CN115854820A

CN115854820A - Expansion type mandrel for precision measurement, radial calibration device and radial calibration method

Info

Publication number: CN115854820A
Application number: CN202211649751.7A
Authority: CN
Inventors: 和玉洁; 李新; 谢熠晨
Original assignee: Research Institute of Physical and Chemical Engineering of Nuclear Industry
Current assignee: Research Institute of Physical and Chemical Engineering of Nuclear Industry
Priority date: 2022-12-21
Filing date: 2022-12-21
Publication date: 2023-03-28

Abstract

The invention belongs to the technical field of precision positioning fixtures, and particularly relates to an expansion mandrel, a radial calibration device and a radial calibration method for precision measurement, wherein the expansion mandrel comprises: the mandrel pull rod and the inner expansion clamping sleeve are sleeved on the outer side of the mandrel pull rod, the clamping sleeve adjusting structure is arranged on the inner expansion clamping sleeve corresponding to the pull rod adjusting structure, the hollow split structure is arranged on the inner expansion clamping sleeve corresponding to the expansion adjusting structure, and the clamping sleeve adjusting structure is connected with the pull rod adjusting structure through the axial adjusting assembly. The radial calibration device comprises: the measuring device comprises a fixing ring coincident with the central axis of the thin-wall cylinder and a straight-in type differential head arranged on the fixing ring through a supporting structure, wherein a measuring rod of the straight-in type differential head is connected with an expansion type mandrel through a special chuck, and the inner wall of the thin-wall cylinder is expanded through the expansion type mandrel. The expansion type mandrel can adjust the volume of the mandrel, eliminate assembly gaps, adapt to the length change of a workpiece and improve the testing precision; the device can improve the testing precision, the testing efficiency and the operation convenience.

Description

Expansion type mandrel for precision measurement, radial calibration device and radial calibration method

Technical Field

The invention belongs to the technical field of precision positioning fixtures, and particularly relates to an expansion mandrel for precision measurement, a radial calibration device and a radial calibration method.

Background

A large number of thin-wall cylindrical workpieces on a detection line need to be placed on a special detection table one by one, radial runout of a certain position of the workpieces is measured in a non-contact mode, and the radial runout value of the certain position is used as a standard for judging the qualified workpieces. The sensor for measuring the radial runout of the workpiece on line on the special detection table is a non-contact eddy current type sensor, the sensor needs to be calibrated before the workpiece is measured,

during calibration, the lower end of the special mandrel is required to be inserted into an opening of a workpiece, the displacement measuring mechanism pushes the upper end of the special mandrel to drive the workpiece to move linearly, and the mathematical correspondence of the output quantity of the electrical parameter and a displacement value is determined by adjusting the distance between the workpiece and the eddy current sensor.

At present, the following main problems of the existing calibration device during the calibration operation of the sensor are:

the first problem is that: at present, a special mandrel in a calibration device is of a stepped shaft structure, and a gap exists between the mandrel and the inner diameter of a workpiece, so that random errors are caused;

the second problem is that: the center height of the displacement measuring rod is fixed, the displacement measuring rod cannot adapt to the length change of a workpiece (within a tolerance range specified by a drawing), and the phenomenon of jamming is easy to occur in operation;

the third problem is that: the motion track of the straight-advancing differential head is not coincident with the axis of the measured sensor, and randomness exists in each installation, so that systematic errors and random errors are caused.

Obviously, the special mandrel in the currently used calibration device cannot eliminate gaps and adapt to the length change of a workpiece; the currently used calibration device has obvious precision error, is inconvenient to operate, is very easy to cause misjudgment on workpieces, influences the testing precision and efficiency, and can not meet the requirements of workpiece online detection.

Disclosure of Invention

The invention aims to solve the problems in the prior art, and designs an expansion mandrel for precision measurement and a device for carrying out field calibration on a radial vibration measurement sensor of a thin-wall cylinder, wherein the expansion mandrel can adjust the volume per se, eliminate an assembly gap, adapt to the length change of a workpiece and improve the test precision; the device can improve test accuracy, efficiency and operation convenience.

The technical scheme adopted by the invention for solving the problem is as follows:

an expanding mandrel for precision measurements, comprising:

the mandrel pull rod comprises a pull rod connecting structure, a pull rod adjusting structure, a pull rod connecting structure and an expansion adjusting structure which are sequentially connected;

the clamping sleeve adjusting structure is connected with the pull rod adjusting structure through an axial adjusting assembly, and when the clamping sleeve adjusting the mandrel pull rod relative to the internal expansion through the axial adjusting assembly generates axial sliding, the hollow split structure is converted between a free state and an expansion state.

Preferably, still including the sliding sleeve subassembly of connection on the pull rod connection structure, be equipped with the side of inserting hole that is used for assembling displacement measurement mechanism on the sliding sleeve subassembly, pull rod connection structure cartridge is in the sliding sleeve subassembly and can follow the sliding sleeve subassembly and slide from top to bottom.

Further preferably, the sliding sleeve subassembly includes gland structure and guide pin bushing structure that the interference cartridge is in the same place, gland structure and guide pin bushing structure all are equipped with the side opening that inserts that is used for assembling displacement measurement mechanism, the structural knurling screw that is used for locking fixed displacement measurement mechanism that is equipped with of gland, pull rod connection structure cartridge is in the guide pin bushing structure and can follow the guide pin bushing structure and slide from top to bottom.

Preferably, the pull rod connecting structure is further provided with an annular clamping groove, the annular clamping groove is sleeved with an elastic check ring, the pull rod adjusting structure is provided with a thread adjusting section, and the expansion adjusting structure is of a conical structure.

Further preferably, the cutting ferrule adjusting structure is arranged at one side end of the internal expansion cutting ferrule and comprises at least one annular hook ring arranged on the outer wall of the end of the internal expansion cutting ferrule.

Further preferably, the axial adjustment assembly comprises:

the lock nut structure is in threaded connection with the threaded adjusting section;

the hanging ring structure is hung on the annular hook ring and comprises two semi-ring structures with opposite openings;

further preferably, the two half ring structures are oppositely pressed on the outer end face of the lock nut structure, and the two half ring structures are fixed on the lock nut structure through screws, so that the lock nut structure and the internal expansion clamping sleeve are clamped together.

Further preferably, the cavity split structure sets up the opposite side tip at the interior bloated cutting ferrule, the cavity split structure is including the tight main part that expands, the tight main part that expands is for having certain elasticity and the cavity cylindricality structure that the diameter is greater than the interior bloated cutting ferrule, expand and separate it for a plurality of split body through being some split seams radially offered in the tight main part, the shaping has the tight conical surface of cavity expansion in the hole of the tight main part that expands, when the relative interior bloated cutting ferrule of dabber pull rod produced the endwise slip, the tight conical surface of the relative cavity expansion of conical structure produced the endwise slip, and each split body carries out outside bloated tightly.

A second object of the present invention is to: there is provided a radial calibration device for a thin-walled cylinder, comprising:

the fixing ring is superposed with the central axis of the thin-wall cylinder, and a radial vibration measurement sensor for calibration is arranged on the fixing ring and is used as an eddy current sensor for preferential selection;

the displacement measuring mechanism comprises a straight-in type differential head, the straight-in type differential head is arranged on a fixed ring through a supporting structure, a measuring rod of the straight-in type differential head is connected with an expansion core shaft through a special chuck, the inner wall of the thin-wall cylinder is expanded through the expansion core shaft, and the movement track of the straight-in type differential head driving the thin-wall cylinder to move is coincided with the central shaft of the radial vibration measurement sensor.

Further preferably, the support structure includes:

the base is fixed on the fixing ring through fixing screws, and a plurality of mounting holes are formed in the base;

the upper end of the supporting seat is provided with a positioning hole for assembling the straight-in type differential head, and the lower end of the supporting seat is provided with a supporting rod which is inserted in the mounting hole in a matching manner.

Further preferably, the base is an arc-shaped block structure with the same diameter as the fixed ring.

The third invention of the present invention is directed to: a radial calibration method for a thin-walled cylinder is provided, which comprises the following steps:

s101: assembled expanding mandrel

Firstly, sleeving an inner expansion clamping sleeve on the outer side of a mandrel pull rod, sleeving a lock nut structure and the inner expansion clamping sleeve together through an axial adjusting assembly, inserting a pull rod connecting structure of the mandrel pull rod into a guide sleeve structure of the sliding sleeve assembly, and finally inserting the lower end split part of an expansion mandrel into an opening of a thin-wall cylinder to expand the inner wall of the thin-wall cylinder;

s102: assembled displacement measuring mechanism

Firstly, a base is arranged on a fixing ring through a fixing screw, then a supporting seat is inserted into an installation hole of the base, then a straight-in type differential head is inserted into a positioning hole of the supporting seat and is fixed by the screw, and finally a measuring rod of the straight-in type differential head is inserted into a central hole of a special chuck and is locked by a nut;

s103: assembly between displacement measuring mechanism and expansion mandrel

Inserting a special chuck into an insertion side hole of a sliding sleeve component at the upper end of the expansion type mandrel, and locking the special chuck by using a knurled screw to ensure that the thin-wall cylinder is coincided with the central axis of the fixed ring, wherein the straight-in type differential head drives the movement track of the thin-wall cylinder to coincide with the central axis of the sensor;

s104: calibration work

After all the components are assembled, the expansion core shaft is pushed to drive the thin-wall cylinder to move by moving the measuring rod of the straight-advancing type differential head, and the distance between the thin-wall cylinder and the radial vibration measurement sensor is adjusted to perform calibration work.

The invention has the advantages and positive effects that:

1. according to the invention, the expansion function of the mandrel and the inner wall of the workpiece is realized through the relative motion between the mandrel pull rod and the inner expansion clamping sleeve, the gap between the mandrel and the inner wall of the workpiece is eliminated, the radial calibration device expands tightly from the inside of the workpiece by utilizing the hollow split structure at the lower end of the expansion mandrel, the gap between the mandrel and the inner diameter of the workpiece is eliminated, the random error caused by the gap can be effectively avoided, and the test precision is improved.

2. According to the invention, the guide sleeve structure is internally provided with a space for the expansion mandrel to move along the axial direction, the central height of the measuring rod can adapt to the length change of the workpiece, and the radial calibration device can automatically adjust the height between the straight-advancing type differential head and the workpiece by utilizing the movable sliding sleeve component at the upper end of the expansion mandrel, so as to adapt to the length change of the workpiece, prevent the occurrence of the clamping phenomenon and improve the testing precision.

3. According to the invention, the straight-in type differential head is arranged on the concentric circumference coaxial with the workpiece by utilizing the arc-shaped base, and can freely swing left and right, so that the position of the straight-in type differential head is automatically adjusted, the motion track of the measuring rod is ensured to be coincident with the axis of the sensor to be measured, and the test precision, efficiency and operation convenience can be improved.

Drawings

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and examples, but it should be understood that these drawings are designed for illustrative purposes only and thus do not limit the scope of the present invention. Furthermore, unless otherwise indicated, the drawings are intended to be illustrative of the structural configurations described herein only, and are not necessarily drawn to scale.

FIG. 1 is a schematic structural diagram of a radial calibration device for a thin-walled cylinder provided in embodiment 2;

FIG. 2 is a schematic top view of the radial calibration device for a thin-walled cylinder provided in embodiment 3;

FIG. 3 is a schematic view of the structure of a base in embodiment 2;

FIG. 4 is a schematic structural view of a backup pad according to embodiment 2;

FIG. 5 is a schematic view showing the structure of a straight type differential head in embodiment 2;

FIG. 6 is a schematic structural view of an expanding mandrel for precision measurement provided in example 1;

FIG. 7 is a side view of FIG. 6;

FIG. 8 is a schematic structural view of a press cover structure in embodiment 1;

FIG. 9 is a schematic structural view of a guide bush structure in embodiment 1;

fig. 10 is a schematic structural view of a lock nut structure in embodiment 1;

FIG. 11 is a schematic structural view of a suspension loop structure in example 1;

FIG. 12 is a schematic view of the structure of a mandrel pull rod in example 1;

fig. 13 is a schematic structural view of the internal expansion ferrule in embodiment 1.

In the figure: 1-a straight-forward differential head; 2-a supporting seat; 3-special chuck; 4-expanding the compact mandrel; 401-a gland structure; 402-a guide sleeve structure; 403-mandrel tie rod; 4031-a drawbar connection structure; 4032-a drawbar adjustment structure; 4033-drawbar connection structure; 4034-expansion adjustment structure; 404-locking nut structure; 405-a half-ring structure; 406-an internal expansion ferrule; 4061-hook and loop shape; 4062-split body; 4063-inner hole; 407-knurled screw; 408-circlip; 409-screw holes; 4010-side hole A; 4011-guide-sleeve hole; 4012-side hole B; 5-an eddy current sensor; 6-thin-walled cylinder; 7-a fixed ring; 8-a base; 9-a set screw; 10-mounting holes; 11-a clamping hole; 12-a support bar; 13-a measuring rod; 14-positioning holes.

Detailed Description

First, it should be noted that the specific structures, features, advantages, etc. of the present invention will be specifically described below by way of example, but all the descriptions are for illustrative purposes only and should not be construed as limiting the present invention in any way. Furthermore, any single feature described or implicit in any embodiment or any single feature shown or implicit in any drawing may still be combined or subtracted between any of the features (or equivalents thereof) to obtain still further embodiments of the invention that may not be directly mentioned herein. In addition, for the sake of simplicity, the same or similar features may be indicated in only one place in the same drawing.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "disposed," "connected," "secured," "screwed" and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; the terms may be directly connected or indirectly connected through an intermediate, and may be communication between two elements or interaction relationship between two elements, unless otherwise specifically limited, and the specific meaning of the terms in the present invention will be understood by those skilled in the art according to specific situations. The present invention will be described in detail with reference to the accompanying drawings.

Example 1:

an expanding mandrel for precision measurements, comprising: the mandrel pull rod 403 comprises a pull rod connecting structure 4031, a pull rod adjusting structure 4032, a pull rod connecting structure 4033 and an expansion adjusting structure 4034 which are connected in sequence; the inner expansion clamping sleeve 406 is sleeved on the outer side of the mandrel pull rod 403, a clamping sleeve adjusting structure is arranged on the inner expansion clamping sleeve 406 corresponding to the pull rod adjusting structure, a hollow split structure is arranged on the inner expansion clamping sleeve 406 corresponding to the expansion adjusting structure, the clamping sleeve adjusting structure is connected with the pull rod adjusting structure 4032 through an axial adjusting assembly, and when the mandrel pull rod 403 is adjusted to axially slide relative to the inner expansion clamping sleeve 406 through the axial adjusting assembly, the hollow split structure is converted between a free state and an expansion state.

In this embodiment, in the assembled state of the expanding mandrel, the inner expanding sleeve 306 is sleeved outside the mandrel pull rod 304, the mandrel pull rod 403 and the inner expanding sleeve 406 can be adjusted to move relatively by operating the axial adjusting assembly, and the hollow split structure can be switched between the free state and the expanding state by the relative movement between the mandrel pull rod 403 and the inner expanding sleeve 406. After the lower end of the expansion type mandrel 4 is inserted into an opening of a workpiece (such as a thin-wall cylinder 6), the volume of the hollow split structure can be adjusted by operating the axial adjusting component, the expansion function of the expansion type mandrel and the inner wall of the workpiece is realized, then the gap between the mandrel and the inner wall of the workpiece is eliminated, and the random error caused by the gap can be effectively avoided.

Further, it can be considered in this embodiment that the expanding mandrel further includes a sliding sleeve assembly connected to the tie bar connecting structure 4031, the sliding sleeve assembly includes a gland structure 401 and a guide sleeve structure 402 which are inserted in an interference manner, the gland structure 401 and the guide sleeve structure 402 are both provided with insertion side holes for assembling the displacement measuring mechanism, specifically: insert the side opening including seting up side opening A and the side opening B on gland structure 401 and guide pin bushing structure 402 respectively, screw 409 has been seted up on the gland structure 401, and the last rotation of screw 409 has connect the knurling screw 407 that is used for locking fixed displacement measurement mechanism.

Furthermore, it can be considered in this embodiment that the pull rod connecting structure 4031 is inserted into the guide sleeve structure 402 and can slide up and down along the guide sleeve structure 402, a free space is provided at the joint between the guide sleeve structure 402 and the pull rod connecting structure 4031, the length of the pull rod connecting structure 4031 inserted into the guide sleeve structure 402 can be properly adjusted according to the length of the workpiece, and the length of the expanding mandrel can adapt to the length change of the workpiece.

Furthermore, it can be considered in this embodiment that, as shown in fig. 6, the mandrel pull rod 403 includes a pull rod connecting structure 4031, a pull rod adjusting structure 4032, a pull rod connecting structure 4033, and an expansion adjusting structure 4034, which are connected in sequence, the pull rod connecting structure 4031, the pull rod adjusting structure 4032, and the pull rod connecting structure 4033 are preferably circular rod structures, and in order to enable relative movement between the mandrel pull rod 403 and the inner expansion sleeve 406, a thread adjusting section is provided on the pull rod adjusting structure 4032.

Furthermore, it can be considered in this embodiment that the pull rod connecting structure 4031 is further provided with an annular clamping groove, the annular clamping groove is sleeved with a circlip 408, and the circlip 408 serves as a mechanical limit preventing component for tripping.

Further, it is also considered in this embodiment that the expansion adjustment structure 4034 is a conical structure, and when a relative motion occurs between the mandrel pull rod 403 and the internal expansion cutting sleeve 406, the expansion adjustment structure 4034 can adjust the hollow valving structure to expand or retract outwards in correspondence to the position of the hollow valving structure.

Still further, it is contemplated in this embodiment that the ferrule adjustment structure is disposed on one side end of the expanding ferrule 406 and that the ferrule adjustment structure includes at least one annular hook loop 4061 that opens onto an outer wall of the end of expanding ferrule 406.

Still further, it is also contemplated in this embodiment that the axial adjustment assembly includes: a locking nut structure 404, which is screwed on the threaded adjusting section; a hanging ring structure, which is hung on the annular hook ring 4061, and comprises two semi-ring structures 405 with opposite openings; the two half-ring structures 405 are pressed against the outer end face of the locking nut structure 404 and the two half-ring structures 405 are fixed on the locking nut structure 404 by screws, so that the locking nut structure 404 and the internal expanding cutting sleeve 406 are hooped together. Two semi-ring structure 405 are two semi-circular ring structures of whole ring cutting, from the fixed female structure of lock of outside installation with interior bloated cutting ferrule, have avoided the structural disturbance that whole ring installation caused.

Furthermore, it can be considered in this embodiment that the hollow split structure is disposed at the other end of the internal expansion cutting sleeve 406, the internal expansion cutting sleeve 406 is a hollow cylindrical structure with an inner hole 4063 in the middle, the hollow split structure includes an expansion main body, the expansion main body is a hollow cylindrical structure with certain elasticity and a diameter larger than that of the internal expansion cutting sleeve 406, the expansion main body is divided into a plurality of split bodies 4062 by split seams radially formed on the expansion main body, a hollow expansion conical surface is formed in the central hole of the expansion main body, as shown in fig. 6, when the mandrel pull rod 3 axially slides upwards relative to the internal expansion cutting sleeve 406, the conical structure axially slides upwards relative to the hollow expansion conical surface, and each split body expands outwards under the condition of internal stress.

Example 1 working principle: the expansion mandrel mainly comprises a gland structure 401, a guide sleeve structure 402, a mandrel pull rod 403, a nut locking structure 404, two semi-ring structures 405, an internal expansion cutting sleeve 406, a knurled screw 407 and a shaft elastic retainer ring 408. Wherein: the gland structure 401 and the guide sleeve structure 402 are arranged together in an interference fit mode, the knurled screw 7 is preassembled on the gland structure 401, the lock nut structure 404 is arranged on a thread adjusting section of the mandrel pull rod 403, the mandrel pull rod 403 is inserted into an inner hole 4063 of the internal expansion clamping sleeve 406, one end of each of the two semi-ring structures 405 is used for hooking an annular hook ring 4061 at the upper end of the internal expansion clamping sleeve 6, and the other end of each of the two semi-ring structures is fixed on the lock nut structure 404 through a screw, so that the lock nut structure 404 and the internal expansion clamping sleeve 406 are clamped together; the circlip 408 for the shaft is installed in the annular clamping groove of the mandrel pull rod 403 to serve as a mechanical limiting component to prevent tripping, the pull rod connecting structure 4031 at the upper end of the mandrel pull rod 3 is inserted into the guide sleeve hole 4011 of the guide sleeve structure 402, and the assembly of the expansion mandrel is finished. During work, the core shaft pull rod 403 is driven to axially move along the internal expansion clamping sleeve 406 by rotating the locking nut structure 404, when the core shaft pull rod 403 moves upwards, each segment 4062 at the lower end of the internal expansion clamping sleeve 406 is changed into an expansion state from a free state, and when the core shaft pull rod 403 moves downwards, each segment 4062 at the lower end of the internal expansion clamping sleeve 406 is restored to the free state, so that the internal expansion function of the core shaft on the thin-wall cylindrical workpiece is realized. And in the use process, the measuring end of the displacement measuring mechanism is simultaneously inserted into the side hole A4010 of the gland structure 401 and the side hole B4012 of the guide sleeve structure 402 and fixed by a knurled screw 407, and the guide sleeve structure 402 is sleeved on the mandrel pull rod 403 and has a free moving space, so that the expansion mandrel with the sliding sleeve assembly can adapt to the length change of a workpiece.

The expansion core shaft realizes the expansion function of the core shaft and the inner wall of a workpiece through the relative motion between the core shaft pull rod and the inner expansion clamping sleeve, the gap between the core shaft and the inner wall of the workpiece is eliminated, meanwhile, the guide sleeve structure has a space moving along the axial direction, and the center height of the displacement measuring mechanism can adapt to the length change of the workpiece.

Example 2:

a radial calibration device for a thin-walled cylinder, comprising: the fixing ring 7 is superposed with the central axis of the thin-wall cylinder 6, and a radial vibration measurement sensor for calibration is arranged on the fixing ring 7 and is used as the preferred selection eddy current sensor 5; the displacement measuring mechanism comprises a straight-in type differential head 1, wherein the straight-in type differential head 1 is installed on a fixed ring 7 through a supporting structure, a measuring rod 13 of the straight-in type differential head 1 is connected with an expansion type mandrel 4 through a special chuck 3, the inner wall of a thin-wall cylinder 6 is expanded through the expansion type mandrel 4 in the embodiment 1, and the movement track of the straight-in type differential head 1 driving the thin-wall cylinder 6 to move is coincident with the central shaft of an eddy current sensor 5.

In this embodiment, as shown in fig. 1-2, when the device is assembled, the straight-in type differential head 1 is mounted on the fixed ring 7 through the supporting structure, the measuring rod 13 of the straight-in type differential head 1 is connected to the expanding mandrel 4 through the special chuck 3, the inner wall of the thin-walled cylinder 6 is expanded through the expanding mandrel 4, the supporting structure is adjusted to make the thin-walled cylinder 6 coincide with the central axis of the fixed ring 7, and the central axis of the straight-in type differential head 1, the central axis of the thin-walled cylinder 6, the central axis of the fixed ring 7, and the central axis of the eddy current sensor 5 are located on the same vertical plane. During calibration, the measuring rod 13 of the moving straight-in type differential head 1 pushes the expansion type mandrel 4 to drive the thin-wall cylinder 6, the distance between the thin-wall cylinder 6 and the eddy current sensor 5 is adjusted, and calibration is carried out; the height between the straight advancing type differential head and the thin-wall cylinder is automatically adjusted by utilizing a movable sliding sleeve structure at the upper end of the expansion type mandrel, so that the length change of the thin-wall cylinder can be adapted; the movement track of the thin-wall cylinder 6 driven by the straight-in type differential head 1 is coincident with the central axis of the eddy current sensor 5, so that the testing precision, the testing efficiency and the operation convenience can be improved.

Still further, it is also contemplated in this embodiment that the support structure includes: the base 8 is an arc-shaped block structure with the same diameter as the fixed ring 7, the base 8 is fixed on the fixed ring 7 through a fixing screw 9, and a plurality of mounting holes 10 are formed in the base 8; the upper end of the supporting seat 2 is provided with a positioning hole 14 for assembling the straight-in type differential head 1 and a clamping hole 11 for clamping the positioning hole 14, and the lower end of the supporting seat 2 is provided with a supporting rod 12 which is inserted into the mounting hole 10 in a matching manner. In this embodiment, a base 8 is fixed on a fixing ring 7 through a fixing screw 9, a plurality of mounting holes 10 are vertically formed in the base 8 along the arc direction of the base 8, for example, two mounting holes 10 are formed in the base 8, an included angle between the two mounting holes is alpha degrees, a support rod 12 at the lower end of a support base 2 can be inserted into the mounting holes 10 in a matching mode, the position of a subsequent thin-wall cylinder can be finely adjusted through rotation adjustment of the support rod 12 in the mounting holes 10, the straight-in type differential head is arranged on a concentric circumference coaxial with the thin-wall cylinder by the aid of the supporting structure, the straight-in type differential head 1 can freely swing left and right, the position of the straight-in type differential head 1 is automatically adjusted, and the motion track of the measuring rod is guaranteed to coincide with the axis of a sensor to be measured. After the supporting seat 2 is installed, firstly, the straight-in type differential head 1 is inserted into the positioning hole 14, the positioning hole 14 can be clamped through screwing a screw into the clamping hole 11, the position of the straight-in type differential head 1 is fixed, then the measuring rod 13 of the straight-in type differential head 1 is connected with the expansion mandrel 4 through the special chuck 3, the inner wall of the thin-wall cylinder 6 is expanded through the expansion mandrel 4, the thin-wall cylinder 6 is enabled to be coincident with the central shaft of the fixed ring 7 through fine adjustment of the supporting rod, and at the moment, the central shaft of the straight-in type differential head 1, the central shaft of the thin-wall cylinder 6, the central shaft of the fixed ring 7 and the central shaft of the eddy current sensor 5 are located on the same vertical plane.

Furthermore, it can be considered in this embodiment that the connection mode of the straight differential head 1 and the expanding mandrel 4 is: the measuring rod 13 of the straight advancing type differential head 1 is inserted into the central hole of the special chuck 3 and is locked by a locking nut, and then the special chuck 3 is inserted into the insertion side hole at the upper end of the expansion core 4 and is locked by a knurled screw 407.

Example 2 working principle: the radial calibration device comprises a straight-in type differential head 1, a supporting seat 2, a special chuck 3, an expansion type mandrel 4, an eddy current sensor 5, a fixing ring 7, a base 8 and a fixing screw 9. During assembly, the base 8 is arranged on a fixing ring 7 which is coaxial with the thin-wall cylinder 6 and is fixed by a fixing screw 9, the lower end split part of the expansion type mandrel 4 is inserted into the opening of the thin-wall cylinder 6, and the inner wall of the thin-wall cylinder 6 is expanded. The supporting seat 2 is inserted into the mounting hole 10 of the base 8, the special chuck 3 is inserted into the insertion side hole of the sliding sleeve structure at the upper end of the expansion mandrel 4, the straight-in type differential head 1 is inserted into the positioning hole 14 of the supporting seat 2 and fixed by a screw, and meanwhile, the central hole of the special chuck 3 is inserted, and a nut is locked. The sliding sleeve structure can slide up and down on the expansion mandrel 4, and the relative position between the straight-advancing type differential head 1 and the thin-wall cylinder 6 is adjusted according to the length change of the thin-wall cylinder 6 to prevent the clamping phenomenon. After all the components are installed, the measuring rod 13 of the straight-advancing type differential head 1 is moved to push the expansion type mandrel 4 to drive the thin-wall cylinder 6, the distance between the thin-wall cylinder 6 and the eddy current sensor 5 is adjusted, and calibration work is carried out.

Example 3:

embodiment 3 of the present invention is further improved on the basis of embodiment 2 so as to be able to sufficiently exert the technical advantages of the present invention, which will be exemplified below. For example: at least two sets of eddy current sensors 5 are installed on the fixing ring 7 through the sensor installation structure, and taking this embodiment as an example, two sets of eddy current sensors 5 are installed on the fixing ring 7 through the sensor installation structure, and the angle α between the two sets of eddy current sensors 5, the straight-in type differential head 1 is installed at the position a and the position B at the same time, and the position angle α between the position a and the position B can be finely adjusted according to the angle α between the two sets of eddy current sensors 5, so that the calibration work of the two sets of eddy current sensors 5 on the same basis can be realized. The radial calibration device eliminates the gap between the mandrel and the workpiece, can adapt to the length change of the workpiece, and improves the test precision and efficiency because the straight-in type differential head 1 drives the motion track of the workpiece to coincide with the central axis of the sensor.

Example 4:

a radial calibration method for a thin-walled cylinder, comprising the steps of:

s101: assembled expanding mandrel 4

Firstly, sleeving an inner expansion clamping sleeve 406 on the outer side of a mandrel pull rod 403;

then, the locking nut structure 404 and the internal expansion clamping sleeve 406 are clamped together by the axial adjustment assembly, and at this time, the two half-ring structures 405 are located outside the pull rod adjustment structure 4032, and the hollow split structure is located outside the expansion adjustment structure 4034;

thereafter, the drawbar connection structure 4031 of the mandrel drawbar 403 is inserted into the guide sleeve structure 402 of the slide bushing assembly;

finally, inserting the lower end split part of the expansion type mandrel 4 into the opening of the thin-wall cylinder 6, and expanding the inner wall of the thin-wall cylinder 6 by rotating the lock nut structure 404;

s102: assembled displacement measuring mechanism

Firstly, a base 8 is arranged on a fixed ring 7 through a fixed screw 9;

then, the support rod 12 of the support base 2 is inserted into the mounting hole 10 of the base 8, and the mounting hole 10 and the sensor 5 are positioned in the same radial direction of the fixed ring 7;

then, inserting the straight-advancing type differential head 1 into the positioning hole 14 of the supporting seat 2 and fixing by using a screw;

finally, inserting the measuring rod 13 of the straight-in type differential head 1 into the center hole of the special chuck 3 and locking by using a nut;

s103: assembly between displacement measuring mechanism and expanding mandrel

Inserting the special chuck 3 into an insertion side hole of a sliding sleeve component at the upper end of the expansion mandrel 4, and locking by using a knurled screw 407 to ensure that the thin-wall cylinder 6 is coincident with the central shaft of the fixed ring 7 and the movement track of the straight-in type differential head 1 driving the thin-wall cylinder 6 to move is coincident with the central shaft of the sensor 5;

s104: calibration work

After all the components are assembled, the expansion core shaft 4 is pushed to drive the thin-wall cylinder 6 to move by moving the measuring rod 13 of the straight-advancing type differential head 1, the distance between the thin-wall cylinder 6 and the eddy current sensor 5 is adjusted, and calibration work is carried out.

The present invention has been described in detail with reference to the above examples, but the description is only for the preferred examples of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.

Claims

1. The utility model provides a compact form dabber expands for precision measurement which characterized in that: the method comprises the following steps:

the mandrel pull rod (403) comprises a pull rod connecting structure (4031), a pull rod adjusting structure (4032), a pull rod connecting structure (4033) and an expansion adjusting structure (4034) which are connected in sequence;

interior bloated cutting ferrule (406), its cover is established in dabber pull rod (403) outside, interior bloated cutting ferrule (406) correspond pull rod regulation structure position and are equipped with cutting ferrule regulation structure, correspond to bloated tight regulation structure position and are equipped with the cavity split structure, cutting ferrule regulation structure passes through axial adjusting part and links to each other with pull rod regulation structure (4032), when adjusting dabber pull rod (403) and producing axial slip relatively interior bloated cutting ferrule (406) through axial adjusting part, the cavity split structure is changed between free state and bloated tight state.

2. An expanding mandrel for precision measurements according to claim 1 wherein: the sliding sleeve assembly is connected onto the pull rod connecting structure (4031), an insertion side hole for assembling a displacement measuring mechanism is formed in the sliding sleeve assembly, and the pull rod connecting structure (4031) is inserted into the sliding sleeve assembly and can slide up and down along the sliding sleeve assembly.

3. An expanding mandrel for precision measurements according to claim 2, wherein: the pull rod adjusting structure (4032) is provided with a thread adjusting section, and the expansion adjusting structure (4034) is of a conical structure.

4. An expanding mandrel for precision measurements according to claim 3, wherein: the cutting sleeve adjusting structure is arranged at one side end of the internal expansion cutting sleeve (406) and comprises at least one ring of annular hook ring (4061) arranged on the outer wall of the end of the internal expansion cutting sleeve (406).

5. An expanding mandrel for precision measurements according to claim 4, wherein: the axial adjustment assembly includes:

a lock nut structure (404) which is in threaded connection with the threaded adjusting section;

the hanging ring structure is hung on the annular hook ring (4061) and comprises two semi-ring structures (405) with opposite openings;

the two half ring structures (405) are oppositely pressed on the outer end face of the lock nut structure (404) and the two half ring structures (405) are fixed on the lock nut structure (404) through screws.

6. An expanding mandrel for precision measurements according to claim 4, wherein: the hollow split structure is arranged at the end part of the other side of the internal expansion clamping sleeve (406), the hollow split structure comprises an expansion main body, the expansion main body is divided into a plurality of split bodies (4062) through split seams radially arranged, and a hollow expansion conical surface is formed in an inner hole of the expansion main body.

7. A radial calibration device for a thin-walled cylinder is characterized in that: the method comprises the following steps:

the fixing ring (7) is superposed with the central axis of the thin-wall cylinder (6), and a radial vibration measurement sensor for calibration is arranged on the fixing ring (7);

the displacement measuring mechanism comprises a straight-advancing type differential head (1), wherein the straight-advancing type differential head (1) is installed on a fixed ring (7) through a supporting structure, a measuring rod (13) of the straight-advancing type differential head (1) is connected with an expansion type mandrel (4) through a special chuck (3), the inner wall of a thin-wall cylinder (6) is expanded through the expansion type mandrel (4) according to any one of claims 2-6, and the motion tracks of the straight-advancing type differential head (1) driving the thin-wall cylinder (6) to move are coincident with the central axis of a radial vibration measurement sensor.

8. A radial calibration device for thin-walled cylinders according to claim 7, wherein: the support structure includes:

the base (8) is fixed on the fixing ring (7) through a fixing screw (9), and a plurality of mounting holes (10) are formed in the base (8);

the upper end of the supporting seat (2) is provided with a positioning hole (14) for assembling the straight-in type differential head (1), and the lower end is provided with a supporting rod (12) which is inserted in the mounting hole (10) in a matching way.

9. A radial calibration device for thin-walled cylinders as claimed in claim 8, wherein: the base (8) is an arc-shaped block structure with the same diameter as the fixed ring (7).

10. A radial calibration method for a thin-wall cylinder is characterized by comprising the following steps: the method comprises the following steps:

s101: assembled expanding mandrel

Firstly, sleeving an internal expansion clamping sleeve (406) on the outer side of a mandrel pull rod (403), then clamping a lock nut structure (404) and the internal expansion clamping sleeve (406) together through an axial adjusting assembly, then inserting a pull rod connecting structure of the mandrel pull rod (403) into a sliding sleeve assembly, finally inserting the lower end split part of an expansion mandrel (4) into an opening of a thin-wall cylinder (6), and expanding the inner wall of the thin-wall cylinder (6);

s102: assembled displacement measuring mechanism

Firstly, a base (8) is installed on a fixing ring (7) through a fixing screw (9), then a supporting seat (2) is inserted into an installation hole (10) of the base (8), then a straight-in type differential head (1) is inserted into a positioning hole (14) of the supporting seat (2) and is fixed by using a screw, and finally a measuring rod (13) of the straight-in type differential head (1) is inserted into a central hole of a special chuck (3) and is locked by using a nut;

s103: assembly between displacement measuring mechanism and expanding mandrel

Inserting a special chuck (3) into an insertion side hole of a sliding sleeve component at the upper end of an expansion core shaft (4), locking by using a knurled screw (407), ensuring that a thin-wall cylinder (6) is coincident with a central shaft of a fixed ring (7), and coinciding a motion track of the straight-in type differential head (1) for driving the thin-wall cylinder (6) to move with the central shaft of a sensor (5);

s104: calibration work

After all the components are assembled, the expansion mandrel (4) is pushed to drive the thin-wall cylinder (6) to move by moving the measuring rod (13) of the straight-advancing type differential head (1), and the distance between the thin-wall cylinder (6) and the radial vibration measurement sensor is adjusted to perform calibration work.