Ultra-thin hard and brittle curved surface grinding clamping device and method based on magneto-rheological fluid

Abstract

An ultra-thin hard and brittle curved surface grinding clamping device and method based on magnetorheological fluid, the device: the center of the base is provided with an adjusting through hole; the axial through hole with internal thread structure is opened in the core rod shaft center, the core rod is fixedly connected with the base, and the axial through hole is communicated with the adjusting through hole; the iron core is coaxially sleeved outside the core rod and is fixedly connected with the base; the cavity shell is coaxially fixedly connected with the upper end of the core rod; the piston rod is composed of a cap and a main rod body, the main rod body is inserted into the axial through hole through thread cooperation, and the cap is axially and slidingly assembled in the inside of the cavity shell; the magnetorheological fluid is filled in the inside of the cavity shell; the excitation coil is wound outside the iron core; the clamping sleeve is clamped outside the upper end of the cavity shell through the cylindrical clamping space, and the inside of the clamping sleeve is provided with an elastic element. The method is: the magnetorheological fluid is raised to a set height; a strong magnetic field is applied to change the shape of the magnetorheological fluid; the blank is assembled; the clamping sleeve is installed; and the blank is ground. The device and method can meet the precise clamping requirements of the ultra-thin hard and brittle curved surface element.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optical element processing equipment, and particularly relates to an ultra-thin hard and brittle curved surface grinding processing clamping device and method based on a magneto-rheological fluid. BACKGROUND

[0002] Some optical elements are usually ultra-thin hard and brittle curved surface structures, and it is difficult to process them. Since the blank material of the elements is hard and brittle, if the grinding force is not enough, the blank cannot be effectively processed, and if the grinding force is too large, the blank is prone to crack and damage. Therefore, a clamp is needed to fill the concave surface of the ultra-thin hard and brittle curved surface blank during processing to effectively avoid the damage of the blank caused by stress during grinding. At present, the common method is to use a mechanical clamp for batch processing of curved surface optical elements. The traditional mechanical clamp is usually a fixed structure, which has poor flexibility, and each mechanical clamp can only clamp a workpiece of one shape, and cannot meet the clamping and positioning requirements of ultra-thin hard and brittle curved surface blanks of various sizes and shapes. Therefore, this processing method is only suitable for ultra-thin hard and brittle curved surface optical elements of the same shape in the same batch, and cannot meet the precise clamping requirements if the style of the ultra-thin hard and brittle curved surface is changed or different processing procedures are adopted.

[0003] In order to effectively meet the positioning and clamping requirements of low rigidity and irregular shaped workpieces, and to effectively shorten the production time and reduce the production cost, it is urgent to provide a precise clamping device that can meet the clamping requirements of various complex shape ultra-thin hard and brittle curved surfaces. SUMMARY

[0004] In view of the problems existing in the prior art, the application provides an ultra-thin hard and brittle curved surface grinding processing clamping device and method based on a magneto-rheological fluid. The device has simple structure, low manufacturing cost, convenient installation process and simple operation process, can meet the precise clamping requirements of various complex shape ultra-thin hard and brittle curved surfaces, greatly reduce the processing cost, improve the production efficiency, and help reduce the probability of fragmentation of thin-walled structure elements during processing. The method has simple steps, can reduce the probability of workpiece fragmentation while reducing the cost.

[0005] The application provides an ultra-thin hard and brittle curved surface grinding processing clamping device based on a magneto-rheological fluid, which comprises a base, a core rod, an iron core, a cavity shell, a piston rod, a magneto-rheological fluid, an excitation coil and a sleeve.

[0006] An adjusting through hole is formed in the central region of the base;

[0007] An axial through hole with an inner thread structure is formed in the axis of the core rod, the lower end of the core rod is fixedly connected to the upper end of the base, and the axial through hole and the adjusting through hole are coaxially communicated.

[0008] The axial center of the iron core is provided with an axial mounting hole matched with the outer diameter of the mandrel, and the iron core is coaxially sleeved outside the mandrel through the axial mounting hole, and the lower end of the iron core is fixedly connected with the upper end of the base;

[0009] The cavity shell is a cylindrical structure, and the inner diameter thereof is greater than the inner diameter of the axial through hole, and the lower end of the cavity shell is coaxially fixedly connected with the upper end of the mandrel;

[0010] The piston rod is composed of a cap and a main rod body, the cap is a spherical cap, and the outer diameter thereof is matched with the inner diameter of the cavity shell; the outer diameter of the main rod body is matched with the inner diameter of the axial through hole, and the length thereof is greater than the height of the mandrel, and a section of external thread structure is arranged at the outer end of the main rod body, and an adjusting counterbore is arranged at the axial center of the end portion, the main rod body of the piston rod is inserted into the axial through hole through thread cooperation, and the cap is axially and slidingly arranged in the cavity shell;

[0011] The magnetorheological fluid is filled in the inside of the cavity shell and located in the space above the cap;

[0012] The excitation coil is arranged outside the iron core;

[0013] The inside of the sleeve has a cylindrical clamping space matched with the outer diameter of the cavity shell, and an annular groove is arranged at the upper end of the cylindrical clamping space, and an annular elastic element is arranged in the annular groove; the sleeve is clamped outside the upper end of the cavity shell through the cylindrical clamping space, and the elastic element in the inside of the sleeve is used for clamping the ultra-thin hard and brittle curved blank to be processed.

[0014] Further, in order to facilitate disassembly and assembly operations, and also to facilitate maintenance operations, four locking bolts are further included; the lower end of the cavity shell is fixedly connected with an annular connecting table, and four circular through holes are uniformly arranged on the annular connecting table in the circumferential direction; four threaded holes are arranged at the upper end of the mandrel at positions corresponding to the four circular through holes; the four locking bolts are inserted into the four threaded holes through thread cooperation after passing through the four circular through holes, and the cavity shell is fixedly connected with the upper end of the mandrel.

[0015] As a preferred, the adjusting counterbore is an internal hexagonal counterbore.

[0016] Further, in order to ensure the clamping fixing effect while also conveniently realizing the quick assembly and separation between the sleeve and the cavity shell, the sleeve is composed of two clamping bodies matched with each other, the clamping body is composed of an arc-shaped clamping plate segment located in the middle and two flat connecting segments fixed and connected in a symmetrical manner at the outer portions of two ends of the arc-shaped clamping plate segment, and an arc-shaped recess is formed in the inner side of one end of the arc-shaped clamping plate segment; a pair of mounting round holes are correspondingly formed in the two flat connecting segments matched with each other on the same side of the two clamping bodies; the two clamping bodies are relatively sleeved on the outside of the cavity shell through the cylindrical clamping space formed by the two arc-shaped clamping plate segments, and the annular recess for accommodating the elastic element is formed through the two arc-shaped recesses in the buckled state, and the two flat connecting segments on the same side are fixed and connected together through the connecting bolt penetrating the pair of mounting through holes.

[0017] As a preferred, the base is a plate structure.

[0018] In the present application, the core rod is fixedly connected to the base, which can make the main body of the clamp more stable, and also can facilitate the connection between the main body of the clamp and the workbench by using the base. The iron core is coaxially sleeved outside the core rod through the axial mounting hole of the shaft center, and is fixedly connected with the base, which not only can play a role in limiting the radial position of the core rod, but also can further enhance the connection strength between the core rod and the base. The cavity shell is coaxially fixedly connected to the upper end of the core rod, which can provide a bearing carrier for the magnetorheological fluid. An axial through hole is formed in the shaft center of the core rod and is communicated with the inner cavity of the cavity shell, and a piston rod with a size suitable for the axial through hole and the inner cavity of the cavity shell is assembled in the axial through hole and the inner cavity of the cavity shell, and the height of the magnetorheological fluid in the cavity shell can be adjusted by using the plug cap assembled in the cavity shell. A section of internal thread structure is arranged in the axial through hole, and a section of external thread structure is arranged on the outside of the main rod body, which can stably assemble the piston rod in the axial through hole through thread cooperation, and then the plug cap can be positioned at any height, and in addition, this threaded assembly method can effectively prevent the piston rod from being forced to retreat during the grinding process, thereby effectively ensuring the stability of the support. An adjusting through hole is formed in the base corresponding to the axial through hole, and an adjusting counterbore is formed in the shaft center of the end of the main rod body, which can facilitate the rotation of the piston rod by using the adjusting wrench from below the base, thereby changing the position of the plug cap in the cavity shell to meet the different height requirements of the magnetorheological fluid during the machining process. By winding the excitation coil outside the iron core, the excitation coil in the electrified state can act on the iron core and apply a strong magnetic field to the magnetorheological fluid. Under the action of the strong magnetic field, the viscosity of the magnetorheological fluid, which originally exhibits non-Newtonian fluid characteristics, increases, and the flowability decreases, exhibiting Bingham fluid characteristics. At this time, the volume of the magnetorheological fluid increases and deforms. In combination with the supporting effect of the spherical cap-shaped plug cap, the deformation of the magnetorheological fluid can be controlled, and the top of the magnetorheological fluid can be bulged. In this way, the concave surface of the ultra-thin hard and brittle curved surface blank can be clamped on the magnetorheological fluid, and the bulged magnetorheological fluid will adapt to the shape of the concave surface of the ultra-thin hard and brittle curved surface blank, realizing the coverage of the entire concave surface of the ultra-thin hard and brittle curved surface blank and completely adhering to the shape of the concave surface of the ultra-thin hard and brittle curved surface blank, thereby effectively supporting and protecting the ultra-thin hard and brittle curved surface during processing. The spherical cap-shaped plug cap is arranged at the bottom of the magnetorheological fluid, which not only can play a supporting role, but also can help to increase the shear yield stress of the magnetorheological fluid when the magnetorheological fluid material is subjected to an external normal stress in the magnetic field direction, thereby increasing the clamping force of the ultra-thin hard and brittle curved surface blank. In addition, due to the reaction force, while the plug cap is extruded by the concave surface of the ultra-thin hard and brittle curved surface blank through the magnetorheological fluid, it also generates a corresponding pressure. Since the plug cap is spherical, the axial positions on its surface are different, so it can play a better supporting role and better maintain the shape of the magnetorheological fluid, effectively improving the stability and reliability of the magnetorheological fluid support.The interior of the sleeve has a cylindrical clamping space, and a resilient element is arranged in the interior of the upper end of the sleeve, so that the outer surface of the ultra-thin hard and brittle curved blank can be fixed by the resilient element in the interior while the cavity shell is clamped by the cylindrical clamping space, and the ultra-thin hard and brittle curved blank can be fixed and supported by the magnetorheological fluid filled in the ultra-thin hard and brittle curved blank and the resilient element, so that the fixing effect of the ultra-thin hard and brittle curved blank is improved, and the probability of breakage during the processing of the ultra-thin hard and brittle curved blank is reduced.

[0019] The present application has the advantages of simple structure, low manufacturing cost, convenient installation process and simple operation process, which can improve the production efficiency of optical elements, reduce the production cost of enterprises, and be suitable for the flexible and precise clamping of various different ultra-thin complex curved elements, and can effectively meet the current production needs.

[0020] The present application provides an ultra-thin hard and brittle curved surface grinding clamping method based on magnetorheological fluid, which adopts an ultra-thin hard and brittle curved surface grinding clamping device based on magnetorheological fluid, including the following steps:

[0021] Step one: first place the ultra-thin hard and brittle curved surface grinding clamping device based on magnetorheological fluid on the workbench, and fix the base to the workbench; then connect the excitation coil to the direct current power supply by using the wire;

[0022] Step two: adjust the adjusting hole to extend into the adjusting counterbore at the lower end of the piston rod by using the adjusting wrench, and adjust the upward movement of the piston rod by rotating, so that the cap rises to the set position, and then drives the magnetorheological fluid to rise to the set clamping position;

[0023] Step three: increase the output current of the direct current power supply, so that the magnetic field generated by the iron core increases, and then a strong magnetic field is applied to the magnetorheological fluid to increase the viscosity of the magnetorheological fluid, and at the same time, the upper end of the magnetorheological fluid is supported by the cap to form a bulge;

[0024] Step four: place the ultra-thin hard and brittle curved blank to be processed outside the bulging magnetorheological fluid in the cavity shell;

[0025] Step five: first, set the elastic element on the outer surface of the ultra-thin hard and brittle curved blank to be processed, then oppositely buckle the two arc-shaped clamping plate segments of the two clamping monomers on the outer surface of the upper end of the cavity shell, and at the same time, limit and fix the elastic element by using the two arc-shaped grooves buckled on the two arc-shaped clamping plate segments, and finally, fix and install the sleeve composed of the two clamping monomers on the outer surface of the upper end of the cavity shell by using the two pairs of connecting bolts;

[0026] Step six: grind the ultra-thin hard and brittle curved blank to be processed;

[0027] Step seven: after the processing is finished, first remove the sleeve and remove the elastic element, then remove the processed ultra-thin hard and brittle curved surface element from the upper end of the cavity shell, then use the adjusting wrench to extend into the adjusting counterbore at the lower end of the piston rod through the adjusting round hole, adjust the piston rod to move downward by rotating, make the plug cap drop to the set position, finally, disconnect the direct current power supply, remove the effect of the applied magnetic field on the magnetorheological fluid, make the flowability of the magnetorheological fluid increase and restore to the initial state.

[0028] In the present application, the plug cap is first adjusted to the set position to drive the magnetorheological fluid to rise to the required height for clamping, then the strong magnetic field generated by the energized excitation coil and the iron core is used to change the properties of the magnetorheological fluid, so that the magnetorheological fluid forms a shape suitable for various different shapes of ultra-thin brittle curved surfaces, thereby effectively filling and completely adhering to the concave surface of the ultra-thin hard and brittle curved surface blank, meeting the requirements of clamping different shapes of ultra-thin hard and brittle curved surface blanks. The elastic element in the sleeve outside the cavity shell is sleeved on the outer surface of the ultra-thin hard and brittle curved surface blank, which can effectively fix the outer surface of the ultra-thin hard and brittle curved surface blank, and then the magnetorheological fluid filled in the concave surface of the ultra-thin hard and brittle curved surface blank can stably and reliably fix and support the ultra-thin hard and brittle curved surface blank, which can effectively reduce the probability of workpiece collapse during processing. The method has simple steps, and the shape of the clamp can be changed according to the shape of the ultra-thin hard and brittle curved surface blank during use, which can not only clamp the ultra-thin hard and brittle curved surface, but also meet the processing requirements of various different ultra-thin hard and brittle curved surfaces. BRIEF DESCRIPTION OF DRAWINGS

[0029] Fig. 1 is a structural schematic diagram of the present application;

[0030] Fig. 2 is an exploded structural schematic diagram of the present application;

[0031] Fig. 3 is a sectional view of the present application;

[0032] Fig. 4 is a structural schematic diagram of the sleeve in the present application.

[0033] In the figure: 1, magnetorheological fluid, 2, cavity shell, 3, piston rod, 4, excitation coil, 5, base, 6, iron core, 7, core rod, 8, sleeve, 9, elastic element, 10, ultra-thin hard and brittle curved surface blank, 11, axial through hole, 12, axial mounting hole, 13, plug cap, 14, main rod body, 15, annular connecting table, 16, circular through hole, 17, threaded hole, 18, clamping monomer, 19, arc-shaped clamping plate segment, 20, flat connecting segment, 21, arc-shaped groove, 22, mounting hole, 23, locking bolt. DETAILED DESCRIPTION

[0034] The present application will be further described below in conjunction with the drawings.

[0035] As shown in Figs. 1 to 4 The application provides an ultra-thin hard and brittle curved surface grinding clamping device based on a magnetorheological fluid, which comprises a base 5, a core rod 7, an iron core 6, a cavity shell 2, a piston rod 3, a magnetorheological fluid 1, an excitation coil 4 and a sleeve 8.

[0036] An adjusting through hole is formed in the central region of the base 5.

[0037] An axial through hole 11 with a size matching that of the circular hole is formed in the axis of the core rod 7, and an internal thread structure is arranged in the axial through hole 11; the lower end of the core rod 7 is fixedly connected with the upper end of the base 5, and the axial through hole 11 is coaxially communicated with the adjusting through hole.

[0038] An axial mounting hole 2212 with a size matching that of the outer diameter of the core rod 7 is formed in the axis of the iron core 6, and the iron core 6 is coaxially sleeved outside the core rod 7 through the axial mounting hole 2212, and the lower end of the iron core 6 is fixedly connected with the upper end of the base 5.

[0039] The cavity shell 2 is a cylindrical structure, and the inner diameter of the cavity shell 2 is greater than the inner diameter of the axial through hole 11; the lower end of the cavity shell 2 is coaxially fixedly connected with the upper end of the core rod 7.

[0040] The piston rod 3 is composed of a cap 13 and a main rod body 14; the cap 13 is a spherical crown, and the outer diameter of the cap 13 matches the inner diameter of the cavity shell 2; the outer diameter of the main rod body 14 matches the inner diameter of the axial through hole 11, and the length of the main rod body 14 is greater than the height of the core rod 7; the first end of the main rod body 14 is coaxially fixedly connected with the bottom plane of the cap 13, an external thread structure is arranged outside the tail end of the main rod body 14, and an adjusting counterbore is formed at the axis of the end; the main rod body 14 of the piston rod 3 is inserted into the axial through hole 11 through thread cooperation, and the cap 13 of the piston rod 3 is coaxially and slidingly arranged inside the cavity shell 2.

[0041] The magnetorheological fluid 1 is filled inside the cavity shell 2 and located in the space above the cap 13.

[0042] The excitation coil 4 is arranged outside the iron core 6.

[0043] The sleeve 8 has a cylindrical clamping space matching the outer diameter of the cavity shell 2 inside, and an annular groove is arranged at the upper end of the cylindrical clamping space, and an annular elastic element 9 is arranged in the annular groove; the sleeve 8 is clamped outside the upper end of the cavity shell 2 through the cylindrical clamping space, and the elastic element 9 inside the sleeve 8 is used to clamp the ultra-thin hard and brittle curved surface blank 10 to be processed.

[0044] For the convenience of disassembly and maintenance, four locking bolts 23 are further included; the lower end of the cavity shell 2 is fixedly connected with an annular connecting table 15, and four circular through holes 16 are evenly arranged on the circumference of the annular connecting table 15; four threaded holes 17 are arranged on the upper end of the mandrel 7 at positions corresponding to the four circular through holes 16; the four locking bolts 23 are inserted into the four threaded holes 17 through the four circular through holes 16 in a threaded manner, and the cavity shell 2 is fixedly connected to the upper end of the mandrel 7.

[0045] As a preferred, the adjusting counterbore is an internal hexagonal counterbore.

[0046] In order to ensure the clamping and fixing effect while facilitating the quick assembly and separation of the sleeve and the cavity shell, the sleeve 8 is composed of two clamping units 18 matched with each other, the clamping unit 18 is composed of an arc-shaped clamping plate segment 19 located in the middle and two flat connecting segments 20 fixedly connected to the outer part of both ends of the arc-shaped clamping plate segment 19 in a symmetrical manner, and an arc-shaped groove 21 is arranged on the inner side of one end of the arc-shaped clamping plate segment 19; a pair of installation through holes 22 are correspondingly arranged on the two flat connecting segments 20 matched with each other on the same side of the two clamping units 18; the two clamping units 18 are relatively sleeved on the outside of the cavity shell 2 through the cylindrical clamping space formed by the two arc-shaped clamping plate segments 19, and the annular groove for accommodating the elastic element 9 is formed by the two arc-shaped grooves 21 in the buckled state, and the two flat connecting segments 20 on the same side are fixedly connected together through the connecting bolt inserted into the pair of installation through holes 22.

[0047] As a preferred, the base 5 is a plate structure.

[0048] In the present application, the core rod is fixedly connected to the base, which can make the main body of the clamp more stable, and also can facilitate the connection between the main body of the clamp and the workbench by using the base. The iron core is coaxially sleeved outside the core rod through the axial mounting hole of the shaft center, and is fixedly connected with the base, which not only can play a role in limiting the radial position of the core rod, but also can further enhance the connection strength between the core rod and the base. The cavity shell is coaxially fixedly connected to the upper end of the core rod, which can provide a bearing carrier for the magnetorheological fluid. An axial through hole is formed in the shaft center of the core rod, which is communicated with the inner cavity of the cavity shell, and a piston rod with a size suitable for the axial through hole and the inner cavity of the cavity shell is assembled in the axial through hole and the inner cavity of the cavity shell, and the height of the magnetorheological fluid in the cavity shell can be adjusted by using the plug cap assembled in the cavity shell. A section of internal thread structure is arranged in the axial through hole, and a section of external thread structure is arranged on the outside of the main rod body, which can stably assemble the piston rod in the axial through hole through thread cooperation, and then the plug cap can be positioned at any height, and in addition, this threaded assembly method can effectively prevent the piston rod from being forced to retreat during the grinding process, thereby effectively ensuring the stability of the support. An adjusting through hole is formed in the base corresponding to the axial through hole, and an adjusting counterbore is formed in the shaft center of the end of the main rod body, which can facilitate the rotation of the piston rod by using the adjusting wrench from below the base, thereby changing the position of the plug cap in the cavity shell to meet the different height requirements of the magnetorheological fluid during the machining process. By winding the excitation coil outside the iron core, the excitation coil in the electrified state can act on the iron core and apply a strong magnetic field to the magnetorheological fluid. Under the action of the strong magnetic field, the viscosity of the magnetorheological fluid, which originally exhibits non-Newtonian fluid characteristics, increases, and the flowability decreases, exhibiting Bingham fluid characteristics. At this time, the volume of the magnetorheological fluid increases and deforms. In combination with the supporting effect of the spherical cap-shaped plug cap, the deformation of the magnetorheological fluid can be controlled, and the top of the magnetorheological fluid can be bulged. In this way, the concave surface of the ultra-thin hard and brittle curved surface blank can be clamped on the magnetorheological fluid, and the bulged magnetorheological fluid will adapt to the shape of the concave surface of the ultra-thin hard and brittle curved surface blank, realizing the coverage of the entire concave surface of the ultra-thin hard and brittle curved surface blank and completely adhering to the shape of the concave surface of the ultra-thin hard and brittle curved surface blank, thereby effectively supporting and protecting the ultra-thin hard and brittle curved surface during processing. The spherical cap-shaped plug cap is arranged at the bottom of the magnetorheological fluid, which not only can play a supporting role, but also can help to increase the shear yield stress of the magnetorheological fluid when the magnetorheological fluid material is subjected to an external normal stress in the magnetic field direction, thereby increasing the clamping force of the ultra-thin hard and brittle curved surface blank. In addition, due to the reaction force, while the plug cap is extruded by the concave surface of the ultra-thin hard and brittle curved surface blank through the magnetorheological fluid, it also generates a corresponding pressure. Since the plug cap is spherical, the axial positions on its surface are different, so it can play a better supporting role and better maintain the shape of the magnetorheological fluid, effectively improving the stability and reliability of the magnetorheological fluid support.The interior of the sleeve has a cylindrical clamping space, and a resilient element is assembled in the interior of the upper end of the sleeve, so that the outer surface of the ultra-thin hard and brittle curved blank can be fixed by the resilient element in the interior at the same time when the cavity shell is clamped by the cylindrical clamping space, so that the ultra-thin hard and brittle curved blank can be fixed and supported together with the magnetorheological fluid filled in the ultra-thin hard and brittle curved blank, the fixing effect of the ultra-thin hard and brittle curved blank is significantly improved, and the probability of fragmentation during the ultra-thin hard and brittle curved surface processing can be significantly reduced.

[0049] The present application has the advantages of simple structure, low manufacturing cost, convenient installation process, simple operation process, improved production efficiency of optical elements, reduced production cost of enterprises, and application to flexible precise clamping of various different ultra-thin complex curved surface elements, and effective satisfaction of current production requirements.

[0050] The present application provides an ultra-thin hard and brittle curved surface grinding processing clamping method based on magnetorheological fluid, and adopts an ultra-thin hard and brittle curved surface grinding processing clamping device based on magnetorheological fluid, including the following steps:

[0051] Step one: first, place the ultra-thin hard and brittle curved surface grinding processing clamping device based on magnetorheological fluid on the workbench, and fix the base 5 to the workbench; then connect the excitation coil 4 to the direct current power supply by using the wire;

[0052] Step two: adjust the adjusting hole to extend into the adjusting counterbore at the lower end of the piston rod 3 by using the adjusting wrench, adjust the upward movement of the piston rod 3 by rotating, make the plug cap 13 rise to the set position, and then drive the magnetorheological fluid 1 to rise to the set clamping position;

[0053] When the adjusting counterbore is an internal hexagonal counterbore, the adjusting wrench is an internal hexagonal adjusting wrench;

[0054] Step three: increase the output current of the direct current power supply, increase the magnetic field generated by the iron core 6, and then exert a strong magnetic field on the magnetorheological fluid 1 to improve the viscosity of the magnetorheological fluid 1, and at the same time, use the supporting effect of the plug cap 13 to make the upper end of the magnetorheological fluid 1 bulge;

[0055] Step four: place the ultra-thin hard and brittle curved blank 10 to be processed outside the bulging magnetorheological fluid 1 in the cavity shell 2;

[0056] Step five: first, the elastic element 9 is set on the outer surface of the ultra-thin hard and brittle curved blank 10 to be processed, then the two arc-shaped clamping plate segments 19 of the two clamping units 18 are buckled on the outer part of the upper end of the cavity shell 2, at the same time, the elastic element 9 is fixed and limited by the two arc-shaped grooves 21 buckled on the two arc-shaped clamping plate segments 19, finally, the clamping sleeve 8 composed of the two clamping units 18 is fixedly installed on the outer part of the upper end of the cavity shell 2 by two pairs of connecting bolts;

[0057] Step six: grinding processing is performed on the ultra-thin hard and brittle curved blank 10 to be processed;

[0058] Step seven: after the processing is completed, the clamping sleeve 8 is removed and the elastic element 9 is removed, then the processed ultra-thin hard and brittle curved element is removed from the upper end of the cavity shell 2, then the adjusting wrench is used to adjust the adjusting round hole to extend into the adjusting counterbore at the lower end of the piston rod 3, the piston rod 3 is adjusted to move downward by rotating, so that the plug cap 13 is lowered to the set position, finally, the direct current power supply is disconnected, the effect of the external magnetic field on the magnetorheological fluid 1 is removed, the flowability of the magnetorheological fluid 1 is enhanced and restored to the initial state.

[0059] In the application, the plug cap is first adjusted to the set position to drive the magnetorheological fluid to rise to the required height for clamping, then the strong magnetic field generated by the energized excitation coil and the iron core is used to change the properties of the magnetorheological fluid, so that the magnetorheological fluid forms a shape suitable for various ultra-thin hard and brittle curved surfaces, thereby effectively filling and completely adhering to the concave surface of the ultra-thin hard and brittle curved blank, and the requirements for clamping different shapes of ultra-thin hard and brittle curved blanks are met. The elastic element in the clamping sleeve fixed on the outer part of the cavity shell is set on the outer surface of the ultra-thin hard and brittle curved blank, which can effectively fix the outer surface of the ultra-thin hard and brittle curved blank, and then the magnetorheological fluid filled in the concave surface of the ultra-thin hard and brittle curved blank can stably and reliably fix and support the ultra-thin hard and brittle curved blank, which can effectively reduce the probability of workpiece collapse during processing. The method has simple steps, and the shape of the clamp can be changed according to the shape of the ultra-thin hard and brittle curved blank during use, which can not only clamp the ultra-thin hard and brittle curved surface, but also meet the processing requirements of various ultra-thin hard and brittle curved surfaces.

Claims

1. A clamping device for ultra-thin hard brittle curved surface grinding based on magnetorheological fluid, comprising a base (5), characterized in that, It also includes a core rod (7), a core (6), a cavity shell (2), a piston rod (3), a magnetorheological fluid (1), an excitation coil (4) and a sleeve (8); The center area of the base (5) is provided with an adjusting through hole; The axial through hole (11) is provided with an internal thread structure, the lower end of the core rod (7) is fixedly connected with the upper end of the base (5), and the axial through hole (11) is coaxially communicated with the adjusting through hole; The axial installation hole (12) is coaxially sleeved on the outside of the core rod (7), and the lower end of the core (6) is fixedly connected with the upper end of the base (5); The cavity shell (2) is a cylindrical structure, the inner diameter of which is larger than the inner diameter of the axial through hole (11), and the lower end of the cavity shell (2) is coaxially fixedly connected with the upper end of the core rod (7); The piston rod (3) is composed of a cap (13) and a main rod body (14), the cap (13) is a spherical cap, the outer diameter of which is matched with the inner diameter of the cavity shell (2); the outer diameter of the main rod body (14) is matched with the inner diameter of the axial through hole (11), the length of the main rod body (14) is larger than the height of the core rod (7), an external thread structure is arranged on the outer end of the main rod body (14), and an adjusting counterbore is arranged at the axial end of the main rod body (14); the main rod body (14) of the piston rod (3) is inserted into the axial through hole (11) through thread cooperation, and the cap (13) is axially and slidingly arranged in the cavity shell (2); The magnetorheological fluid (1) is filled in the cavity shell (2), and is located in the space above the cap (13); The excitation coil (4) is arranged on the outside of the core (6); The sleeve (8) has a cylindrical clamping space matched with the outer diameter of the cavity shell (2), an annular groove is arranged at the upper end of the cylindrical clamping space, and an annular elastic element (9) is arranged in the annular groove; the sleeve (8) is clamped on the outside of the upper end of the cavity shell (2) through the cylindrical clamping space, and the elastic element (9) in the sleeve (8) is used for clamping the ultra-thin hard and brittle curved blank (10) to be processed; It also includes four locking bolts (23); the lower end of the cavity shell (2) is fixedly connected with an annular connecting table (15), and four circular through holes (16) are uniformly arranged on the circumference of the annular connecting table (15); four threaded holes (17) are arranged on the upper end of the core rod (7) at positions corresponding to the four circular through holes (16); after passing through the four circular through holes (16), the four locking bolts (23) are inserted into the four threaded holes (17) through thread cooperation, and the cavity shell (2) is fixedly connected with the upper end of the core rod (7). The clamping sleeve (8) is composed of two clamping units (18) matched with each other, the clamping unit (18) is composed of an arc-shaped clamping plate segment (19) located in the middle and two straight connecting segments (20) fixedly connected to the outer sides of the two ends of the arc-shaped clamping plate segment (19) in a symmetrical manner, and an arc-shaped recess (21) is formed in the inner side of one end of the arc-shaped clamping plate segment (19); a pair of mounting through holes (22) are formed in the two straight connecting segments (20) on the same side of the two clamping units (18) in a corresponding manner; the two clamping units (18) are relatively sleeved outside the cavity shell (2) through the cylindrical clamping space formed by the two arc-shaped clamping plate segments (19) buckled to each other, and the annular recess for accommodating the elastic element (9) is formed through the two arc-shaped recesses (21) in the buckled state, and the two straight connecting segments (20) on the same side are fixedly connected together through the connecting bolt penetrating the pair of mounting through holes (22).

2. The ultra-thin hard brittle curved surface grinding clamping device based on the magnetorheological fluid according to claim 1, characterized in that, The adjusting counterbore is an internal hexagonal counterbore.

3. The ultra-thin hard brittle curved surface grinding clamping device based on the magnetorheological fluid according to claim 1, characterized in that, The base (5) is a plate-shaped structure.

4. A clamping method for ultra-thin hard and brittle curved surface grinding based on magnetorheological fluid, characterized in that the method uses the clamping device for ultra-thin hard and brittle curved surface grinding based on magnetorheological fluid according to any one of claims 1 to 3. The method comprises the following steps: Step one: first, place the ultra-thin hard and brittle curved surface grinding clamping device based on the magnetorheological fluid on the workbench, and fix the base (5) to the workbench; then connect the excitation coil (4) to the direct current power supply through the wire; Step two: use the adjusting wrench to adjust the adjusting counterbore in the lower end of the piston rod (3) through the adjusting circular hole, and adjust the upward movement of the piston rod (3) through the rotating mode, so that the cap (13) rises to the set position, and then drives the magnetorheological fluid (1) to rise to the set clamping position; Step three: control the output current of the direct current power supply to increase, so that the magnetic field generated by the iron core (6) increases, and then a strong magnetic field is applied to the magnetorheological fluid (1) to increase the viscosity of the magnetorheological fluid (1), and at the same time, the support of the cap (13) makes the upper end of the magnetorheological fluid (1) bulge; Step four: place the ultra-thin hard and brittle curved surface blank (10) to be processed outside the magnetorheological fluid (1) bulging in the cavity shell (2); Step five: first, the elastic element (9) is sleeved on the outer surface of the ultra-thin hard and brittle curved surface blank (10) to be processed, and then the two arc-shaped clamping plate segments (19) of the two clamping units (18) are buckled to each other outside the upper end of the cavity shell (2), and at the same time, the two arc-shaped recesses (21) buckled to each other on the two arc-shaped clamping plate segments (19) limit and fix the elastic element (9), and finally, the clamping sleeve (8) composed of the two clamping units (18) is fixedly installed outside the upper end of the cavity shell (2) through the two pairs of connecting bolts; Step six: grind the ultra-thin hard and brittle curved surface blank (10) to be processed. Step seven: after the processing is finished, first remove the sleeve (8) and remove the elastic element (9), and then remove the processed ultra-thin hard and brittle curved surface element from the upper end of the cavity shell (2), then use the adjusting wrench to extend into the adjusting counterbore at the lower end of the piston rod (3) through the adjusting round hole, adjust the downward movement of the piston rod (3) by rotating, make the plug cap (13) drop to the set position, finally, disconnect the direct current power supply, remove the effect of the external magnetic field on the magnetorheological fluid (1), and make the flowability of the magnetorheological fluid (1) increase and return to the initial state.

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