阅读说明：本技术 一种车削薄壁钢套的方法 (Method for turning thin-wall steel sleeve ) 是由 徐嘉乐 汤龙昊 邹华杰 周岳 俞浩荣 姚素芹 袁志刚 吴新平 于 2020-11-04 设计创作，主要内容包括：本发明提出了一种车削薄壁钢套的方法,属于机械加工技术领域。解决了现有薄壁钢套工件难以批量生产,无法保证进度的问题。它包括将96％碳酰胺和4％火硝的混合物加热到140℃以上,制成自凝固剂,将第一批自凝固剂填充到工件的内孔中,填充高度为A,待第一批自凝固剂凝固,第一批自凝固剂凝固后,将第二批自凝固剂填充到工件的内孔中,填充高度为A,在工件的上端口盖上橡皮垫并将工件翻转180°,使未凝固的第二批自凝固剂流向下方,带第二批自凝固剂凝固,第二批自凝固剂凝固后,车削工件的外圆和端面,使用专用夹具对工件进行装夹,装夹后依次对工件内孔进行粗车和精车加工。它主要用于薄壁钢套的批量加工。(The invention provides a method for turning a thin-wall steel sleeve, and belongs to the technical field of machining. The problem of current thin wall steel bushing work piece be difficult to batch production, unable assurance progress is solved. Heating a mixture of 96% of carbamide and 4% of potassium nitrate to more than 140 ℃ to prepare a self-solidifying agent, filling a first batch of self-solidifying agent into an inner hole of a workpiece, wherein the filling height is A, after the first batch of self-solidifying agent is solidified, filling a second batch of self-solidifying agent into the inner hole of the workpiece, the filling height is A, covering a rubber pad on the upper end cover of the workpiece, turning the workpiece by 180 degrees, enabling the non-solidified second batch of self-solidifying agent to flow downwards, solidifying with the second batch of self-solidifying agent, turning the outer circle and the end face of the workpiece after the second batch of self-solidifying agent is solidified, clamping the workpiece by using a special clamp, and performing rough turning and finish turning on the inner hole of the workpiece in sequence after clamping. The method is mainly used for batch processing of the thin-wall steel sleeve.)

1. A method for turning a thin-wall steel sleeve is characterized in that: it comprises the following steps:

step 1: heating a mixture of 96% of carbamide and 4% of potassium nitrate to over 140 ℃ to prepare a self-solidifying agent, filling a first batch of self-solidifying agent (2) into an inner hole of a workpiece (1), wherein the filling height is A, and waiting for the first batch of self-solidifying agent (2) to solidify;

step 2: after the first batch of self-solidifying agent (2) is solidified, filling a second batch of self-solidifying agent (3) into an inner hole of the workpiece (1), wherein the filling height is A, a rubber pad (4) is arranged on an upper end cover of the workpiece (1), the workpiece (1) is turned over by 180 degrees, and the second batch of non-solidified self-solidifying agent (3) flows downwards and is solidified with the second batch of self-solidifying agent (3);

and step 3: after the second batch of self-solidifying agent (3) is solidified, turning the outer circle and the end face of the workpiece (1), positioning and clamping the left end of the workpiece (1) by using a three-jaw self-centering chuck, roughly turning and finely turning the outer circle of the right end part of the workpiece (1) in sequence and turning the end face, turning around by using a soft jaw to position and clamp the right end of the workpiece (1), and roughly turning and finely turning the outer circle of the left end part of the workpiece (1) in sequence and turning the end face by using a lathe;

and 4, step 4: after the outer circle and the end face are machined, soaking the machined workpiece (1) into hot water at the temperature of 40-50 ℃ to dissolve the self-solidifying agent and separate the workpiece (1), and cleaning the workpiece (1);

and 5: use special fixture to carry out the clamping to work piece (1), special fixture includes main shaft connector (5) and nut (6), the hole of main shaft connector (5) links to each other with the excircle cooperation of work piece (1), restricts 4 degrees of freedom of work piece (1), and the terminal surface contact of work piece (1) terminal surface and main shaft connector (5) restricts 1 degree of freedom, main shaft connector (5) and nut (6) threaded connection press from both sides tight work piece (1) through nut (6) axial, carry out rough turning and finish turning to work piece (1) hole in proper order after the clamping.

2. A method of turning a thin-walled steel sleeve according to claim 1, characterized in that: and 3, the turning tool used for turning the excircle in the step 3 is a 93-degree crater excircle turning tool, the blade is made of YT15, the cutter bar is made of 45 steel, the main deflection angle is equal to 93 degrees, and a crater chip groove is ground on the front cutter face.

3. A method of turning a thin-walled steel sleeve according to claim 1, characterized in that: the rough turning excircle cutting consumption in the step 3 is as follows: the cutting speed is 240m/min, the feed rate is 1.2mm/r, and the back cutting depth is 0.6 mm.

4. A method of turning a thin-walled steel sleeve according to claim 1, characterized in that: the amount of excircle finish turning in the step 3 is as follows: the cutting speed is 300m/min, the feed rate is 0.2mm/r, and the back cutting depth is 0.3 mm.

5. A method of turning a thin-walled steel sleeve according to claim 1, characterized in that: and 3, cutting fluid used in the turning in the step 3 is cutting oil.

6. A method of turning a thin-walled steel sleeve according to claim 1, characterized in that: the turning tool used for turning the inner hole in the step 5 is an inner hole turning tool, the blade is made of YT15, the cutter bar is made of 45 steel, the main deflection angle is 60 degrees, the front angle is 30 degrees, the rear angle is 12 degrees, and the blade inclination angle is-45 degrees.

7. A method of turning a thin-walled steel sleeve according to claim 1, characterized in that: and 5, roughly turning inner holes, wherein the cutting consumption is as follows: the cutting speed is 150m/min, the feed rate is 0.1mm/r, and the back bite amount is 0.5 mm.

8. A method of turning a thin-walled steel sleeve according to claim 1, characterized in that: the cutting amount of the finish turning inner hole in the step 5 is as follows: the cutting speed is 200m/min, the feed rate is 0.05mm/r, and the back bite amount is 0.1 mm.

9. A method of turning a thin-walled steel sleeve according to claim 1, characterized in that: and in the step 5, the inner hole of the main shaft connecting piece (5) is in clearance fit with the outer circle of the workpiece (1).

10. A method of turning a thin-walled steel sleeve according to claim 1, characterized in that: the height A is 15mm added to the length of the lathe three-jaw chuck required for clamping the workpiece (1) when the workpiece (1) is machined.

Technical Field

The invention belongs to the technical field of machining, and particularly relates to a method for turning a thin-wall steel sleeve.

Background

The thin-wall steel sleeve is a thin-wall sleeve with three dimensions of excircle dimension, inner hole dimension and length dimension, and is made of medium carbon steel. The thin-wall steel sleeve part has very thin wall thickness and very weak radial rigidity, is easily deformed under the influence of factors such as cutting force, cutting heat, clamping force and the like in the processing process, and causes the difficulty in ensuring the requirements of the excircle size, the excircle roundness and the excircle cylindricity of the thin-wall sleeve; the requirements on the size of the inner circle, the roundness of the inner circle and the cylindricity of the inner circle of the thin-wall sleeve are difficult to guarantee; the coaxiality requirement of the inner circle and the outer circle of the thin-wall sleeve is difficult to guarantee.

The processing of the thin-wall steel sleeve part cannot be directly clamped by using a common three-jaw chuck or a four-jaw chuck. Because the wall thickness of the thin-wall steel sleeve part is small, the integral rigidity of the part is poor, and once the part is subjected to a large radial clamping force, the circular section of the thin-wall steel sleeve part is easily changed into a triangle or a square with chamfered corners. Although the triangle and the square do not directly appear at the processed part, they also affect the processed part, so that the processed part is not an absolute circle and the outer diameter of the arc is more or less locally straightened during processing. Therefore, the problem that the actual cutting depth is smaller than the theoretical cutting depth when the outer circle is cut or larger than the theoretical cutting depth when the inner circle is cut is caused, and the problem that the wall thickness of the part of the processed workpiece is over-poor after the deformation generated by clamping is recovered after the workpiece is finally unloaded.

Clamping the excircle of the thin-wall steel sleeve by using a three-jaw chuck on a lathe, finely turning inner holes of a batch of thin-wall steel sleeves, wherein the cross section of the turned holes is triangular; because the workpiece is a thin-wall steel sleeve and has poor rigidity, the workpiece deforms under the action of clamping force; in the clamped state, the cross section of the turned hole is circular, but after the clamping force is removed, the hole is triangular and circular due to the elastic recovery of the workpiece.

The existing method for turning the thin-wall steel sleeve comprises the following steps:

1. the allowance of the inner hole of the thin-wall steel sleeve is greatly increased, the thin-wall steel sleeve is changed into a non-thin-wall steel sleeve, the turning problem of the excircle is solved by three-jaw chuck clamping, the fine reference excircle is clamped by an opening sleeve, and the inner hole of the thin-wall steel sleeve is turned: the three-point clamping of the three-jaw chuck is changed into full circle holding by the opening sleeve, namely the three-jaw chuck is used for clamping the opening sleeve to enable the opening sleeve to deform and evenly hold the thin-wall sleeve tightly, and then an inner hole is turned.

2. Increase the surplus of thin wall steel bushing hole by a wide margin, make the thin wall steel bushing become non-thin wall steel bushing, the turning problem of excircle is solved in the clamping of three-jaw chuck, adopts the accurate benchmark excircle of big arc soft jaw clamping again, turning thin wall steel bushing hole: three clamping jaws of the three-jaw chuck are refitted, and large arc-shaped soft jaws are welded on the three general clamping jaws, so that the clamping area is increased, and the clamping and turning deformation of the thin-wall sleeve is reduced.

3. The allowance of the inner hole of the thin-wall steel sleeve is greatly increased, the thin-wall steel sleeve is changed into a non-thin-wall steel sleeve, the turning problem of the excircle is solved by clamping with the three-jaw chuck, the precise reference excircle is clamped by adopting a special clamp, and the inner hole of the thin-wall steel sleeve is turned.

4. Clamping the thin-wall sleeve on a disc chuck and turning the thin-wall sleeve.

But the allowance of the inner hole of the thin-wall steel sleeve is greatly increased, the turning problem of the reference excircle is solved, raw materials are wasted, labor and time are wasted, the waste of batch production is remarkable, and the number of feed times is increased when the inner hole is turned. The turning of the thin-wall steel sleeve on the faceplate can only solve the turning problem of the large-diameter thin-wall sleeve and can not solve the turning problem of the small-diameter thin-wall steel sleeve. When the allowance of the inner hole and the excircle of the thin-wall steel sleeve is normal, the three-jaw chuck cannot be used for clamping, and the turning problem of the reference excircle cannot be solved. The outer circle cannot be clamped by the opening sleeve without the fine reference of the outer circle, and an inner hole of the thin-wall steel sleeve is turned; the excircle cannot be clamped by a large arc-shaped soft claw, and the inner hole of the thin-wall steel sleeve is turned; the thin-wall steel sleeve can not be clamped by a special clamp, and an inner hole of the thin-wall steel sleeve is turned; even if the lathe is turned, the coaxiality requirement of the inner circle and the outer circle cannot be ensured at all.

Disclosure of Invention

The invention provides a method for turning a thin-wall steel sleeve, aiming at solving the problems in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme: a method for turning a thin-walled steel sleeve comprises the following steps:

step 1: heating a mixture of 96% of carbamide and 4% of potassium nitrate to over 140 ℃ to prepare a self-solidifying agent, filling a first batch of self-solidifying agent into an inner hole of a workpiece, wherein the filling height is A, and waiting for the first batch of self-solidifying agent to solidify;

step 2: after the first batch of self-solidifying agent is solidified, filling a second batch of self-solidifying agent into an inner hole of the workpiece, wherein the filling height is A, a rubber pad is arranged on an upper end cover of the workpiece, the workpiece is turned over by 180 degrees, so that the second batch of non-solidified self-solidifying agent flows downwards and is solidified with the second batch of self-solidifying agent;

and step 3: after the second batch of self-solidifying agent is solidified, turning the outer circle and the end face of the workpiece, positioning and clamping the left end of the workpiece by using a three-jaw self-centering chuck, roughly turning and finely turning the outer circle of the right end part of the workpiece in sequence by using a lathe and then turning the end face, turning around by using a soft jaw to position and clamp the right end of the workpiece, and roughly turning and finely turning the outer circle of the left end part of the workpiece in sequence by using the lathe and then turning the end face;

and 4, step 4: after the outer circle and the end face are machined, soaking the machined workpiece into hot water at 40-50 ℃ to dissolve the self-solidifying agent and separate the self-solidifying agent from the workpiece, and cleaning the workpiece;

and 5: the special fixture is used for clamping a workpiece and comprises a main shaft connecting piece and a nut, an inner hole of the main shaft connecting piece is connected with the outer circle of the workpiece in a matched mode, 4 degrees of freedom of the workpiece are limited, the end face of the workpiece is in contact with the end face of the main shaft connecting piece, 1 degree of freedom is limited, the main shaft connecting piece is in threaded connection with the nut, the workpiece is clamped through the nut in the axial direction, and rough turning and finish turning are sequentially carried out on the inner hole of the workpiece after clamping.

Furthermore, the turning tool used for turning the excircle in the step 3 is a 93-degree crater excircle turning tool, the blade is made of YT15, the cutter bar is made of 45 steel, the main deflection angle is equal to 93 degrees, and a crater chip pocket is ground on the front cutter face.

Furthermore, the amount of rough turning and excircle cutting in the step 3 is as follows: the cutting speed is 240m/min, the feed rate is 1.2mm/r, and the back cutting depth is 0.6 mm.

Furthermore, the amount of excircle finish turning in step 3 is as follows: the cutting speed is 300m/min, the feed rate is 0.2mm/r, and the back cutting depth is 0.3 mm.

Furthermore, the cutting fluid used in the turning in the step 3 is cutting oil.

Furthermore, the turning tool used for turning the inner hole in the step 5 is an inner hole turning tool, the blade is made of YT15, the cutter bar is made of 45 steel, the main deflection angle is 60 degrees, the front angle is 30 degrees, the rear angle is 12 degrees, and the blade inclination angle is-45 degrees.

Furthermore, the amount of rough turning inner hole cutting in the step 5 is as follows: the cutting speed is 150m/min, the feed rate is 0.1mm/r, and the back bite amount is 0.5 mm.

Furthermore, the amount of finish turning inner holes in the step 5 is as follows: the cutting speed is 200m/min, the feed rate is 0.05mm/r, and the back bite amount is 0.1 mm.

Furthermore, in the step 5, the inner hole of the main shaft connecting piece is in clearance fit with the outer circle of the workpiece.

Furthermore, the height A is 15mm added to the length required by the lathe three-jaw chuck for clamping the workpiece when the workpiece is machined.

Compared with the prior art, the invention has the beneficial effects that: the invention solves the problems that the existing thin-wall steel sleeve workpiece is difficult to produce in batches and cannot ensure the progress. The invention does not need to greatly increase the allowance of the inner hole of the thin-wall steel sleeve, when the allowance of the inner hole and the excircle of the thin-wall steel sleeve is normal, the three-jaw chuck can be used for clamping the thin-wall steel sleeve, and all the precisions of the thin-wall steel sleeve can be ensured. The rigidity of the thin-wall steel sleeve blank can be greatly improved, the thin-wall steel sleeve can be clamped by using the three-jaw chuck, and the machining precision is high. The special turning tool is used, so that the cutting force is small, and the deformation of the workpiece is reduced; the special clamp is used for clamping, so that the clamping tool is only subjected to axial clamping force and is not subjected to radial clamping force.

The invention has the following advantages:

1. the rigidity of a blank of the thin-wall steel sleeve is greatly improved by using a self-solidifying agent, the excircle of the thin-wall steel sleeve is positioned and clamped by using a three-jaw self-centering chuck, the excircle is positioned and clamped by turning a soft jaw, the excircle and the end face are turned, the cylindricity requirement of the excircle is ensured, and the verticality requirement of the excircle and the end face can be ensured.

2. By using a 93-degree small crater cylindrical lathe tool, the shape of the lathe tool is shown in figures 3 and 4, the depth cutting resistance of the lathe tool is almost equal to zero, and therefore the deformation of a workpiece can be reduced. And selecting reasonable cutting amount according to a special excircle turning tool and a thin-wall steel sleeve workpiece.

3. The inner hole of the thin-wall steel sleeve is turned and clamped by using a special clamp shown in figure 2, so that the workpiece is only clamped by axial force and is not clamped by radial clamping force, and the coaxiality requirement of the excircle and the inner hole of the thin-wall steel sleeve is ensured.

4. The special inner bore lathe tool is used, the cutting edge of the inner bore lathe tool is sharp, the cutting force is small, and the cutting deformation is reduced. The chips are discharged to the surface to be machined without damaging the machined surface of the inner bore.

Drawings

FIG. 1 is a schematic diagram of steps 1 and 2 of a method for turning a thin-walled steel sleeve according to the invention;

FIG. 2 is a schematic view of a connection structure of a workpiece and a special fixture according to the present invention;

FIG. 3 is a schematic structural diagram of an external lathe tool according to the present invention;

FIG. 4 is an enlarged schematic view of the cylindrical turning tool according to the present invention;

FIG. 5 is a schematic view of the inner bore turning tool of the present invention;

FIG. 6 is a schematic diagram of a top view of the inner bore lathe tool according to the present invention;

FIG. 7 is an enlarged schematic view of the inner bore lathe tool of the present invention;

FIG. 8 is an enlarged view of the other side of the female turning tool according to the present invention.

1-workpiece, 2-first batch of self-solidifying agent, 3-second batch of self-solidifying agent, 4-rubber cushion, 5-main shaft connecting piece and 6-nut.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely explained below with reference to the drawings in the embodiments of the present invention.

Referring to fig. 1-8, the present embodiment, a method of turning a thin-walled steel sleeve:

1. and processing the blank workpiece of the thin-wall steel sleeve, wherein the blank of the thin-wall steel sleeve is a blank with normal allowance.

Heating a mixture of 96% of carbamide and 4% of potassium nitrate to over 140 ℃ to prepare a self-solidifying agent, wherein the self-solidifying agent has high viscosity, strong adhesion and high solidification speed, filling a first batch of self-solidifying agent 2 into an inner hole of a workpiece 1, the filling height is A, and after the first batch of self-solidifying agent 2 is solidified, the height A is 15mm added to the length required by a lathe three-jaw chuck for clamping the workpiece 1 when the workpiece 1 is machined;

after the first batch of self-solidifying agent 2 is solidified, filling a second batch of self-solidifying agent 3 into an inner hole of the workpiece 1, wherein the filling height is A, a rubber pad 4 is arranged on an upper end cover of the workpiece 1, and the workpiece 1 is immediately turned over by 180 degrees, at the moment, the second batch of self-solidifying agent 3 is not solidified, so that the second batch of non-solidified self-solidifying agent 3 flows downwards and is solidified with the second batch of self-solidifying agent 3;

the self-solidifying agent is used for increasing the process rigidity of the workpiece 1, when the self-solidifying agent is in a liquid state, the self-solidifying agent is filled into a cavity of the workpiece 1 or wraps the workpiece, and after the self-solidifying agent is solidified, the self-solidifying agent and the workpiece 1 form a rigid body to enhance the rigidity of the workpiece 1 and enable the processing to be carried out smoothly. The two ends of the processed workpiece 1 are provided with self-solidifying substances, the self-solidifying substances at the two ends and the workpiece 1 form a rigid body, namely longitudinal, transverse and oblique ribs are arranged in the workpiece 1, so that the rigidity of the thin-wall steel sleeve workpiece 1 is greatly improved, the radial rigidity is greatly improved, and the workpiece is not easy to deform under the influence of factors such as cutting force, clamping force and the like in the processing process.

2. Turning excircle and end surface of thin-wall steel sleeve

After the second batch of self-setting agent 3 is solidified, turning the outer circle and the end face of the workpiece 1, positioning and clamping the left end of the workpiece 1 by using a three-jaw self-centering chuck, roughly turning and finely turning and turning the end face of the outer circle of the right end part of the workpiece 1 in sequence through a lathe, turning the right end of the workpiece 1 by using a soft jaw to position and clamp the right end of the workpiece in order to ensure the requirements on the size, roundness and cylindricity of the outer circle of the workpiece 1 and the verticality of the outer circle and the end face, roughly turning and finely turning and turning the end face of the outer circle of the left end part of the workpiece 1 through the lathe, wherein the cutting fluid used during turning is cutting oil, and cannot be dissolved by water solution and emulsion.

The thin-wall steel sleeve workpiece 1 is a workpiece difficult to machine, a conventional external turning tool cannot be used, the geometric parameters of the tool cannot be conventional, and a special external turning tool and special geometric parameters must be used. The lathe tool that this embodiment used is 93 little crater excircle lathe tools, and the lathe tool shape is shown in fig. 3 and 4, and the blade material is YT15, and the cutter arbor material is 45 steel, and the main declination equals 93, and the rake grinds out the crater chip groove. The depth resistance of the turning tool is almost equal to zero, so that the deformation of the workpiece can be reduced. The cutter has good heat dissipation, can reduce cutting temperature, reduce thermal deformation of the workpiece 1 and effectively improve the excircle quality of the thin-wall steel sleeve.

The thin-wall steel sleeve workpiece 1 is a workpiece difficult to process and cannot use conventional cutting consumption, and the cutting consumption of the rough turning excircle of the embodiment is as follows: the cutting speed is 240m/min, the feed rate is 1.2mm/r, and the back cutting depth is 0.6 mm. The amount of finish turning excircle cutting is: the cutting speed is 300m/min, the feed rate is 0.2mm/r, and the back cutting depth is 0.3 mm.

After the outer circle and the end face are machined, the machined workpiece 1 is immersed into hot water at the temperature of 40-50 ℃ to enable the self-solidifying agent to be dissolved and separated from the workpiece 1, the workpiece 1 is cleaned, or the workpiece 1 is heated to the temperature of more than 140 ℃, the self-solidifying agent is poured out, the workpiece 1 is cleaned, and the poured self-solidifying agent can be used continuously.

3. Turning inner hole of thin-wall steel sleeve

The special fixture is used for clamping the workpiece 1 and comprises a main shaft connecting piece 5 and a nut 6, an inner hole of the main shaft connecting piece 5 is connected with an outer circle of the workpiece 1 in a matched mode, 4 degrees of freedom of the workpiece 1 are limited, the end face of the workpiece 1 is in contact with the end face of the main shaft connecting piece 5, 1 degree of freedom is limited, 5 degrees of freedom are limited totally, and incomplete positioning is achieved. The main shaft connecting piece 5 is in threaded connection with the nut 6, the workpiece 1 is axially clamped through the nut 6, the workpiece is free from radial clamping force, the inner hole of the main shaft connecting piece 5 is in small-gap fit with the outer circle of the workpiece 1, the coaxiality of the outer circle and the inner hole of the thin-wall steel sleeve is effectively guaranteed, and the inner hole of the workpiece 1 is subjected to rough turning and finish turning sequentially after clamping.

The thin-wall steel sleeve is a workpiece difficult to machine, a conventional inner bore turning tool cannot be used, the geometric parameters of the tool cannot be conventional, a special inner bore turning tool must be used, the special geometric parameters are adopted, the inner bore turning tool blade used in the embodiment is YT15, the tool bar is 45 steel, the main deflection angle is equal to 60 degrees, the front angle is 30 degrees, the rear angle is 12 degrees, the blade inclination angle is minus 45 degrees, the cutting edge of the inner bore turning tool is sharp, the cutting force is small, and the cutting deformation caused by the cutting force is effectively reduced. Due to the adoption of the negative blade inclination angle, the chips are discharged to the surface to be machined and are discharged through the inner hole of the main shaft, so that the machined surface of the inner hole is not damaged.

The thin-wall steel sleeve is a workpiece difficult to process, conventional cutting consumption cannot be used, and the cutting consumption of the rough turning inner hole is as follows: the cutting speed is 150m/min, the feed rate is 0.1mm/r, and the back bite amount is 0.5 mm. The cutting amount of the finish turning inner hole is as follows: the cutting speed is 200m/min, the feed rate is 0.05mm/r, and the back bite amount is 0.1 mm.

The method for turning the thin-wall steel sleeve provided by the invention is described in detail, a specific example is applied in the method for explaining the principle and the implementation mode of the invention, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.