CN205342586U - Fine special fixture that mills of high speed of small -size accurate work piece - Google Patents

Abstract

The utility model relates to the technical field of fixtures for mechanical processing, in particular to a special fixture for high-speed micro-milling of small precision workpieces. The utility model is installed on the main shaft of the Nanotech 350FG five-axis CNC ultra-precision machine tool through a vacuum suction cup. It is composed of a clamp body, a clamping sleeve, a replaceable positioning mandrel, and a diamond-shaped positioning pin. The replaceable positioning mandrel is used in conjunction with the workpiece; The clamping sleeve is set on the disc base in a moving fit relationship, and is fixed on the clamping body with screws. The utility model is a special fixture for high-speed micro-milling of small precision workpiece parts, with simple structure and reliable clamping. According to the workpiece size and matching requirements, the interchangeable positioning mandrel is turned, which greatly improves the positioning accuracy of the single workpiece processed by the clamp body. Since there are multiple processing windows on the end face and cylindrical surface of the sleeve, only one clamping can complete the milling of one end face and the cylindrical surface of the workpiece in multiple directions, which improves the processing efficiency on the basis of ensuring the processing accuracy. .

Description

A special fixture for high-speed micro-milling of small precision workpieces

1. Technical field

The utility model relates to the technical field of fixtures for mechanical processing, in particular to a special fixture for high-speed micro-milling of small precision workpieces.

2. Background technology

Micromachining technology, especially micromilling technology, plays a decisive role in the processing and manufacturing of tiny parts. In order to improve processing efficiency and obtain higher processing quality, it is planned to use high-speed micro-milling to complete the processing of multiple surfaces of a small precision workpiece. Due to the small size of the workpiece, it is difficult to clamp, and the accuracy of important structures is very high, and it is required to be processed on a Nanotech350FG five-axis CNC ultra-precision machine tool, which can perform ultra-precision turning, milling, and grinding. Ordinary fixtures are inefficient and cannot meet the machining accuracy. Therefore, it is necessary to design a special fixture that is suitable for this machine tool and can reliably and accurately clamp the workpiece. It can complete the processing of multiple positions with fewer clamping times and improve the processing efficiency.

3. Contents of the invention

The purpose of the utility model is to provide a special fixture for high-speed micro-milling of small precision workpieces in order to overcome the defects of poor processing accuracy and low processing efficiency in the processing technology of small precision workpieces with high precision requirements.

The utility model is installed on the main shaft of the Nanotech350FG five-axis CNC ultra-precision machine tool through a vacuum suction cup, and its technical scheme is composed of a clamping body, a clamping sleeve, a replaceable positioning mandrel, and a diamond-shaped positioning pin;

The clamp body is composed of a disc base, a clamping sleeve positioning shoulder, a step surface, and a threaded hole. A workpiece positioning plane and a center hole are set on the top, and a replaceable positioning mandrel is fixedly installed in the center hole. The replaceable positioning mandrel and the workpiece Supporting use; the positioning pin hole is set on the workpiece positioning plane, the position of the positioning pin hole corresponds to the position of the blind hole on the end surface of the workpiece, the diamond-shaped positioning pin is fixed in the positioning pin hole, and the clamping sleeve is provided under the workpiece positioning plane for positioning Shaft shoulder, the diameter of the clamping sleeve positioning shaft shoulder matches the outer diameter of the workpiece; 8 threaded holes are evenly distributed on the step surface of the clamp body;

The clamping sleeve is a cylinder whose inner cavity matches the positioning shoulder of the clamping sleeve of the clamping body. A flange chassis is arranged at the bottom, and there are 4 through holes evenly distributed on the flange chassis, which are evenly distributed on the step surface of the clamping body. Any 4 of the 8 threaded holes correspond to each other; the top is provided with a chamfered hole as a processing window for the end face of the workpiece to accommodate the tool; the difference between the diameter of the chamfered hole and the diameter of the upper inner cavity of the clamping sleeve constitutes a Clamping ring; 4 processing windows for accommodating tools that match the position of the hole to be processed on the circumferential surface of the workpiece are evenly distributed on the cylinder at the lower part of the clamping sleeve;

The clamping sleeve is set on the disc base in a moving fit relationship, and is fixed on the clamping body with screws.

Mechanism of the invention: In order to improve the processing accuracy and production efficiency of small precision workpieces, this utility model is a special fixture designed for processing small workpieces with through holes in the core and blind holes in the end face. Before use, the utility model is installed and fixed on the workpiece spindle of the machine tool, the replaceable positioning mandrel is installed in the center hole of the clamp body, and the axis center of the clamp body of the utility model is adjusted to be consistent with the axis center of the machine tool spindle. The interchangeable positioning mandrel is used together with the workpiece. In order to ensure that the positioning mandrel and the machine tool spindle achieve a sufficiently high coaxiality and improve the positioning accuracy of the workpiece, a small machining allowance is left for the replaceable positioning mandrel. Before installing the workpiece, according to the workpiece The actual size of the inner hole, according to the matching requirements, the in-situ precision turning replaceable positioning mandrel to the matching required size; then insert the diamond-shaped positioning pin into the positioning pin hole. Put the central through hole of the workpiece into the replaceable positioning mandrel of the clamp body, and install the blind hole of the workpiece into the diamond-shaped positioning pin of the clamp body; then install the clamping sleeve into the clamp body and tighten it evenly with hexagon socket head screws On the clamp body, the workpiece is clamped by the clamping ring of the clamping sleeve, and the machine tool is started to process the workpiece. After a workpiece is processed, the turned and used replaceable mandrel is removed from the center hole of the fixture. , replace it with a replaceable positioning mandrel with a certain machining allowance, so as to prepare for the machining of the next workpiece.

Beneficial effects of the utility model: the utility model is a special fixture for high-speed micro-milling of small precision workpiece parts, with simple structure and reliable clamping. According to the workpiece size and matching requirements, the interchangeable positioning mandrel is turned, which greatly improves the positioning accuracy of the single workpiece processed by the clamp body. Since there are multiple processing windows on the end face and cylindrical surface of the sleeve, only one clamping can complete the milling of one end face and the cylindrical surface of the workpiece in multiple directions, which improves the processing efficiency on the basis of ensuring the processing accuracy. .

4. Description of drawings

Fig. 1 is the partial cross-sectional view of the overall structure schematic diagram of the present utility model;

Fig. 2 is the top view of Fig. 1;

Fig. 3 is a half-sectional view of the structure schematic diagram of the clamp body of the present invention;

Fig. 4 is the top view of Fig. 3;

Fig. 5 is a cross-sectional view of the structural schematic diagram of the clamping sleeve of the present invention.

Reference signs:

1. Clamp body 1-1, workpiece positioning plane 1-2, center hole 1-3, positioning pin hole 1-4, clamping sleeve positioning shoulder 1-5, step surface 1-6, threaded hole 1-7 , disc base 2, clamping sleeve 2-1, flange chassis 2-2, side processing window 2-3, top processing window 2-4, compression ring 2-5, through hole 2-6, clamping Sleeve cavity 3, replaceable positioning mandrel 4, diamond-shaped positioning pin 5, hexagon socket screw 6, workpiece

5. Specific implementation

The specific implementation process of the utility model is described in detail in conjunction with the accompanying drawings.

As shown in Figure 1, the workpiece 6 is a cylinder with a through hole in the center, and a blind hole is pre-processed on one end surface. It needs to be processed in eight directions evenly distributed on the end surface and the circumferential surface, and the machining accuracy reaches microns. class.

The utility model is installed on the main shaft of the Nanotech350FG five-axis CNC ultra-precision machine tool through a vacuum suction cup, and is composed of a clamping body 1, a clamping sleeve 2, a replaceable positioning mandrel 3, and a diamond-shaped positioning pin 4;

The clamp body 1 is composed of a disc base 1-7, a clamping sleeve positioning shoulder 1-4, a step surface 1-5, and a threaded hole 1-6, and a workpiece positioning plane 1-1 and a center hole 1-2 are set on the top , a replaceable positioning mandrel 3 is fixedly installed in the center hole 1-2, and a small amount of machining allowance is left for the replaceable positioning mandrel 3. The diameter after turning matches the inner diameter of the workpiece 6, and the positioning is set on the workpiece positioning plane 1-1. Pin hole 1-3, the position of positioning pin hole 1-3 corresponds to the position of the blind hole on the end face of the workpiece, the positioning pin hole 1-3 is fixedly installed with diamond-shaped positioning pin 4, and a clamp is provided under the workpiece positioning plane 1-1. The tight sleeve locates the shaft shoulder 1-4; 8 threaded holes 1-6 are evenly distributed on the step surface 1-5 of the clamp body.

The clamping sleeve 2 is a cylindrical body whose inner cavity matches the positioning shoulder 1-4 of the clamping sleeve of the clamping body, and a flange chassis 2-1 is arranged at the bottom, and there are 4 holes evenly distributed on the flange chassis 2-1. Holes 2-5 correspond to 4 of the 8 threaded holes 1-6 evenly distributed on the step surface 1-5 of the clamp body; the top is provided with a chamfered hole as the top processing window 2 for accommodating the tool on the end surface of the workpiece -3; The difference between the diameter of the chamfered hole and the diameter of the upper inner cavity of the clamping sleeve 2 constitutes the compression ring 2-4; the plane of the compression ring 2-4 in contact with the workpiece, to the flange chassis 2-1 The distance from the bottom surface should be smaller than the distance from the upper end surface of the workpiece being compressed to the step surface 1-5, so as to ensure the clamping amount of the clamping sleeve 2; The processing window 2-2 for accommodating the tool that matches the position of the hole to be processed on the circumferential surface of the workpiece;

The clamping sleeve 2 is sleeved on the disc base 1-7 with a moving fit, and is fixed on the clamping body with a screw 5 .

Before using the fixture of the utility model, it needs to be assembled and turned for pretreatment. The pretreatment process of the fixture of the utility model is as follows. The disc base 1-7 of the fixture body is installed on the main shaft of the Nanotech350FG five-axis CNC ultra-precision machine tool through vacuum adsorption, and the replaceable positioning mandrel 3 with a small amount of machining allowance is left. It is fixedly installed in the central hole 1-2 of the clamp body, and the axis of the clamp body of the utility model is adjusted to be consistent with the axis of the machine tool spindle. Before installing the workpiece 6, first measure the actual size of the inner hole of the workpiece 6 matched with the interchangeable positioning mandrel 3, and determine the machining capacity of the interchangeable positioning mandrel 3 according to the inner hole size of the workpiece 6 and according to the matching precision requirements. On the Nanotech350FG five-axis CNC ultra-precision machine tool, the replaceable positioning mandrel 3 is precisely turned in-situ to the size required by the matching accuracy, so as to ensure that the replaceable positioning mandrel 3 and the workpiece 6 are assembled with high positioning accuracy. Then rhombus locating pin 4 is packed in locating pin hole 1-3, finishes the pretreatment of clamp of the present utility model so far. The installation process of the workpiece 6 is as follows, the central through hole of the workpiece 6 is packed into the replaceable positioning mandrel 3 through turning, and the blind hole on the end surface of the workpiece 6 is loaded into the diamond-shaped positioning pin 4 of the clamp body to play a positioning role. Place the clamping sleeve 2 above the workpiece, insert the clamping sleeve positioning shoulder 1-4 into the clamping body 1 through the clamping sleeve positioning shaft shoulder 1-4 of the clamping sleeve 1, and clamp the compression ring 2-4 on the inner side of the top of the clamping sleeve 2 and the end surface of the workpiece 6 Contact, there is a certain gap between the flange chassis 2-1 of the clamping sleeve 2 and the step surface 1-5 of the clamping body 1 as the clamping gap, and the four hexagon socket screws 5 are evenly tightened to install the clamping sleeve 2 on the clamping body. Specifically, 1, the compression ring 2-4 on the inner side of the top of the clamping sleeve squeezes the end face of the workpiece 6 to achieve axial clamping of the workpiece 6. Processing windows are arranged on the side and top of the clamping sleeve 2, so that the parts to be processed of the workpiece are exposed and a certain movement space is left for the tool. The machining process of the end face of the workpiece 6 is as follows. Start the machine tool, install the milling cutter on the tool spindle, adjust the axis of the milling cutter to be consistent with the axis of the machine tool spindle, and move the milling cutter to the top processing window 2-3 of the clamping sleeve 2. Milling is performed on the end face of the workpiece 6 . The machining process of the peripheral surface of the workpiece 6 is as follows, the tool spindle is rotated 90° relative to the workpiece, and the milling cutter faces the peripheral surface of the workpiece 6 . Adjust the main shaft of the machine tool so that the axis of the peripheral surface processing window 2-2 on the clamping sleeve 2 is consistent with the axis of the milling cutter, and move the tool into the peripheral surface processing window 2-2 to mill the cylindrical surface of the workpiece 6. After the position is processed, the milling cutter returns to the original position, the machine tool spindle drives the fixture to rotate 90° along its axis, and the second circumferential surface processing window 2-2 on the cylinder of the clamping sleeve 2 rotates to face the milling cutter Move the milling cutter to the inside of the processing window for milling. Repeat the above operation twice again to complete the processing of the four azimuth structures on the peripheral surface of the workpiece 6 . Then, unscrew 4 hexagon socket screws 5, rotate the clamping sleeve 2 around its axis by 45°, and simultaneously screw the 4 hexagon socket screws 5 evenly into the other 4 threaded holes 1-6 of the clamp body 1, and at the same time Tighten the hexagon socket head cap screw 5 to clamp the workpiece 6. In the same process as above, the milling cutter is moved into the four circumferential surface processing windows 2-2 of the clamping sleeve 2 in sequence, so as to provide the remaining four directions of the circumferential surface of the workpiece 6 for milling. After the milling process is completed, the hexagon socket head cap screw 5 is removed, the clamping sleeve 2 is taken out, and the workpiece 6 is taken out, so that the machining of one side end surface and the circumferential surface of the workpiece 6 can be completed at one time. After processing one piece, use a replaceable positioning mandrel with a small machining allowance to replace the turned and used positioning mandrel, which can prepare for the processing of the next workpiece.

Claims (1)

1. a high speed minuteness milling special fixture for miniature precision workpiece, is arranged on the main shaft of Nanotech350FG five axle CNC ultra-precision machine tool by vacuum cup, it is characterized by be made up of clamp body, closing sleeve, interchangeable positioning core axle, diamond positioning pin；

Clamp body is by disc base, and the closing sleeve location shaft shoulder, step surface, screwed hole are constituted, and arrange workpiece location plane and centre bore at top, fixedly mount interchangeable positioning core axle in centre bore, and interchangeable positioning core axle and workpiece support the use；Workpiece location plane arranges dowel hole, the position of dowel hole is corresponding with the position of the blind hole of workpiece end face, fixed installation diamond positioning pin in dowel hole, workpiece location plane is connected with the closing sleeve location shaft shoulder, and the diameter of the closing sleeve location shaft shoulder matches with the external diameter of work piece；Uniform 8 screwed holes on clamp body step surface；

The cylinder that closing sleeve is inner chamber to match with the clamp body closing sleeve location shaft shoulder, bottom arranges flange chassis, and flange chassis is evenly equipped with 4 through holes, any 4 Corresponding matchings in 8 screwed holes uniform with on clamp body step surface；Top is provided with the hole of chamfering and holds the process window of cutter as processing work end face；Aperture with chamfered bore constitutes compacting ring with the poor of closing sleeve upper lumen diameter；The process window holding cutter that the position in uniform 4 holes to be processed with on work piece periphery matches on the cylinder of closing sleeve compacting ring bottom；Closing sleeve is sleeved on disc base with the matching relationship of dynamic cooperation, is screwed on clamp body.