Resistance strain gauge with quick-connect terminal

Abstract

The utility model discloses a kind of resistance strain gauges with quick connector terminal, it is related to engineering survey sensor technical field, including strain gauge body, two original lead wires are led out on the strain gauge body, the end of the original lead wire is fixedly connected with a male terminal connection terminal;It further includes two extension wires, one end of the extension wire is fixedly connected with a female terminal connection terminal matched with the male terminal connection terminal, and a docking assembly is arranged between the male terminal connection terminal and the female terminal connection terminal;The utility model is connected by the quick connector terminal designed, field personnel do not need any tool and professional welding skill, just need to align and insert female-male terminal, and connection can be completed, time consumption only needs several seconds, is suitable for the monitoring project needing a large number of strain gauge layout.

Description

Technical Field

[0001] This utility model relates to engineering measurement sensor technology, specifically to a resistance strain gauge with quick-connect terminals. Background Technology

[0002] A resistance strain gauge is a sensor that converts strain (dimensional change) in an engineering component into resistance change. It is widely used in health monitoring and material performance testing in fields such as bridges, buildings, and heavy machinery. It typically consists of a sensing grid, leads, adhesive, substrate, and capping layer. The lead length included with the strain gauge at the factory is limited (usually between 3 mm and 15 cm). However, in practical outdoor applications, the data acquisition instrument is often far from the measurement point, so an extension wire must be used to connect the strain gauge to the acquisition instrument.

[0003] Currently, there are two main methods for connecting strain gauge leads and extension wires in the field: soldering and knotting. Soldering requires tools such as soldering irons and solder wire, and typically requires a 220V AC power supply, making it extremely inconvenient to operate in the field or in locations without power. Knotting, on the other hand, requires tools such as wire strippers and electrical tape, resulting in low mechanical strength at the connection points, easy loosening, unstable contact resistance, and susceptibility to moisture and oxidation, leading to data drift or distortion and poor reliability. Both methods require carrying multiple tools and are performed by operators with specific professional skills, severely hindering the deployment efficiency of large-scale, distributed strain monitoring projects. Utility Model Content

[0004] The purpose of this invention is to provide a resistance strain gauge with quick-connect terminals to solve the problems in the prior art where, when the wire length of the resistance strain gauge is insufficient, on-site wiring requires specialized tools, resulting in cumbersome operation and poor connection reliability.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a resistance strain gauge with quick-connect terminals, comprising a strain gauge body, wherein two original leads are led out from the strain gauge body, and each of the original leads is fixedly connected to a male terminal.

[0006] It also includes two extension wires, one end of which is fixedly connected to a female connector that matches and plugs into the male connector terminal. A mating assembly is provided between the male connector terminal and the female connector terminal.

[0007] Furthermore, the male and female terminals adopt a spring-loaded quick-connect design.

[0008] Furthermore, the male and female connectors are aviation plug-type terminals.

[0009] Furthermore, the male connector terminal is fixed and electrically connected to the original lead through a micro-crimping method, and the female connector terminal is also fixed and electrically connected to the extension wire through a crimping method.

[0010] Furthermore, the original lead wire between the male connector and the strain gauge body is externally fitted with a corrugated protective hose to enhance mechanical strength.

[0011] Furthermore, the male connector and the matching female connector have corresponding color markings on their respective outer shells on their left and right sidewalls.

[0012] Furthermore, the docking assembly includes a plug plate, a docking plate, and a limiting protrusion. The plug plate is installed at the top and bottom of the male connector terminal, and the vertical cross-sectional profile of the plug plate is an inverted "L" shape. The docking plate is installed at the top and bottom of the female connector terminal.

[0013] Furthermore, the docking plate is provided with a through docking hole, and the height of the docking hole is greater than the height of the insert plate. The limiting protrusions are respectively installed on the opposite sides of the two insert plates. The limiting protrusions are made of plastic material. After the insert plate is inserted into the docking hole, the side wall of the limiting protrusion is stuck on the side of the docking plate away from the limiting protrusion.

[0014] Compared with the prior art, the present invention provides a resistance strain gauge with quick-connect terminals. By setting a male terminal on the original lead wire and a female terminal on one end of the extension wire, when the wire length is insufficient, the male lead wire terminal and the female terminal are plugged into each other. In use, only the strain gauge and the required wire length need to be purchased. In outdoor sites, the lead wire connection is completed simply by plugging in the terminals. This saves time and does not require professional technicians, improving wiring efficiency. Moreover, it eliminates welding and other processes, and prevents abnormal damage to the strain gauge due to operational errors. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0016] Figure 1 A schematic diagram of the overall structure of a resistance strain gauge with quick-connect terminals provided for an embodiment of this utility model;

[0017] Figure 2 This is a schematic diagram of the two terminals in the open state provided in an embodiment of the present utility model;

[0018] Figure 3 A schematic diagram of the structure of male connector terminals and plug-in plates provided in the embodiments of this utility model;

[0019] Figure 4 A schematic diagram of the structure of components such as the female connector terminal and the mating plate provided in the embodiments of this utility model.

[0020] Explanation of reference numerals in the attached figures:

[0021] 1. Strain gauge body; 2. Original lead wire; 3. Male terminal block; 4. Extension wire; 5. Female terminal block; 6. Corrugated protective hose; 7. Color marking; 8. Insert plate; 9. Connecting plate; 10. Limiting protrusion; 11. Connecting hole. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0023] As attached Figure 1 To be continued Figure 4 As shown:

[0024] Example 1:

[0025] This utility model provides a resistance strain gauge with quick-connect terminals, including a strain gauge body 1, on which two original leads 2 are led out, and each of the original leads 2 is fixedly connected to a male terminal 3.

[0026] It also includes two extension wires 4, one end of which is fixedly connected to a female connector 5 that matches and plugs into the male connector terminal 3, and a mating assembly is provided between the male connector terminal 3 and the female connector terminal 5.

[0027] It should be noted that by setting a male terminal 3 on the original lead wire 2 and a female terminal 5 on one end of the extension wire 4, when the wire length is insufficient, the male lead wire terminal and the female terminal 5 can be plugged together. When in use, only the strain gauge and the required wire length need to be purchased. In outdoor sites, the lead wire connection is completed simply by plugging in the terminal. This saves time and does not require professional technicians, improving wiring efficiency. Moreover, it eliminates welding and other processes, and will not cause abnormal damage to the strain gauge due to operational errors.

[0028] It should be added that: this utility model has two original leads 2 leading out from the strain gauge body 1, but it is not limited to the number of original leads 2 in this embodiment. The number of original leads 2 is determined according to the specific number of wires connected on the strain gauge body 1. When the number of original leads 2 changes, the plugging method of the male terminal 3 and the female terminal 5 is not limited to the one in this example.

[0029] In this embodiment, the male terminal 3 and the female terminal 5 adopt a spring-loaded quick-connect terminal design.

[0030] It should be noted that the male connector contains a precision spring and a retractable needle bar. When the male connector is mated with the female connector, the needle bar is compressed, and the spring provides continuous and stable positive pressure to ensure tight contact between the needle bar and the inner wall of the female connector.

[0031] This design improves contact reliability. The spring compensates for minute dimensional tolerances and thermal expansion and contraction, resists vibration and fretting wear, ensures long-term stable contact resistance, and has a long insertion and removal life, typically reaching tens of thousands of times or more, far exceeding the lifespan of the strain gauge itself.

[0032] In this embodiment, the male connector 3 and the female connector 5 are aviation plug-type terminals.

[0033] It should be noted that the male terminal block 3 and the female terminal block 5 are designed as aviation plug-type terminals. On the one hand, due to the stability of their materials, the connection can be strengthened and it is not easy for them to fall off. On the other hand, their shells combined with sealing rings can provide a high IP protection level, which can effectively prevent the intrusion of rainwater, dust and moisture, and ensure long-term stability in extreme outdoor environments.

[0034] In this embodiment, the male terminal 3 and the original lead 2 are fixed and electrically connected by a micro-crimping method, and the female terminal 5 and the extension wire 4 are also fixed and electrically connected by a crimping method.

[0035] It should be noted that using crimping instead of welding has the following advantages: First, there is no heat damage. Crimping is a cold process that does not produce the high temperatures and flux fumes that occur during welding. This avoids the heat damage that high temperatures may cause to the internal insulation materials of the terminals, the elasticity of the springs, and the delicate strain gauge leads.

[0036] Secondly, using professional crimping tools allows for precise control of crimping force and deformation, ensuring consistent mechanical strength and electrical conductivity at each connection point, resulting in stable and reliable product quality.

[0037] In this embodiment: the original lead wire 2 between the male terminal 3 and the strain gauge body 1 is covered with a corrugated protective hose 6 for enhancing mechanical strength.

[0038] It should be noted that the original lead wire 2 is a stress concentration area. During frequent plugging and unplugging or when the cable is under tension, force will act on this area. Therefore, a corrugated protective flexible tube 6 (usually made of nylon or PE) is installed here. Firstly, the corrugated tube has good flexibility, which can disperse stress and prevent the original lead wire 2 from breaking due to repeated bending at the base of the male connector terminal 3. Secondly, together with the outer shell of the male connector terminal 3, it clamps and protects the original lead wire 2, significantly improving the mechanical strength of the connection point and making the overall structure more durable.

[0039] In this embodiment: the male terminal block 3 and the matching female terminal block 5 are provided with corresponding color markings 7 on their respective outer shells.

[0040] It should be noted that color markings 7 are provided on the left and right side walls of the housings of the male terminal block 3 and the matching female terminal block 5. One side can be set to blue and the other side to red. This allows the male terminal block 3 and the female terminal block 5 to be inserted directly by matching the colors of the two sides of the male terminal block 3 and the female terminal block 5 without having to observe the internal shape of the connector, thus improving the insertion efficiency.

[0041] In this embodiment: the docking assembly includes a plug plate 8, a docking plate 9, and a limiting protrusion 10. The plug plate 8 is installed at the top and bottom of the male terminal 3. The vertical cross-sectional profile of the plug plate 8 is an inverted "L" shape. The docking plate 9 is installed at the top and bottom of the female terminal 5.

[0042] It should be noted that the inverted "L"-shaped insert plate 8, in conjunction with the mating plate 9 on the female terminal block 5, forms a guiding and preliminary positioning function. When the user performs the insertion operation, the insert plate 8 on the male terminal block 3 is aligned with the mating plate 9 on the female terminal block 5, and then it is pushed in horizontally. This design simplifies the insertion process, and even without precise axial alignment, the initial insertion steps can be easily completed, improving the stability after insertion.

[0043] In this embodiment: the docking plate 9 is provided with a through docking hole 11, and the height of the docking hole 11 is greater than the height of the insert plate 8. The limiting protrusions 10 are respectively installed on the opposite sides of the two insert plates 8. The limiting protrusions 10 are made of plastic. After the insert plate 8 is inserted into the docking hole 11, the side wall of the limiting protrusion 10 is stuck on the side of the docking plate 9 away from the limiting protrusion 10.

[0044] It should be noted that the height difference of the mating hole 11 provides a space channel for the insertion of the plug plate 8. The limiting protrusion 10 is made of a plastic material with a certain degree of elasticity (such as POM or nylon). When the plug plate 8 is pushed horizontally into the mating hole 11, the limiting protrusion 10 will be squeezed by the side wall of the mating hole 11 and undergo elastic deformation. When the plug plate 8 is fully inserted and the limiting protrusion 10 passes the mating plate 9, it will rely on its own elasticity to return to its original shape, so that its side wall will be firmly "locked" on the back of the mating plate 9. When a "click" is heard, the self-locking is completed. On the one hand, the mechanical self-locking provides the ability to resist accidental pulling, avoiding the situation where the male terminal 3 and the female terminal 5 are accidentally dislodged after being plugged in, further improving the stability after plugging in. Moreover, in the later stage, it is only necessary to press the limiting protrusion 10 to deform it and disengage it from the mating hole 11 to achieve unlocking, which is convenient to operate.

[0045] The working principle of this embodiment is as follows: Take out the strain gauge with a male terminal 3 at one end and the extension wire 4 with a female terminal 5 at the other end. First, observe the color markings 7 (such as red and blue) on the terminal housing, align the colors of the male and female terminals, and ensure correct pairing.

[0046] The inverted "L"-shaped insert plate 8 on the male terminal is initially aligned with the notch of the mating plate 9 on the female terminal. A horizontal pushing force is applied to smoothly insert the male terminal into the female terminal. During the insertion process, the pin bar of the male terminal (if it is a spring pin type) contacts the female seat and is compressed, forming a tight electrical connection by relying on the spring pressure. At the same time, the limiting protrusion 10 on the insert plate 8 is deformed by pressure and slides into the mating hole 11 until it is completely passed through and springs back to its original position with a "click", locking on the back of the mating plate 9 to achieve mechanical self-locking.

[0047] At this point, a robust electrical and mechanical connection has been established, and the resistance change signal caused by component deformation is stably transmitted to the remote data acquisition instrument through the path of strain gauge sensitive grid → original lead 2 → male terminal → female terminal → extension wire 4.

[0048] When disconnection is required, simply pinch the exposed limiting protrusions 10 on both sides with your fingers to disengage them from the snap-fit ​​position of the mating plate 9, and the male terminal 3 and female terminal 5 can be easily separated horizontally.

[0049] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A resistance strain gauge with quick-connect terminals, characterized in that, include: The strain gauge body (1) has two original leads (2) extending from it, and each of the original leads (2) is fixedly connected to a male terminal (3). It also includes two extension wires (4), one end of which is fixedly connected to a female connector (5) that matches and plugs into the male connector (3), and a mating assembly is provided between the male connector (3) and the female connector (5).

2. A resistance strain gauge with quick-connect terminals according to claim 1, characterized in that, The male connector (3) and the female connector (5) are designed with spring pin quick-connect terminals.

3. A resistance strain gauge with quick-connect terminals according to claim 2, characterized in that, The male connector (3) and female connector (5) are aviation plug-type terminals.

4. A resistance strain gauge with quick-connect terminals according to claim 1, characterized in that, The male terminal (3) and the original lead (2) are fixed and electrically connected by a micro-crimping method, and the female terminal (5) and the extension wire (4) are also fixed and electrically connected by a crimping method.

5. A resistance strain gauge with quick-connect terminals according to claim 1, characterized in that, The original lead wire (2) between the male terminal (3) and the strain gauge body (1) is covered with a corrugated protective hose (6) for enhancing mechanical strength.

6. A resistance strain gauge with quick-connect terminals according to claim 1, characterized in that, The male connector terminal (3) and the matching female connector terminal (5) have corresponding color markings (7) on their respective outer shells.

7. A resistance strain gauge with quick-connect terminals according to claim 1, characterized in that, The docking assembly includes a plug plate (8), a docking plate (9), and a limiting protrusion (10). The plug plate (8) is installed on the top and bottom of the male terminal block (3). The vertical cross-sectional profile of the plug plate (8) is an inverted "L" shape. The docking plate (9) is installed on the top and bottom of the female terminal block (5).

8. A resistance strain gauge with quick-connect terminals according to claim 7, characterized in that, The docking plate (9) is provided with a through docking hole (11), and the height of the docking hole (11) is greater than the height of the insert plate (8). The limiting protrusion (10) is installed on the opposite sides of the two insert plates (8). The limiting protrusion (10) is a component made of plastic material. After the insert plate (8) is inserted into the docking hole (11), the side wall of the limiting protrusion (10) is stuck on the side of the docking plate (9) away from the limiting protrusion (10).

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