A displacement sensor

Abstract

The application discloses a displacement sensor, which comprises a shell, a carrier sheet, a probe and a cover plate. The carrier sheet comprises an elastic supporting sheet in a ring shape and strain amplification sheets, the strain amplification sheets are symmetrically arranged on two sides of the elastic supporting sheet, and strain gauges are fixed on the sides, away from the elastic supporting sheet, of the strain amplification sheets. The probe is arranged in a through hole of the shell, one end of the probe is used for contacting a lower end of the elastic supporting sheet, the other end of the probe extends to the outside of the shell in an axial direction and is used for contacting a workpiece, the cover plate is fixed on two ends of the shell respectively, an inner wall of the cover plate is fixed with a circuit board, and the circuit board is electrically connected with the strain gauges. The elastic supporting sheet is deformed under the action of the probe, the strain amplification sheets are attached to the elastic supporting sheet, the strain amount can be amplified, the signal-to-noise ratio is improved, the strain gauges on the strain amplification sheets generate signal output to the circuit board, therefore, the carrier sheet can generate larger surface strain under smaller acting force, and the measurement precision of the displacement sensor is improved.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a displacement sensor. Background Technology

[0002] Displacement sensors, also known as linear sensors, are a type of linear device that uses metal induction. The function of a sensor is to convert various measured physical quantities into electrical quantities.

[0003] Chinese Patent Publication No. CN215296146U discloses a resistance strain gauge four-sided displacement sensor for measuring component deformation, including an east displacement sensor, a south displacement sensor, a west displacement sensor, a north displacement sensor, and a horizontal frame auxiliary device. The east displacement sensor includes an elastically sensitive low-carbon steel element, a low-carbon steel connecting piece, an upper clamp, a resistance strain gauge, a lower clamp, and a lower surface resistance strain gauge. However, the signal-to-noise ratio and sensitivity of this sensor need to be improved, and it cannot be applied to high-precision measurement applications.

[0004] Therefore, how to improve the signal-to-noise ratio to enhance the measurement accuracy of displacement sensors is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a displacement sensor that is simple in structure, easy to assemble and disassemble, and has high measurement accuracy.

[0006] To achieve the above objectives, the present invention provides a displacement sensor, comprising:

[0007] The shell is cylindrical and has through holes;

[0008] The carrier plate is fixed to the upper end face of the shell. The carrier plate includes an elastic support plate and a strain amplification plate, both of which are annular. The strain amplification plate is symmetrically arranged on both sides of the elastic support plate, and a strain gauge is fixed on the side of the strain amplification plate away from the elastic support plate.

[0009] The probe is located inside the through hole and can move along the axial direction of the through hole. One end of the probe is used to contact the lower end of the elastic support sheet, and the other end extends axially to the outside of the housing and is used to contact the workpiece.

[0010] Cover plates are fixed at both ends of the housing. A circuit board is fixed on the inner wall of the cover plate and is electrically connected to the strain gauge.

[0011] A displacement sensor has a cover plate comprising an upper cover plate and a lower cover plate. The upper cover plate is fixedly connected to the upper end of a housing so that a carrier plate is located inside the upper cover plate. The lower cover plate has an insertion hole through which a probe passes and is fixedly connected to the lower end of the housing.

[0012] A displacement sensor includes an elastic support sheet with a contact portion, one end of which extends to the inner edge of the elastic support sheet and is used to contact a probe; a strain amplification sheet with a placement portion, one end of which extends to the inner edge of the strain amplification sheet, one side of which is used to mount the strain amplification sheet and the other side is used to fit the contact portion.

[0013] A displacement sensor in which the outer diameter of an elastic support plate is equal to the outer diameter of a strain gauge.

[0014] A displacement sensor, wherein spherical probes are provided at both ends of the probe.

[0015] A displacement sensor has a guide assembly fixed inside a through hole, through which a probe passes to move axially within the through hole.

[0016] A displacement sensor includes a guiding assembly comprising a first guide member and a second guide member, wherein the first guide member is fixed in the middle of a through hole and the second guide member is fixed in the bottom of the through hole.

[0017] A displacement sensor, wherein both the first guide and the second guide are linear bearings.

[0018] A displacement sensor has a probe with limiting elements, including a first limiting element and a second limiting element. The first limiting element is fixed on the probe located between the first guide element and the second guide element, and the second limiting element is fixed on the probe located outside the housing.

[0019] A displacement sensor, wherein both the first limiting member and the second limiting member are limiting screws.

[0020] Regarding the aforementioned background technology, the displacement sensor provided by the present invention includes a housing, a carrier plate, a probe, and a cover plate. During assembly, it is only necessary to place the probe in the through hole, fix the carrier plate on the upper end face of the housing, and fix the cover plate to the upper and lower ends of the housing, resulting in a simple structure.

[0021] During use, the housing provided by this invention remains stationary relative to the workpiece. As the workpiece moves, the probe undergoes axial displacement, and one end of the probe contacts the lower end of the elastic support sheet. The elastic support sheet deforms under the action of the probe. Since the strain gauge is attached to the elastic support sheet, it can amplify the strain and improve the signal-to-noise ratio. The strain gauge on the strain amplification plate generates a signal output to the circuit board. The strain of the carrier is measured by the strain gauge, and then the axial displacement of the probe is calculated. Since the carrier of this application can generate a large surface strain under a small force, the measurement accuracy of the sensor can be improved. Attached Figure Description

[0022] Figure 1 This is a schematic cross-sectional view of the displacement sensor provided in an embodiment of this application;

[0023] Figure 2 This is a schematic diagram of the main cross-section of the slide provided in an embodiment of this application;

[0024] Figure 3 This is a top view of the elastic support sheet structure provided in the embodiments of this application;

[0025] Figure 4 This is a top view of the strain gauge structure provided in an embodiment of this application.

[0026] in:

[0027] 1-Housing, 2-Carrier, 3-Strain gauge, 4-Probe, 5-Circuit board, 6-Upper cover, 7-Lower cover, 8-Guide assembly, 9-Limiting component

[0028] 11-Through hole, 21-Elastic support plate, 211-Contact part, 22-Strain amplifier, 221-Placement part, 41-Spherical probe. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] See Figures 1-4 This application provides a displacement sensor, including:

[0031] The housing 1 is columnar and has a through hole 11, i.e., the through hole 11 is a through hole; the carrier 2 is fixed on the upper end face of the housing 1, i.e., the carrier 2 is located above the through hole 11. The carrier 2 includes an annular elastic support 21 and a strain amplification plate 22. The strain amplification plate 22 is symmetrically arranged on both sides of the elastic support 21. A strain gauge 3 is fixed on the side of the strain amplification plate 22 away from the elastic support 21; the probe 4 is columnar and is located in the through hole 11 and can move along the axial direction of the through hole 11. One end of the probe 4 is used to contact the lower end of the carrier 2, and the other end extends along the axial direction to the outside of the housing 1 and is used to contact the workpiece; the cover plate is fixed at both ends of the housing 1. A circuit board 5 is fixed on the inner wall of the cover plate. The circuit board 5 is electrically connected to the strain gauge 3.

[0032] Since the displacement sensor provided in this application includes a housing 1, a carrier 2, a probe 4 and a cover plate, during assembly, it is only necessary to place the probe 4 in the through hole, fix the carrier 2 on the upper end face of the housing 1, and fix the cover plate to the upper and lower ends of the housing 1 to make the housing 1 closed. Therefore, the displacement sensor provided in this application has a simple structure and is easy to assemble.

[0033] During use, the housing 1 of this application remains stationary relative to the workpiece. As the workpiece moves, the probe 4 is displaced in the axial direction. Since one end of the probe 4 contacts the lower end of the carrier 2, the carrier 2 deforms under the action of the probe 4. Since a strain gauge 3 is provided on the carrier 2, the deformation of the carrier 2 causes the strain gauge 3 to generate a signal output to the circuit board 5. The strain of the carrier 2 is measured by the strain gauge 3, and the axial displacement of the probe 4 is calculated. Since the carrier 2 of this application can generate a large surface strain under a small force, the measurement accuracy of the displacement sensor is improved.

[0034] The cover plate includes an upper cover plate 6 and a lower cover plate 7. The upper cover plate 6 is fixedly connected to the upper end of the housing 1 so that the carrier plate 2 is located inside the upper cover plate 6, thereby protecting the carrier plate 2 and the strain gauge 3. A circuit board 5 is fixed on the inner wall of the upper cover plate 6. The circuit board 5 is electrically connected to the strain gauge 3. The upper end face of the upper cover plate 6 is provided with a wire hole for the signal line of the circuit board 5 to be discharged. The lower cover plate 7 is provided with an insertion hole. The lower cover plate 7 passes through the probe 4 and is fixedly connected to the lower end of the housing 1. The connection between the upper cover plate 6 and the lower cover plate 7 and the housing 1 is a threaded connection. That is, the outer wall of the housing 1 is provided with external threads, and the inner walls of the upper cover plate 6 and the lower cover plate 7 are provided with internal threads.

[0035] In the embodiments of this application, as shown in the appendix to the specification... Figure 2-4 As shown, the carrier 2 includes an elastic support sheet 21, on both sides of which strain amplification sheets 22 are symmetrically arranged. The elastic support sheet 21 is annular, i.e., the middle part is a through hole, and the elastic support sheet 21 is elastic. The elastic support sheet 21 is provided with a contact portion 211, one end of which extends to the inner edge of the elastic support sheet 21. That is, the elastic support sheet 21 of this application is provided with a contact portion 211 in the radial direction. Since one side of the contact portion 211 is connected to the inner edge of the elastic support sheet 21, the contact portion 211 is a cantilever beam structure. The center of the contact portion 211 is set as the contact point, which is used to contact the probe 4 so that the elastic support sheet 21 deforms.

[0036] The strain amplification plate 22 is annular, with a through hole in the middle. The strain amplification plate 22 is provided with a placement part 221. One end of the placement part 221 extends to the inner edge of the strain amplification plate 22. One side of the placement part 221 is used to install the strain gauge 3. In this embodiment, the strain gauge 3 is bonded to the placement part 221, or the strain gauge 3 can be snapped onto the placement part 221. The other side of the placement part 221 is used to fit the contact part 211. The shape of the strain amplification plate 22 in this application is similar to the shape of the elastic support plate 21, so that the strain amplification plate 22 is completely fitted onto the elastic support plate 21. The length of the placement part 221 is less than the length of the contact part 211, thereby ensuring that when the probe 4 is in contact with the contact part 211, the placement part 221 does not interfere with the movement of the probe 4.

[0037] Both the elastic support plate 21 and the strain amplification plate 22 in this application are provided with mounting holes. The elastic support plate 21 and the strain amplification plate 22 are detachably fixed to the upper end face of the housing 1 by screws or bolts. The mounting holes are arranged circumferentially, and the number of mounting holes can be determined according to the degree of installation and fixation. The outer diameter of the elastic support plate 21 is equal to the outer diameter of the strain amplification plate 22, and the outer diameter of the upper end face of the housing 1 is equal to the outer diameter of the elastic support plate 21, thereby ensuring that the elastic support plate 21 and the strain amplification plate 22 are completely attached to the upper end face of the housing 1.

[0038] In this embodiment, the damping of the probe 4 during movement can be adjusted by regulating the thickness of the elastic support plate 21, thereby adjusting the damping of the displacement sensor and improving its measurement accuracy. However, due to the limitation of the displacement sensor's damping, the thickness of the elastic support plate 21 is restricted. If the probe 4 is displaced, the surface strain of the elastic support plate 21 is relatively small, resulting in a weak output signal and low signal-to-noise ratio from the strain gauge 3, leading to reduced measurement accuracy. By attaching the strain amplification plate 22 to the elastic support plate 21, and considering that the elastic modulus of the strain amplification plate 22 is greater than that of the strain gauge 3 but much smaller than that of the elastic support plate 21, it does not significantly affect the sensor's damping while amplifying the strain and improving the signal-to-noise ratio. Therefore, under the premise that the elastic modulus is between that of the elastic support plate and the strain gauge, adjusting the elastic modulus and thickness of the strain amplification plate 22 can adjust the output sensitivity of the displacement sensor, thereby improving its sensitivity.

[0039] In this embodiment, a spherical probe 41 is provided at both ends of the probe 4. The spherical probe 41 is made of a material with high hardness, such as diamond, so as to avoid errors caused by elastic deformation or wear of the spherical probe 41, thereby improving the working stability of the displacement sensor.

[0040] In this embodiment, a guide assembly 8 is fixedly installed inside the through hole 11. The probe 4 passes through the guide assembly 8 so that the probe 4 moves axially within the through hole 11, ensuring that the probe 4 moves along the central axis within the through hole 11 and always maintains contact between the probe 4 and the contact point of the contact portion 211. The guide assembly includes a first guide member and a second guide member, both of which are linear bearings. The linear bearings used in this embodiment are directly applied from existing technology; therefore, the specific structure of the linear bearing is not disclosed in this application. This application only describes the working principle of the linear bearing. Since the bearing ball in the linear bearing makes point contact with the bearing outer sleeve, the steel ball rolls with minimal frictional resistance. Therefore, the linear bearing has low friction and is relatively stable, not changing with the bearing speed, and can obtain stable linear motion with high sensitivity and high precision.

[0041] The first guide member is fixed in the middle of the through hole 11, and the second guide member is fixed in the bottom of the through hole 11. The first guide member and the second guide member can be fixed in the through hole 11 by interference fit, or the side wall of the housing 1 is provided with a locking hole, and the first guide member and the second guide member can be fixed in the through hole 11 by locking screw.

[0042] In this embodiment, a limiting member 9 is provided on the probe 4. The limiting member 9 includes a first limiting member and a second limiting member. Both the first limiting member and the second limiting member are limiting screws or pins. The lengths of the first limiting member and the second limiting member are both greater than the diameter of the probe 4 and less than the inner diameter of the through hole 11, so as to play a limiting role and not interfere with the axial movement of the probe 4. The first limiting member is fixed on the probe 4 located between the first guide member and the second guide member. The setting of the first limiting member ensures that the probe 4 is always located inside the guide member 8. When the probe 4 has axial displacement, it ensures that the probe 4 is in contact with the contact point of the contact part 211. The second limiting member is fixed on the probe 4 located outside the housing 1 to prevent the axial displacement of the probe 4 from being too large and causing damage to the components of the position sensor.

[0043] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from another, and do not necessarily require or imply any such actual relationship or order between these entities.

[0044] The displacement sensor provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A displacement sensor, characterized in that, include: The shell (1) is columnar and has a through hole (11). The carrier plate (2) is fixed on the upper end face of the housing (1). The carrier plate (2) includes an annular elastic support plate (21) and a strain amplification plate (22). The strain amplification plate (22) is symmetrically arranged on both sides of the elastic support plate (21). A strain plate (3) is fixed on the side of the strain amplification plate (22) away from the elastic support plate (21). The probe (4) is located in the through hole (11) and can move along the axial direction of the through hole (11). One end of the probe (4) is used to contact the lower end of the elastic support piece (21), and the other end extends along the axial direction to the outside of the housing (1) and is used to contact the workpiece. Cover plates are respectively fixed at both ends of the housing (1), and circuit boards (5) are fixed on the inner wall of the cover plates. The circuit boards (5) are electrically connected to the strain gauges (3). The elastic support sheet (21) is provided with a contact portion (211), one end of which extends to the inner edge of the elastic support sheet (21), and the center of the contact portion (211) is used to contact the probe (4); the strain amplification sheet (22) is provided with a placement portion (221), one end of which extends to the inner edge of the strain amplification sheet (22), one side of the placement portion (221) is used to install the strain gauge (3), and the other side is used to fit the contact portion (211).

2. The displacement sensor according to claim 1, characterized in that: The cover plate includes an upper cover plate (6) and a lower cover plate (7). The upper cover plate (6) is fixedly connected to the upper end of the housing (1) so that the carrier plate (2) is located inside the upper cover plate (6). The lower cover plate (7) is provided with an insertion hole. The lower cover plate (7) passes through the probe (4) and is fixedly connected to the lower end of the housing (1).

3. The displacement sensor according to claim 1, characterized in that: The outer diameter of the elastic support plate (21) is equal to the outer diameter of the strain amplification plate (22).

4. The displacement sensor according to claim 1, characterized in that: The probe (4) has a spherical probe (41) at each end.

5. The displacement sensor according to claim 1, characterized in that: A guide assembly (8) is fixed inside the through hole (11), and the probe (4) passes through the guide assembly (8) so that the probe (4) moves along the axial direction inside the through hole (11).

6. The displacement sensor according to claim 5, characterized in that: The guide assembly (8) includes a first guide and a second guide, the first guide being fixed in the middle of the through hole (11) and the second guide being fixed in the bottom of the through hole (11).

7. The displacement sensor according to claim 6, characterized in that: Both the first guide member and the second guide member are linear bearings.

8. The displacement sensor according to claim 6 or 7, characterized in that, The probe (4) is provided with a limiting member (9), which includes a first limiting member and a second limiting member. The first limiting member is fixed on the probe (4) located between the first guide member and the second guide member, and the second limiting member is fixed on the probe (4) located outside the housing (1).

9. The displacement sensor according to claim 8, characterized in that, Both the first limiting member and the second limiting member are limiting screws.

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