CN108526964B

CN108526964B - Fixture and method for preventing reprocessing to obtain continuous turning titanium alloy surface detection sample

Info

Publication number: CN108526964B
Application number: CN201810343320.5A
Authority: CN
Inventors: 梁晓亮; 刘战强; 王兵; 宋清华; 任小平; 万熠
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2018-04-17
Filing date: 2018-04-17
Publication date: 2020-11-06
Anticipated expiration: 2038-04-17
Also published as: CN108526964A

Abstract

The invention discloses a fixture and a method for preventing reprocessing to obtain a continuous turning titanium alloy surface detection sample, wherein the fixture comprises a central shaft, an installation disc, a positioning baffle and a locking nut, the installation disc is a circular thin plate, a fracture groove matched with a workpiece is formed in the outer circumferential direction of the circular thin plate, the bottom surface and the bottom of the side surface of the fracture groove form a right angle, and the side surface of the fracture groove is provided with a positioning part protruding into the fracture groove; the round thin plate is connected with the central shaft through a key; and positioning baffles arranged on the central shaft are arranged on two sides of the mounting disc, and the mounting disc and the positioning baffles are locked through locking nuts.

Description

Fixture and method for preventing reprocessing to obtain continuous turning titanium alloy surface detection sample

Technical Field

The invention relates to a cutting clamp and an experimental method, in particular to a clamp and a method for obtaining a continuous turning titanium alloy surface detection sample by preventing reprocessing.

Background

The titanium alloy belongs to novel structural metal with strategic significance which is intensively developed in the country of the 21 st century, and is widely applied to the fields of aerospace and national defense high and new technology weaponry. Many researchers have focused on the turning of titanium alloys and the quality of the machined surface. After the corresponding titanium alloy is turned, a sample with a small size and suitable for detection needs to be obtained from a corresponding workpiece by reprocessing through a wire cutting technology and the like. Because titanium alloy is easy to oxidize at high temperature, if the titanium alloy is subjected to reprocessing technology, the generated cutting heat can affect the original machined surface, so that an oxide film is generated on the machined surface, especially a common blue phenomenon is generated, and the difference between the observed surface and the actual turned surface of a sample is caused. If the titanium alloy is firstly divided into the sizes of the detection samples for intermittent machining through the related technology, the cutting heat and the cutting force generated in the cutting process are discontinuous, and the obtained machined surface has larger difference with the surface obtained by actual continuous turning. The reasons of the above analysis all directly affect the reliability of the subsequent detection and data analysis of the experimental sample.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a new thought for obtaining a surface detection sample and a related experimental method after continuous turning of the titanium alloy by designing a related cutting clamp and an experimental method, and improves the accuracy of related experiments and tests for researching the influence of cutting processing on the surface quality; the clamp can improve the accuracy of a test sample and can be repeatedly used.

In order to solve the technical problems, the invention adopts the following technical scheme:

a fixture for preventing continuous turning titanium alloy surface detection samples from being obtained by reprocessing comprises a central shaft, a mounting disc, a positioning baffle and a locking nut, wherein the mounting disc is a circular thin plate, a fracture groove matched with a workpiece is formed in the outer circumferential direction of the circular thin plate, the bottom surface and the bottom of the side surface of the fracture groove form a right angle, and the side surface of the fracture groove is provided with a positioning part protruding into the fracture groove; the round thin plate is connected with the central shaft through a key; and positioning baffles arranged on the central shaft are arranged on two sides of the mounting disc, and the mounting disc and the positioning baffles are locked through locking nuts.

Furthermore, the workpiece is in a circular ring-shaped structure with the thickness consistent with that of the mounting disc, and the radius of the workpiece thin plate is larger than that of the mounting disc; the inner ring of the workpiece is provided with a bulge matched with the fracture groove, the side surface of the bulge is provided with a clamping groove, and the clamping groove is matched with a positioning part on the mounting disc; the workpiece is just mounted on the mounting disc, a gap does not exist between the workpiece and the mounting disc after the workpiece and the mounting disc are matched, a complete annular structure is formed, and the structural design of the workpiece sheet can be complementary with that of the mounting disc.

Further, the shapes of the mounting disc and the workpiece are finished by using a wire cutting technology. Before cutting, both sides of the workpiece sheet are polished to remove the influence of linear cutting on both sides of the workpiece.

Further, the center pin on still be equipped with spacing key, spacing to the locating plate, the size of locating plate is by the mounting disc sheet metal, the keyway design decision on work piece sheet metal and the baffle.

Furthermore, the locking nut has self-locking capacity, can fix the assembled clamp and has anti-loose and anti-vibration effects.

Furthermore, the positioning baffle comprises a left positioning baffle and a right positioning baffle, the left positioning baffle and the right positioning baffle are circular, and the sizes of the left positioning baffle and the right positioning baffle are determined according to the size of the workpiece; the middle part is a hollow circle and is provided with a key slot.

Furthermore, the tail end of the central shaft is provided with threads which are matched with the locking nut.

A cutting experiment method for preventing reprocessing from directly obtaining a continuous turning titanium alloy surface detection sample comprises the following steps:

1. the mounting disc and the workpiece are machined in advance by utilizing a linear cutting technology;

2. the central shaft is clamped on a three-jaw chuck of the numerical control lathe, then a left positioning baffle, a mounting disc, a workpiece and a right positioning baffle are sequentially mounted, a limiting key and a locking nut are used for fixing, and finally the central shaft is fixed by a machine tool tip;

3. firstly, roughly turning an outer circle of a workpiece to enable a surface to be processed of the workpiece and a central shaft to be on the same cylindrical surface; rough turning is continued, so that the reserved distance is met between the machining surface of the workpiece and the outermost circle of the mounting disc; the requirements for this distance are: not only can enough removal amount in cutting process be ensured, but also the detection sample which can be smoothly obtained after the cutting experiment is finished can be ensured;

4. continuously processing the workpiece according to the set cutting experiment parameters; and after the cutting experiment is finished, taking down the machined workpiece, and directly obtaining a corresponding detection sample of the machined surface without secondary auxiliary machining.

The working principle of the invention is as follows:

a method for directly obtaining a continuous turning titanium alloy surface detection sample by preventing reprocessing. By designing a special cutting clamp and a special workpiece structure, after rough turning and experimental parameter processing are carried out in sequence, a required processing surface detection sample is effectively broken at the designed position of a fracture groove, and a corresponding detection sample of a processing surface is directly obtained. The method not only avoids the influence of cutting heat and cutting force generated in the secondary machining process on the original turning surface, but also can ensure the continuity of the cutting process, ensure the consistency between the surface of the obtained detection sample and the actual turning surface, and improve the accuracy of relevant experiments and tests for researching the influence of the cutting process on the surface quality.

Compared with the prior art, the invention has the following advantages:

1) the fixture and the experimental method for obtaining the continuous turning titanium alloy surface detection sample are suitable for common machine tools and numerical control machine tools, and have strong universality.

2) The fixture for continuously turning the titanium alloy surface detection sample is prevented from being obtained after reprocessing, is simple and convenient in structural design, and can be recycled.

3) The design of the special fracture groove structures of the mounting disc sheet and the workpiece sheet in the clamp structure can obtain a plurality of machined surface detection samples at one time, and the non-uniformity of the samples after multiple machining is avoided.

4) The fixture and the experimental method for obtaining the continuous turning titanium alloy surface detection sample are used for preventing reprocessing, and are particularly suitable for special materials which cannot be subjected to secondary processing.

5) The fixture and the experimental method for preventing continuous turning titanium alloy surface detection samples from being obtained after reprocessing are prevented, the consistency between the surface of the obtained detection sample and the actual turning surface is guaranteed, and the accuracy of relevant experiments and tests for researching the influence of cutting on the surface quality is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.

FIG. 1 is a schematic structural section view of a fixture for obtaining a continuous turning titanium alloy surface detection sample for preventing reprocessing according to the present invention;

FIG. 2(1), FIG. 2(2), FIG. 2(3) are schematic structural views of the special mounting plate thin plate in the fixture of the present invention;

FIG. 3(1), FIG. 3(2), and FIG. 3(3) are schematic structural views of the workpiece sheet in the clamping apparatus according to the present invention;

FIG. 4 is a schematic view of the configuration of the fixture of the present invention after the mounting sheet and the workpiece sheet have been mated;

FIG. 5(a) is a structural diagram of a sample after processing in FIGS. 5(b) and 5 (c);

the device comprises a limiting key 1, a central shaft 2, a left positioning baffle 3, a workpiece sheet 4, an installation disc sheet 5, a right positioning baffle 6, a gasket 7, a locking nut 8, a key groove 9, a hollow circle 10 and a fracture groove 11.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an", and/or "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof;

for convenience of description, the words "up", "down", "left" and "right" in the present invention, if any, merely indicate correspondence with up, down, left and right directions of the drawings themselves, and do not limit the structure, but merely facilitate the description of the invention and simplify the description, rather than indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention.

The term explains that the 'breaking groove' is a U-shaped groove-shaped structure.

As described in the background, in the prior art, after the corresponding titanium alloy is turned, a sample with a smaller size and suitable for detection needs to be obtained from the corresponding workpiece by a re-machining process such as a wire cutting process. Because titanium alloy is easy to oxidize at high temperature, if the titanium alloy is subjected to reprocessing technology, the generated cutting heat can affect the original machined surface, so that an oxide film is generated on the machined surface, especially a common blue phenomenon is generated, and the difference between the observed surface and the actual turned surface of a sample is caused. If the titanium alloy is firstly divided into the sizes of the detection samples for intermittent machining through the related technology, the cutting heat and the cutting force generated in the cutting process are discontinuous, and the obtained machined surface has larger difference with the surface obtained by actual continuous turning. The reasons of the above analysis all directly affect the reliability of the subsequent detection and data analysis of the experimental sample. In order to solve the technical problems, the invention provides a new thought for obtaining a surface detection sample and a related experimental method after continuous turning of titanium alloy by designing a related cutting clamp and an experimental method, and improves the accuracy of related experiments and tests for researching the influence of cutting on the surface quality; the clamp can improve the accuracy of a test sample and can be repeatedly used.

Example 1

A fixture for preventing continuous turning titanium alloy surface detection samples from being obtained by reprocessing. As shown in figure 1, the clamp mainly comprises a central shaft 2, a mounting disc 5, a workpiece 4, a left positioning baffle 3, a right positioning baffle 6, a limiting key 1 and a locking nut 8.

Further preferably, the length of the central shaft 2 may be designed to be 200mm, the diameter of the clamping end may be designed to be 50mm, and the diameter of the mounting end may be designed to be 30 mm.

The left end of the central shaft is provided with a left positioning baffle which is circular; a further preferred diameter is 100mm and a thickness is 10 mm.

The rightmost end of the central shaft is provided with a thread for locking the nut and is provided with a central hole.

Further preferably, the material of the central shaft may be 45# steel.

As shown in fig. 2(1), 2(2), and 2(3), the diameter of the mounting plate is larger than the diameter of the two positioning baffles, and more preferably, the diameter of the mounting plate is designed to be 100 mm. The thickness of the mounting plate can be designed to be 2 mm. In order to obtain a plurality of processing surface test sample pieces at one time, a plurality of corresponding fracture grooves 11 are arranged at the circumference of the mounting disc, and the outer ring of the mounting disc thin plate forms a structure similar to a gear shape; aiming at the related testing technology required by the processed surface after the detection sample is obtained, the structure of the fracture groove is designed to be that the bottom edge is a right angle, and the outer side of the fracture groove is superposed with the circular edge of the circular plate of the mounting disc; more preferably, the depth of the side surface is 10mm, the width of the bottom is 15mm, and a convex positioning part is arranged on the inner side surface of the fracture groove.

The middle part of the mounting disc is provided with a hollow circle 10 structure, and the size of the hollow circle is consistent with that of the mounting part at the right end of the central shaft; further preferably, the size of the hollow circle is preferably 30mm, and a key groove 9 is arranged on the inner circle of the hollow circle and is used for being connected with a key of the central shaft; the circular mounting disc thin plate is made of die steel H13.

As shown in fig. 3(1), 3(2), and 3(3), the shape of the workpiece is a circular thin plate with a thickness consistent with that of the mounting plate; preferably, it can be designed to be 2 mm. The diameter of the workpiece thin plate is larger than that of the mounting disc, 2mm of rough machining thickness and 1mm of experimental cutting machining thickness are reserved, and in addition, the thickness of a continuous layer of 0.5mm is arranged, and the diameter is 115 mm. The inner circumference direction of the workpiece sheet is provided with a bulge matched with the fracture groove of the mounting disc, and the structural design of the bulge is matched with that of the mounting disc; the bellied side is equipped with the joint groove, and this joint groove cooperates with the location portion on the mounting disc.

As shown in fig. 4, the structural design of the workpiece thin plate and the structural design of the mounting plate can be complementary, and no gap exists between the two after the two are matched, so that a complete circular structure is formed. More preferably, the material of the round workpiece thin plate is titanium alloy TC 4. The two cooperate in a manner similar to that of meshing with a gear.

The mounting plate thin plate and the workpiece thin plate are both completed by utilizing a linear cutting technology. Before cutting, both sides of the workpiece sheet are polished to remove the influence of linear cutting on both sides of the workpiece.

The right positioning baffle is also circular, the diameter and the thickness of the right positioning baffle are consistent with those of the left positioning baffle, and further preferably, the right positioning baffle is made of 45# steel.

Further preferably, the limiting key is a common flat key, the size length is 20mm, the width is 20mm, and the thickness is 5 mm. The material is 45# steel.

Further preferably, the nut is a locking nut, has self-locking capacity and can play a role in preventing looseness and vibration.

Example 2

This example uses numerically controlled turning of the workpiece, further preferably done on a PUMA200M lathe. The material is titanium alloy TC 4.

And (3) clamping the central shaft on a three-jaw chuck of the numerical control lathe, then sequentially mounting the mounting disc thin plate, the workpiece thin plate and the right positioning baffle plate, fixing by using a limiting key and a locking nut, and finally fixing the central shaft by using the tip of the machine tool.

The outer circle is roughly turned, the cutting parameters are 40m/min and 0.1mm/rev, and the surface to be processed of the workpiece sheet and the central shaft are on the same cylindrical surface. And (5) continuously roughly turning the outer circle to enable the distance between the processing surface of the workpiece thin plate and the cylindrical surface of the mounting disc to be 1.3 mm.

Machining is carried out according to cutting experiment parameters, wherein the cutting speed is 120m/min, and the feeding speed is 0.1 mm/rev. After the cutting experiment is finished, the thickness of the fracture layer of the workpiece sheet is 0.3mm, the workpiece sheet can be easily fractured, the corresponding detection sample of the machined surface is directly obtained, and secondary auxiliary machining is not needed.

The clamp and the cutting experimental method for obtaining the continuous turning titanium alloy surface detection sample for preventing reprocessing can directly obtain the corresponding detection sample of the machined surface. The method not only avoids the influence of cutting heat and cutting force generated in the secondary machining process on the original turning surface, but also can ensure the continuity of the cutting process, ensure the consistency between the surface of the obtained detection sample and the actual turning surface, and improve the accuracy of relevant experiments and tests for researching the influence of the cutting process on the surface quality.

The above description is only a preferred example of the present application and is not intended to limit the present application, and various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A fixture for preventing continuous turning titanium alloy surface detection samples from being obtained by reprocessing is characterized by comprising a central shaft, a mounting disc, a positioning baffle and a locking nut, wherein the mounting disc is a circular thin plate, a fracture groove matched with a workpiece is formed in the outer circumferential direction of the circular thin plate, the bottom surface and the bottom of the side surface of the fracture groove form a right angle, and the side surface of the fracture groove is provided with a positioning part protruding into the fracture groove; the round thin plate is connected with the central shaft through a key; positioning baffles arranged on the central shaft are arranged on two sides of the mounting disc, and the mounting disc and the positioning baffles are locked through locking nuts;

the workpiece is clamped by the fixture, after rough turning and experimental parameter processing are carried out in sequence, the required detection sample of the processed surface is effectively broken at the designed position of the fracture groove, and the corresponding detection sample of the processed surface is directly obtained.

2. The fixture for preventing reprocessing to obtain a continuous turning titanium alloy surface detection sample as claimed in claim 1, wherein the workpiece is of a circular ring-shaped structure with the thickness consistent with that of the mounting disc, and the radius of the workpiece is larger than that of the mounting disc; the inner ring of the workpiece is provided with a bulge matched with the fracture groove, the side surface of the bulge is provided with a clamping groove, and the clamping groove is matched with a positioning part on the mounting disc; the workpiece is just installed on the installation disc, and a gap does not exist between the workpiece and the installation disc after the workpiece and the installation disc are matched, so that a complete annular structure is formed.

3. The fixture for preventing the reprocessing to obtain the continuous turning titanium alloy surface detection sample as claimed in claim 1, wherein the shapes of the mounting disc and the workpiece are both completed by using a wire cutting technology.

4. The fixture for preventing the reprocessing to obtain the continuous turning titanium alloy surface detection sample as claimed in claim 1, wherein a limiting key is further arranged on the central shaft to limit the position of the positioning baffle.

5. The fixture for preventing the reprocessing to obtain the continuous turning titanium alloy surface detection sample as claimed in claim 1, wherein the positioning baffle comprises a left positioning baffle and a right positioning baffle, the left positioning baffle and the right positioning baffle are circular, and the size of the left positioning baffle and the right positioning baffle is determined according to the size of a workpiece; the middle parts of the left positioning baffle and the right positioning baffle are hollow circles and are provided with key grooves.

6. The fixture for preventing the reprocessing to obtain the continuous turning titanium alloy surface detection sample as claimed in claim 1, wherein the size of the positioning baffle is determined by the design of key grooves on a mounting plate, a workpiece and the baffle.

7. The fixture for preventing continuous turning titanium alloy surface inspection samples from being reprocessed as claimed in claim 1, wherein the end of the central shaft is threaded to engage with the lock nut.

8. A method for carrying out a cutting experiment by using the fixture for preventing reprocessing of the continuous turning titanium alloy surface detection sample as claimed in any one of claims 1 to 7,

step 1, machining a mounting disc and a workpiece in advance by using a linear cutting technology; polishing both side surfaces of the workpiece before cutting;

step 2, the central shaft is clamped on a three-jaw chuck of the numerical control lathe, then a left positioning baffle, a mounting disc, a workpiece and a right positioning baffle are sequentially mounted, fixed by a limiting key and a locking nut, and finally fixed by a machine tool center;

step 3, roughly turning the outer circle of the workpiece to enable the surface to be processed of the workpiece and the central shaft to be on the same cylindrical surface; rough turning is continued, so that the reserved distance is met between the machining surface of the workpiece and the outermost circle of the mounting disc; the requirements for this distance are: the removal amount in the cutting process can be ensured, and the detection sample which can be smoothly obtained after the cutting experiment is finished can be ensured;

step 4, continuing to process the workpiece according to the set cutting experiment parameters; after the cutting experiment is completed, the machined workpiece is taken down, the required machined surface detection sample is effectively broken at the designed position of the fracture groove, the corresponding machined surface detection sample is directly obtained, and secondary auxiliary machining is not needed.