previous outer diameter. The tool extension should not exceed 0.02mm.

[0018] Furthermore, the centerless grinding equipment needs to grind the rough-turned outer diameter to meet the following requirements: straightness machining to within 0.05 (per 300mm), and outer diameter dimension consistency machining to within 0.01.

[0019] Furthermore, centerless grinding must ensure that straightness and consistency of outer diameter dimensions are met:

[0020] Green silicon carbide 60 mesh, grinding wheel width 255mm;

[0021] With a blade length of 800mm, the blade is coarsely ground to 0.08mm and finely ground to 0.02mm to meet the requirements for straightness and dimensions.

[0022] Furthermore, the step mill uses a spring chuck to clamp the workpiece, and the dial indicator is used to calibrate the workpiece so that the runout at the far end is no more than 0.03; the step mill uses a V-block support device to press the workpiece (1), and uses a double grinding wheel to grind 5 outer circles and end faces at one time.

[0023] Furthermore, the step grinding uses two CBN grinding wheels: a coarse grinding wheel with a diameter of 250mm and a grit size of 65, and a fine grinding wheel with a diameter of 145mm and a grit size of 46.

[0024] Furthermore, the step mill uses oil cooling, and the V-block support device is made of nylon with a width of 12mm.

[0025] This invention solves the problems of easy deformation and low machining efficiency of high aspect ratio rotary workpieces made of alloy 3J01 for elastic elements. The key to this process lies in the use of extended blades and wide grinding wheels for centerless grinding of the outer diameter, along with the proper allocation of roughing and finishing allowances to ensure consistency and straightness of the reference outer diameter. Step grinding requires aligning the workpiece runout and employing specially designed widened nylon pressure rollers to provide clamping force. Roughing and finishing grinding are performed using appropriate grinding parameters and allocating machining allowances to achieve the required outer diameter dimensions, straightness, and coaxiality. Furthermore, this method effectively reduces the need for manual straightening of parts, enabling efficient CNC grinding of shaft parts. The workpieces processed using this method significantly reduce the need for manual straightening, achieving efficient CNC grinding of shaft parts. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a workpiece according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of a workpiece clamping according to an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of a centerless grinding process according to an embodiment of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0031] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0032] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] refer to Figures 1-3 The material to be machined is a difficult-to-machine material (alloy 3J01 for elastic elements), with a hardness of HRC36-42 after heat treatment. Compared to traditional grinding materials, it has lower hardness, higher viscosity, and elasticity. The smallest diameter is φ2.3, the length-to-diameter ratio is 42:1, the straightness requirement is less than or equal to 0.12mm, and the coaxiality between the outer circles is less than or equal to 0.05mm.

[0034] This invention provides an integrated grinding method for rotary workpieces made of alloy 3J01 for elastic elements, comprising the following steps:

[0035] Clamp the workpiece with a spring collet on a CNC lathe or manual lathe, and use the right end to support the rough turning of the outer diameter of the workpiece.

[0036] Rough grinding was performed on a centerless grinding machine using a green silicon carbide grinding wheel with 60 abrasive grains and a width of 255mm to remove 0.08mm of excess material.

[0037] Fine grinding is performed on a centerless grinding machine using a green silicon carbide grinding wheel with 60 abrasive grains and a width of 255mm to remove 0.02mm of excess material, thereby achieving consistency in the straightness and outer diameter of the workpiece.

[0038] The workpiece is clamped by spring collets and supported by V-blocks on a step grinding machine, and coarse and fine grinding wheels grind simultaneously to achieve the outer diameter and geometric tolerances.

[0039] In some embodiments, center holes need to be machined on both ends of the workpiece, and the size of the center holes is A1 / 2.12.

[0040] In some embodiments, a spring collet is used for clamping on a manual lathe or CNC lathe, with an extension length of 130mm and support at the right end. The outer diameter is rough-turned with a 1mm allowance. After turning, a spring collet is used for clamping and rough-turning the outer diameter, with an extension length of 130mm and support at the right end. The other end is rough-turned with a 1mm allowance, and the outer diameter is flush with the previous outer diameter. The tool extension is no more than 0.02mm.

[0041] In some instances, centerless grinding uses an extended blade length of 800mm, a wheel width of 255mm, a wheel grit of 60 mesh, and a wheel material of green silicon carbide.

[0042] In some examples, the centerless grinding roughing depth is 0.08 mm, the grinding wheel speed is 1520 r / min, and the guide wheel speed is 70 r / min.

[0043] In some examples, the centerless mill finish grinding depth is 0.02 mm, the grinding wheel speed is 1520 r / min, and the guide wheel speed is 50 r / min.

[0044] In some instances, step grinding clamping and alignment ( Figure 2 The setup includes: a spring collet 1, a workpiece 2, a pressure roller 3, and a dial indicator 4. The spring collet has a clamping diameter of Φ15. The workpiece is clamped with the spring collet at its left end (20mm) and extends 230mm beyond its original length. The dial indicator is used to ensure the workpiece's far-end runout is no greater than 0.03 mm. After alignment, the V-block support is tightened, and the workpiece runout is re-measured. If it exceeds 0.03 mm, the alignment is repeated. If the runout is no greater than 0.03 mm with the V-block tightened, the clamping is complete.

[0045] In some examples, the step grinder uses an internal head to probe the right end face of the workpiece, sets the cutting coordinate system at point Z0, uses a CBN grinding wheel with a diameter of Φ250mm, a grit size of B65, a wheel speed of 4500 r / min, and a feed rate of 0.17 mm / s, and a CBN grinding wheel with a diameter of Φ145mm, a grit size of B46, a wheel speed of 5250 r / min, and a feed rate of 0.15 mm / s. Both grinding wheels grind simultaneously, machining five stepped outer diameters and end faces in a single pass. The maximum grinding depth of the rough grinding wheel is 13.3 mm, and the grinding depth of the finish grinding wheel is 0.4 mm. Oil cooling is used to meet the precision requirements of the machined workpiece.

[0046] Figure 1 This is a schematic diagram of a rotary workpiece containing a high aspect ratio elastic element made of alloy 3J01, according to another embodiment of the present invention. The processing steps are as follows:

[0047] Step 1: Clamp the outer circle with the spring collet, extending it by about 20mm, flatten the end face of the workpiece, remove the excess material of 0.5mm, and machine the center hole A1 / 2.12.

[0048] Step 2: Clamp the outer diameter with the spring collet, extending 120mm. Support the outer diameter with the right end center, and rough machine the outer diameter, removing 1mm of excess material.

[0049] Step 3: Turn around and clamp, extend the length by 120mm, support the right end, rough machine the outer diameter, remove the excess 1mm, connect it to the previous outer diameter, and the tool thickness should not exceed 0.02mm.

[0050] Step 4: Roughly grind the outer diameter of the workpiece using a centerless grinder. Select a green silicon carbide 60-mesh grinder with a grinding wheel width of 255mm. The cutter length is 800mm, the grinding wheel speed is 1520r / min, the guide wheel speed is 70r / min, and the remaining material is removed by 0.08mm.

[0051] Step 5: Use a centerless grinder to finish grinding the outer diameter of the workpiece. The grinding wheel speed is 1520 r / min, the guide wheel speed is 50 r / min, and the excess material removed is 0.02 mm.

[0052] Step Six: Clamping and Alignment for the Step Grinding. Use a Φ13 spring collet to clamp the workpiece 20mm from the left end, with an extension length of 220mm. Use a dial indicator to ensure the workpiece's far-end runout is no greater than 0.04. After alignment, tighten the V-block support and re-measure the workpiece runout. If it is greater than 0.03, repeat the alignment process. If the runout is no greater than 0.04 with the V-block tightened, the clamping is complete.

[0053] Step 7: The workpiece's right end face is probed by the machine's internal side head during step grinding. The cutting coordinate system is set to point Z0. The rough grinding wheel is a CBN wheel with a diameter of Φ250mm, a grit size of B65, a wheel speed of 5500 r / min, and a feed rate of 0.2 mm / s. The finish grinding wheel is also a CBN wheel with a diameter of Φ145mm, a grit size of B46, a wheel speed of 6250 r / min, and a feed rate of 0.15 mm / s. Both wheels grind simultaneously, grinding four outer diameters and end faces in a single setup. The maximum grinding depth of the rough grinding wheel is 7mm, and the maximum grinding depth of the finish grinding wheel is 0.3mm. Oil cooling is used to meet the workpiece's precision requirements.

[0054] This invention solves the problems of easy deformation and low machining efficiency in machining rotary workpieces made of alloy 3J01 with large aspect ratio elastic elements. The key to this invention lies in centerless grinding combined with stepped grinding to achieve machining of shaft-like workpieces with large aspect ratios. This invention also addresses the problems of large deformation, difficulty in dimensional control, low machining efficiency, and high tooling costs in machining rotary workpieces made of alloy 3J01 with large aspect ratio elastic elements. The method described in this invention produces workpieces with good consistency, good surface finish, very high product precision, and a high degree of CNC automation.

[0055] It should be noted that, without conflict, those skilled in the art can flexibly adjust the order of the above operation steps or flexibly combine the above steps as needed.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

[0057] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0058] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for integrated grinding of rotary workpieces made of alloy 3J01 for elastic elements, characterized in that, Includes the following steps: The bar stock is mounted on the lathe using a lathe collet; Clamp the outer circle of one end of the bar stock, and perform rough machining on the outer circle and both end faces of the workpiece to obtain the rough-machined workpiece. After rough machining, the workpieces are placed in batches on the automatic feeding tray of the centerless mill; The workpiece after rough turning is rough ground using a centerless grinding machine, and the outer diameter is semi-finished. The semi-finished workpiece is precision ground using a centerless grinding machine to ensure the consistency of the outer diameter and the straightness of the outer diameter. The workpiece after precision grinding is mounted on the step grinding equipment using step grinding spring chucks; By aligning the workpiece to within 0.03, the V-block support device presses the workpiece after fine grinding. The coarse and fine grinding wheels grind the outer circle and end face simultaneously, and the fine grinding wheel finely grinds the outer circle and end face after the coarse grinding wheel, thus obtaining the rotating workpiece.

2. The method according to claim 1, characterized in that, The hardness of the material after heat treatment for rotary workpieces is HRC36-42; the smallest diameter of rotary workpieces is φ2.3, the length-to-diameter ratio is 42:1, and the coaxiality between the outer circles is required to be less than or equal to 0.05mm.

3. The method according to claim 1, characterized in that, The outer diameter of one end of the clamping bar is rough-machined, and the outer diameter and both end faces of the workpiece are rough-machined to obtain the rough-machined workpiece, including: Clamp the outer circle with the spring collet, extend 20-30mm to the right as the part to be machined, flatten both ends of the workpiece, remove the excess 0.5mm, and machine the center holes A1 / 2.12 at both ends; The spring collet clamps the outer circle, extending 130-140mm to the right as the part to be machined. The right end is supported by the center. The outer circle of the part to be machined is rough-machined, and the excess 1mm is removed. Turn the machine around and clamp it, extending 130-140mm to the right as the part to be machined. Support the right end with the center, rough turn the outer diameter of the part to be machined, remove the excess material of 1mm, and connect it to the previous outer diameter. The tool extension should not exceed 0.02mm.

4. The method according to claim 1, characterized in that, The centerless grinding equipment needs to grind the rough-turned outer diameter to meet the following requirements: straightness is machined to within 0.05 (per 300mm), and the consistency of the outer diameter dimensions is machined to within 0.

01.

5. The method according to claim 4, characterized in that, Centerless grinding must ensure that straightness and consistency of outer diameter dimensions are met: Green silicon carbide 60 mesh, grinding wheel width 255mm; With a blade length of 800mm, the blade is coarsely ground to 0.08mm and finely ground to 0.02mm to meet the requirements for straightness and dimensions.

6. The method according to claim 1, characterized in that, in: The step grinding uses a spring chuck to clamp the workpiece, and the dial indicator is used to calibrate the workpiece so that the runout at the far end is no more than 0.

03. The step grinding uses a V-block support device to press the workpiece (1), and uses a double grinding wheel to grind 5 outer circles and end faces at one time.

7. The method according to claim 6, characterized in that, The step grinding uses two CBN grinding wheels: a coarse grinding wheel with a diameter of 250mm and a grit size of 65, and a fine grinding wheel with a diameter of 145mm and a grit size of 46.

8. The method according to claim 7, characterized in that, The step mill uses oil cooling, and the V-block support device is made of nylon with a width of 12mm.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-9.

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