CN111673644A - Device and method for testing rigidity of grinding spindle - Google Patents

Abstract

A test device and a test method for the rigidity of a grinding spindle are provided, wherein the test device comprises: the top of the test board is provided with a through limiting part, and the grinding spindle to be tested is arranged on the limiting part; a fixing member coaxially connected to an outer peripheral side of the grinding spindle and overlapping the stopper; the fixed component is provided with an air floating structure, the air floating structure is opposite to the top surface of the test board, and gas introduced into the air floating structure supports the grinding spindle; the axial rigidity detection assembly is arranged on the test bench and positioned on the upper side of the grinding spindle so as to measure the axial rigidity of the grinding spindle; and the radial rigidity detection assembly is arranged on the test bench and positioned on the side surface of the grinding spindle so as to measure the radial rigidity of the grinding spindle.

Description

Device and method for testing rigidity of grinding spindle

Technical Field

The invention belongs to the technical field of ultra-precise grinding of wafers, and particularly relates to a device and a method for testing the rigidity of a grinding spindle.

Background

With the gradual mass production of 128 layers or even 256 layers of 3DNAND memory chips and the like, the requirements of the stacking technology of the NAND chips on the Thickness of a wafer of 300mm or less and the integral flatness (TTV) are continuously improved, and the TTV requirement is even lower than 1 micron, so that the unprecedented high requirement is provided for the rigidity of a grinding spindle.

The ultra-precision grinding is used for the leveling processing in the wafer preparation stage, replaces the grinding and etching processes, can effectively reduce the damage depth of the processed surface, and reduces the processing amount of subsequent polishing. The ultra-precision grinding is performed on wafer thinning equipment, and a grinding spindle is a key part of the wafer thinning equipment, and the use performance, particularly the rigidity of the grinding spindle, directly determines the grinding processing level. Before the grinding spindle is mounted to the wafer thinning equipment, the rigidity of the grinding spindle, particularly the bearing mounting position of the grinding spindle, needs to be tested.

In the prior art, a simple measuring device is used for testing the rigidity of a grinding spindle. Because the grinding main shaft is heavy, a hoisting tool is needed to be used for placing and adjusting the position of the grinding main shaft. The position of the grinding spindle cannot be accurately adjusted in the test process, so that the problem of inconvenient operation exists; in addition, there is a risk of gouging the finished surface of the spindle during adjustment of the position of the grinding spindle. If the finish machining surface of the grinding spindle is gouged, the grinding spindle is scrapped integrally.

Disclosure of Invention

The invention provides a device for testing the rigidity of a grinding spindle, which aims to solve one of the technical problems to a certain extent, and comprises: the top of the test board is provided with a through limiting part, and the grinding spindle to be tested is arranged on the limiting part; a fixing member coaxially connected to an outer peripheral side of the grinding spindle and overlapping the stopper; the fixed component is provided with an air floating structure, the air floating structure is opposite to the top surface of the test board, and gas introduced into the air floating structure supports the grinding spindle; the axial rigidity detection assembly is arranged on the test bench and positioned on the upper side of the grinding spindle so as to measure the axial rigidity of the grinding spindle; and the radial rigidity detection assembly is arranged on the test bench and positioned on the side surface of the grinding spindle so as to measure the radial rigidity of the grinding spindle.

As the preferred embodiment, fixed subassembly includes ring flange and clamping ring, the bottom of ring flange is provided with the air supporting groove, the clamping ring set up in the upper portion of ring flange, both form with the sealed cavity of air supporting groove intercommunication, gaseous through sealed cavity, top-down carry extremely the air supporting groove is in order to upwards bearing fixed subassembly and grinding main shaft.

As a preferred embodiment, an air storage groove is arranged at the upper part of the flange plate, and the pressure ring and the air storage groove form a sealed cavity; the flange plate is also provided with a communication hole for communicating the gas storage tank with the air floating tank, and gas introduced into the sealed cavity is conveyed to the air floating tank through the communication hole.

As a preferred embodiment, the limiting part is an elliptical notch, and the grinding spindle with the fixing component mounted thereon is lapped on the limiting part and moves along the length direction thereof.

As a preferred embodiment, the air flotation grooves are symmetrically arranged at the bottom of the flange plate.

In a preferred embodiment, the air flotation grooves are elongated holes, and the number of the communication holes is plural, and the communication holes are distributed at intervals along the length direction of the elongated holes.

As a preferred embodiment, the flange is provided with a vent hole along the radial direction, and the vent hole is communicated with the sealing chamber; and gas is conveyed to the air flotation tank through the vent hole, the gas storage tank and the communication hole.

As a preferred embodiment, the fixing component further comprises positioning pins symmetrically arranged at the bottom of the flange plate; the setting position of the positioning pin is matched with the width of the limiting part.

As a preferred embodiment, the testing device for the rigidity of the grinding spindle further comprises an axial detection fixing column which is vertically arranged at the top of the test bench, and the axial rigidity detection assembly is detachably arranged on the axial detection fixing column.

As a preferred embodiment, the axial stiffness detection assembly comprises a support mechanism, an axial loading piece, a pressure sensor, a loading disc and a displacement measurement piece; the supporting mechanism is connected to the axial detection fixing column, and the axial loading piece is arranged on the supporting mechanism; a loading disc is arranged at the moving end of the axial loading piece, and the pressure sensor is arranged between the moving end and the loading disc; the displacement measuring piece is abutted against the end part of the grinding spindle to measure the axial displacement of the grinding spindle after being subjected to preset loading.

As a preferred embodiment, the device for testing the rigidity of the grinding spindle further comprises a radial detection fixing seat which is arranged at the top of the test bench; the radial rigidity detection assembly comprises a radial loading piece, a pressure sensor, a loading part and a displacement measurement piece; the radial loading piece is arranged on the radial detection fixing seat, a loading part is arranged at the moving end of the radial loading piece, and the pressure sensor is arranged between the moving end and the loading part; the displacement measuring part is abutted against the peripheral side face of the grinding spindle to measure the radial displacement of the grinding spindle after being subjected to a predetermined load.

Meanwhile, the invention also discloses a method for testing the rigidity of the grinding spindle, which comprises the following steps:

lapping a grinding main shaft assembled with a fixing component on a limiting part of a test bench, wherein an air floatation structure of the fixing component is opposite to the top surface of the test bench;

introducing gas into the air floating structure of the fixing component, and conveying the gas to the air floating structure from top to bottom so as to upwards support the grinding main shaft provided with the fixing component;

moving the grinding spindle provided with the fixing component from the mounting position to a testing position and fixing the fixing component on the testing platform;

and detecting the rigidity of the grinding spindle by using an axial rigidity detection assembly and a radial rigidity detection assembly.

Compared with the prior art, the embodiment of the invention has the following beneficial effects: the grinding spindle provided with the fixing component has the advantages of convenience in moving, accurate adjustment of the test position, prevention of collision between the grinding spindle and other parts of the test device, and avoidance of scrapping due to damage of a finished grinding spindle surface; in addition, this device can measure the axial rigidity and the radial rigidity of grinding main shaft simultaneously to the rigidity detects to operating condition has good practical value.

Drawings

The advantages of the invention will become clearer and more readily appreciated from the detailed description given with reference to the following drawings, which are given by way of illustration only and do not limit the scope of protection of the invention, wherein:

FIG. 1 is a schematic structural diagram of a grinding spindle rigidity testing device according to the invention;

FIG. 2 is a schematic diagram of a device under test according to the present invention;

FIG. 3 is a schematic view of a lower view of the DUT shown in FIG. 2;

FIG. 4 is a cross-sectional view of the securing assembly according to the present invention;

FIG. 5 is an enlarged view of a portion of FIG. 4 at A;

FIG. 6 is a schematic pressure diagram of an air bearing chamber formed by the fixture assembly and the test station according to the present invention;

FIG. 7 is a schematic view of the construction of the flange according to the present invention;

FIG. 8 is a schematic structural view of an axial stiffness sensing assembly according to the present invention;

fig. 9 is a schematic structural diagram of a radial stiffness detection assembly according to the present invention.

Detailed Description

The following describes the technical solutions related to the embodiments of the present invention in detail with reference to the specific embodiments and the accompanying drawings. The examples set forth herein are specific, non-limiting, embodiments of the present invention and are presented to illustrate the concepts and concepts of the present invention; the description is illustrative, exemplary, and schematic and is not to be construed as limiting the embodiments of the invention and the scope of the invention. In addition to all of the embodiments described herein, those skilled in the art will be able to employ other technical solutions which are obvious or will be easily conceived based on the disclosure of the claims and the specification thereof, and these technical solutions include those which employ any obvious replacement or modification of the embodiments described herein. In order to explain the technical means of the present invention, the following description will be given by way of specific examples.

Fig. 1 shows a schematic structural diagram of a grinding spindle rigidity testing device 1 according to the present invention, and the grinding spindle rigidity testing device 1 includes a testing table 10, an axial rigidity detecting assembly 20, and a radial rigidity detecting assembly 30. The axial stiffness detection assembly 20 and the radial stiffness detection assembly 30 are provided at the test stand 10 to simultaneously measure the stiffness of the grinding spindle.

The top of the test bench 10 is provided with a limiting part 11, and the grinding spindle 50 to be tested is placed in the limiting part 11. The axial stiffness detecting assembly 20 is disposed at the test stand 10 and on the upper side of the limiting portion 11 to measure the axial stiffness of the grinding spindle 50. The radial stiffness detection assembly 30 is disposed at the test bench 10 and located at the side of the limiting portion 11 to measure the radial stiffness of the grinding spindle 50.

In fig. 1, the test stand 10 includes a support frame 12 and a top plate 13, and the support frame 12 is made of square steel by tailor welding and forms a rectangular frame structure. The top plate 13 is fixed on the top of the supporting frame 12 by bolts, and the limiting part 11 is arranged in the middle of the top plate 13.

The top plate 13 is made of stainless steel, and the thickness of the top plate is 12mm-20mm, so that the test board 10 has good strength, and the influence on the accuracy of the rigidity test due to insufficient strength of the test board 10 is avoided. In the embodiment shown in fig. 1, the top plate 13 is a rectangular plate structure having dimensions of 1200mm × 800mm and a thickness of 15mm to ensure sufficient strength of the test apparatus. It will be appreciated that top plate 13 may also be made of plain carbon steel, such as Q195, Q235, etc.; the top plate 13 may also be made of high quality carbon steel, such as 10#, 20#, or 45 #.

When testing the rigidity of the grinding spindle, firstly, the grinding spindle 50 needs to be placed in the limiting part 11 of the test bench 10; then adjusting the grinding spindle 50 from the hoisting position to the testing position; next, the grinding spindle 50 is fixed to the test stand 10; finally, the grinding spindle stiffness is measured using the axial stiffness sensing assembly 20 and the radial stiffness sensing assembly 30.

The grinding spindle 50 is made of metal and weighs 50kg to 200kg, or even more. When adjusting the position of the grinding spindle 50, a tester needs to move the heavy grinding spindle 50, and therefore, there are problems that the operation is inconvenient and the position of the grinding spindle is not accurately adjusted. In the process of adjusting the position of the grinding spindle, a tester may collide the grinding spindle 50 with the test board 10 and other components, and even gouge the finish machining surface of the grinding spindle 50, so that the grinding spindle is scrapped integrally.

In order to solve the above technical problem, the device 1 for testing the rigidity of the grinding spindle according to the present invention further includes a fixing assembly 40, and the fixing assembly 40 is coaxially connected to the outer peripheral side of the grinding spindle 50, as shown in fig. 1. The grinding spindle 50 and the fixing component 40 are assembled to form a component to be tested, and the component to be tested is lapped on the limiting part 11 of the test bench 10. For convenience of description, the assembly body formed by the grinding spindle 50 to which the fixing member 40 is attached is simply referred to as "the member under test".

In the embodiment shown in FIG. 1, the fixture assembly 40 is configured with an air-floating structure that opposes the top plate 13 of the test stand 10. Specifically, the gas introduced into the air floating structure acts vertically downward on the top plate 13 of the test stand 10. Based on the acting force and the reacting force, a vertically upward air buoyancy force for supporting the component to be tested exists between the fixing component 40 and the top plate 13. Since the direction of the air bearing force is opposite to the direction of the gravity of the component to be measured, the gravity of the grinding spindle 50 is partially or completely cancelled. Thus, the tester can conveniently move the grinding spindle 50 and accurately adjust the grinding spindle 50 to the position to be tested. The accuracy of the position adjustment of the grinding spindle 50 can also prevent the grinding spindle from colliding with other components, and avoid the damage of the finish machining surface of the grinding spindle 50.

The pressure of the gas introduced into the fixed component 40 is 0.5MPa-0.6MPa, and the flow rate is 2L/min-8L/min. The air floating structure at the bottom of the fixing assembly 40 forms an air floating chamber with the top plate 13 of the test bench 10. When the upward gas buoyancy formed by the gas in the gas buoyancy chamber is smaller than the gravity of the component to be tested, the fixed component 40 abuts against the top plate 13 of the test bench 10, and the gas buoyancy counteracts partial gravity of the component to be tested. When the upward gas buoyancy force formed by the gas in the gas buoyancy chamber is greater than the gravity of the component to be tested, the fixing component 40 is separated from the top plate 13 of the test bench 10. When the fixing member 40 is disengaged from the test stand 10, the distance between the fixing member 40 and the top plate 13 of the test stand 10 is 10 μm to 50 μm. The air floating structure of the fixing component 40 and the top plate 13 of the test platform 10 form an open air floating chamber, that is, the air entering the air floating chamber through the fixing component 40 can be discharged through the gap between the fixing component 40 and the top plate 13, and the air buoyancy and the gravity of the component to be tested form dynamic balance. The tester can move the position of the grinding spindle 50 conveniently and accurately. Thus, controlling the air buoyancy of the air bearing chamber enables the stator assembly 40 to be disengaged from the top plate 13.

Fig. 2 is a schematic diagram of the connection between the fixing assembly 40 and the grinding spindle 50, wherein the fixing assembly 40 includes a flange 41 and a pressing ring 42, the flange 41 is disposed coaxially with the grinding spindle 50, specifically, the flange 41 is connected with a spindle flange 51 of the grinding spindle 50, and the pressing ring 42 is coaxially connected with an upper portion of the flange 41.

In fig. 3, an air flotation groove 41a is provided in the bottom of the flange 41. The pressure ring 42 provided on the upper portion of the flange 41 and the air bearing groove 41a form a sealed chamber. The gas is delivered to the air floating groove 41a from top to bottom through the sealed chamber, and the air floating groove 41a and the top plate 13 of the test bench 10 form an air floating chamber. The gas introduced into the air floatation chamber forms vertical upward air buoyancy, the gravity of the component to be tested is offset by the air buoyancy received by the grinding main shaft 50, and a tester can conveniently and accurately adjust the position of the component to be tested.

Fig. 4 is a longitudinal sectional view of the fixing member 40, in which an air receiver 41b is provided at an upper portion of the flange 41, and the air receiver 41b is concentrically disposed with the flange 41, and has a rectangular cross section. The air-reserving groove 41b of the flange 41 and the pressing ring 42 form a sealed chamber. The flange 41 is also provided with a communication hole 41c provided in the thickness direction of the flange 41 and located in the air reservoir 41 b. The communication hole 41c extends vertically downward from the air receiver 41b to the air floating groove 41a at the bottom of the flange 41. The gas introduced into the sealed chamber formed by the flange 41 and the pressure ring 42 is supplied to the gas floating tank 41a through the communication hole 41 c.

In the present invention, a gap is provided between the fixing assembly 40 and the top plate 13 of the testing table 10, that is, there is no friction between the fixing assembly 40 and the top plate 13. This arrangement can effectively prevent the grinding spindle 50 and the top plate 13 from rubbing against each other and damaging the finished surface of the grinding spindle 50.

In order to form a sealed chamber between the flange 41 and the pressure ring 42, seal grooves are disposed on both sides of the gas storage groove 41b, the seal grooves are disposed concentrically with the gas storage groove 41b, and a seal ring is disposed inside the seal grooves to seal the flange 41 and the pressure ring 42. The pressing ring 42 is coaxially disposed on the upper portion of the flange 41 to form a sealed chamber.

Fig. 5 is a partial enlarged view of a portion a in fig. 4, and the air flotation groove 41a is provided at the bottom of the flange 41, and has a thickness of not more than 1mm and not less than 0.3 mm. The communication hole 41c provided between the air flotation tank 41a and the air storage tank 41b should be located at the middle position of the air flotation tank 41 a. Thus, the gas in the gas storage tank 41b can be introduced into the gas floating tank 41a substantially uniformly through the communication hole 41 c. The air floating groove 41a and the top plate 13 of the test platform 10 form an air floating chamber, and the air introduced into the air floating chamber forms an air floating force opposite to the gravity of the component to be tested.

Fig. 6 is a schematic diagram of the pressure inside the air floating chamber corresponding to fig. 5, and it can be seen from fig. 6 that the pressure inside the air floating chamber corresponding to the air floating groove 41a is P1, the pressure inside the air floating chamber corresponding to the outer side of the air floating groove 41a is less than P1, and finally approaches to the atmospheric pressure P0. The gas entering the air flotation tank 41a through the gas storage tank 41b and the communication hole 41c is continuously discharged from the gap between the flange 41 and the top plate 13, and the air buoyancy in the air flotation chamber is balanced with the gravity of the component to be measured.

In fig. 3, the air flotation grooves 41a are kidney-shaped holes and are symmetrically arranged at the bottom of the flange 41. After the to-be-tested component formed by assembling the grinding spindle 50 and the fixing component 40 is lapped on the limiting part 11, the air floating grooves 41a at the bottom of the flange 41 are symmetrically positioned at two sides of the limiting part 11. The gas introduced into the gas storage groove 41b is introduced into the gas floating groove 41a through the communication hole 41c so that an upward gas buoyancy is formed between the fixing member 40 and the top plate 13 of the test stand 10. As an embodiment of the present invention, the number of the air flotation grooves 41a may be plural, and they are symmetrically arranged at the bottom of the flange 41. A plurality of communication holes 41c are provided in the air flotation groove 41 a. The air-floating groove 41a is disposed opposite to the top plate 13 of the test stand 10 to ensure that the air-floating groove 41a always faces the top surface of the top plate 13 when the grinding spindle 50 provided with the fixing member 40 moves in the longitudinal direction of the stopper 11.

In FIG. 3, 4 communication holes 41c are provided in the air flotation tank 41a on the flange 41 side, and are arranged at regular intervals in the longitudinal direction of the air flotation tank 41a, so that the gas in the gas storage tank 41b can uniformly and rapidly enter the air flotation tank 41 a. It is understood that the communication holes 41c may be formed in other numbers, such as 3, 5, 6, 8, etc., which are substantially uniformly distributed in the air floating groove 41a to communicate the air storage groove 41b of the flange 41 with the air floating groove 41a, so as to transfer the air in the air storage groove 41b to the air floating groove 41 a.

Fig. 7 is a longitudinal sectional view of the flange plate 41. The flange 41 further includes vent holes 41d, and the vent holes 41d are arranged in the radial direction of the flange 41. The flange 41 further includes a vertical hole 41e vertically disposed in the air floating groove 41a and connecting the air floating groove 41a and the air vent hole 41 d. The gas enters the gas receiver 41b through the vent hole 41d and the vertical hole 41e, and is then transferred to the gas floating tank 41a at the bottom of the flange 41 through the communication hole 41 c.

In the embodiment shown in fig. 2 and 3, the fixing assembly 40 further comprises a quick-connect plug 43 mounted to the vent 41d shown in fig. 7 for introducing gas into the sealed chamber inside the fixing assembly 40 through a conduit. As a variation of the present embodiment, the vent hole 41d may be provided at other positions. If the vent hole 41d is provided in the press ring 42, the vent hole 41d is vertically provided in the thickness direction of the press ring 42 and communicates with the gas reserving groove 41b of the flange 41, and the gas can be introduced into the gas reserving groove 41b of the flange 41 through the vent hole in the press ring 42.

In the embodiment shown in fig. 1, the roughness of the top plate 13 on the upper portion of the testing table 10 is ra0.2-ra0.8, and a stable air floating structure can be formed before the fixing assembly 40 and the top plate 13, so as to ensure that the distance between the grinding spindle 50 provided with the fixing assembly 40 and the top plate 13 is controlled to be 10um-50 um.

In the embodiment shown in fig. 2, the flange 41 and the pressure ring 42 are made of a non-metallic material, such as plastic. In particular, the flange 41, which may be in contact with the top plate 13, is made of a non-metallic material. In this way, the material of the fixing member 40 is different from the material of the top plate 13 of the test stand 10, so as to prevent the roughness of the top plate 13 from being damaged during the process of hoisting the grinding spindle 50 provided with the fixing member 40 to the stopper 11. As an embodiment of the present invention, the flange 41 is made of polyphenylene sulfide to effectively prevent the grinding spindle 50 from affecting the roughness of the top plate 13 of the test stand 10 during the hoisting process. It will be appreciated that the flange 41 may also be made of rigid polyvinyl chloride, polyethylene, polypropylene, polystyrene, polytetrafluoroethylene, nylon, PET or ABS. It will be appreciated that the flange 41 and the pressure ring 42 may also be made of a metallic material. As long as when hoist and mount and place, let in gas to the inside of fixed subassembly 40 for form the air supporting structure between the roof 13 of fixed subassembly 40 and testboard 10, can avoid grinding main shaft 50 and testboard 10 direct contact, and then avoided the influence of grinding main shaft 50 hoist and mount in-process to the roughness of roof 13. At the same time, this arrangement also prevents the wear spindle 50 from coming into direct contact with the test stand 10 and affecting the finished surface of the grinding spindle 50.

The axial stiffness sensing assembly 20 and the radial stiffness sensing assembly 30 are secured to the top surface of the test stand 10. In order to prevent the axial stiffness detection assembly 20 and the radial stiffness detection assembly 30 from interfering with the hoisting of the component to be tested, the limiting portion 11 on the top surface of the test bench 10 is an oval notch. The axial stiffness detection component 20 and the radial stiffness detection component 30 are arranged at one end of the limiting part 11, and the component to be detected can be hung at the other end of the limiting part 11. After the grinding spindle 50 provided with the fixing component 40 is hung on the limiting part 11, the grinding spindle can move to the positions of the axial stiffness detection component 20 and the radial stiffness detection component 30 along the length direction of the limiting part 11. Namely, the component to be tested can be moved to the testing position from the hoisting position of the limiting part 11 so as to carry out the rigidity test of the grinding spindle.

It is easy to understand that the size of the limiting part 11 is matched with the size of the grinding spindle 50, and the diameter of the limiting part 11 is slightly larger than the size of the corresponding position of the grinding spindle 50, so that the grinding spindle 50 mounted with the fixing component 40 can move smoothly along the length direction of the limiting part 11 without interference.

In order to prevent the component to be measured from shifting during the moving process, even the air floating groove 41a at the bottom of the flange 41 is opposite to the limiting part 11, so as to destroy the pressure in the air floating chamber. The bottom of the flange 41 is further provided with positioning pins 44, as shown in fig. 3, the positioning pins 44 are symmetrically arranged on the bottom of the flange 41, and the positioning pins 44 are positioned on one side of the air flotation groove 41a and near the grinding spindle 50. The positioning pin 44 at the bottom of the fixing component 40 is located inside the limiting portion 11 to ensure that the air floating groove 41a is always opposite to the top surface of the test bench 10, and ensure that the fixing component 40 and the test bench 10 form stable air floating force.

Further, the positioning pin 44 is provided at a position matching the size of the stopper portion 11. The distance between the positioning pins 44 symmetrically disposed on both sides of the flange 41 should not be greater than the dimension of the inner side surface of the limiting portion 11 along the length direction, so as to ensure that the air floating groove 41a is always opposite to the top surface of the test board 10, and ensure the stability of the air floating force in the air floating chamber.

When the distance between the positioning pins 44 is equal to the dimension of the inner side surface of the stopper portion 11 in the longitudinal direction, the positioning pins 44 contact the inner side surface of the stopper portion 11, and the positioning pins 44 move smoothly along the inner side surface of the stopper portion 11. As a modification of this embodiment, a rolling bearing may be fitted around the outer peripheral side of the positioning pin 44, and the outer peripheral side surface of the rolling bearing may abut against the inner side surface of the stopper portion 11. Thus, the grinding spindle 50 with the fixed component 40 mounted thereon and the inner side surface of the limiting part 11 are in rolling friction, and the component to be measured can stably move along the length direction of the limiting part 11.

In fig. 2, the flange 41 of the fixing member 40 is further provided with fixing holes 45 arranged in a circumferential direction of the flange 41. Correspondingly, mounting holes are arranged on the top plate 13 of the test bench 10 in a matching manner. After the tester accurately adjusts the position of the component to be tested, the component to be tested is fixed on the test bench 10 by bolts penetrating through the fixing holes 45 and the mounting holes, so that the rigidity test can be performed on the load applied to the grinding spindle 50.

In the embodiment shown in fig. 1, the device 1 for testing the rigidity of the grinding spindle further comprises an axial detection fixing column 60 which is vertically arranged on the top plate 13 of the test bench 10. In fig. 1, the number of the axial direction detection fixing posts 60 is four, and the axial direction detection fixing posts are symmetrically arranged on two sides of the limiting portion 11. The axial rigidity detection assembly 20 is detachably arranged on the axial detection fixing column 60. In the embodiment shown in fig. 1, the axial direction detection fixing post 60 is made of stainless steel, and the outer diameter thereof is 30mm to 50mm, so as to ensure that the axial direction detection fixing post 60 has good strength. When the grinding spindle is loaded with force in the axial direction, the rigidity test of the grinding spindle cannot be influenced due to insufficient strength of the axial detection fixing column 60.

Further, the axial stiffness detection assembly 20 can move along the length direction of the axial detection fixing column 60, so as to adjust the distance between the axial stiffness detection assembly 20 and the end of the grinding spindle 50, and improve the applicability of the grinding spindle stiffness testing device. The axial rigidity detection assembly 20 can be detached from the upper end of the axial detection fixing column 60 so as to perform maintenance and overhaul of the axial rigidity detection assembly 20.

Fig. 8 is a schematic structural diagram of the axial stiffness detecting assembly 20, and the axial stiffness detecting assembly 20 includes a support mechanism 21, an axial loading member 22, a pressure sensor 23, a loading disc 24, and a displacement measuring member 25 shown in fig. 1.

In fig. 8, the supporting mechanism 21 is connected to the axial direction detection fixing column 60, and the axial direction loading member 22 is disposed on the supporting mechanism 21. The support mechanism 21 includes a base 21a and a fixing frame 21 b. The base 21a is provided with a rectangular through hole at the middle part, and the fixing frame 21b is arranged in the through hole in a matching manner. The axial loading member 22 is disposed on the fixing frame 21b, and a moving end of the axial loading member 22 moves in a vertical direction through the through hole of the base 21a to apply an axial load to an end portion of the grinding spindle 50 to be measured.

Further, support mechanism mounting holes 21c are provided at four corners of the base 21a, and the axial direction detection fixing column 60 passes through the support mechanism mounting holes 21c to fix the support mechanism 21 to the upper portion of the test stand 10. The support mechanism mounting hole 21c is a circular hole whose diameter matches the diameter of the axial detection fixing column 60. The diameter of the support mechanism mounting hole 21c is slightly larger than the diameter of the axial direction detection fixing column 60 so that the support mechanism 21 can slidably adjust the mounting position of the axial direction detection fixing column 60.

In fig. 8, the base 21a further includes a spacer portion 21d provided along the diameter direction of the support mechanism mounting hole 21c and penetrating in the thickness direction of the base 21 a. The spacer 21d extends from one side surface of the base 21a toward the inside of the base 21a and exceeds the inner peripheral wall of the support mechanism mounting hole 21c by a distance. Correspondingly, a locking hole 21e is formed in the adjacent side surface of the base 21a, and a locking bolt passes through the locking hole 21e to lock the support mechanism mounting hole 21c and the axial direction detection fixing column 60, so as to fix the setting position of the axial rigidity detection assembly 20. In the embodiment shown in fig. 8, the width of the spacer 21d is 0.5mm to 1.5 mm.

The movable end of the axial loading member 22 is provided with a loading disc 24, the pressure sensor 23 is arranged between the movable end of the axial loading member 22 and the loading disc 24, and the pressure sensor 23 can measure the loading force of the axial loading member 22 in real time. In the axial stiffness test, the axial loading force can be preset, and the pressure sensor 23 is used for monitoring the axial loading condition.

In the embodiment shown in fig. 1, the middle of the upper end of the grinding spindle 50 is provided with an outwardly projecting part. In order to prevent the loading disc 24 from interfering with the protruding part, the middle part of the loading disc 24 is a hollow structure, and the outer end edge part of the loading disc 24 applies a load to the upper end of the grinding spindle 50.

In fig. 1, the displacement measuring device 25 for measuring the axial displacement of the grinding spindle 50 is a dial indicator, and a measuring rod thereof is abutted against the upper end surface of the grinding spindle 50 to measure the axial displacement of the grinding spindle 50 after a predetermined load is applied. The axial stiffness of the grinding spindle 50 is calculated by the stiffness calculation formula K = F/.

In the embodiment shown in fig. 1, the displacement measuring unit 25 may alternatively be a contact type measuring device such as a strain gauge displacement sensor or an inductive displacement sensor to measure the displacement of the end of the grinding spindle 50. As a variation of this embodiment, the displacement measuring member 25 may also be a non-contact displacement measuring device, such as a magnetostrictive displacement sensor, an eddy current displacement sensor, or the like.

In fig. 8, the pressure sensor 23 is an S-type pressure sensor, which is a resistance strain gauge pressure sensor. The S-shaped pressure sensor has the dual-purpose functions of pulling and pressing, and has the advantages of high measurement precision and convenience in installation. Other types of pressure sensors may be used for the pressure sensor 23, such as capacitive pressure sensors, piezoelectric pressure sensors, inductive pressure sensors, or eddy current pressure sensors.

In fig. 1, the device 1 for testing the rigidity of the grinding spindle further comprises a radial detection fixing base 70 which is detachably connected to the top plate 13 of the test stand 10. Fig. 9 is a schematic view of the radial stiffness detecting assembly 30 connected to the radial detecting fixing base 70, and a fixing groove 70a is formed in a side surface of the radial detecting fixing base 70. The fixing groove 70a is disposed along a height direction of the radial detection fixing base 70, and the radial stiffness detection assembly 30 is connected to the radial detection fixing base 70 through the fixing groove 70 a. The radial stiffness detecting assembly 30 can move along the length direction of the fixing groove 70a to flexibly adjust the position of the radial stiffness test.

In fig. 9, the radial rigidity detecting assembly 30 includes a radial loading member 31, a pressure sensor 23, a loading portion 32, and a displacement measuring member 25. The radial loading member 31 is disposed on the radial detection fixing seat 70, and the moving end thereof is disposed along the horizontal direction. The moving end of the radial loading member 31 is provided with a loading part 32, the pressure sensor 23 is arranged between the moving end of the radial loading member 31 and the loading part 32, and the pressure sensor 23 can measure the loading force of the radial loading member 31 in real time.

In fig. 1, the displacement measuring device 25 for measuring the radial displacement of the grinding spindle 50 is a dial indicator, and a measuring rod thereof is abutted against the outer peripheral side surface of the grinding spindle 50 to measure the radial displacement of the grinding spindle 50 after a predetermined load is applied. The radial stiffness of the grinding spindle 50 is calculated by the stiffness calculation formula K = F/.

In the embodiment shown in fig. 9, the loading portion 32 is composed of a lateral pressing plate 32a and a pad 32b, an outer end surface of the lateral pressing plate 32a is in a V-shaped configuration, and the pad 32b is disposed on the V-shaped surface of the lateral pressing plate 32 a. The V-shaped structure at the end of the loading portion 32 abuts against the outer peripheral side surface of the grinding spindle 50 to load a radial load.

The rigidity of the grinding spindle 50 is measured at a bearing mounting position, the peripheral side surface of the grinding spindle is a finish machining surface, and the grinding spindle needs to be mounted with an inner ring of a bearing in a matched mode in the later period. In order to prevent the loading portion 32 from scratching the grinding spindle 50 during the rigidity measurement, the pad 32b is made of nylon-based plastic, which may be made of polyurethane, polytetrafluoroethylene, polyethylene terephthalate (PET), or the like.

The axial stiffness and the radial stiffness of the grinding spindle 50 need to meet the requirements at the same time to ensure the normal use of the grinding spindle 50. Therefore, the axial stiffness detection assembly 20 and the radial stiffness detection assembly 30 are required to be loaded simultaneously to measure the axial stiffness and the radial stiffness of the grinding spindle 50, and whether the stiffness of the grinding spindle meets the design requirements under the actual working condition is detected.

It is easy to understand that the testing device for the rigidity of the grinding spindle can also respectively detect the axial rigidity of the spindle and the radial rigidity of the grinding spindle. In the embodiment shown in fig. 1, the axial loading member of the axial stiffness detecting assembly 20 is an air cylinder, and the end of the piston rod of the air cylinder is provided with a loading disc. The radial loading member of the radial stiffness detecting assembly 30 is a cylinder, and the end of the piston rod of the cylinder is provided with a loading part.

Further, the device for testing the rigidity of the grinding spindle further comprises a pneumatic control assembly, and the pneumatic control assembly is connected with the air floating structure of the fixing assembly 40 through a pipeline so as to control the air buoyancy force applied to the assembly to be tested. The pneumatic control assembly is connected with the axial loading part of the axial rigidity detection assembly 20 through a pipeline so as to control the axial loading condition. The pneumatic control assembly is connected with the radial loading part of the radial rigidity detection assembly 30 through a pipeline to control the radial loading condition.

In addition, the invention also discloses a method for testing the rigidity of the grinding spindle, which comprises the following steps:

firstly, a grinding spindle 50 equipped with a fixing component 40 is installed on a limiting part 11 of a test bench 10, and an air floating structure of the fixing component 40 is opposite to the top surface of the test bench 10;

then, introducing gas into the air floating structure of the fixing component 40, and conveying the gas to the air floating structure from top to bottom so as to upwards support the grinding spindle 50 provided with the fixing component 40;

then, moving the grinding spindle 50 equipped with the fixing assembly 40 from the hoisting position to the testing position, and fixing the fixing assembly 40 on the top plate 13 of the testing table 10;

next, the axial stiffness detection assembly 20 and the radial stiffness detection assembly 30 are used to simultaneously apply a load to the grinding spindle 50 to be measured according to a set value and measure a corresponding displacement, and the stiffness of the grinding spindle 50 is calculated by using a stiffness formula K = F/.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In the above embodiments, the description of the embodiments is focused on, and these embodiments can be arbitrarily combined, and a new embodiment formed by combining them is also within the scope of the present application. For parts of one or some embodiments that are not described or specified in detail, reference may be made to the description of other embodiments. The above embodiments and implementation manners are only used for illustrating the technical solutions of the present invention, and are not limited or restricted thereto; although the present invention has been described with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be replaced with similar or equivalent ones; such modifications and substitutions should not be considered as included within the scope of the present invention, unless they depart from the spirit or essential characteristics or points of the present invention. In other words, while embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (12)

1. A device for testing the rigidity of a grinding spindle is characterized by comprising:

the top of the test board is provided with a through limiting part, and the grinding spindle to be tested is arranged in the limiting part;

a fixing member coaxially connected to an outer peripheral side of the grinding spindle and overlapping the stopper; the fixed component is provided with an air floating structure, the air floating structure is opposite to the top surface of the test board, and gas introduced into the air floating structure supports the grinding spindle;

the axial rigidity detection assembly is arranged on the test bench and positioned on the upper side of the limiting part so as to measure the axial rigidity of the grinding spindle;

and the radial rigidity detection assembly is arranged on the test bench and positioned on the side surface of the limiting part so as to measure the radial rigidity of the grinding spindle.

2. The testing device of claim 1, wherein the fixing assembly comprises a flange plate and a pressing ring, an air floatation groove is formed in the bottom of the flange plate, the pressing ring is arranged on the upper portion of the flange plate and forms a sealing chamber communicated with the air floatation groove, and air is conveyed to the air floatation groove from top to bottom through the sealing chamber so as to upwards support the fixing assembly and the grinding spindle.

3. The testing device of claim 2, wherein an air storage groove is arranged at the upper part of the flange plate, and the pressure ring and the air storage groove form a sealed chamber; the flange plate is also provided with a communication hole for communicating the gas storage tank with the air floating tank, and gas introduced into the sealed cavity is conveyed to the air floating tank through the communication hole.

4. The test device as claimed in claim 1, wherein the position-limiting portion is an oval notch, and the grinding spindle mounted with the fixing member is overlapped with the position-limiting portion and moved in a length direction thereof.

5. The test apparatus as claimed in claim 2, wherein the air-bearing slots are symmetrically disposed at the bottom of the flange.

6. The test device as claimed in claim 3, wherein the air-bearing groove is a long hole, and the number of the communication holes is plural and is distributed at intervals along the length direction of the long hole.

7. The test assembly of claim 3, wherein the flange is provided with radial vent holes in communication with the sealed chamber; and gas is conveyed to the air flotation tank through the vent hole, the gas storage tank and the communication hole.

8. The test apparatus as claimed in claim 2, wherein the fixing member further comprises positioning pins symmetrically disposed at the bottom of the flange; the setting position of the positioning pin is matched with the width of the limiting part.

9. The testing device as claimed in claim 1, further comprising an axial detection fixing column vertically disposed on top of said testing table, said axial stiffness detection assembly being detachably disposed on said axial detection fixing column.

10. The test device of claim 9, wherein the axial stiffness detection assembly includes a support mechanism, an axial loading member, a pressure sensor, a loading disc, and a displacement measurement member; the supporting mechanism is connected to the axial detection fixing column, and the axial loading piece is arranged on the supporting mechanism; a loading disc is arranged at the moving end of the axial loading piece, and the pressure sensor is arranged between the moving end and the loading disc; the displacement measuring piece is abutted against the end part of the grinding spindle to measure the axial displacement of the grinding spindle after being subjected to preset loading.

11. The testing device of claim 1, further comprising a radial test fixture disposed at a top of the testing table; the radial rigidity detection assembly comprises a radial loading piece, a pressure sensor, a loading part and a displacement measurement piece; the radial loading piece is arranged on the radial detection fixing seat, a loading part is arranged at the moving end of the radial loading piece, and the pressure sensor is arranged between the moving end and the loading part; the displacement measuring part is abutted against the peripheral side face of the grinding spindle to measure the radial displacement of the grinding spindle after being subjected to a predetermined load.

12. A method for testing the rigidity of a grinding spindle is characterized by comprising the following steps:

lapping a grinding main shaft assembled with a fixing component on a limiting part of a test bench, wherein an air floatation structure of the fixing component is opposite to the top surface of the test bench;

introducing gas into the air floating structure of the fixing component, and conveying the gas to the air floating structure from top to bottom so as to upwards support the grinding main shaft provided with the fixing component;

moving the grinding spindle provided with the fixing component from the mounting position to a testing position and fixing the fixing component on the testing platform;

and detecting the rigidity of the grinding spindle by using an axial rigidity detection assembly and a radial rigidity detection assembly.

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