Strain gauge for large impact sensor and application thereof

Abstract

The invention relates to the technical field of strain gauges for large impact sensors, in particular to a strain gauge for a large impact sensor and application of the strain gauge, the strain gauge comprises a substrate, a sensitive grid and a bonding pad, the sensitive grid and the bonding pad cover the substrate, the bonding pad is connected with the sensitive grid, and adjacent side end faces of the bonding pad are in transition through a fillet; according to the strain gauge for the large-impact sensor, the vertex angle position of the bonding pad is subjected to rounding processing, so that stress concentration of the strain gauge for the large-impact sensor when the strain gauge is subjected to large impact can be reduced, stress dispersion is realized, the damage probability of the strain gauge for the large-impact sensor is reduced, and the use reliability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of strain gauges for large impact sensors, and specifically relates to a strain gauge for large impact sensors and its application. Background Art

[0002] Automobiles, high-speed rails and airplanes have currently become the three most commonly used means of transportation for people to travel, and their safety is directly related to the lives of every passenger; once a safety accident occurs, it may cause a large number of casualties and has a wide range of impacts.

[0003] To ensure operational safety, various safety tests will be carried out before the formal operation of automobiles and high-speed rails to verify their reliability, and the collision test is one of the necessary test items. During the collision test, since the impact force is an instantaneous signal with a short duration and a high frequency, it is difficult to measure. Conventional test systems cannot meet the requirements, and an impact-resistant test system with anti-impact and high dynamic response speed is required to meet the test requirements. The impact-resistant test system requires an impact-resistant force sensor as a support.

[0004] Since sensors based on the resistance strain principle have high precision and mature technology, they have gradually become the preferred solution in the industry. The impact-resistant force sensor is developed based on this principle. Since the impact-resistant force sensor needs to collect signals instantaneously, has a short duration, and a large impact force, conventional resistance strain gauges cannot meet the requirements of large impact tests and are prone to failures of the strain gauge, such as the wire and solder joint falling off, the cover layer and the sensitive grid peeling off, and the sensitive grid and the substrate being easily peeled off, etc. Eventually, the force sensor cannot collect relevant data during the collision, resulting in the failure of the collision test, so it cannot meet the actual use requirements. Summary of the Invention

[0005] The purpose of the present invention is to provide a strain gauge for large impact sensors and its application, and solve the technical problem of low reliability of the current strain gauge for large impact sensors.

[0006] The solution of the present invention to the above technical problem is as follows: A strain gauge for large impact sensors, including a substrate, a sensitive grid and a pad. The sensitive grid and the pad are both covered on the substrate. The pad is connected to the sensitive grid, and the adjacent side end faces of the pad are transitioned by a rounded corner.

[0007] Further defined, the radius of the rounded corner is 0.3 mm to 0.5 mm.

[0008] Further defined, a cover layer film is covered on both the sensitive grid and the pad. A wiring hole is opened on the pad, and the cover layer film is located on the periphery of the wiring hole.

[0009] Further defined, the number of the pads is two, both of the two pads are connected to the sensitive grid, and the two pads are located on the same side or opposite sides of the sensitive grid.

[0010] Further defined, the sensitive grid includes a biaxial first sensitive grid and a biaxial second sensitive grid, and the pads include a biaxial first pad, a biaxial second pad and a biaxial third pad; The biaxial first sensitive grid is located on one side of the biaxial second sensitive grid, and the included angle between the biaxial first sensitive grid and the biaxial second sensitive grid is 90°. The biaxial third pad is located between the biaxial first sensitive grid and the biaxial second sensitive grid, and the biaxial third pad is respectively connected to one end of the biaxial first sensitive grid and one end of the biaxial second sensitive grid. The biaxial first pad is connected to the other end of the biaxial first sensitive grid, and the biaxial second pad is connected to the other end of the biaxial second sensitive grid.

[0011] Further defined, the sensitive grid includes a biaxial first sensitive grid and a biaxial second sensitive grid, and the pads include a biaxial first pad, a biaxial second pad, a biaxial third pad and a biaxial fourth pad; Both the biaxial first pad and the biaxial second pad are connected to the biaxial first sensitive grid, and both the biaxial third pad and the biaxial fourth pad are connected to the biaxial second sensitive grid.

[0012] Further defined, the biaxial first sensitive grid is located on one side of the biaxial second sensitive grid, and the biaxial first sensitive grid and the biaxial second sensitive grid are arranged in the same direction.

[0013] Further defined, the biaxial first sensitive grid is located on one side of the biaxial second sensitive grid, and the included angle between the biaxial first sensitive grid and the biaxial second sensitive grid is 90°.

[0014] Further defined, the included angles between both the biaxial first sensitive grid and the biaxial second sensitive grid and the horizontal direction are both 45°.

[0015] An application of the strain gauge for a large-impact sensor according to the above in a large-impact sensor.

[0016] The beneficial effects of the present invention are as follows: 1. By chamfering the top corner positions of the pads, the present invention can slow down the stress concentration of the strain gauge for a large-impact sensor when it is subjected to a large impact, realize stress dispersion, reduce the damage probability of the strain gauge for a large-impact sensor, and improve the use reliability.

[0017] 2. By covering a cover film on the sensitive grid and the pads, the present invention increases the adhesion between the cover film and the sensitive grid and between the pads and the substrate, and further improves the reliability of the strain gauge when it is subjected to a large impact. Description of the Drawings

[0018] Figure 1 Structural diagram of the strain gauge for the large impact sensor described in Embodiment 1 of the present invention; Figure 2 Structural diagram of the strain gauge for the large impact sensor described in Embodiment 2 of the present invention; Figure 3 Structural diagram of the strain gauge for the large impact sensor described in Embodiment 3 of the present invention; Figure 4 Structural diagram of the strain gauge for the large impact sensor described in Embodiment 4 of the present invention; Figure 5 Structural diagram of the strain gauge for the large impact sensor described in Embodiment 5 of the present invention; Figure 6 Structural diagram of the strain gauge for the large impact sensor described in Embodiment 6 of the present invention; In the figure, 10 - substrate; 20 - sensitive grid; 21 - biaxial first sensitive grid; 22 - biaxial second sensitive grid; 30 - pad; 31 - biaxial first pad; 32 - biaxial second pad; 33 - biaxial third pad; 34 - biaxial fourth pad. Detailed implementation manners

[0019] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0021] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0022] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if the terms "set", "installed", "connected", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0023] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "inner", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is usually placed during use, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0024] The present invention provides a strain gauge for a large impact sensor, including a substrate 10, a sensitive grid 20 and a pad 30. The sensitive grid 20 and the pad 30 are both covered on the substrate 10. The pad 30 is connected to the sensitive grid 20. The end faces between the adjacent sides of the pad 30 are transitioned by fillets, that is, fillets are provided at the four corner positions on the periphery of the pad 30, which can slow down the stress concentration when the strain gauge for the large impact sensor is subjected to a large impact, realize stress dispersion, reduce the damage probability of the strain gauge for the large impact sensor, and improve the use reliability.

[0025] Among them, the fillet is not less than R0.3, and can be selected as R0.3~R0.5.

[0026] Preferably, a cover film is covered on both the sensitive grid 20 and the pad 30. The cover film preferably covers the sensitive grid 20 and the pad 30 simultaneously as a whole; it reduces the operation difficulty of covering multiple cover films, reduces splicing, and ensures the covering quality; by covering the cover film, the adhesion between the cover film and the sensitive grid, the pad and the substrate is increased, and the reliability of the strain gauge when subjected to a large impact is further improved.

[0027] Since a wiring hole is provided on the pad 30, after covering the cover film, it is necessary to remove the cover film at the position of the wiring hole so that the cover film is located on the periphery of the wiring hole.

[0028] Embodiment 1 The strain gauge for the large impact sensor provided in this embodiment is a uniaxial strain gauge.

[0029] Correspondingly, the number of pads 30 is two, and the number of sensitive grids 20 is one. Both of the two pads 30 are connected to the sensitive grid 20.

[0030] Reference Figure 1 , wherein, according to the principle of arranging as many strain gauges as possible within a certain area to reduce costs, it is selected to arrange the two pads 30 on the same side of the sensitive grid 20, preferably on the wide side of the sensitive grid 20 along the length direction of the sensitive grid 20.

[0031] Embodiment 2 Based on Embodiment 1, the difference from Embodiment 1 is that the two pads 30 are arranged on opposite sides of the sensitive grid 20. For example, they can be selected to be arranged on opposite sides in the length direction of the substrate 10; this can increase the number of strain gauges within a certain area.

[0032] In order to reduce the size of the pads 30, preferably, the angle between the sensitive grid 20 and the symmetry axis in the length direction of the substrate 10 is 45°.

[0033] Embodiment 3 The strain gauge for a large impact sensor provided in this embodiment is a biaxial strain gauge.

[0034] Correspondingly, the number of sensitive grids 20 is two, and the number of pads 30 is three.

[0035] Reference Figure 3 , specifically, the sensitive grid 20 includes a biaxial first sensitive grid 21 and a biaxial second sensitive grid 22, and the pads 30 include a biaxial first pad 31, a biaxial second pad 32, and a biaxial third pad 33.

[0036] The biaxial first sensitive grid 21 is located on one side of the biaxial second sensitive grid 22, and the angle between the biaxial first sensitive grid 21 and the biaxial second sensitive grid 22 is 90°.

[0037] Preferably, the biaxial first sensitive grid 21 and the biaxial second sensitive grid 22 are symmetrically arranged with respect to the symmetry axis in the length direction of the substrate 10. Therefore, the angles between the biaxial first sensitive grid 21 and the biaxial second sensitive grid 22 and the symmetry axis in the length direction of the substrate 10 are both 45°, which is convenient for collecting shear stresses in 2 directions.

[0038] The biaxial third pad 33 is located between the biaxial first sensitive grid 21 and the biaxial second sensitive grid 22. The biaxial third pad 33 is respectively connected to one end of the biaxial first sensitive grid 21 and one end of the biaxial second sensitive grid 22. The biaxial first pad 31 is connected to the other end of the biaxial first sensitive grid 21, and the biaxial second pad 32 is connected to the other end of the biaxial second sensitive grid 22.

[0039] Embodiment 4 The strain gauge for large impact sensors provided in this embodiment is a biaxial strain gauge. Different from Embodiment 3, the number of sensitive grids 20 provided in this embodiment is two, and the number of pads 30 is four.

[0040] Reference Figure 4 , the sensitive grid 20 includes a biaxial first sensitive grid 21 and a biaxial second sensitive grid 22, and the pad 30 includes a biaxial first pad 31, a biaxial second pad 32, a biaxial third pad 33 and a biaxial fourth pad 34.

[0041] Both the biaxial first pad 31 and the biaxial second pad 32 are connected to the biaxial first sensitive grid 21, and both the biaxial third pad 33 and the biaxial fourth pad 34 are connected to the biaxial second sensitive grid 22.

[0042] Among them, the biaxial first sensitive grid 21 is located on one side of the biaxial second sensitive grid 22, and the biaxial first sensitive grid 21 and the biaxial second sensitive grid 22 are arranged in the same direction. Preferably, the biaxial first sensitive grid 21 and the biaxial second sensitive grid 22 are symmetrically arranged about the axis of symmetry in the width direction of the substrate 10.

[0043] At this time, preferably, the biaxial first pad 31 and the biaxial second pad 32 are located on the same side, the biaxial third pad 33 and the biaxial fourth pad 34 are located on the same side, and the biaxial second pad 32 and the biaxial third pad 33 are located on the same side.

[0044] Embodiment 5 Based on Embodiment 4, the difference between this embodiment and Embodiment 4 is that the included angle between the biaxial first sensitive grid 21 and the biaxial second sensitive grid 22 is 90°.

[0045] Reference Figure 5 , preferably, the biaxial first sensitive grid 21 is arranged along the transverse direction, and the biaxial second sensitive grid 22 is arranged along the longitudinal direction, mainly for collecting stresses in 2 directions.

[0046] At this time, the biaxial first pad 31, the biaxial second pad 32, the biaxial third pad 33 and the biaxial fourth pad 34 are all located on the same side.

[0047] Embodiment 6 Reference Figure 6 , based on Embodiment 5, the difference between this embodiment and Embodiment 4 is that the biaxial first sensitive grid 21 and the biaxial second sensitive grid 22 are symmetrically arranged about the axis of symmetry in the length direction of the substrate 10. Therefore, the included angles between the biaxial first sensitive grid 21 and the biaxial second sensitive grid 22 and the axis of symmetry in the length direction of the substrate 10 are both 45°.

[0048] At this time, the biaxial first sensitive grid 21 is located between the biaxial first pad 31 and the biaxial second pad 32, and the biaxial second sensitive grid 22 is located between the biaxial third pad 33 and the biaxial fourth pad 34, for collecting shear stresses in 2 directions.

[0049] The effects achieved by the present invention: The strain gauge for large impact sensors described in any one of Embodiments 1 to 6 of the present invention has the advantages of high measurement accuracy, impact resistance, and high reliability, and can be applied to large impact sensors.

[0050] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the present invention; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

[0051] Although the inventions of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, replacements, and variations can be made to these inventions without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A strain gauge for a large impact sensor, characterized in that, It includes a substrate (10), a sensitive grid (20) and pads (30). The sensitive grid (20) and the pads (30) are both covered on the substrate (10). The pads (30) are connected to the sensitive grid (20), and the adjacent side end faces of the pads (30) are transitioned by rounded corners.

2. The strain gauge for a large impact sensor according to claim 1, wherein, The radius of the rounded corner is 0.3 mm to 0.5 mm.

3. The strain gauge for a large impact sensor according to claim 2, wherein, Both the sensitive grid (20) and the pads (30) are covered with a cover film. Wiring holes are provided on the pads (30), and the cover film is located on the periphery of the wiring holes.

4. The strain gauge for a large impact sensor according to claim 3, characterized in that, The number of the pads (30) is two. Both of the two pads (30) are connected to the sensitive grid (20), and the two pads (30) are located on the same side of the sensitive grid (20) or on the opposite sides of the sensitive grid (20).

5. The strain gauge for a large impact sensor according to claim 3, characterized in that, The sensitive grid (20) includes a biaxial first sensitive grid (21) and a biaxial second sensitive grid (22), and the pads (30) include a biaxial first pad (31), a biaxial second pad (32) and a biaxial third pad (33); The biaxial first sensitive grid (21) is located on one side of the biaxial second sensitive grid (22), and the included angle between the biaxial first sensitive grid (21) and the biaxial second sensitive grid (22) is 90°. The biaxial third pad (33) is located between the biaxial first sensitive grid (21) and the biaxial second sensitive grid (22), and the biaxial third pad (33) is respectively connected to one end of the biaxial first sensitive grid (21) and one end of the biaxial second sensitive grid (22). The biaxial first pad (31) is connected to the other end of the biaxial first sensitive grid (21), and the biaxial second pad (32) is connected to the other end of the biaxial second sensitive grid (22).

6. The strain gauge for a large impact sensor according to claim 3, characterized in that, The sensitive grid (20) includes a biaxial first sensitive grid (21) and a biaxial second sensitive grid (22), and the pads (30) include a biaxial first pad (31), a biaxial second pad (32), a biaxial third pad (33) and a biaxial fourth pad (34); Both the biaxial first pad (31) and the biaxial second pad (32) are connected to the biaxial first sensitive grid (21), and both the biaxial third pad (33) and the biaxial fourth pad (34) are connected to the biaxial second sensitive grid (22).

7. The strain gauge for a large impact sensor according to claim 6, characterized in that, The biaxial first sensitive grid (21) is located on one side of the biaxial second sensitive grid (22), and the biaxial first sensitive grid (21) and the biaxial second sensitive grid (22) are arranged in the same direction.

8. The strain gauge for a large impact sensor according to claim 6, characterized in that, The biaxial first sensitive grid (21) is located on one side of the biaxial second sensitive grid (22), and the included angle between the biaxial first sensitive grid (21) and the biaxial second sensitive grid (22) is 90°.

9. The strain gauge for a large impact sensor according to claim 5 or 8, characterized in that, The included angles between both the biaxial first sensitive grid (21) and the biaxial second sensitive grid (22) and the horizontal direction are both 45°.

10. Application of the strain gauge for a large impact sensor according to any one of claims 1 to 9 in a large impact sensor.

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