CN105538007A - Flexible fixture for batch machining of shaft workpieces - Google Patents

Abstract

A flexible fixture for batch processing shaft workpieces, which is composed of a fixture base plate, an indexing system, a centering positioning clamping mechanism, an auxiliary support mechanism and a floating device; when in use, the centering positioning clamping mechanism and the floating positioning device can cooperate At the same time, the five degrees of freedom of multiple workpieces to be processed are restricted, and the auxiliary support mechanism provides auxiliary support for the area to be processed on the workpiece. On the vertical machining center equipment, 10 pieces of slender shaft workpieces with a diameter of Ф10mm-Ф30mm and a length of 100-800mm are installed in batches through this fixture to realize milling, drilling, expanding, reaming, boring and other technological processes. Advantages: 1. By replacing some mechanical workpieces, the number of installed workpieces can be increased or decreased, the range of workpiece diameters can be expanded, and the range of workpiece lengths can be expanded. 2. On the relatively low-cost vertical machining center, 2 servo motors are added to the fixture to realize mass processing of slender shaft workpieces.

Description

A Flexible Fixture for Batch Processing of Shaft Workpieces

technical field

The invention relates to the field of fixture design for slender shaft workpieces.

Background technique

Slender shaft workpieces are commonly used workpieces. After the outer circle is processed, there are planes, curved surfaces, straight holes, tapered holes, pin holes, etc. that need to be processed. There are two main process solutions: 1. The principle of dispersed processes is more adopted. Each process is designed with a special fixture and processed on general-purpose equipment. The overall cost is high and the efficiency is low. 2. Adopting the principle of process concentration and processing on the turning-milling compound machining center, the input cost is high, the quality is not guaranteed, and the overall efficiency is low.

Contents of the invention

The invention provides a flexible fixture for batch processing shaft workpieces, which comprehensively improves the processing efficiency and reduces the processing cost under the premise of ensuring the processing quality.

In order to solve the above technical problems, the technical solution of the present invention is: a flexible fixture for batch processing shaft workpieces, including a fixture bottom plate, a left bracket is arranged on the left plate surface of the fixture bottom plate, and a plurality of intervals are arranged on the top of the left bracket. Arranged bearing holes, each bearing hole is equipped with a left sliding bearing, the cavity of the left sliding bearing is equipped with a centering positioning clamping mechanism, and the outer surface of the left bracket is equipped with an indexing system, which can simultaneously drive multiple A centering positioning and clamping mechanism; a linear guide rail is provided on the right plate surface of the fixture bottom plate, and an auxiliary support mechanism and a right bracket arranged at intervals are arranged on the linear guide rail, and the auxiliary support mechanism is located between the centering positioning clamping mechanism and the right bracket , the auxiliary support mechanism and the right bracket can slide towards the direction of the centering positioning clamping mechanism, wherein the auxiliary support mechanism is driven by a ball screw and a motor, and the right bracket and the fixture bottom plate are detachably connected; the top of the right bracket is equipped with A plurality of bearing holes arranged at intervals, each bearing hole is provided with a right sliding bearing, and a floating positioning device is provided in the cavity of the right sliding bearing, and the floating positioning device is set correspondingly to the centering positioning and clamping mechanism; when in use, the positioning After the center positioning clamping mechanism cooperates with the floating positioning device, it can limit the five degrees of freedom of the workpiece to be processed at the same time, and the auxiliary support mechanism provides auxiliary support for the area to be processed on the workpiece.

The above-mentioned technical solution is further limited, the structure of each of the centering positioning and clamping mechanisms is the same, including a rotating sleeve, which is fitted in the cavity of the left sliding bearing, and the rotating sleeve is covered with inner sleeves from the head to the tail in sequence. Thrust bearings, outer thrust bearings, driven gears and lock nuts, inner thrust bearings and outer thrust bearings are respectively located at the two ends of the bearing holes, and the inner thrust bearings, outer thrust bearings and rotating sleeves are It is connected in the way of surplus fit, the driven gear and the rotating sleeve are connected by a key connection structure, and the lock nut and the tail of the rotating sleeve are connected by a thread structure; The cylinder drives the spring chuck to clamp/release the end of the workpiece. The advantages of this structure are: by replacing the spring chuck and the rotating sleeve in the centering positioning clamping mechanism, it is possible to position and clamp slender shafts with different diameters; the application of inner thrust bearings, outer thrust bearings and sliding bearings is reduced. Friction, which is convenient for the indexing and accurate position of this mechanism; the key connection structure is to transmit the indexing of the driven gear to the entire centering and positioning clamping mechanism; the lock nut and the tail of the rotating sleeve are connected by a threaded structure to adjust the axial clearance , which ensures that the entire mechanism can be shifted freely and avoids the axial movement of the mechanism; the tail end is equipped with a hydraulic cylinder, and the hydraulic cylinder drives the spring chuck to clamp/loosen the end of the workpiece, which is to improve the automation of the flexible fixture , Reduce the labor intensity of workers and reduce the clamping time.

To further limit the above technical solution, the floating positioning device includes a floating sleeve, which is assembled in the cavity of the right sliding bearing, the head of the floating sleeve is covered with a return spring, and the tail is provided with a lock nut , the lock nut and the tail of the floating sleeve are connected by a threaded structure. The advantage of this structure: Since the end of the part needs to have a length of 8 mm to be placed in the spring chuck for centering positioning and clamping, the return spring can be compressed by more than 10 mm when the floating sleeve slides axially, which can facilitate the entire part. Put it into the centering and positioning clamping mechanism, and at the same time, the elastic force of the return spring can ensure that the end surface of the part is in full contact with the inner positioning surface in the spring chuck; the inner hole of the head of the floating sleeve is a 45-degree conical surface, which can be used for parts of different diameters 45 degree outer chamfer on the right end of the . The tail of the lock nut and the floating sleeve is connected by a threaded structure, which can fine-tune the compression of the return spring to ensure a fixed elastic force when clamping.

To further define the above technical solution, the transposition system includes symmetrically arranged rack left brackets and rack right brackets, the left rack bracket and the right rack bracket are assembled on the outer surface of the left bracket, and the two ends of the rack They are respectively placed on the left bracket of the rack and the right bracket of the rack. The top surface of the rack meshes with the driven gears in multiple centering positioning clamping mechanisms. The outer surface of the left bracket is provided with a driving gear. The bottom surface meshes with the driving gear, and the driving gear drives the rack through the driving motor to perform linear reciprocating motion. The advantages of this structure: There are adjustment structures in the left bracket of the rack and the right bracket of the rack, which is convenient for the alignment of the rack position. The adjustment structure is a well-known technology in this field; The adjustment mechanism adjusts the position of the drive gear; the drive gear drives the rack to make linear reciprocating motion through the drive motor, and the rack drives the driven gear to make a rotary motion, so that the rotation angle of the servo drive motor is converted into the index of the centering positioning clamping mechanism Angle, but this mechanism has a limit, its rotation range is -180°≤θ≤180°. In addition, the toothed rack can also be replaced with a synchronous toothed belt.

The above technical solution is further defined, the auxiliary support mechanism includes a floating support frame that can be assembled on the linear guide rail, the floating support frame is connected with the ball screw through the internal thread hole on it, and the top surface of the floating support frame is provided with A plurality of lifting hydraulic cylinders are distributed at intervals, a floating block is arranged on the lifting end of the lifting hydraulic cylinder, and a V-shaped floating groove is arranged on the supporting surface of the floating block. The advantages of this structure: the floating support frame is connected with the ball screw through the internal thread hole on it, so that the V-shaped floating block can be adjusted at any time according to the different processing areas of the parts, improving the rigidity of the clamping, reducing deformation, and improving Processing quality, as shown in Figure 9; the lifting hydraulic cylinder ensures that the V-shaped floating block moves up and down, moves up and is firm, and provides reliable auxiliary support; the V-shaped is suitable for parts with different diameters, and the floating V-shaped is also Over-positioning is realized, and the rigidity of clamping is improved.

As a further improvement to the above technical solution, a coolant hole communicating with the floating tank is provided on one side of the floating block. Advantages: In order to prevent the iron filings from sticking to the V-shaped floating groove and cause the V-shaped auxiliary positioning to be inaccurate, there are coolant holes inside, which can take away the iron filings through the coolant.

Beneficial effects: 1. The processing quality is improved, and the rigidity of the processed part on the workpiece is improved through the movable auxiliary support mechanism. 2. Clamping in batches reduces the tool change time of the vertical machining center, reduces the machining time, and improves the processing efficiency. 3. The flexible fixture can be applied to different types of slender shaft workpieces, which reduces the investment in fixtures, machine tools, and labor, and requires the lowest technical level of workers, and the overall cost is the lowest.

Description of drawings

Fig. 1 is a front view of the present invention.

Fig. 2 is a left side view of Fig. 1 .

FIG. 3 is a top view of FIG. 1 .

Fig. 4 is a perspective view of the present invention.

Fig. 5 is a structural schematic diagram of the centering positioning clamping mechanism in the present invention.

Fig. 6 is a perspective view of the centering positioning clamping mechanism in the present invention.

Fig. 7 is a schematic structural view of the auxiliary supporting mechanism in the present invention.

Fig. 8 is a perspective view of the auxiliary supporting mechanism in the present invention.

Fig. 9 is a diagram of the use state of the present invention.

detailed description

As shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4, a flexible fixture for batch processing shaft workpieces includes a fixture bottom plate 1, a left bracket 2 fixed on the left plate surface of the fixture bottom plate 1 by bolts, and a left bracket 2 There are a plurality of bearing holes arranged at intervals on the top of the bearing hole, and a left sliding bearing 3 is arranged in each bearing hole, and a centering positioning clamping mechanism 4 is arranged in the cavity of the left sliding bearing 3, and the outer surface of the left bracket 2 stockings An indexing system 5 is provided, which can drive multiple centering positioning and clamping mechanisms 4 at the same time; the linear guide rail 6 is fixed on the right plate surface of the fixture bottom plate 1 through countersunk bolts, and the linear guide rail 6 is provided with interval arrangements The auxiliary supporting mechanism 7 and the right bracket 8, the auxiliary supporting mechanism 7 is located between the centering positioning clamping mechanism 4 and the right bracket 8, the auxiliary supporting mechanism 7 and the right bracket 8 can slide toward the centering positioning clamping mechanism 4 direction, the ball The screw 9 and the motor 10 are arranged between the two linear guide rails 6 and fixed on the fixture bottom plate 1, wherein the auxiliary support mechanism 7 is driven by the ball screw 9 and the motor 10, and the right bracket 8 and the fixture bottom plate 1 are fixed by the fixing screws 11 Connect; the top of the right bracket 8 is provided with a plurality of bearing holes arranged at intervals, each bearing hole is provided with a right sliding bearing 12, and the cavity of the right sliding bearing 12 is provided with a floating positioning device 13, and the floating positioning device 13 Set corresponding to the centering positioning clamping mechanism 4; when in use, the centering positioning clamping mechanism 4 can limit the five degrees of freedom of the workpiece 14 to be processed at the same time after the cooperation of the centering positioning clamping mechanism 4 and the floating positioning device 13. Auxiliary support for the area to be processed.

As shown in Figure 5 and Figure 6, the structures of each of the centering positioning and clamping mechanisms 4 are the same, including a rotating sleeve 41, which is assembled in the cavity of the left sliding bearing 2, and the rotating sleeve 41 is connected from the head The inner thrust bearing 42, the outer thrust bearing 43, the driven gear 44 and the first lock nut 45 are jacketed successively to the tail, and the inner thrust bearing 42 and the outer thrust bearing 43 are respectively located at the two ends of the bearing hole, namely An inner thrust bearing 42 is provided between the limiting shoulder on the head of the rotating sleeve 41 and the inner side of the left bracket 2, and an outer thrust bearing 43 is arranged between the driven gear 44 and the outer side of the left bracket 2, wherein the inner stop The push bearing 42 and the outer thrust bearing 43 are connected with the rotary sleeve 41 by interference fit, the driven gear 44 is connected with the rotary sleeve 41 by a key connection structure, and the first lock nut 45 is connected with the tail part 41 of the rotary sleeve by a thread structure; The head of the rotary sleeve 41 is provided with a spring chuck 46, and the tail end is provided with a hydraulic cylinder 47. The hydraulic cylinder 74 drives the spring chuck 46 to clamp/release the end of the workpiece 14, that is, the piston in the hydraulic cylinder 47 The tail end of the rod and the spring chuck 46 is connected by bolts. The floating positioning device 13 includes a floating sleeve 131, the floating sleeve 131 is assembled in the cavity of the right sliding bearing 12, and the head of the floating sleeve 131 is covered with a return spring 132, that is, the return spring 132 is assembled in the floating sleeve. A second locking nut 133 is provided between the limiting shoulder on the head of the barrel 131 and the right bracket 8, and on the tail, and the second locking nut 133 is connected with the tail of the floating sleeve 131 by a threaded structure.

As shown in Figures 1 and 2, the indexing system 5 includes a symmetrically arranged rack left bracket 51 and a rack right bracket 52, and the rack left bracket 51 and the rack right bracket 52 are assembled on the outer surface of the left bracket 2 The two ends of the rack 53 are placed on the rack left bracket 51 and the rack right bracket 52 respectively, the top surface of the rack 53 meshes with the driven gear 44 in a plurality of centering positioning clamping mechanisms 4, and the left The outer surface of the support 2 is provided with a rotatable driving gear 54, the bottom surface of the rack 53 is engaged with the driving gear 54, and the driving gear 54 drives the rack 53 to perform linear reciprocating motion through the driving motor 55; the rack can also be replaced by a synchronous toothed belt. .

As shown in Figures 7 and 8, the auxiliary support mechanism 7 includes a floating support frame 71 that can be assembled on the linear guide rail 6, and the floating support frame 71 is connected with the ball screw 9 through an internal thread hole on it, and the floating support frame The top surface of the 71 is provided with a plurality of lifting hydraulic cylinders 72 distributed at intervals, the tail end of the lifting hydraulic cylinders 72 is fixedly connected with the floating support frame 71, and the lifting end of the lifting hydraulic cylinders 72 is provided with a floating block 73, A V-shaped floating groove 74 is provided on the supporting surface of the floating block 73 . A cooling liquid hole communicating with the floating tank 71 is provided on one side of the floating block 73 , and the cooling liquid pipe is connected to the cooling liquid hole through a connector 75 .

Working principle: This fixture includes mechanical, electrical, hydraulic and other parts:

1. By replacing the spring chuck and the rotating sleeve in the centering positioning clamping mechanism of the part, the slender shafts with different diameters can be positioned and clamped; after the centering positioning clamping mechanism cooperates with the floating positioning sleeve, it can

The positioning limits the five degrees of freedom of the workpiece to be processed; at the same time, the floating block in the auxiliary support mechanism needs to be replaced. In order to prevent iron filings from sticking to the V-shaped floating groove, there are coolant holes in it, which can pass through the coolant;

2. By moving the right bracket on the linear guide rail, the centering positioning clamping mechanism and the floating positioning device can clamp slender shafts of different lengths. After the right bracket is adjusted in place, the position of the right bracket is fixed by fixing screws.

3. The auxiliary support mechanism on the linear guide rail is moved by the ball screw and the motor. This mechanism moves with the change of the processing position, which improves the rigidity of the clamping, reduces deformation and improves the processing quality. As shown in Figure 9: when processing area A, the auxiliary support mechanism is at the position of area 1; when processing area B, the lifting hydraulic cylinder drives the floating block to move down 15mm, and then drives the auxiliary support mechanism to balance to area 2 through the ball screw. Then the lifting hydraulic cylinder lifts the floating block and moves it 15mm, so that the floating groove on the floating block is in contact with the workpiece to realize the auxiliary support of the new position;

4. Since the fixture is installed on the vertical machining center, the tool change time is relatively long, so the tool change time can be reduced through batch installation. The indexing of the workpiece is driven by the motor to rotate the driving gear, and is transmitted to the driven gear through the rack to realize the overall rotation of multiple centering positioning and clamping mechanisms, so as to realize the synchronous rotation of ten workpieces, and the rotation range is -180°≤θ≤ 180°. Due to the relatively low precision of gear transmission, it is necessary to improve the gear precision or change it to synchronous toothed belt transmission. On the vertical machining center equipment, 8-20 pieces of slender shaft workpieces with a diameter of Ф10mm-Ф30mm and a length of 100-800mm are installed in batches through this fixture to realize milling, drilling, expanding, reaming, boring and other technological processes. By replacing some mechanical workpieces, the number of installed workpieces can be increased or decreased, the range of workpiece diameters can be expanded, and the range of workpiece lengths can be expanded.

What is not described in detail in this specification is a well-known technology in the art. Both the motor and the driving motor are servo motors, both of which are controlled by a control system.

Claims (6)

1. the flexible fixture of a batch machining shaft-like workpiece, comprise clamp bottom board, it is characterized in that: the left plate face of clamp bottom board is provided with left socle, the top of left socle is provided with multiple spaced dead eye, left sliding bearing is equipped with in each dead eye, be provided with centering positioning and clamping mechanism in the chamber of left sliding bearing, left socle lateral surface is provided with indexing system, and indexing system can drive multiple centering positioning and clamping mechanism simultaneously; The right panel face of clamp bottom board is provided with line slideway, line slideway is provided with spaced apart assistant supporting mechanism and right support, assistant supporting mechanism is between centering positioning and clamping mechanism and right support, assistant supporting mechanism and right support can slide towards centering positioning and clamping mechanism direction, and wherein assistant supporting mechanism is undertaken driving by ball screw and motor, right support is connected by removably with clamp bottom board; The top of right support is provided with multiple spaced dead eye, is equipped with right sliding bearing, is provided with float positioning device in the chamber of right sliding bearing in each dead eye, float positioning device and the corresponding setting of centering positioning and clamping mechanism; During use, after centering positioning and clamping mechanism coordinates with float positioning device, aiding support can be carried out with five of a limit workpiece to be machined free degree, assistant supporting mechanism to region to be processed on workpiece.

2. the flexible fixture of a kind of batch machining shaft-like workpiece according to claim 1, it is characterized in that: the structure of described each centering positioning and clamping mechanism is all identical, comprise rotary sleeve, rotary sleeve is assemblied in the chamber of left sliding bearing, rotary sleeve there is interior thrust bearing from head to afterbody successively overcoat, outer thrust bearing, driven gear and locking nut, interior thrust bearing and outer thrust bearing lay respectively at the two ends place of dead eye, wherein interior thrust bearing adopts interference fit to be connected with outer thrust bearing and rotary sleeve, driven gear and rotary sleeve adopt key syndeton to be connected, locking nut and rotary sleeve afterbody adopt helicitic texture to be connected, be provided with spring chuck in the head of rotary sleeve, tail end is provided with hydraulic cylinder, hydraulic cylinder drives the end of spring chuck to workpiece to clamp/unclamp.

3. a kind of flexible fixture of batch machining shaft-like workpiece according to claim 1 or 2, it is characterized in that: described float positioning device comprises tripping sleeve, tripping sleeve is assemblied in the chamber of right sliding bearing, on the head of tripping sleeve, overcoat has return spring, afterbody is provided with locking nut, and locking nut adopts helicitic texture to be connected with the afterbody of tripping sleeve.

4. the flexible fixture of a kind of batch machining shaft-like workpiece according to claim 3, it is characterized in that: described indexing system comprises symmetrically arranged tooth bar left socle and tooth bar right support, tooth bar left socle and tooth bar right support are assemblied on the lateral surface of left socle, the two ends of tooth bar are placed on tooth bar left socle and tooth bar right support respectively, the end face of tooth bar engages with the driven gear in multiple centering positioning and clamping mechanism, the lateral surface of left socle is provided with driven wheel, the bottom surface of tooth bar is engaged with driven wheel, driven wheel does straight reciprocating motion by drive motors band carry-over bar, tooth bar is also replaceable is in addition synchronous cog belt.

5. the flexible fixture of a kind of batch machining shaft-like workpiece according to claim 4, it is characterized in that: described assistant supporting mechanism comprises the float support frame that can be assemblied on line slideway, float support frame is connected with ball-screw by the internal thread hole on it, the end face of float support frame is provided with multiple lifting hydraulic cylinder spaced apart, the lifting end of lifting hydraulic cylinder is provided with rocker piece, and the bearing-surface of rocker piece is provided with the floating trough of V-type.

6. the flexible fixture of a kind of batch machining shaft-like workpiece according to claim 5, is characterized in that: a side of described rocker piece is provided with the cooling fluid apertures communicated with floating trough.