CN114536121A

CN114536121A - Flexible clamping mechanism for grinding machining and grinding machining device

Info

Publication number: CN114536121A
Application number: CN202210288373.8A
Authority: CN
Inventors: 马海峰; 周金华; 陈杰; 田素坤; 刘战强; 宋清华
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2022-03-23
Filing date: 2022-03-23
Publication date: 2022-05-27
Anticipated expiration: 2042-03-23
Also published as: CN114536121B

Abstract

The invention relates to a flexible clamping mechanism for grinding and a grinding device, which comprise a chuck, wherein the chuck is connected with a clamp plate through a plurality of connecting pieces, the clamp plate is provided with an opening for a workpiece to pass through, a flexible gasket is fixed on the hole surface of the opening, the connecting pieces are provided with a first piezoelectric stack positioned on one side of the clamp plate and a second piezoelectric stack positioned on the other side of the clamp plate, the first piezoelectric stack is pressed on the end surface of one side of the clamp plate through a first pressing piece, the second piezoelectric stack is pressed on the end surface of the other side of the clamp plate through a second pressing piece, and the clamp plate is provided with a vibration sensor.

Description

Flexible clamping mechanism for grinding machining and grinding machining device

Technical Field

The invention relates to the technical field of ultra-precision machining, in particular to a flexible clamping mechanism and a machining device for grinding machining.

Background

The statements herein merely provide background information related to the present disclosure and may not necessarily constitute prior art.

According to the requirement of ultra-precision grinding of a large thin-wall revolving body ceramic workpiece with the length of 1-4 meters, the surface precision of the large thin-wall revolving body ceramic workpiece is poor due to the influence of factors such as mechanical vibration and clamp clearance in the machining process of a machine tool, the requirement of ultra-precision machining precision is difficult to meet, and meanwhile, the influence of factors such as a plurality of common assembly clearances and rotational inertia causes great deviation in the ultra-precision grinding process of the machine tool, so that the machining precision of the surface of the workpiece is seriously influenced.

The inventor finds that when a large-sized thin-wall rotary body ceramic workpiece is machined at present, the workpiece is fixed only by a chuck at the end part to form a cantilever beam structure, the workpiece vibrates greatly in the rotating process, and machining precision is reduced.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a flexible clamping mechanism for grinding, which improves the grinding precision and the production efficiency.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, an embodiment of the present invention provides a flexible clamping mechanism for grinding, including a chuck, the chuck being connected to a clamp plate through a plurality of connecting members, the clamp plate being provided with an opening for a workpiece to pass through, a flexible washer being fixed to a hole surface of the opening, the connecting members being provided with a first piezoelectric stack located on one side of the clamp plate and a second piezoelectric stack located on the other side of the clamp plate, the first piezoelectric stack being pressed against an end surface of one side of the clamp plate by a first pressing member, the second piezoelectric stack being pressed against an end surface of the other side of the clamp plate by a second pressing member, and the clamp plate being provided with a vibration sensor.

Optionally, the clamp plate and the chuck are coaxially arranged, the connecting piece is a connecting rod, and the connecting rods are uniformly distributed along a circumference with the center of the clamp plate as a circle center.

Optionally, a first pressure sensor is arranged between the first piezoelectric stack and the first pressing member, and a second pressure sensor is arranged between the second piezoelectric stack and the second pressing member.

Optionally, the first pressing member is a first pressing nut in threaded connection with the connecting member, and the second pressing member is a second pressing nut in threaded connection with the connecting member.

Optionally, a plurality of balancing weights are further installed on the clamp plate, the balancing weights and the vibration sensor are arranged at equal intervals along the same circumference with the center of the clamp plate as the center of the circle, and the weight of the balancing weights is equal to that of the vibration sensor.

Optionally, a plurality of linear motion driving pieces are installed on the clamp plate, the plurality of linear motion driving pieces are arranged along a circumference which is as a circle center with the center of the clamp plate at equal intervals, a moving part of each linear motion driving piece is connected with a push plate, the push plate is provided with a flexible supporting block matched with the shape of the workpiece, and the push plate can apply pressure to the workpiece through the flexible supporting block.

Optionally, the flexible supporting block is provided with a clamping groove, the push plate is located inside the clamping groove, and the push plate is detachably connected with the flexible supporting block through the clamping groove.

Optionally, the linear motion driving member is rotatably connected with one end of the adjusting rod, and the other end of the adjusting rod is in threaded connection with a positioning block fixed on the clamp plate.

In a second aspect, embodiments of the present invention provide an abrasive machining apparatus including the flexible clamping mechanism for abrasive machining according to the first aspect.

Optionally, a vibration sensor and a tool bar vibration suppression element are mounted on a tool bar of the grinding device.

The invention has the beneficial effects that:

1. according to the clamping device, the clamp plate is arranged, so that the workpiece is supported and centered, the workpiece is prevented from deflecting in the rotating process, meanwhile, the vibration sensor is arranged on the clamp plate, real-time vibration information of the clamp plate can be collected, the randomness of vibration is considered, and when the vibration is too large, the first piezoelectric stack and the second piezoelectric stack are electrified, so that vibration suppression signals are generated through the first piezoelectric stack and the second piezoelectric stack, the vibration amplitude and frequency of the clamp plate are reduced, the clamp is prevented from generating large vibration, and the machining quality is guaranteed.

2. The clamping device is provided with the first pressure sensor and the second pressure sensor, and can detect pressure information received by the clamp plate, so that axial offset generated by the clamp plate in the machining process is detected, the first piezoelectric stack and the second piezoelectric stack are electrified at the moment, position compensation can be performed on the clamp plate, the clamp body can be attached to a workpiece through the flexible gasket, the influence of a gap error on machining precision is avoided, the problem that vibration suppression of the corresponding workpiece and the clamp and corresponding gap compensation combination are lacked in the prior art is solved, vibration suppression can be realized, gap compensation and vibration suppression can be automatically completed, and grinding precision and production efficiency are improved.

3. The clamping device provided by the invention is provided with the linear motion driving piece, the push plate and the flexible supporting block, can buffer the shaking generated in the clamping process of the workpiece, and also plays a centering role in clamping the workpiece.

4. According to the clamping device, the connecting piece, the linear motion driving piece, the balancing weight and the vibration sensor are distributed at equal intervals along the circumference, so that the instability of the rotational inertia in a working state is avoided, and the machining precision is guaranteed.

5. According to the grinding device, the vibration motor and the vibration sensor are mounted on the cutter bar, so that the vibration information of the cutter bar can be detected, the vibration motor can be controlled to work, the vibration of the cutter bar is restrained by the vibration motor, and the machining precision is guaranteed.

Drawings

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

FIG. 1 is a schematic view of the overall structure of embodiment 1 of the present invention;

FIG. 2 is a side view of the whole structure of embodiment 1 of the present invention;

FIG. 3 is a schematic view of the assembly of the cushion cylinder with the flexible supporting block and the adjusting rod in embodiment 1 of the present invention;

the vibration-damping device comprises a cutter bar 1, a bolt 2, a cutter bar vibration-damping element 3, a vibration sensor 4, a rotary body workpiece 5, a grinding wheel 6, a connecting rod 7, a first compression nut 8, a first pressure sensor 9, a first piezoelectric stack 10, a positioning block 11, an adjusting rod 12, a buffer cylinder 13, a piston rod 14, a push plate 15, a flexible supporting block 16, a vibration sensor 17, a chuck 18, a connecting rod adjusting nut 19, a second compression nut 20, a second pressure sensor 21, a second piezoelectric stack 22, a balancing weight 23, a clamp plate 24 and a flexible washer 25.

Detailed Description

Example 1

The present embodiment provides a flexible clamping mechanism for grinding, as shown in fig. 1 to 3, comprising a chuck 18 and a clamp plate 24, wherein the chuck 18 is a conventional chuck for a grinding machine. Chuck 18 and 24 intervals of anchor clamps board set for the distance and coaxial setting, chuck 18 and 24 connect through a plurality of connecting pieces and become a whole with anchor clamps board, traditional grinding machine only relies on the chuck to fix the work piece, when the great thin wall solid of revolution ceramic work piece of machining dimension, the vibration that the work piece produced is great, rotate the easy production deflection of in-process, consequently set up the anchor clamps board in this embodiment, utilize the anchor clamps board to support the middle part position of work piece, the vibration that the work piece produced in the rotation process has been reduced.

The connecting piece adopts connecting rods 7, and a plurality of connecting rods 7 are distributed at equal intervals along the circumference with the center of the clamp plate 24 as the center of a circle.

Along the even a plurality of locating holes that have seted up of circumference on the chuck 18, the locating hole is the screw hole, and connecting rod 7 passes through locating hole and 18 threaded connection of chuck, and threaded connection has connecting rod adjusting nut 19 on the connecting rod 7, and connecting rod adjusting nut 19 compresses tightly on the surface of chuck 18, guarantees connecting

rod

7 and 18's joint strength, prevents not hard up.

In this embodiment, the chuck 18 is provided with six positioning holes distributed at equal intervals along the circumference, wherein three positioning holes are used for installing the connecting rods 7, and three connecting rods 7 are distributed at equal intervals along the circumference.

One end of each of the three connecting rods 7 is fixed with the chuck 18, and the other end of each of the three connecting rods passes through the clamp plate 24 through a mounting hole arranged on the clamp plate 24.

All install annular first piezoelectric stack 10 and second piezoelectric stack 22 on three connecting rod 7, first piezoelectric stack 10 and second piezoelectric stack 22 adopt current component can, constitute by a plurality of piezoceramics chips, can produce the concertina movement along its self axis direction after the circular telegram.

The installation of the first piezoelectric stack 10 and the second piezoelectric stack 22 on one of the connecting rods 7 is taken as an example for illustration:

the first piezoelectric stack 10 is sleeved on the periphery of the connecting rod 7 and located on one side of the clamp plate 24, and the connecting rod 7 is connected with a first pressing element which presses the first piezoelectric stack on the side face of the clamp plate.

The first compression element adopts a first compression nut 8, the first compression nut 8 is in threaded connection with the connecting rod 7, and the first piezoelectric stack 10 can be pressed on the side face of the clamp plate by rotating the first compression nut 8.

A first pressure sensor 9 is arranged between the first gland nut 8 and the first piezoelectric stack 10, and the first pressure sensor 9 is used for detecting pressure information applied to the first piezoelectric stack 10 by the first piezoelectric stack 9.

The second piezoelectric stack 22 is fitted around the outer periphery of the connecting rod 7 and located on the other side of the clamp plate 24, and a second pressing member is connected to the connecting rod 7, and the second piezoelectric stack 22 is pressed against the side surface of the clamp plate 24 by the second pressing member.

The second compression element adopts a second compression nut 20, the second compression nut 20 is in threaded connection with the connecting rod 7, and the second piezoelectric stack 22 can be pressed on the side surface of the clamp plate by rotating the second compression nut 20.

A second pressure sensor 21 is disposed between the second gland nut 20 and the second piezoelectric stack 22, and the second pressure sensor 21 is configured to detect pressure information applied thereto by the second piezoelectric stack.

The first piezo stack 10 and the second piezo stack 22 are both connected to a power supply system, which can be supplied with power.

The clamp plate 24 is provided with an opening, the opening and the clamp plate 24 are coaxially arranged, namely, the opening is arranged at the central position of the clamp plate 24, and the size of the opening is matched with that of the revolving body workpiece 5 to be processed and is used for fixedly connecting the revolving body workpiece 5 with the chuck 18 after penetrating through the clamp plate 24.

The hole face of trompil is fixed with flexible packing ring 25, and in this embodiment, the hole face of trompil is provided with the draw-in groove, and flexible packing ring 25 passes through the draw-in groove and fixes on the hole face of trompil with detachable.

The flexible gasket 25 can be made of rubber material, and can also be made of other flexible materials, and the flexible gasket can be arranged by those skilled in the art according to actual needs.

The flexible gasket 25 is made a plurality of, forms one set of perfect standardized flexible external member, can change corresponding model according to the different external diameter structural parameter of work piece to install it in the draw-in groove of anchor clamps board trompil hole face, convenient dismantlement, simultaneously, because the flexible gasket 25 adopts flexible material to make, also possesses the function of shaking.

The shape of the flexible washer 25 is matched to the shape of the workpiece to ensure that the flexible washer 25 can better secure the workpiece to be machined.

The jig plate 24 is provided with a vibration sensor 17 for detecting vibration information of the jig plate 24.

The vibration sensor 17 may be an existing vibration sensor mounted on the side of the clamp plate 24 remote from the chuck 18.

Since the vibration sensor 17 is mounted on the jig plate 24, the jig plate may have a moment of inertia instability during high-speed rotation, and therefore, a plurality of weights 23 are mounted on the side of the jig plate on which the vibration sensor is mounted, for balancing the weight of the vibration sensor.

The weight of the balancing weight 23 is the same as that of the vibration sensor, the vibration sensor 17 and the balancing weights 23 are arranged on the same circumference which takes the center of the clamp plate 24 as the center of a circle, and the vibration sensor 17 and the balancing weights 23 are distributed at equal intervals.

In this embodiment, two balancing weights 23 are provided, and the two balancing weights 23 and one vibration sensor 17 are equally spaced on the same circumference around the center of the clamp plate 24.

The clamp plate 24 is provided with a plurality of positioning blocks on the side surface for mounting the vibration sensor 17 and the counterweight 23, the positioning blocks 11 are arranged at equal intervals along the circumference which takes the center of the clamp plate as a circle, and six positioning blocks are arranged in the embodiment.

Wherein three locating pieces 11 are connected with the linear motion driving piece through adjusting pole 12, and the linear motion driving piece is along the circumference that uses the anchor clamps body center as the centre of a circle equidistant distribution, adjusts the radial direction setting of pole along the anchor clamps board, can follow the radial position of adjusting the linear motion driving piece of anchor clamps board, satisfies the user demand of not unidimensional work piece.

In this embodiment, the linear motion driving member employs a cushion cylinder 13, and the cushion cylinder 13 has three piston rods 14.

One end of the adjusting rod 12 is in threaded connection with the positioning block 11, the other end of the adjusting rod is in rotary connection with a cylinder body of the buffer cylinder 13 through a bearing, and the position of the buffer cylinder 13 can be adjusted along the radial direction of the clamp plate by rotating the adjusting rod 12.

The end parts of three piston rods 14 of the buffer cylinder 13 are fixedly connected to the push plate 15, the piston rods 14 can drive the push plate 15 to move along the radial direction of the clamp plate 24, the push plate 15 is provided with a flexible supporting block 16, the shape of the flexible supporting block 16 is matched with that of a workpiece, the flexible supporting block 16 can move synchronously with the push plate, and the push plate 15 can apply load to the workpiece through the flexible supporting block 16.

The push plate 15 is made of a metal material with a micro-deformation function so as to meet different workpiece surface structures, and the buffer cylinder can adjust pressure output through adjusting internal air pressure, so that the output force of the three piston rods 14 can be adjusted.

In this embodiment, the flexible supporting block 16 is provided with a clamping groove, and the pushing plate is arranged inside the clamping groove and detachably clamped and fixed with the flexible supporting block 16 through the clamping groove.

The flexible supporting block 16 is made in a plurality of forms a set of perfect parts, the models of different flexibility and different radian angles can be changed according to different workpiece structure parameters, and the flexible supporting block is connected with the push plate 15 through the clamping groove and is convenient to detach.

Through setting up buffer cylinder 13, push pedal 15 and flexible supporting shoe 16, can cushion the rocking that the work piece produced at the clamping in-process, also play the centering effect to the clamping of work piece simultaneously.

In this embodiment, gather the vibration information in the course of working in real time as vibration sensor 17, when the vibration is too big, to first piezoelectric stack 10 and second piezoelectric stack 22 circular telegram, thereby produce the vibration suppression signal through first piezoelectric stack 10 and second piezoelectric stack 22, first piezoelectric stack 10 and second piezoelectric stack 22 produce concertina movement increase to the clamp force of anchor clamps board 24, reduce the vibration range and the frequency of anchor clamps board 24, avoid anchor clamps to produce great vibration, guaranteed processingquality.

Meanwhile, the first pressure sensor 9 and the second pressure sensor 21 can acquire pressure values of the first piezoelectric stack 10 and the second piezoelectric stack 22, when the acquired pressure values are changed greatly, it is indicated that the clamp plate 24 generates axial displacement, at the moment, the first piezoelectric stack 10 and the second piezoelectric stack 22 are electrified, position compensation can be performed on the clamp plate 24, the clamp plate 24 can be attached to a workpiece through the flexible gasket 25, the influence of gap errors on machining precision is avoided, the problem that in the prior art, corresponding workpiece and clamp vibration suppression and corresponding gap compensation combination are lacked is solved well, vibration suppression can be achieved, gap compensation and vibration suppression can be completed automatically, and grinding precision and production efficiency are improved.

In this embodiment, connecting rod 7, buffer cylinder 13, balancing weight 23 and vibration sensor all are along circumference equal interval distribution, have avoided operating condition's inertia unstability, have guaranteed the machining precision.

Example 2

The embodiment provides a grinding device, which is provided with the flexible clamping mechanism for grinding in embodiment 1, and further comprises a cutter bar 1, wherein a grinding wheel 6 is arranged at the end part of the cutter bar, a vibration sensor 4 and a cutter bar vibration suppression element 3 are fixed on the cutter bar 1 through a bolt 2, the cutter bar vibration suppression element 3 in the embodiment adopts an ultrasonic motor, and it can be understood that the vibration suppression element can also adopt a micro vibration motor and the like, and the selection is carried out by the technical personnel in the field according to the actual needs.

In the embodiment, the vibration sensor, the pressure sensor, the power supply system, the cutter bar vibration suppression element 3, the buffer cylinder 13 and other components are connected with the control system, the vibration sensor and the pressure sensor can transmit acquired information to the control system, and the control system controls the work of the power supply system, the cutter bar vibration suppression element 3, the buffer cylinder 13 and other components, so that the aims of grinding wheel and clamp vibration suppression and clearance error compensation are automatically achieved along with the machining process.

Other configurations of the grinding device may be those of a conventional grinding machine, and will not be described in detail here.

The grinding device has the advantages of reasonable structural design, good operation quality, reliable operation and high generalization degree, and completely meets the requirements of the ultra-precise grinding process of the large thin-wall revolving body ceramic workpiece on a high-precision grinding vibration suppression system, an error compensation system and a high-precision control method.

The working method of the grinding device of the embodiment comprises the following steps:

when ultra-precision grinding is carried out on large-scale thin-wall revolving body parts, firstly, according to the structural appearance parameter size of a revolving body workpiece 5, three matched connecting rods 7 are selected, the mounting positions of second compression nuts 20, second pressure sensors 21 and annular second piezoelectric stacks 22 on the three connecting rods 7 are adjusted, all structures are guaranteed to be aligned with the connecting rods, a clamp plate 24 is adjusted to be parallel to a machine tool reference surface, the positions of first compression nuts 8, first pressure sensors 9 and annular first piezoelectric stacks 10 are adjusted and mounted, and the contact force between each annular piezoelectric stack and the clamp plate is adjusted; selecting the type of a flexible gasket 25 matched with the structural parameters of the workpiece, installing the flexible gasket in an opening of a clamp plate 24, and fixing; selecting three sets of flexible supporting blocks 16 matched with the structural parameters of the workpiece, and mounting the flexible supporting blocks on a push plate 15; clamping the tail end of the revolving body workpiece 5 on a chuck 18 of a machine tool, positioning, adjusting the position between a flexible gasket 25 on a clamp plate 24 and the revolving body workpiece 5, and ensuring that the revolving body workpiece 5 can be attached to the flexible gasket 25; the three sets of adjusting rods 12 are adjusted to realize the perfect fit of the flexible supporting block and the revolving body workpiece, and the clamping of the clamp is completed; selecting a proper cutter bar 1 and a grinding wheel 6, and adjusting and installing the position of a cutter bar vibration suppression element 3 on the cutter bar 1 of a vibration sensor 4;

in the process of starting the machine tool to process, the grinding wheel 6 is in contact with the revolving body workpiece 5, and meanwhile, if the vibration sensor is detected to generate a vibration signal on the cutter bar 1, the cutter bar vibration suppression element 3 starts to generate a vibration suppression signal to reduce the vibration amplitude of the cutter bar 1; if the first pressure sensor 9 and the second pressure sensor 21 detect that the clamp plate 24 has small deviation, the three sets of annular second piezoelectric stacks 22 and the three sets of annular first piezoelectric stacks 10 work cooperatively, and meanwhile, the position compensation is carried out on the clamp plate 24, so that the clamp plate 24 can be perfectly attached to the revolving body workpiece 5 through the flexible gasket 25, and the influence of clearance errors on the machining precision is avoided; meanwhile, if the vibration sensor on the clamp plate 24 detects that the clamp plate has a larger vibration signal, the three sets of annular first piezoelectric stacks 10 and second piezoelectric stacks 22 start to work, corresponding vibration suppression signals are generated, the clamping force on the clamp plate 24 is increased, the vibration amplitude and frequency of the clamp plate are reduced, the revolving body workpiece is prevented from generating larger vibration, and the processing quality is improved.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.

Claims

1. The utility model provides a flexible fixture for abrasive machining, a serial communication port, including the chuck, the chuck is connected with the anchor clamps board through a plurality of connecting pieces, the anchor clamps board is provided with the trompil that is used for the work piece to pass, the pore face of trompil is fixed with flexible packing ring, the connecting piece is provided with the first piezoelectric stack that is located anchor clamps board one side and the second piezoelectric stack that is located the anchor clamps board opposite side, first piezoelectric stack compresses tightly a side terminal surface at the anchor clamps board through first, the second piezoelectric stack compresses tightly a side terminal surface at the anchor clamps board through the second, vibration sensor is installed to the anchor clamps board.

2. A first flexible clamping mechanism for grinding operations as defined in claim 1 wherein said clamp plate is disposed coaxially with said chuck, and said connecting members are in the form of connecting rods, a plurality of said connecting rods being evenly spaced along a circumference centered on the center of said clamp plate.

3. A first type of flexible clamping mechanism for abrasive machining according to claim 1 wherein a first pressure transducer is disposed between the first piezo stack and the first clamping member and a second pressure transducer is disposed between the second piezo stack and the second clamping member.

4. A first flexible clamping mechanism for grinding operations as defined in claim 1 wherein the first clamping member is a first compression nut threadably engaged with the attachment member and the second clamping member is a second compression nut threadably engaged with the attachment member.

5. A first flexible clamping mechanism for grinding operations as defined in claim 1 wherein a plurality of counterweights are mounted on the clamping plate, the counterweights and the vibration sensor are equally spaced along a circle centered on the center of the clamping plate, and the counterweights are of equal weight to the vibration sensor.

6. A first type of flexible clamping mechanism for grinding operations as defined in claim 1, wherein the clamping plate is provided with a plurality of linear actuators mounted thereon, the plurality of linear actuators being spaced at equal intervals along a circumference centered on the center of the clamping plate, the linear actuators having a moving portion connected to a pushing plate, the pushing plate being provided with flexible support blocks adapted to the shape of the workpiece, the pushing plate being capable of applying pressure to the workpiece through the flexible support blocks.

7. A first flexible clamping mechanism for grinding according to claim 6, wherein the flexible support block is provided with a slot, and the push plate is located inside the slot and is detachably connected with the flexible support block through the slot.

8. The first flexible clamping mechanism for grinding according to claim 6, wherein the linear actuator is rotatably connected to one end of the adjustment lever, and the other end of the adjustment lever is threadedly connected to a positioning block fixed to the clamping plate.

9. An abrasive machining apparatus, characterized in that a flexible clamping mechanism for abrasive machining according to any one of claims 1 to 8 is provided.

10. A grinding apparatus according to claim 9, wherein the tool holder of the grinding apparatus is provided with a vibration sensor and a tool holder vibration suppressing member.