CN115958495A - Eccentricity processing device and method for tiny thin-wall cylindrical part - Google Patents

Abstract

The invention relates to an eccentricity processing device and method for small thin-walled cylindrical parts. It is arranged under the main shaft of a machine tool. A tool is embedded in the main shaft of a machine tool. The workpiece and the tool are arranged parallel to each other. The eccentricity processing device It includes a base, a turntable, an eccentric adjustment assembly, a three-jaw chuck, a motor and a controller, the three-jaw chuck is arranged on the eccentric adjustment assembly; the eccentric adjustment assembly is arranged on the turntable, and is a top A cylinder with a groove, the side wall of the cylinder is provided with a hole symmetrically arranged along the axis of the cylinder and penetrating through it, and a hole for pushing and clamping the three-jaw chuck is arranged in the hole adjusting screw; the turntable is arranged on the base; the motor is arranged on one side of the base and connected to the turntable to provide adjustable rotational power for the turntable; the controller and the motor connections described above. Compared with the prior art, the invention can more accurately process the micro eccentricity of tiny thin-walled parts.

Description

Device and method for eccentricity processing of tiny thin-walled cylindrical parts

technical field

The invention relates to the technical field of mechanical parts processing, in particular to an eccentricity processing device and method for tiny thin-walled cylindrical parts.

Background technique

The eccentric workpiece is defined as a part whose outer circle is parallel to the axis of the inner hole without coincidence and has a certain offset. With the rapid development of industrial manufacturing technology, eccentric machining of tiny cylindrical parts is often required in some important fields. The processing methods and eccentric adjustment devices currently used are mainly for parts with large radial dimensions, but it is very difficult for eccentric processing of tiny thin-walled cylindrical parts with a diameter of less than 1.5mm.

At present, the most widely used method in the eccentric machining of cylindrical parts is turning. Place a shim on any jaw of the three-jaw chuck of the lathe to meet the eccentricity required for workpiece processing, and then clamp the workpiece for processing. Or use a four-jaw single-action chuck to adjust the eccentricity required by the workpiece by adjusting the position of its jaws, and then clamp and process the workpiece. The above two methods are only suitable for parts with large radial size and relatively large eccentricity. For the eccentric machining of micro-small cylindrical parts, it is not only difficult to clamp the parts, but also difficult to adjust the micro-cylindrical parts during processing. The required small amount of eccentricity, and the rigidity of small and thin-walled parts is poor. When the turning method is used for processing, the workpiece will produce a large deflection due to the radial force of the turning tool, and it is difficult to ensure the required dimensional accuracy of the workpiece. .

To sum up, the main disadvantages of current existing technologies include:

(1) Ordinary lathes are only suitable for eccentricity processing of workpieces with large radial dimensions, and cannot be clamped for tiny parts;

(2) It is difficult to micro-adjust the workpiece processing to the required eccentricity with the existing fixture;

(3) During the eccentric processing of micro-small thin-walled parts, large deflection will occur, and the existing eccentric adjustment device is difficult to guarantee its dimensional accuracy;

Contents of the invention

The purpose of the present invention is to provide an eccentricity processing device and method for small thin-walled cylindrical parts in order to overcome the defects of the prior art that the eccentricity cannot be adjusted in a small amount.

The purpose of the present invention can be achieved through the following technical solutions:

One of the technical solutions of the present invention is to provide an eccentricity processing device for tiny thin-walled cylindrical parts, which is arranged under the spindle of the machine tool. The spindle of the machine tool is also embedded with a tool for cutting the workpiece. The workpiece and the tool are mutually Set in parallel, the eccentricity processing device includes a base, a turntable, an eccentric adjustment assembly, a three-jaw chuck, and a motor,

The three-jaw chuck is arranged on the eccentric adjustment assembly for clamping workpieces;

The eccentric adjustment assembly is arranged on the turntable, and is a cylinder with a groove on the top, and a hole is arranged on the side wall of the cylinder symmetrically along the axis of the cylinder and runs through it. An adjustment screw for pushing and clamping the three-jaw chuck is provided inside;

The turntable is arranged on the base for rotating the eccentric adjustment assembly and the three-jaw chuck;

The motor is arranged on one side of the base and is connected to the turntable for providing adjustable rotational power to the turntable.

Further, the bottom of the three-jaw chuck is provided with a boss embedded in the groove, so that when the adjusting screw is turned close to or away from the groove, the adjusting screw can push the three-jaw chuck Disc to the specified position and clamp the three-jaw chuck.

Further, the outer wall of the adjustment screw is provided with a fine thread, which is used for fine adjustment of the position of the three-jaw chuck when the adjustment screw is turned close to or away from the groove.

Further, the motor is a servo motor, and the motor is also connected to a controller for regulating the power of the motor.

Further, the range of eccentricity adjusted by the eccentric adjustment assembly is 0-1mm.

Further, the diameter range of the workpiece clamped by the three-jaw chuck is 1-33mm.

The second technical solution of the present invention is to provide an eccentricity processing method for tiny thin-walled cylindrical parts, which is based on the device described in the first technical solution, and the processing method includes the following steps:

S1. Fix the base on the guide rail of the machine tool, clamp the standard part in the three-jaw chuck, and clamp the centering rod perpendicular to the top of the three-jaw chuck. Carry out tool setting on the standard part, and adjust the position of the three-jaw chuck by turning the adjusting screw;

S2. Remove the reference piece, clamp the workpiece in the three-jaw chuck, and clamp the tool for grinding the workpiece on the machine tool spindle, and process the Eccentricity of the machined workpiece.

Further, in step S1, the reference piece is a cylindrical rod, and the accuracy of the centering rod is 0.001 mm.

Further, in step S2, the tool is a grinding rod, and the grinding rod is provided with a CBN grinding head for grinding the workpiece; a liner with the same inner diameter as the workpiece is also installed in the inner ring of the workpiece, so as to increase its stiffness.

Further, in step S2, the processing technology is: the turntable rotates the workpiece, the machine tool spindle drives the tool to rotate, and the machine tool spindle also feeds the tool horizontally so that the tool is adjusted to the The center of the inner ring of the workpiece is the axis, first rough grinding removes 90% of the maximum machining allowance of the outer ring of the workpiece, then increases the speed of the machine tool spindle and vertically feeds the tool to fine grind the outer ring of the workpiece, so that the After machining, the workpiece meets the required eccentricity.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention provides a new idea and method for controlling the rotational speed of the workpiece. The rotational speed and steering of the servo motor are controlled by the controller to improve the precise control of the rotational speed of the workpiece during the machining process.

(2) The present invention provides a new orientation eccentricity adjustment method, which adjusts the tiny eccentricity through the micro-translation generated by the fine thread transmission on the adjustment screw, and adjusts the eccentricity of the workpiece within a certain small range. The versatility of the device of the present invention is improved.

(3) In the process of processing, the present invention installs a lining with the same inner diameter inside the workpiece, which improves the overall rigidity of the workpiece and reduces the processing error caused by deflection.

(4) The present invention adopts the processing method of grinding, and in order to avoid the impact of grinding wheel wear on the processing quality, also adopts the CBN grinding head as the processing tool, so that the processing accuracy of the workpiece with less machining allowance is high.

(5) The processing process of the present invention is divided into rough grinding and fine grinding, which improves the processing efficiency of the workpiece on the one hand, and ensures the dimensional accuracy and surface quality of the workpiece on the other hand.

Description of drawings

Fig. 1 is a schematic diagram of a three-dimensional structure of the device of the present invention.

Fig. 2 is a three-dimensional structural schematic diagram of the assembled eccentric adjustment assembly and the three-jaw chuck of the present invention.

Fig. 3 is a schematic front view of the assembled eccentric adjustment assembly and the three-jaw chuck of the present invention.

Fig. 4 is a schematic cross-sectional view of the assembled eccentric adjustment assembly and the three-jaw chuck of the present invention.

Fig. 5 is a three-dimensional structural schematic diagram of the eccentric adjustment assembly of the present invention.

Fig. 6 is a schematic front view of the eccentric adjustment assembly of the present invention.

Fig. 7 is a schematic cross-sectional view of the eccentric adjustment assembly of the present invention.

Fig. 8 is a structural schematic diagram of the workpiece processing process of the present invention.

FIG. 9 is a schematic diagram of the formula for calculating the maximum deflection in Embodiment 2. FIG.

Fig. 10 is the dimensional parameters of the workpiece raw material (A) and the processed workpiece (B) in embodiment 2.

The markings in the figure are as follows:

1 is the motor; 2 is the base; 3 is the turntable; 4 is the eccentric adjustment component; 5 is the adjustment screw; 6 is the three-jaw chuck; 7 is the workpiece; 8 is the controller; 9 is the boss; 10 is the machine tool spindle; 11 is a cutter.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

In the following embodiments, if there is no specific functional component or structure, it means that they are conventional components or conventional structures adopted in the art to realize corresponding functions.

Example 1:

As shown in Figure 1-8, it is an eccentric distance processing device for tiny thin-walled cylindrical parts, which is installed under the machine tool spindle 10. The machine tool spindle 10 is also embedded with a tool 11 for cutting the workpiece 7, and the workpiece 7 and the tool 11 are connected to each other. Arranged in parallel, the eccentricity processing device includes a base 2 , a turntable 3 , an eccentric adjustment assembly 4 , a three-jaw chuck 6 , a motor 1 and a controller 8 . The three-jaw chuck 6 is arranged on the eccentric adjustment assembly 4, and is used for clamping the workpiece 7; the eccentric adjustment assembly 4 is arranged on the turntable 3, and is a cylinder with grooves on the top, and a groove along the side wall of the cylinder. A hole that is symmetrically arranged and penetrated by the axis of the cylinder is provided with an adjusting screw 5 for pushing and clamping the three-jaw chuck 6 in the hole, and there are 4 adjusting screws 5 in total; the turntable 3 is arranged on the base 2 for Rotate the eccentric adjustment assembly and the three-jaw chuck 6; the motor 1 is a servo motor, located on one side of the base 2 and connected to the turntable 3, for providing adjustable rotational power for the turntable 3; the controller 8 is connected to the motor 1, and used Used to adjust the power of motor 1.

As shown in Figure 4, the bottom of the three-jaw chuck 6 is provided with a boss 9 embedded in the groove of the eccentric adjustment assembly 4, so that when the adjusting screw 5 is turned close to or away from the groove, the adjusting screw 5 can push the three-jaw chuck 6 to the designated position and clamp the three-jaw chuck 6. The outer wall of the adjusting screw 5 is provided with a fine thread, which is used for fine-tuning the position of the three-jaw chuck 6 when the adjusting screw 5 is turned close to or away from the groove. The range of eccentricity adjusted by the eccentric adjustment assembly 4 is 0-1 mm. The diameter range of the workpiece 7 clamped by the three-jaw chuck 6 is 1-33mm.

This embodiment also provides an eccentricity processing method for tiny thin-walled cylindrical parts. The structure of the processing process is specifically shown in Figure 8. The processing method includes the following steps:

S1. Fix the base 2 on the guide rail of the machine tool, clamp the standard cylindrical rod in the three-jaw chuck 6, and clamp the center rod on the machine tool spindle 10 perpendicular to the top of the three-jaw chuck 6, and place the center rod on the cylinder The bar is used for tool setting, and the position of the three-jaw chuck 6 is adjusted by turning the adjusting screw 5; the accuracy of the centering bar is 0.001mm.

S2. Take off the cylindrical rod, put a liner with the same inner diameter as the workpiece 7 into the inner ring of the workpiece 7, clamp it in the three-jaw chuck 6, and clamp the grinding rod with the CBN grinding head on the machine tool spindle 10 To grind the workpiece 7, the turntable 3 rotates the workpiece 7, the machine tool spindle 10 drives the grinding rod to rotate, and the machine tool spindle 10 first feeds the grinding rod horizontally so that the grinding rod takes the center of the inner circle of the workpiece 7 after adjusting its position as the axis for rough grinding to remove the outer surface of the workpiece 7. 90% of the maximum machining allowance of the ring, and then increase the speed of the machine tool spindle 10 and vertically give the grinding rod to fine-grind the outer ring of the workpiece 7, so that the processed workpiece meets the required eccentricity.

Example 2:

This embodiment provides a kind of eccentricity processing method for tiny thin-walled cylindrical parts, processing a workpiece 7 whose outer diameter b is 1.4mm and inner diameter a is 0.7mm, the outer diameter b' of the processed workpiece is 1.0mm, and the inner diameter a is 0.7mm, and the eccentricity c is 0.12mm, as shown in Figure 10.

The method comprises the steps of:

(1) After fixing the base 2 on the guide rail of the machine tool, connect the servo motor and the controller 8 through the data line. The workpiece 7 will be subjected to the radial force of the grinding rod during processing, which will generate a certain deflection, so it is necessary to perform tool calibration before processing.

After the workpiece 7 is subjected to the radial force of the tool 11, the deflection generated can be analyzed through the model diagram shown in Figure 9, and the maximum deflection calculation formula is:

In the formula:

F is the radial force that workpiece 7 is subjected to, and the grinding method that present embodiment adopts is about 5N to the radial force that workpiece 7 produces during cutting;

l is the length that protrudes outward after the workpiece 7 is clamped, and the present embodiment l is 10mm;

E is the elastic modulus of workpiece 7, and the present embodiment workpiece 7 is high-strength steel, and its elastic modulus is 210GPa;

I is the section moment of inertia of the workpiece 7, and the section moment of inertia calculated according to its cross-sectional shape is 0.177mm ⁴ ;

The eccentric distance that needs to be adjusted by the three-jaw chuck 6 can be calculated by the following formula:

p = ω _B + hΔ

In the formula:

p is the eccentricity that needs to be guaranteed for the processing of the workpiece 7, and the eccentricity of the workpiece after processing in this embodiment is 0.12 mm;

ω _B is the deflection that workpiece 7 produces, and the deflection ω _B of present embodiment is calculated as 0.045mm;

h is the cutting depth, and the initial cutting depth of the tool setting in this embodiment is 0.05mm;

Δ is the eccentricity that needs to be adjusted by the three-jaw chuck 6, which can be calculated to be 0.025 mm.

In order to facilitate the operation, the present embodiment uses the three-jaw chuck 6 to first clamp a solid cylindrical rod with a diameter of 6mm. Reaching 0.001mm can further improve the accuracy of the tool setting process. After the tool setting is completed, the solid cylindrical rod is removed, and the workpiece 7 is clamped on the three-jaw chuck 6 and then processed.

(2) in the present embodiment, the maximum machining allowance of the workpiece 7 is 0.32mm, and the grinding process is completed in two kinds of cutting paths. At first, the rotating speed of the machine tool spindle 10 is set to be 6000r/min, and the feed rate is 0.05mm/min. The servo motor sets the rotational speed of the turntable 3 to 1r/min, removes the 0.3mm machining allowance of the workpiece 7 through the machining method of the machine tool spindle 10 horizontal feed, and then changes the cutting path of the machine tool spindle 10, adopts the vertical feed of the machine tool spindle 10 The cutting method cuts the workpiece 7 from top to bottom, and cuts the remaining 0.02mm machining allowance of the workpiece 7. The rotation speed of the machine tool spindle 10 is set to 8000r/min, and the descending speed of the machine tool spindle 10 is 10mm/min. While cutting the remaining machining allowance, the surface quality and dimensional accuracy of the workpiece after machining are improved by increasing the rotational speed of the machine tool spindle 10 .

The above descriptions of the embodiments are for those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative effort. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (10)

1. An eccentricity processing device for a tiny thin-wall cylindrical workpiece is arranged below a machine tool spindle (10), a cutter (11) for cutting the workpiece (7) is embedded in the machine tool spindle (10), the workpiece (7) and the cutter (11) are arranged in parallel, and the eccentricity processing device is characterized by comprising a base (2), a rotary table (3), an eccentricity adjusting component (4), a three-jaw chuck (6) and a motor (1),

the three-jaw chuck (6) is arranged on the eccentric adjusting assembly (4) and used for clamping and exposing the workpiece (7);

the eccentric adjusting assembly (4) is arranged on the rotary table (3) and is a cylinder with a groove formed in the top, holes which are symmetrically arranged along the axis of the cylinder and penetrate through the cylinder are formed in the side wall of the cylinder, and adjusting screws (5) used for pushing and clamping the three-jaw chuck (6) are arranged in the holes;

the rotary table (3) is arranged on the base (2) and is used for rotating the eccentric adjusting assembly (4) and the three-jaw chuck (6);

the motor (1) is arranged on one side of the base (2) and connected with the rotary table (3) and used for providing adjustable rotating power for the rotary table (3).

2. The eccentricity processing device for tiny thin-walled cylindrical workpieces as claimed in claim 1, characterized in that the bottom of the three-jaw chuck (6) is provided with a boss (9) embedded in the groove, so that when the adjusting screw (5) is turned to approach or move away from the groove, the adjusting screw (5) can push the three-jaw chuck (6) to a designated position and clamp the three-jaw chuck (6).

3. The eccentricity processing device for tiny thin-walled cylindrical workpieces as claimed in claim 1, wherein the outer wall of the adjusting screw (5) is provided with fine threads for rotating the adjusting screw (5) to approach or leave the groove, so that the position of the three-jaw chuck (6) can be finely adjusted.

4. The eccentricity processing device for the tiny thin-wall cylindrical workpiece, according to claim 1, is characterized in that the motor (1) is a servo motor, and the motor (1) is further connected with a controller (8) for regulating and controlling the power of the motor (1).

5. The eccentricity processing device for tiny thin-wall cylindrical workpieces as claimed in claim 1, wherein the eccentricity adjusted by the eccentricity adjusting component (4) ranges from 0mm to 1mm.

6. The eccentricity processing device for tiny thin-walled cylindrical workpieces as claimed in claim 1, wherein the diameter of the three-jaw chuck (6) for clamping the workpiece (7) ranges from 1mm to 33mm.

7. An eccentricity processing method for a minute thin-walled cylindrical workpiece based on the apparatus as claimed in any one of claims 1 to 6, characterized in that the eccentricity processing method comprises the steps of:

s1, fixing a base (2) on a machine tool guide rail, clamping a calibration piece in a three-jaw chuck (6), clamping a centering rod in a machine tool spindle (10) perpendicular to the top of the three-jaw chuck (6), setting the calibration piece, and adjusting the position of the three-jaw chuck (6) by rotating an adjusting screw (5);

s2, the calibration piece is taken down, the workpiece (7) is clamped in the three-jaw chuck (6), the tool (11) for grinding the workpiece (7) is clamped by the machine tool spindle (10), and the machined workpiece with the eccentric distance from the workpiece (7) is machined.

8. The eccentricity processing method for a tiny thin-walled cylindrical workpiece, according to claim 7, wherein in step S1, the calibration object is a cylindrical rod; the precision of the centering rod is 0.001mm.

9. The eccentricity processing method for a tiny thin-walled cylindrical workpiece, according to claim 7, wherein in step S2, the tool (11) is a grinding rod, and the grinding rod is provided with a CBN grinding head for grinding the workpiece (7); and an inner lining with the same inner diameter as the workpiece (7) is additionally arranged on the inner ring of the workpiece to increase the rigidity of the workpiece.

10. The eccentricity processing method for a tiny thin-walled cylindrical workpiece, according to claim 7, is characterized in that in step S2, the processing technique is as follows: the rotary table (3) rotates the workpiece (7), the machine tool spindle (10) drives the cutter (11) to rotate, the machine tool spindle (10) further horizontally feeds the cutter (11) to enable the cutter (11) to use the adjusted circle center of the inner ring of the workpiece (7) as an axis to firstly coarsely grind and remove 90% of the maximum machining allowance of the outer ring of the workpiece (7), then the rotating speed of the machine tool spindle (10) is increased, the cutter (11) is vertically fed to finely grind the outer ring of the workpiece (7), and the machined workpiece meets the required eccentric distance.

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