CN219319306U - High-precision displacement measuring device for low-temperature magnetic field environment - Google Patents

Abstract

The utility model provides a high-precision displacement measuring device for a low-temperature magnetic field environment. According to one embodiment, a displacement measuring device includes: the base comprises a base bottom plate, a fixed bracket arranged on the base bottom plate and a base top plate supported on the fixed bracket; an elastic cross beam connected to the fixed support and positioned between the base bottom plate and the base top plate, wherein an objective table for bearing a sample is arranged on the elastic cross beam, and the sample is positioned between the base top plate and the objective table; a capacitive sensor top plate connected to a lower end of the stage and a capacitive sensor bottom plate disposed on the base bottom plate, the capacitive sensor top plate and the capacitive sensor bottom plate being opposite each other and spaced apart a distance to form a capacitive sensor.

Description

High-precision displacement measuring device for low-temperature magnetic field environment

Technical Field

The present utility model relates to a high-precision displacement measuring device that can be used in extreme environments such as low temperatures and magnetic fields.

Background

As is well known, detection of displacement or fine change in size of an article is becoming an important subject in the technical field represented by development of electronic products. For example, detecting changes in an article when subjected to external processing or due to environmental changes is of great practical significance to some precision instruments. In particular, low temperatures or strong magnetic fields may induce changes in the lattice structure of the article in the environment. For example, objects may undergo phase changes in low temperature or high magnetic field environments, resulting in changes in crystallographic axis orientation, lattice spacing, etc., and thus changes in the dimensions of the article. Therefore, by measuring the dimensional change of the article under low temperature or strong magnetic field conditions, it is possible to assist in detecting whether or not the phase change and the degree of the phase change have occurred inside the article.

In addition, even if no phase change occurs, a low temperature or a strong magnetic field may affect the vibration frequency and amplitude of atoms in the crystal lattice, the orientation angle of the crystal axis, and the like, resulting in a change in the size of the article. More and more high precision manufacturing is performed under low temperature or high magnetic field conditions, and dimensional changes of the article and the sample stage carrying the article may affect manufacturing precision. Thus, accurately measuring dimensional changes in an article is becoming increasingly important for accurately controlling product shape, improving manufacturing accuracy.

In view of the foregoing, there remains a need for a device that can accurately measure dimensional or displacement changes of an article under extreme conditions such as low temperature or high magnetic fields.

Disclosure of Invention

The utility model provides a device for accurately measuring displacement or dimensional change of an article by utilizing the principle that the capacitance of a capacitance sensor is inversely proportional to the distance between polar plates, which can be used under extreme conditions such as low temperature or strong magnetic field.

According to an exemplary embodiment, there is provided a displacement measuring device including: the device comprises a base bottom plate, a fixed bracket arranged on the base bottom plate and a base top plate supported on the fixed bracket; an elastic cross beam connected to the fixed bracket and positioned between the base bottom plate and the base top plate, wherein a stage for carrying a sample is arranged on the elastic cross beam, and the sample is positioned between the base top plate and the stage; and a capacitive sensor top plate connected to a lower end of the stage and a capacitive sensor bottom plate disposed on the base bottom plate, the capacitive sensor top plate and the capacitive sensor bottom plate being opposite to each other and spaced apart by a distance to form a capacitive sensor.

In an exemplary embodiment, the displacement measuring device further comprises a measuring unit connected to the capacitance sensor bottom plate and the capacitance sensor top plate of the capacitance sensor by wires for measuring a capacitance change of the capacitance sensor and converting it into a displacement value.

In an exemplary embodiment, a through hole is provided in the base top plate, and a post is provided in the through hole, the post being provided in the through hole to be movable up and down to contact a top surface of the sample.

In an exemplary embodiment, the position of the top post in the through hole is controlled by a displacement driving element.

In an exemplary embodiment, the elastic beam includes two or more layers of laterally extending spring structures disposed one above the other, and the stage extends through and is connected to the spring structures in a vertical direction.

In an exemplary embodiment, the fixing bracket supports one end, opposite ends, or all around of the dome structure.

In an exemplary embodiment, the displacement measuring device further includes: a top metal shield surrounding and electrically insulated from a top surface and a periphery of the capacitive sensor top plate, the top metal shield exposing a bottom surface of the capacitive sensor top plate opposite the capacitive sensor bottom plate; and a bottom metal shield surrounding and electrically insulated from the bottom surface of the capacitive sensor chassis and surrounding the bottom surface of the capacitive sensor chassis, the bottom metal shield exposing a top surface of the capacitive sensor chassis opposite the capacitive sensor top plate.

In an exemplary embodiment, the top metal shield is adhered to the capacitive sensor top plate by an insulating glue or is connected to the capacitive sensor top plate by an insulating screw, and an insulating pad is provided between the top metal shield and the capacitive sensor top plate to electrically insulate therebetween. The bottom metal shielding layer is adhered to the capacitive sensor bottom plate through insulating glue or connected to the capacitive sensor bottom plate through insulating screws, and an insulating pad is arranged between the bottom metal shielding layer and the capacitive sensor bottom plate so as to realize electric insulation between the bottom metal shielding layer and the capacitive sensor bottom plate.

In an exemplary embodiment, the capacitive sensor floor is embedded in and electrically insulated from the base floor, the base floor surrounding at least a portion of the perimeter of the capacitive sensor floor and a bottom surface.

In an exemplary embodiment, one or more of the base bottom plate, the fixed bracket, and the base top plate are formed of titanium or a titanium alloy material, and the resilient beam is formed of a beryllium copper alloy material.

The displacement measuring device can measure the displacement of the sample under the extreme conditions of low temperature, strong magnetic field and the like, which is caused by the external action or the change of the sample caused by the environmental change, and has higher application value in the fields of scientific research, high-precision manufacture and the like.

Drawings

FIG. 1 shows a schematic view of a sample-carrying flexible portion in a displacement measurement device according to an embodiment of the utility model;

FIG. 2 shows a schematic view of a sample-carrying flexible portion in a displacement measurement device according to another embodiment of the utility model;

FIG. 3 shows a schematic view of a capacitive sensor ranging section in a displacement measurement device according to an embodiment of the present utility model;

FIG. 4 shows a schematic view of a capacitive sensor ranging section in a displacement measurement device according to another embodiment of the present utility model;

FIG. 5 shows a schematic view of a displacement measuring device according to an embodiment of the utility model; and

fig. 6 shows a schematic view of a displacement measuring device according to another embodiment of the utility model.

Detailed Description

Fig. 1 and 2 show schematic views of a sample-carrying flexible portion in a displacement measurement device according to an embodiment of the utility model, respectively. Referring first to fig. 1, the sample-carrying flexible portion includes a fixed bracket 3, an elastic beam 2 connected to the fixed bracket 3, and a stage 1 supported by the elastic beam 2. The stage 1 may pass through a flexible beam 2, and the flexible beam 2 may be attached, e.g., welded or glued, to the peripheral side walls of the stage 1. In one embodiment, the stage 1 and the stationary support 3 may be made of a non-magnetic material having a small coefficient of thermal expansion over a large temperature range, examples of such materials include, but are not limited to, titanium or titanium alloys, boron manganese alloys, and the like. Titanium or titanium alloys are preferred because they also have the advantages of corrosion resistance, light weight, etc. The elastic cross beam 2 can be made of beryllium copper alloy, has the advantage of excellent elasticity besides non-magnetic property, can effectively avoid the fact that the object stage 1 cannot timely and accurately change along with the displacement of an object placed on the object stage or the dimensional change under the action of a magnetic field or temperature due to the elastic modulus of the material, and reduces the system error. The elastic beam 2 may be formed in a thin-wall structure, or a spring structure, both sides of which may be riveted or welded to the fixing bracket 3, and the stage 1 may be fixedly mounted to the elastic beam 2. A sample (not shown) may be placed on the stage 1. When the sample is displaced by an external force or is subjected to a dimensional change by an environmental influence, the position of the stage 1 may be changed, and the elastic beam 2 may be elastically deformed. The initial positions of the stage 1 and the elastic beam 2 are schematically shown in solid lines in fig. 1, and the changing positions of the stage 1 and the elastic beam 2 are schematically shown in broken lines. Preferably, two upper and lower layers of elastic beams 2 may be provided, and the stage 1 extends through and is connected to the two layers of elastic beams 2 in a vertical direction, so that a stable support can be provided to the stage 1, preventing the stage 1 from being skewed when subjected to an external force. It will be appreciated that more (e.g. three, four or more) or fewer (e.g. one) resilient beams 2 may be provided.

The embodiment shown in fig. 2 is substantially identical to that of fig. 1, except that the fixing brackets 3 in fig. 1 are arranged on opposite sides of the elastic cross-beam 2, whereas the fixing brackets 3 in fig. 2 are arranged on only one side of the elastic cross-beam 2. It will be appreciated that in another embodiment, the elastic beam 2 may have a circular planar shape, and the fixing bracket 3 may be disposed around the elastic beam 2. Other aspects of the embodiment shown in fig. 2 may be the same as fig. 1, and a repetitive description thereof will be omitted herein.

Fig. 3 and 4 respectively show schematic diagrams of a capacitive sensor ranging section in a displacement measuring device according to an embodiment of the present utility model. Referring first to fig. 3, the capacitive sensor ranging section includes a capacitive sensor top plate 5 and a capacitive sensor bottom plate 8, both of which form a capacitive sensor. The periphery and the top surface of the capacitive sensor top plate 5 are surrounded by the top metal shielding layer 4, only the bottom surface facing the capacitive sensor bottom plate 8 is exposed, and the capacitive sensor top plate 5 is adhered to the top metal shielding layer 4 through the insulating adhesive layer 9 while electrical insulation between the capacitive sensor top plate 5 and the top metal shielding layer 4 is achieved. The periphery and bottom surface of the capacitive sensor bottom plate 8 are surrounded by the bottom metal shielding layer 7, only the top surface facing the capacitive sensor top plate 5 is exposed, and the capacitive sensor bottom plate 8 is adhered to the bottom metal shielding layer 7 through the insulating adhesive layer 9 while electrical insulation between the capacitive sensor bottom plate 8 and the bottom metal shielding layer 7 is achieved. The metal shielding layers 4 and 7 can prevent the influence of an external electric field or a magnetic field on the electrode plates 5 and 8 of the capacitive sensor, thereby ensuring measurement accuracy. In addition, by electrically insulating the capacitive sensor plates 5 and 8 from the metal shield layers 4 and 7, short-circuiting between the two can be prevented, and the measurement accuracy can be prevented from being affected by loss of electric charge.

Further, the first wire 6a may be connected to the capacitive sensor top plate 5 via a via in the top metal shield layer 4, and the second wire 6b may be connected to the capacitive sensor bottom plate 8 via a via in the bottom metal shield layer 7, whereby the capacitive sensor can be charged to detect a change in capacitance of the capacitive sensor. For convenience of description, the first wire 6a and the second wire 6b may be collectively referred to as a wire 6. In an embodiment, the top metal shielding layer 4, the top capacitive sensor plate 5, the bottom metal shielding layer 7 and the bottom capacitive sensor plate 8 may be made of a non-magnetic metal material with a small coefficient of thermal expansion and contraction, examples of which include titanium or titanium alloy, boron-manganese alloy, and the like, so as to reduce the influence of the size change thereof on the measurement accuracy. It should be understood that the metallic materials in this application also include alloy materials, and that the alloy materials may include other nonmetallic elements in addition to at least one metallic element.

The embodiment shown in fig. 4 is substantially identical to that of fig. 3, except that in fig. 4 the capacitive sensor top and bottom plates 5, 8 are fixed to the top and bottom metal shield layers 4, 7, respectively, using screws 10. In this embodiment, the screw 10 is formed of an insulating material such as ceramic, metal oxide, polymer, or the like. Insulating spacers 11 are provided between the capacitive sensor top and bottom plates 5, 8 and the top and bottom metallic shield layers 4, 7 to prevent electrical connection therebetween. Other aspects of the embodiment shown in fig. 4 are the same as those of fig. 3, and a repetitive description thereof is omitted here.

Fig. 5 and 6 show schematic diagrams of a displacement measuring device according to an embodiment of the present utility model, respectively, wherein the displacement measuring device mainly comprises the sample-carrying flexible portion described above with reference to fig. 1 and 2 and the capacitive sensor ranging portion described above with reference to fig. 3 and 4.

Referring first to fig. 5, the displacement measuring device includes a base bottom plate 15, a fixing bracket 3 is provided on the base bottom plate 15, and a base top plate 13 may be supported at the top end of the fixing bracket 3. It will be appreciated that the base bottom plate 15, the fixing bracket 3 and the base top plate 13 may be formed of the same material, and they may be formed as separate parts and then connected to each other in the structure shown in fig. 5, or they may be formed as a unitary structure.

The capacitive sensor floor 8 and the bottom metal shield 7 arranged around the capacitive sensor floor 8 can be supported on a base floor 15. Although fig. 5 shows it embedded on the base bottom plate 15, it may be entirely located on the upper surface of the base bottom plate 15. In an embodiment, when the capacitive sensor chassis base 8 is embedded in the base chassis base 15, the base chassis base 15 formed of a metal material may be used as a metal shielding layer, and the bottom metal shielding layer 7 may be omitted. In this case, the base bottom plate 15 may surround at least a portion of the periphery of the capacitive sensor bottom plate 8 and the bottom surface, while completely exposing the top surface of the capacitive sensor bottom plate 8 opposite to the capacitive sensor top plate 5. It will be appreciated that the base plate 15 and the capacitive sensor plate 8 may be spaced apart by an insulating material to provide electrical isolation therebetween.

As described earlier with reference to fig. 1 and 2, the elastic beam 2 may be supported at both ends thereof by the fixing brackets 3, and the stage 1 may be provided on the elastic beam 2. The lower end of the stage 1 may be connected to a structure formed by a capacitive sensor top plate 5 and a top metal shielding layer 4 of the capacitive sensor such that the capacitive sensor top plate 5 faces the capacitive sensor bottom plate 8 and is spaced apart from the capacitive sensor top plate by a distance. In one embodiment, the top metal shield 4 may be bonded, welded, or screwed to the lower end of the stage 1.

With continued reference to fig. 5, a through-hole may be provided in the base top plate 13, and the top post 12 may be disposed in the through-hole and may sealingly engage with the through-hole. The top column 12 may be moved up and down in the through hole under the control of a displacement driving member (not shown), such as a stepping motor, or its position may be fixed. The sample 14 may be placed on the stage 1 and the top column 12 may be pressed against the sample 14.

The displacement measuring device shown in fig. 6 is substantially similar to that of fig. 5, except that in fig. 6 the fixed bracket 3 is provided on only one side of the elastic cross member 2. One end (proximal end) of the elastic beam 2 is connected to the fixed bracket 3, the other end (distal end) is suspended, and the stage 1 is disposed at the suspended end of the elastic beam 2. Other aspects of the displacement measuring device shown in fig. 6 may be the same as fig. 5, and a repetitive description thereof will be omitted here.

The operation principle of the displacement measuring device of the present utility model is described below. The sample 14 may be placed on the stage 1 and the top post 12 may be pressed against the sample 14, with the capacitive sensor top plate 5 attached to the stage 1 in the first position.

In one embodiment, the position of the top post 12 may remain unchanged. When the environment such as temperature, magnetic field, etc. changes, the size of the sample 14 may change, resulting in a change in the position of the stage 1 and the capacitive sensor top plate 5 attached to the stage 1. In another embodiment, the movement of the top post 12 may also be controlled to vary its position to cause displacement of the sample 14, the stage 1, and the capacitive sensor top plate 5 attached to the stage 1. Here, the changed position of the capacitive sensor top plate 5 is referred to as a second position.

By measuring the capacitance change of the capacitive sensor formed by the capacitive sensor top plate 5 and the capacitive sensor bottom plate 8, the size (in this embodiment, the dimension in the vertical direction) change or displacement of the sample 14 described above can be determined. In particular, the capacitance is inversely proportional to the distance between the capacitor plates, so that by measuring the capacitance value the distance of the capacitive sensor top plate 5 relative to the capacitive sensor bottom plate 8 can be determined, whereas the position of the capacitive sensor bottom plate 8 is unchanged, and thus the position of the sample 14 can be determined. Alternatively, the displacement of the capacitive sensor top plate 5 in the vertical direction, that is, the displacement or the change in the size of the sample 14, may be determined by measuring the change in the capacitance value.

In an embodiment, the displacement measuring device may further comprise a measuring unit, which may be connected to the capacitive sensor bottom plate 8 and the capacitive sensor top plate 5 by a wire 6, for measuring a capacitance change between the capacitive sensor bottom plate 8 and the capacitive sensor top plate 5 and converting the capacitance change into a displacement value. The measurement unit may also provide the resulting displacement value to an output device, such as a display.

The principles and advantages of any of the embodiments described above may be used with any system or facility that may benefit from any of the embodiments described herein, such as any device for measuring displacement or dimensional changes of an article with high accuracy and methods of using the device to make high-accuracy measurements of displacement or dimensional changes of an article. The teachings herein are applicable to a variety of systems. Although the present disclosure includes some example embodiments, the teachings described herein may be applied to other systems, devices, or methods without departing from the principles of the present disclosure.

Throughout the specification and claims, the words "comprise," "include," "including," and the like are to be construed in an inclusive sense, rather than an exclusive or exhaustive sense, unless the context clearly requires otherwise. That is, meaning "including but not limited to". The term "coupled" as generally used herein refers to two or more elements that may be connected directly or through one or more intervening elements. As generally used herein, the term "connected" refers to two or more elements that may be connected directly or through one or more intervening elements. Furthermore, as used in this application, the words "herein," "above," "below," and words of similar import shall refer to this application as a whole and not to any particular portions of this application. The term "or" refers to a list of two or more items, where the context permits, and encompasses all of the following interpretations of the term: any item in the list, all items in the list, and any combination of items in the list.

Furthermore, unless specifically stated otherwise or otherwise understood in the context of use, conditional language such as "capable," "may," "might," "could," "for example," "such as," etc., as used herein are generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that one or more embodiments require features, elements and/or states in any way or that one or more embodiments must include logic for making a decision with or without author input or prompting that such features, elements and/or states are included in or are to be performed in any particular embodiment.

While certain embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the present disclosure. Indeed, the novel apparatus, methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. For example, while blocks are presented in a given arrangement, alternative embodiments may perform similar functions to different components and/or circuit topologies, and some blocks may be deleted, moved, added, subdivided, combined, and/or modified. Each of these blocks may be implemented in a variety of different ways. Any suitable combination of the elements and acts of the various embodiments described above can be combined to provide further embodiments. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.

Claims (10)

1. A displacement measuring device characterized by comprising:

the device comprises a base bottom plate, a fixed bracket arranged on the base bottom plate and a base top plate supported on the fixed bracket;

an elastic cross beam connected to the fixed bracket and positioned between the base bottom plate and the base top plate, wherein a stage for carrying a sample is arranged on the elastic cross beam, and the sample is positioned between the base top plate and the stage; and

a capacitive sensor top plate connected to a lower end of the stage and a capacitive sensor bottom plate disposed on the base bottom plate, the capacitive sensor top plate and the capacitive sensor bottom plate being opposite each other and spaced apart a distance to form a capacitive sensor.

2. The displacement measurement device according to claim 1, further comprising:

and the measuring unit is connected to the capacitance sensor bottom plate and the capacitance sensor top plate of the capacitance sensor through wires and is used for measuring the capacitance change of the capacitance sensor and converting the capacitance change into a displacement value.

3. The displacement measuring device according to claim 1, wherein a through hole is provided in the base top plate, and a post is provided in the through hole, the post being provided in the through hole so as to be movable up and down to contact a top surface of the sample.

4. A displacement measuring device according to claim 3, wherein the position of the top post in the through hole is controlled by a displacement driving element.

5. The displacement measurement device of claim 1, wherein the elastic beam comprises two or more layers of laterally extending spring structures disposed one above the other, the stage extending through and connected to the spring structures in a vertical direction.

6. The displacement measuring device of claim 5, wherein the fixed bracket supports one end, opposite ends, or the periphery of the spring structure.

7. The displacement measurement device according to claim 1, further comprising:

a top metal shield surrounding and electrically insulated from a top surface and a periphery of the capacitive sensor top plate, the top metal shield exposing a bottom surface of the capacitive sensor top plate opposite the capacitive sensor bottom plate; and

a bottom metal shield surrounding and electrically insulated from the bottom surface of the capacitive sensor backplane, the bottom metal shield exposing a top surface of the capacitive sensor backplane opposite the capacitive sensor top plate.

8. The displacement measuring device according to claim 7, wherein the top metal shield is adhered to the capacitive sensor top plate by an insulating paste or is connected to the capacitive sensor top plate by an insulating screw, and an insulating pad is provided between the top metal shield and the capacitive sensor top plate to electrically insulate therebetween,

the bottom metal shielding layer is adhered to the capacitive sensor bottom plate through insulating glue or connected to the capacitive sensor bottom plate through insulating screws, and an insulating pad is arranged between the bottom metal shielding layer and the capacitive sensor bottom plate so as to realize electric insulation between the bottom metal shielding layer and the capacitive sensor bottom plate.

9. The displacement measurement device of claim 1, wherein the capacitive sensor floor is embedded in and electrically insulated from the base floor, the base floor surrounding at least a portion of the periphery of the capacitive sensor floor and a bottom surface.

10. The displacement measurement device of claim 1, wherein one or more of the base bottom plate, the fixed bracket, and the base top plate are formed of titanium or a titanium alloy material, and the elastic cross member is formed of a beryllium copper alloy material.

Images