Metal gate strip and displacement sensor

Abstract

The utility model discloses a metal grid belt and a displacement sensor, which comprise a metal belt body, the metal belt body is in a long strip-shaped sheet structure, grids are arranged in the length direction of the metal belt body in an array mode, the thickness of the metal belt body does not exceed 1mm, and the metal belt body can be curled and folded. The beneficial effects of the utility model are that the structure is simple, only one metal belt body is provided, the metal belt body is used as a grating ruler for displacement measurement, and the metal belt body can be directly formed on a single blank by adopting high-precision stamping, CNC or laser engraving technology, so that the displacement sensor can realize high-precision measurement. And the product is thin, and the metal has certain flexibility, so that the product can be curled and packaged and is convenient to transport. When in use, the film is directly unfolded and pasted and fixed on the base layer, thereby facilitating production and assembly.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a metal grid strip. Background Art

[0002] A displacement sensor is a component used to measure and record the distance moved by moving parts. Its working principle is mainly based on converting mechanical displacement into electrical signals or other forms of information output to meet the requirements of information transmission, processing, storage, display, recording and control.

[0003] Based on different measurement principles, current displacement sensors primarily include resistive, inductive, capacitive, photoelectric, and ultrasonic displacement sensors. With the continuous advancement of industrial automation, different fields are placing increasingly stringent demands on the accuracy and precision of displacement sensor measurements. However, sensors based on existing measurement principles have almost all reached their development limits, making significant technological breakthroughs difficult to achieve.

[0004] To this end, a new displacement sensor based on the principle of mutual electromotive force variation among multiple coils is proposed. The physical principle of this sensor is as follows: a primary coil and a secondary coil are placed within the sensing head. When an oscillating current is passed through them, a mutual electromotive force is generated between the primary and secondary coils. When a metallic target element approaches, the electromagnetic fields of the two coils are disturbed, causing a change in the mutual electromotive force. This change is primarily related to the gap between the target element and the coils, as well as the projected area of ​​the target element. Based on this principle, if the secondary coil is printed as a functional coil, and the target element is a long scale with a grid array on the scale, when the primary and secondary coils move linearly relative to the scale, the grid effectively reduces the metal thickness at that location. Therefore, the mutual electromotive force between the coils will vary when the sensing head passes through grid- and non-grid-positions. Therefore, as the sensing head moves along the length of the scale, the mutual electromotive force between the coils varies according to the grid arrangement. Displacement measurement can be obtained by converting the change in mutual electromotive force into displacement.

[0005] The above research and development concept involves a long strip scale. In the traditional scale process, the grid is usually formed by directly printing tin foil on the PCB. Although PCB has the advantages of mature manufacturing and low cost, the existing PCB photosensitive film manufacturing process has a large absolute tolerance, generally plus or minus 0.2mm, which makes it difficult to achieve high-precision manufacturing. The base material of the PCB is usually FR4, which has a large thermal deformation coefficient, which in turn causes thermal deformation of the copper foil layer. The rigidity of the PCB is insufficient. For example, it will warp if it exceeds 0.5 meters. The impact resistance of the PCB itself is insufficient. For example, it is easily damaged by metal collisions. The PCB has insufficient corrosion resistance and cannot be directly used in humid, submerged, various oil products, chemical media and other environments. The existence of these deficiencies will hinder the development of displacement sensors that measure displacement based on the change of mutual inductance electromotive force of multiple coils in terms of high-precision and large-scale displacement measurement. Utility Model Content

[0006] In view of this, the utility model provides a metal grid strip, which is applied in a sensor for displacement measurement based on the change of mutual electromotive force of multiple coils, and can achieve high-precision and large displacement measurement.

[0007] To achieve the above purpose, the technical solution of this utility model is as follows:

[0008] A metal grid strip, the key features of which are: comprising a metal strip body, the metal strip body being in a long strip-shaped sheet structure, with grids arranged in an array along its length, the grids being through holes or downwardly concave groove structures.

[0009] Preferably, the metal strip is no thicker than 1 mm and can be rolled and folded. This design allows for an ultra-thin, flexible product that can be rolled and packaged for easy transportation. When used, it can be directly unfolded, glued, and fixed to the base layer, facilitating production and assembly.

[0010] Preferably, the metal strip is a rigid metal sheet, and the grid is a through hole or a strip-shaped groove.

[0011] Preferably, the thickness of the metal strip is 0.05-0.5 mm.

[0012] Preferably, there is a metal segment between two adjacent grids, and the length ratio between the grids and the metal segment is 3:1 or 1:3.

[0013] Preferably, the sum of the lengths of a single grid and its adjacent metal segments is a grid pitch period, and the grid pitch period is 5.12 mm or an integer multiple of 5.12 mm.

[0014] Preferably, a flexible coating is provided on one or both surfaces of the metal strip, with a thickness of no more than 0.5 mm. This design protects and shapes the metal strip, and particularly when the metal strip is ultra-thin and flexible, prevents grid deformation during attachment or bending, thereby ensuring displacement measurement accuracy.

[0015] Preferably, an insulating layer is provided on the surface of the metal strip, and the thickness of the insulating layer is not less than 1 mm.

[0016] Preferably, the insulating layer is connected to the surface of the metal strip by a gluing or pressing process.

[0017] Preferably, the insulating layer is pressed together with the metal strip using a pressing edge structure.

[0018] Preferably, the surface of the insulating layer is connected to a base layer.

[0019] The utility model also provides a displacement sensor, the key of which is that it comprises a sensing head and the metal grid strip.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. The metal grid strip provided by the present invention has a simple structure and only has one metal strip body. It is used as a scale for displacement measurement and can be directly formed on a single blank using high-precision stamping, CNC, or laser engraving technology, thereby ensuring that the displacement sensor can achieve high-precision measurement.

[0022] 2. The metal scale strip can be manufactured as a continuous strip to achieve continuous accuracy of long-length scales and meet the needs of large displacement measurement.

[0023] 3. It can be made into ultra-thin flexible products, which can be rolled up for easy transportation. When in use, it can be directly unfolded and fixed on the base layer, which can facilitate production and assembly.

[0024] 4. The flexible layer on the surface of the metal strip can protect and shape the metal strip, especially when the metal strip is an ultra-thin flexible product. It can prevent the grid from deforming during the pasting or bending of the metal strip, thereby ensuring the accuracy of displacement measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural diagram of a sensor that measures displacement based on the variation law of the mutual electromotive force of multiple coils.

[0026] Figure 2 Schematic diagram of the planar structure of the metal grid.

[0027] Figure 3 Schematic diagram of the layered structure of the metal grid. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0029] like Figure 1 As shown, a displacement sensor includes a sensing head 5 and a metal grid strip. The metal grid strip is composed of a metal strip 1. After the metal strip 1 and the sensing head 5 are installed in the device to be tested, the sensing head 5 is arranged on one side of the metal strip 1 and can move relative to the length direction of the metal strip 1. Figure 2 As can be seen, the metal strip 1 is arranged with grids 1a arranged in an array along its length. The grids 1a are through-holes. Metal segments 1b are located between adjacent grids 1a. The induction head 5 contains two induction coils: a primary coil 6 and a secondary coil 7. The secondary coil 7 is a sinusoidal coil located within the primary coil 6. When an oscillating current is passed through the primary coil 6, a mutual electromotive force is generated between the primary coil 6 and the secondary coil 7.

[0030] Based on the above structure, after an oscillating current is passed through the primary coil 6 and the metal strip 1 is aligned with the primary and secondary coils, a mutual induced electromotive force (EMF) is generated only at the position of grid 1. The remaining mutual induced electromotive force is shielded by the metal segment 1b. Furthermore, because the secondary coil 7 is a sinusoidal coil, the mutual induced electromotive force between the primary and secondary coils also varies sinusoidally as the sensing head 5 moves relative to grid 1a. In other words, the mutual induced electromotive force varies with the displacement of grid 1a. Therefore, as the sensing head 5 moves along the length of the metal strip 1, the displacement of the sensing head 5 can be calculated by converting the variation in the mutual induced electromotive force into displacement, thereby enabling displacement measurement of the target product.

[0031] In this embodiment, the metal strip 1 is a long, thin sheet with a thickness not exceeding 1 mm, preferably ranging from 0.05 to 0.5 mm. The ultra-thin metal strip 1 can be rolled and folded for convenient transportation. When in use, it can be directly unfolded and affixed to the substrate of the device under test, facilitating production and assembly. Furthermore, since only a single metal strip is required, it can be directly formed from a single blank using high-precision stamping, CNC, or laser engraving techniques, ensuring high-precision measurement for the displacement sensor.

[0032] In addition to the thin products mentioned above, the metal strip 1 can also be a rigid metal sheet with a thickness exceeding 1 mm. In this case, the grid 1a can be a through hole, a blind hole strip groove, or directly constructed from the teeth of a metal rack. The strip groove can be formed directly by digging a hole in the metal sheet, or it can be surrounded by raised structures on both sides of the groove.

[0033] Re-attend Figure 2As shown, the length ratio between grid 1a and metal segment 1b is 3:1 or 1:3, which corresponds exactly to 90 degrees (1 / 4) of a 360-degree sine function. When the sensing head 5 moves relative to the metal strip 1, the inductance of the secondary coil changes sinusoidally within a single grid pitch period, facilitating data acquisition. The sum of the lengths of one metal segment 1b and one grid 1a constitutes one grid pitch period. The grid pitch for each period can be set to 5.12 mm or an integer multiple of 5.12 mm, which facilitates 12-bit ADC data acquisition.

[0034] For example Figure 3 As shown, a flexible coating 2 is provided on one or both sides of the metal strip 1. The thickness of the flexible coating 2 does not exceed 0.5 mm, preferably 0.2 mm. The flexible coating 2 protects and shapes the metal strip 1, preventing deformation of the grid 1a during bonding or bending of the metal strip 1, thereby ensuring displacement measurement accuracy.

[0035] An insulating layer 3 may also be provided on the surface of the metal strip 1. The preferred insulating layer is rubber, but it may also be made of fiberglass board, plastic, glass, ceramic, etc. The purpose of providing the insulating layer 3 is to separate the metal strip 1 from the metal at the installation location to avoid interference. The insulating layer 3 may be directly connected to the surface of the metal strip 1, or as Figure 3 As shown, the insulating layer 3 is attached to the surface of the metal strip 1 via a flexible adhesive layer 2. In this embodiment, the insulating layer 3 is 2 mm thick. The insulating layer 3 can be attached by gluing, pressing, or using a crimping mechanism to press it tightly against the metal strip 1. Alternatively, a base layer 4 can be attached to the surface of the insulating layer 3 to facilitate direct installation in the device.

[0036] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make various similar expressions without violating the purpose and claims of the present invention. Such changes fall within the scope of protection of the present invention.

Claims

1. A metal grid strip, characterized in that: The metal strip (1) comprises a metal strip (1) in a long sheet-like structure, with grids (1a) arranged in an array along its length, wherein the grids (1a) are through holes or downwardly concave groove structures.

2. The metal grid strip according to claim 1, wherein: The thickness of the metal strip (1) does not exceed 1 mm, and the metal strip (1) can be curled and folded.

3. The metal grid strip according to claim 1, wherein: The metal strip (1) is a rigid metal sheet, and the grid (1a) is a through hole or a strip-shaped groove.

4. The metal grid strip according to claim 1, wherein: A metal segment (1b) is provided between two adjacent grids (1a), and the length ratio between the grid (1a) and the metal segment (1b) is 3:1 or 1:

3.

5. The metal grid strip according to claim 1, 2, 3 or 4, characterized in that: The sum of the lengths of a single grid (1a) and its adjacent metal segments (1b) is a grid pitch period, and the grid pitch period is 5.12 mm or an integral multiple of 5.12 mm.

6. The metal grid strip according to claim 2, characterized in that: A flexible coating (2) is provided on one or both surfaces of the metal strip (1).

7. The metal grid strip according to claim 6, characterized in that: The thickness of the flexible layer (2) does not exceed 0.5 mm.

8. The metal grid strip according to claim 2, characterized in that: An insulating layer (3) is provided on the surface of the metal strip (1).

9. The metal grid strip according to claim 8, characterized in that: The thickness of the insulating layer (3) is not less than 1 mm.

10. The metal grid strip according to claim 8 or 9, characterized in that: The insulating layer (3) is connected to the surface of the metal strip (1) by a gluing or pressing process.

11. The metal grid strip according to claim 8 or 9, characterized in that: The insulating layer (3) is pressed tightly together with the metal strip (1) using a pressing edge structure.

12. A displacement sensor, characterized in that: The invention comprises an induction head and the metal grid strip according to any one of claims 1 to 11.

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