CN219725118U

CN219725118U - Positioning tool of passive shimming structure

Info

Publication number: CN219725118U
Application number: CN202322260119.XU
Authority: CN
Inventors: 王兆连; 王前; 曾范昊; 张义廷; 齐玉宁
Original assignee: Weifang Xinli Superconducting Magnet Technology Co ltd
Current assignee: Weifang Xinli Superconducting Magnet Technology Co ltd
Priority date: 2023-08-22
Filing date: 2023-08-22
Publication date: 2023-09-22
Anticipated expiration: 2033-08-22

Abstract

The positioning tool of the passive shimming structure disclosed by the utility model is used for positioning the mounting clamping strips on the inner wall of the superconducting magnet. The positioning tool comprises a positioning shaft and a positioning disc. The positioning shaft is provided with a disc positioning part. The positioning disk is at least two sleeved on the positioning shaft, the positioning disk is detachably connected with the disk positioning part, and a plurality of connecting parts used for being connected with the mounting clamping strips are uniformly arranged on the circumferential outer wall of the positioning disk. In the passive shimming structure installation process, the installation clamping strips are fixed on the circumferential outer wall of the positioning tool through the connecting parts, so that the installation clamping strips are shaped like a circular ring, then the positioning tool and the installation clamping strips are fed into the inner cavity of the superconducting magnet together, then the installation clamping strips and the superconducting magnet are welded and fixed in sequence, finally the positioning tool is evacuated, namely the fixing of the installation clamping strips and the superconducting magnet is completed, and finally the drawer component is installed in the shimming channel. The positioning tool disclosed by the utility model is simple in structure, convenient and reliable to use and accurate in positioning.

Description

Positioning tool of passive shimming structure

Technical Field

The utility model relates to the technical field of nuclear magnetic resonance imaging, in particular to a positioning tool of a passive shimming structure.

Background

With the development and maturation of magnetic resonance technology, magnetic resonance imaging devices are widely used in the clinical medical field. The magnetic resonance imaging superconducting magnet is a core component of magnetic resonance imaging equipment, and the size of the magnetic field uniformity of a central spherical region of the superconducting magnet directly influences the imaging effect of an image.

The uniformity of the magnetic field of the magnetic resonance superconducting magnet in the central spherical region is about hundreds of PPM after the manufacture is finished, which cannot meet the basic requirement of clear imaging, and the uniformity of the central magnetic field is generally required to be less than tens of PPM, so that the smaller the PPM is, the clearer the imaging is. There is therefore a need for using shimming techniques to meet the homogeneity of the magnetic field in the centre of MRI (magnetic resonance imaging ) superconducting magnets. The conventional shimming technology is mainly divided into a passive shimming technology and an active shimming technology.

In connection with fig. 1, one passive shimming technique (structure) in the prior art is to manufacture shimming channels in the inner cavity of the superconducting magnet 10 by mounting the clamping bars 20, and the shimming channels are used for realizing the mounting of the drawer assembly 30. As shown in fig. 3, a plurality of storage grooves 35 are arranged on the shimming drawer, the positions and thicknesses of the silicon steel sheets used for being placed in the storage grooves 35 are determined according to the distribution of the magnetic field and the simulation calculation of shimming software, and the simulation calculation is repeated for several times to adjust the uniformity of the central magnetic field of the superconducting magnet to finally meet the use requirement.

The arrangement mode of the shimming drawer is not influenced by the length and the heating value of the gradient coil any more, and is almost suitable for any situation, especially for some situations which are not suitable for opening shimming channels in the gradient coil. However, if the passive shimming structure installed on the inner cavity of the superconducting magnet is installed by adopting a scribing mode, the installation of the installation clamping strips can cause larger error, and the final shimming effect can be possibly affected.

Therefore, how to realize positioning and mounting of the mounting clamping strip and the superconducting magnet is a technical problem to be solved urgently by those skilled in the art.

Disclosure of Invention

Therefore, the utility model aims to provide a positioning tool of a passive shimming structure so as to realize positioning and mounting of a mounting clamping strip and a superconducting magnet.

In order to achieve the above purpose, the present utility model provides the following technical solutions:

a positioning tooling for a passive shimming structure, comprising:

a passive shimming structure's location frock for with installation card strip location in the inner wall of superconducting magnet, include:

the positioning shaft is provided with a disc positioning part;

the positioning disc is sleeved on the positioning shaft at least, the positioning disc is detachably connected with the disc positioning part, and a plurality of connecting parts used for being connected with the mounting clamping strips are uniformly arranged on the circumferential outer wall of the positioning disc.

Optionally, in the positioning tool of the passive shimming structure, the positioning disc includes:

the positioning disc body is sleeved on the positioning shaft and is detachably connected with the disc positioning part;

the positioning circular ring is connected to the circumferential side wall of the positioning disc body, and the connecting part is arranged on the positioning circular ring.

Optionally, in the positioning tool of the passive shimming structure, the connecting portion is a fixing hole formed in a circumferential side wall of the positioning ring, and the fixing hole is used for being connected with the mounting clamping strip through a bolt.

Optionally, in the positioning tool of the passive shimming structure, a positioning groove for embedding the mounting clamping strips is formed in the circumferential outer wall of the positioning ring, and the positioning grooves are communicated with the fixing holes in a one-to-one correspondence manner.

Optionally, in the positioning tool of the passive shimming structure, the fixing hole is a waist-shaped hole, and the fixing hole extends along an axial direction of the positioning ring.

Optionally, in the positioning tool of the passive shimming structure, a clamping strip positioning portion is disposed on the positioning disc at the end of the positioning shaft, and the clamping strip positioning portion is used for being abutted to an end face of one end where the clamping strip is installed.

Optionally, in the positioning tool of the passive shimming structure, the disc positioning portion is a fixed disc fixedly connected to the positioning shaft, one side of the fixed disc is provided with a reinforcing rib, and the fixed disc is used for being connected to the other side of the fixed disc.

Optionally, in the positioning tool of the passive shimming structure, a disassembly hole is formed in the disc positioning portion, and the position of the disassembly hole corresponds to the position of the positioning disc, and is used for separating the positioning disc from the disc positioning portion through a disassembly tool.

Optionally, in the positioning tool of the passive shimming structure, two positioning discs are provided.

Optionally, in the positioning tool of the passive shimming structure, two ends of the positioning shaft are supported on the ground by a bracket, and the height of the bracket is adjustable.

The positioning tool of the passive shimming structure is used for positioning the mounting clamping strips on the inner wall of the superconducting magnet, and is used for assisting in realizing connection of the mounting clamping strips and the superconducting magnet, so that the mounting clamping strips form shimming channels for mounting shimming drawers. The positioning tool comprises a positioning shaft and a positioning disc. The positioning shaft is provided with a disc positioning part. The positioning disk is at least two sleeved on the positioning shaft, the positioning disk is detachably connected with the disk positioning part, and a plurality of connecting parts used for being connected with the mounting clamping strips are uniformly arranged on the circumferential outer wall of the positioning disk.

In the process of passive shimming structure installation, the installation clamping strips are fixed on the circumferential outer wall of the positioning tool through the connecting parts, so that the installation clamping strips are shaped like a circular ring, then the positioning tool and the installation clamping strips are fed into the inner cavity of the superconducting magnet together, then the installation clamping strips and the superconducting magnet are welded and fixed in sequence, finally the installation clamping strips are separated from the positioning tool, the positioning disc is detached from the positioning shaft, the positioning tool is evacuated, namely the fixing of the installation clamping strips and the superconducting magnet is completed, and finally the drawer assembly is installed in the shimming channel.

Compared with the prior art, the positioning tool provided by the utility model has the advantages that the structure is simple, the use is convenient and reliable, the positioning is accurate, and the positioning and the mounting of the mounting clamping strip and the superconducting magnet can be realized in an auxiliary manner.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a passive shimming structure in the prior art;

FIG. 2 is a schematic view of a prior art mounting clip;

FIG. 3 is an exploded view of a drawer assembly of the prior art;

FIG. 4 is a schematic view of a prior art mounting structure for mounting a card bar and drawer assembly;

FIG. 5 is an exploded view of a positioning tool for a passive shimming structure according to an embodiment of the present utility model;

FIG. 6 is a schematic diagram of a positioning disc according to an embodiment of the present utility model;

FIG. 7 is a schematic view of a positioning plate according to another embodiment of the present utility model;

fig. 8 to 11 are views illustrating steps of fixing the mounting clip strip on the inner wall of the superconducting magnet by the positioning tool according to the embodiment of the utility model.

Wherein 10 is a superconducting magnet; 20 is a mounting clamping strip, 21 is a clamping strip body, 22 is a mounting boss, 23 is a welding avoidance port, 24 is a first connecting hole, and 25 is a second connecting hole; 30 is a drawer assembly, 31 is a shimming strip, 32 is a cover plate, 33 is a mounting plate, 34 is an embedded part, and 35 is a storage tank;

100 is a positioning shaft, 110 is a disc positioning part, 111 is a reinforcing rib;

200 is a positioning disk, 210 is a positioning disk body, 220 is a positioning ring, 221 is a positioning groove, 222 is a connecting part, and 230 is a clamping strip positioning part.

Detailed Description

The utility model discloses a positioning tool of a passive shimming structure so as to realize positioning and mounting of a mounting clamping strip and a superconducting magnet.

Hereinafter, embodiments will be described with reference to the drawings. Furthermore, the embodiments shown below do not limit the summary of the utility model described in the claims. The whole contents of the constitution shown in the following examples are not limited to the solution of the utility model described in the claims.

Wherein, in the description of the embodiments of the present utility model, unless otherwise indicated, "/" means or, for example, a/B may represent a or B; "and/or" herein is merely an association relationship describing an association object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, in the description of the embodiments of the present utility model, "plurality" means two or more than two.

The terms "first" and "second" are used below for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

Referring to fig. 1, the positioning tool of the passive shimming structure disclosed in the embodiment of the utility model is used for positioning the installation clamping strip 20 on the inner wall of the superconducting magnet 10, and is used for assisting in realizing the connection between the installation clamping strip 20 and the superconducting magnet 10, so that the installation clamping strip 20 forms a shimming channel for installing the drawer assembly 30. The drawer assembly 30 and the mounting clip 20 together are assembled inside the superconducting magnet 10 into a ring-like structure similar to that shown in fig. 4.

As shown in fig. 5, the positioning fixture includes a positioning shaft 100 and a positioning disk 200. The positioning shaft 100 is provided with a disk positioning portion 110. The positioning plate 200 is at least two sleeved on the positioning shaft 100, the positioning plate 200 is detachably connected with the disc positioning part 110, and a plurality of connecting parts 222 for connecting with the mounting clamping strips are uniformly arranged on the circumferential outer wall of the positioning plate 200.

In the process of passive shimming structure installation, the installation clamping strips 20 are fixed on the circumferential outer wall of the positioning tool through the connecting parts 222 to form a ring-like shape, then the positioning tool and the installation clamping strips 20 are fed into the inner cavity of the superconducting magnet 10 together, then the installation clamping strips 20 and the superconducting magnet 10 are welded and fixed in sequence, finally the installation clamping strips 20 are separated from the positioning tool, the positioning disc 200 is detached from the positioning shaft 100, the positioning tool is removed, the fixing of the installation clamping strips 20 and the superconducting magnet 10 is completed, and finally the drawer assembly 30 is installed in the shimming channel.

Compared with the prior art that the mounting clamping strip 20 is directly fixed on the inner wall of the superconducting magnet 10 by scribing, the positioning tool disclosed by the embodiment of the utility model has the advantages of simple structure, convenience and reliability in use and accurate positioning, and can assist in positioning and mounting the mounting clamping strip 20 and the superconducting magnet 10.

The number of the positioning disks 200 on the positioning shaft 100 is generally two, the two positioning disks 200 can stably fix the mounting clamping strips 20 on the positioning tool, and the two positioning disks 200 are simpler in structure and simpler and more convenient in disassembly and assembly process.

In a specific embodiment of the present disclosure, as shown in fig. 6, puck 200 includes puck body 210 and puck ring 220. The positioning disc 210 is sleeved on the positioning shaft 100 and is detachably connected with the disc positioning portion 110. The positioning ring 220 is connected to the circumferential sidewall of the positioning disc 210, and the positioning ring 220 is provided with the connecting portion 222.

A connection hole for penetrating the positioning shaft 100 is formed at the center of the positioning plate 210.

Referring to fig. 6, the positioning ring 220 extends along the axial direction of the positioning shaft 100 to provide a certain supporting length for the mounting clip 20. The positioning ring 220 may be symmetrically disposed or asymmetrically disposed with respect to the positioning plate 210.

In order to reduce weight, a plurality of weight reducing grooves are formed in the positioning plate 210 under the premise of ensuring structural strength.

As shown in fig. 6, the connecting portion 222 is a fixing hole formed in a circumferential side wall of the positioning ring 220, and the fixing hole is used for being connected with the mounting clip 20 through a connecting piece bolt, so as to fix the mounting clip 20.

Specifically, the mounting clip 20 is bolted to the fixing hole, and the head of the bolt is closer to the positioning ring 220 than the mounting clip 20.

The number of fixing holes is generally 24 to correspond to the number of mounting clips 20.

The fixing holes are waist-shaped holes, and extend along the axial direction of the positioning circular ring so as to improve fault tolerance and complement machining deviation and assembly deviation of parts.

Further, a positioning groove 221 for embedding the mounting clamping strip 20 is formed in the circumferential outer wall of the positioning ring 220, the width of the positioning groove 221 corresponds to the width of the mounting clamping strip 20, and when the mounting clamping strip 20 is embedded into the positioning groove 221, the preliminary positioning of the positioning tool on the mounting clamping strip 20 is realized. The positioning grooves 221 are communicated with the fixing holes in a one-to-one correspondence manner, and are connected with the fixing holes after the mounting clamping strips 20 are embedded into the positioning grooves 221.

The depth of the positioning groove 221 can be designed according to practical requirements, for example, 0.5mm.

The positioning groove 221 can be formed by arranging a positioning block on the circumferential outer wall of the positioning ring 220, but the preparation cost of the scheme is higher.

Since the positioning ring 220 needs to be provided with the fixing hole and the mounting clamping strip 20 for fixing, the positioning plate 210 needs to be avoided at the position of the fixing hole, and therefore if the positioning ring 220 is symmetrically arranged relative to the positioning plate 210, the size of the positioning ring 220 needs to be properly increased.

The connecting portion 222 may be disposed on only two positioning discs 200, where the two positioning discs 200 are located at two ends of the positioning shaft 100, so as to fix the end of the installation clamping strip 20, and facilitate the subsequent operator to detach the installation clamping strip 20 from the positioning tool.

In order to position the mounting clip 20 along the length direction thereof, as shown in fig. 7, a clip positioning portion 230 is provided on the positioning plate 200 at the end of the positioning shaft 100, and the clip positioning portion 230 is used as a positioning reference for abutting against the end face of one end of the mounting clip 20.

The clip strip positioning portion 230 is only disposed on one positioning disc 200 at the end portion, so as to ensure the positioning effect.

Positioning of the mounting clip 20 and the positioning fixture can also be achieved through bolting of the mounting clip to the positioning plate 200.

The disc positioning portion 110 is used for positioning and installing the positioning shaft 100 and the positioning disc 200, in an embodiment, the disc positioning portion 110 is a fixed disc fixedly connected to the positioning shaft 100, one side of the fixed disc is provided with a reinforcing rib 111, and the positioning disc 200 is detachably connected to the other side of the fixed disc.

The fixing disc can be a flange disc.

When the positioning disks 200 are plural, the positioning shaft 100 may also be a stepped shaft structure, and the disc positioning portion 110 may be a stepped surface of the stepped shaft, so as to position the plural positioning disks 200.

After the mounting clip 20 is welded to the superconducting magnet 10, the mounting clip 20 and the puck 200 need to be separated, and the fixture is removed, so that the fixture shaft 100 and the puck 200 need to be separated first.

The disc positioning portion 110 is provided with a dismounting hole, the position of the dismounting hole corresponds to the position of the positioning disc 200, the dismounting tool is a push rod or other structure capable of penetrating through the dismounting hole, so that after the connecting bolt of the positioning shaft 100 and the positioning disc 200 is dismounted, the positioning disc 200 is pushed out of the superconducting magnet 10 along the extending direction of the positioning shaft 100 by penetrating through the dismounting hole, and finally the positioning shaft 100 is taken out.

The disassembly holes may be a plurality of holes uniformly arranged along the circumferential direction of the puck 200 to facilitate uniform stressing and pushing out of the puck 200. The disassembly holes can be threaded holes, and correspondingly, the disassembly tools are screws.

The disc positioning part 110 and the positioning disc 200 can be connected by bolts, and the number of the connecting holes on the disc positioning part 110 and/or the positioning disc 200 can be waist-shaped holes so as to improve the fault tolerance, and the number of the connecting holes can be 3.

When fixing the mounting clip 20 to the positioning tool and welding the mounting clip 20 on the positioning tool to the superconducting magnet 10, the positioning tool disclosed in the embodiment of the utility model further includes a bracket, wherein the bracket is supported at two ends of the positioning shaft 100, and the positioning shaft 100 is rotatable relative to the bracket, so that each mounting clip 20 is conveniently fixed on the positioning tool by rotation.

Further, the height of the bracket is adjustable to accommodate the same or different working heights when fixing the mounting clip 20 to the positioning fixture and welding the mounting clip 20 on the positioning fixture to the superconducting magnet 10.

In a specific embodiment of the present disclosure, as shown in fig. 2, the mounting clip 20 includes a clip body 21 and a mounting boss 22, the clip body 21 is connected with the mounting boss 22, the clip body 21 is used for welding with the superconducting magnet 10, the number of the mounting bosses 22 is two, and symmetrically arranged at one end of the clip body 21 far away from the superconducting magnet 10, an embedded groove is formed between the mounting boss 22 and the superconducting magnet 10, two sides of the drawer assembly 30 are provided with embedded parts 34, the embedded parts 34 are embedded and matched with the embedded groove, and the drawer assembly 30 is connected with the mounting clip 20 by bolts.

Referring to fig. 3, the drawer assembly 30 includes a shim bar 31, a cover plate 32 and a mounting plate 33, the shim bar 31 is provided with a storage groove 35 for mounting a silicon steel sheet, the cover plate 32 is used for plugging the storage groove 35, the mounting clamp bar 20 is provided with a first connecting hole 24 and a second connecting hole 25, the first connecting hole 24 is used for connecting with a positioning tool through a connecting piece, and the connecting piece passes through the second connecting hole 25 and is connected with the mounting plate 33.

When the positioning tool disclosed by the utility model is used for installing the installation clamping strip 20 and the drawer assembly 30 on the superconducting magnet 10, the two positioning plates 200 (the first positioning plate and the second positioning plate are respectively provided with the clamping strip positioning part 230) are penetrated into the positioning shaft 100, are fixed with the two flange plates of the positioning shaft 100 by bolts, and ensure that the positioning grooves 221 on the two positioning plates 200 correspond to each other in position.

Taking one mounting clamping strip 20, combining with fig. 8, putting one end with a threaded hole (a second connecting hole 25) into a positioning groove 221 of a second positioning disk, putting the other end into a positioning groove 221 of a first positioning disk, propping up the end face of the mounting clamping strip 20 with a clamping strip positioning part 230 of the second positioning disk, penetrating a bolt from the bottom direction of the positioning groove 221 and screwing into the threaded hole on the mounting clamping strip 20 for fixing, fastening the other end of the mounting clamping strip 20 by the same bolt, and fixing all the mounting clamping strips 20 by the same method to obtain the structure shown in fig. 9.

As shown in fig. 10, the positioning fixture with the mounting clamping bars 20 is inserted into the inner cavity of the superconducting magnet 10, the axial mounting position is adjusted, the mounting clamping bars are concentric with the superconducting magnet 10, then the two ends of all the mounting clamping bars 20 are fixed with the inner cavity of the superconducting magnet 10 by spot welding, then the bolts for connecting the first positioning plate, the second positioning plate and the flange of the positioning shaft 100 are removed, the first positioning plate and the second positioning plate are taken out, if the clamping is tight, the bolts can be screwed in from the dismounting holes on the end surfaces of the first positioning plate and the second positioning plate, the first positioning plate and the second positioning plate are slowly ejected out, then the positioning shaft 100 is pulled out from the superconducting magnet 10, and then the mounting clamping bars 20 and the inner cavity of the superconducting magnet 10 are further welded and fixed in the axial direction by the welding avoidance openings 23, so that the mounting structure of the superconducting magnet 10 and the mounting clamping bars 20 shown in fig. 11 is obtained.

Finally, the drawer assembly 30 is inserted between the two mounting clips 20 and is fastened by bolting.

In order to reduce welding deformation, the superconducting magnet 10 and the mounting clamping strips 20 do not need to be fully welded, so that welding points are selected to the minimum under the premise of ensuring firm welding, welding is performed at a welding avoidance port 23 on the mounting clamping strips 20, and finally the drawer assembly 30 is inserted between two adjacent mounting clamping strips 20 and is fixed by bolts.

It should be noted that, since a large number of countersunk screws need to be screwed into the cover plate 32 to be connected with the shimming strip 31, if there is a situation that the countersunk screws are not assembled in place, the countersunk screws are higher than the surface of the cover plate 32, so that the smoothness of the installation process of the drawer assembly 30 is affected, and the countersunk screws are made of plastic materials, if the countersunk screws are forcibly dragged, the countersunk screws and the cover plate 32 are damaged, further the silicon steel sheets in the drawer assembly 30 are scattered on the superconducting magnet 10, and because the magnetic force is large, the absorbed silicon steel sheets are difficult to take off, therefore, in combination with fig. 4, a gap can be reserved between the drawer assembly 30 and the inner wall of the superconducting magnet 10, so as to fault tolerance for assembling the countersunk screws.

The terms first and second and the like in the description and in the claims, are used for distinguishing between different objects and not for describing a particular sequential order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to the listed steps or elements but may include steps or elements not expressly listed.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the utility model. Thus, the present utility model is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The above description is only illustrative of the preferred embodiments of the present utility model and the technical principles applied, and is not intended to limit the present utility model. Various modifications and variations of the present utility model will be apparent to those skilled in the art. The scope of the present utility model is not limited to the specific combination of the above technical features, but also includes other technical features formed by any combination of the above technical features or their equivalents without departing from the spirit of the present utility model. Such as the above-mentioned features and the technical features disclosed in the present utility model (but not limited to) having similar functions are replaced with each other.

Claims

1. The utility model provides a location frock of passive shimming structure for with installation card strip location in the inner wall of superconducting magnet, its characterized in that includes:

a positioning shaft (100) provided with a disk positioning section (110);

the positioning disc (200) is at least sleeved on two of the positioning shafts (100), the positioning disc (200) is detachably connected with the disc positioning part (110), and a plurality of connecting parts (222) used for being connected with the mounting clamping strips are uniformly arranged on the circumferential outer wall of the positioning disc (200).

2. The positioning fixture of a passive shimming structure according to claim 1, characterized in that the positioning disk (200) comprises:

the positioning disc body (210) is sleeved on the positioning shaft (100) and is detachably connected with the disc positioning part (110);

the positioning circular ring (220) is connected to the circumferential side wall of the positioning disc body (210), and the connecting part (222) is arranged on the positioning circular ring (220).

3. The positioning tool of the passive shimming structure according to claim 2, wherein the connecting portion (222) is a fixing hole formed in a circumferential side wall of the positioning ring (220), and the fixing hole is used for being connected with an installation clamping bolt.

4. A positioning tool for a passive shimming structure according to claim 3, wherein a positioning groove (221) for embedding an installation clamping strip is formed in the circumferential outer wall of the positioning circular ring (220), and the positioning grooves (221) are communicated with the fixing holes in a one-to-one correspondence manner.

5. A positioning fixture for a passive shimming structure according to claim 3, characterized in that the fixing hole is a waist-shaped hole extending in the axial direction of the positioning ring (220).

6. The positioning tool of the passive shimming structure according to claim 1, wherein a clamping strip positioning portion (230) is arranged on the positioning disc (200) at the end portion of the positioning shaft (100), and the clamping strip positioning portion (230) is used for abutting against an end face of one end of the mounting clamping strip.

7. The positioning tool of a passive shimming structure according to claim 1, wherein the disc positioning portion (110) is a fixed disc fixedly connected to the positioning shaft (100), one side of the fixed disc is provided with a reinforcing rib (111), and the positioning disc (200) is used for being connected to the other side of the fixed disc.

8. The positioning tool of a passive shimming structure according to claim 7, wherein the disc positioning portion (110) is provided with a disassembly hole, and the position of the disassembly hole corresponds to the position of the positioning disc (200), so as to separate the positioning disc (200) from the disc positioning portion (110) through a disassembly tool.

9. The positioning fixture of a passive shimming structure according to any one of claims 1-8, wherein there are two positioning discs (200).

10. The positioning tool of a passive shimming structure according to any one of claims 1-8, wherein two ends of the positioning shaft (100) are supported on the ground by a bracket, and the height of the bracket is adjustable.