Portable multichannel polarity testing device

Abstract

The invention relates to the technical field of polarity detection devices, in particular to a portable multichannel polarity testing device which comprises a universal meter body and two meter pens, each meter pen is provided with a pen body part and a pen point part, each pen point part comprises a fixed section and a telescopic section, the periphery of each telescopic section is sleeved with a rubber sleeve, and the rubber sleeves are connected with the universal meter body. The two ends of the rubber sleeve are fixed to the pen point head and the fixed section respectively, when the pen point is broken, the rubber sleeve can wrap the broken pen point stub inside, the stub is prevented from flying out to damage a detection target or cause personal injury to detection personnel, meanwhile, a plurality of elastic guide strips are arranged on the side wall of the rubber sleeve, and the elastic guide strips are arranged on the side wall of the rubber sleeve. The rubber sleeve and the plurality of elastic guide strips greatly improve the bending strength of the pen point part, when the telescopic section is shortened, the elastic guide strips bend outwards in the radial direction of the rubber sleeve and abut against the inner wall of the hole, the contact area is remarkably increased, interference on polarity detection data is reduced, and the accuracy of a detection result is improved.

Description

Technical Field

[0001] This invention relates to the field of polarity detection device technology, and in particular to a portable multi-channel polarity testing device. Background Technology

[0002] There are generally three methods for polarity measurement: DC method, AC method, and instrument method. The AC method is generally not used due to difficulties in obtaining power and safety risks; the DC method is generally used on construction sites; and the instrument method is suitable for use in instrument transformer laboratories.

[0003] When using the DC method for testing, the necessary tools include a DC power supply (such as a 1.5V dry cell battery or a 9V battery), a multimeter (set to the DC milliamp or DC microamp range), and several wires. During testing, the instantaneous change in magnetic flux generated when the DC current passes through the primary winding is used to achieve the test. An instantaneous electromotive force is induced in the secondary winding, and the polarity is determined by the direction of the multimeter pointer deflection.

[0004] For example, Chinese patent CN210071917U discloses a multimeter probe. This solution includes a first test probe tip and a second test probe tip of different sizes. The finer first test probe tip can be used to measure precision electronic circuits or components such as terminal blocks with fine apertures, while the coarser second test probe tip is suitable for conventional measurements and can meet the testing requirements of components of conventional sizes. When using it, the operator can reasonably select the first or second test probe tip for measurement according to the size of the component to be measured, which broadens the versatility of the multimeter probe and enables it to be widely used in various application environments.

[0005] However, the tips of the multimeter probes may bend or even break after prolonged use, requiring replacement and affecting testing efficiency. If a break occurs, the broken tip may fly out and damage the target, potentially injuring the testing personnel. Furthermore, when testing perforated targets, a cylindrical probe is used, which is generally smaller than the diameter of the hole, resulting in poor contact with the hole and increased contact resistance, thus affecting the test results. Summary of the Invention

[0006] Therefore, it is necessary to provide a portable multi-channel polarity testing device to address the problems of the current multimeter probe tips being prone to bending and breaking after prolonged use, and the inability of the probe tips to fit tightly against the holes, thus affecting the test results.

[0007] The above objectives are achieved through the following technical solutions: A portable multi-channel polarity testing device, comprising: The multimeter body is equipped with a display screen.

[0008] Two probes are connected to the multimeter body. Each probe has a body and a tip. The tip includes a fixed section and a telescopic section. The end of the telescopic section away from the fixed section is the tip. A rubber sleeve is fitted around the telescopic section, and the tip and the fixed section are fixedly connected to the rubber sleeve at both ends.

[0009] Multiple elastic guide strips are provided, with their two ends electrically connected to the pen tip and the fixed section, respectively. The multiple elastic guide strips are parallel to the axis of the rubber sleeve and are evenly distributed circumferentially on the sidewall of the rubber sleeve. The multiple elastic guide strips are elastic and conductive. The multiple elastic guide strips are configured to bend radially outward along the rubber sleeve when the telescopic section is shortened. The degree to which the multiple elastic guide strips bend radially outward along the rubber sleeve is positively correlated with the diameter of the hole.

[0010] Furthermore, the telescopic section includes a guide rod and an elastic element. The guide rod is slidably inserted into the fixed section, and the elastic element is located between the guide rod and the fixed section. The elastic element has a tendency to push the guide rod out of the fixed section.

[0011] Furthermore, a sealed cavity is formed between the guide rod and the rubber sleeve, and the thickness of the rubber sleeve gradually decreases from the fixed section to the pen tip.

[0012] Furthermore, multiple protrusions facing the axis of the rubber sleeve are formed on the side wall of the rubber sleeve, and multiple elastic guide bars are respectively disposed in the multiple protrusions facing the axis of the rubber sleeve. The multiple elastic guide bars gradually extend outward from the outside of the rubber sleeve as the diameter of the rubber sleeve increases.

[0013] Furthermore, there are four protrusions facing the axis of the rubber sleeve, and the number of elastic guide strips is four.

[0014] Furthermore, the elastic element is a compression spring.

[0015] Furthermore, a wire is provided between the body of the two probes and the multimeter body.

[0016] Furthermore, a threaded post is provided on the fixed section of the pen away from the telescopic section, and the threaded post is threadedly connected to the pen body.

[0017] Furthermore, the plurality of elastic guide bars are made of stainless steel.

[0018] Furthermore, the pen body is provided with an anti-slip sleeve.

[0019] The beneficial effects of this invention are: This invention solves the safety hazards of traditional pen tip breakage by using a rubber sleeve around the telescopic section of the pen tip. The sleeve is fixed at both ends to the pen tip and the fixed section, respectively. When the pen tip breaks, the rubber sleeve encloses the broken fragments, preventing them from flying out and damaging the target (such as a current transformer) or causing personal injury to the personnel. Simultaneously, multiple elastic guide strips are installed on the sidewall of the rubber sleeve. These strips significantly improve the pen tip's bending resistance. When inspecting non-perforated targets, even if the pen body is tilted and the pen tip is subjected to force, the elasticity of the guide strips allows the pen tip to automatically return to its original position after the force is removed, reducing bending deformation after long-term use and extending the pen tip's lifespan.

[0020] This invention uses multiple elastic guide strips in conjunction with rubber sleeves. When the telescopic section shortens, the elastic guide strips bend radially outward along the rubber sleeve and abut against the inner wall of the hole, significantly increasing the contact area. Since the contact resistance is inversely proportional to the contact area, the contact resistance is greatly reduced, thus minimizing its interference with polarity detection data and improving the accuracy of the detection results.

[0021] This invention incorporates multiple elastic guides, the degree of which is positively correlated with the diameter of the hole. The larger the hole diameter, the greater the compression of the telescopic section, and the more pronounced the bending of the elastic guides, ensuring a tight fit with the inner wall of the hole. When the hole diameter is smaller, the degree of bending of the elastic guides is lower, yet stable contact is still maintained. Compared to traditional fixed-size pen tips, this device can adapt to various hole-type targets with different hole diameters, avoiding contact loosening problems caused by size mismatch.

[0022] This invention features a rubber sleeve with a sidewall thickness that gradually decreases from near the fixed section to near the pen tip. When the pen tip is inserted into a hole-type target, only the portion of the rubber sleeve extending into the hole expands and exposes the elastic conductor, while the elastic conductor located outside the hole remains covered by the rubber sleeve. This ensures the conductivity required for detection and reduces the probability of personnel accidentally touching exposed conductive parts. At the same time, air inside the hole is expelled when the rubber sleeve expands, reducing the risk of localized electric arcs.

[0023] The embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention.

[0025] Figure 2 This is a schematic diagram of the probe structure of the present invention.

[0026] Figure 3 This is a structural view of the pen tip portion of the present invention.

[0027] Figure 4This is an exploded view of the pen tip portion of the present invention.

[0028] Figure 5 for Figure 3 Front view of the tip of the marker pen.

[0029] Figure 6 for Figure 5 A cross-sectional view of the tip of the marker along line AA.

[0030] Figure 7 for Figure 5 A cross-sectional view of the tip of the marker along BB.

[0031] Figure 8 This is a view showing the expanded state of the rubber sleeve on the tip of the pen in this invention.

[0032] Figure 9 for Figure 8 Front view of the expanded rubber sleeve of the pen tip.

[0033] Figure 10 for Figure 9 A cross-sectional view along CC of the rubber sleeve of the pen tip when it is inflated.

[0034] In the picture: 100. Multimeter body; 110. Display screen; 120. Wires; 200. Stamp; 210. Pen body; 211. Anti-slip sleeve; 220. Pen tip; 221. Threaded post; 230. Fixed section; 240. Telescopic section; 241. Guide rod; 242. Elastic element; 250. Pen tip; 260. Rubber sleeve; 270. Elastic guide strip; 280. Protrusion; 290. Sealed cavity. Detailed Implementation

[0035] See Figure 1-10A portable multi-channel polarity testing device, suitable for CT polarity testing, includes a multimeter body 100, a display screen 110 on the multimeter body 100 for displaying measurement data, and two probes 200 connected to the multimeter body 100 for connecting to the device under test. In the prior art, the probes 200 connect to the target device using their tips. Both probes 200 have a body portion 210 and a tip portion 220. The prior art probes 200 have various usage methods, including for non-perforated detection targets. In some testing methods, the pen body 210 is tilted so that the pen tip 220 is tilted and pressed against the device to be tested. However, this method may cause the pen tip 220 to bend or even break after prolonged use. In this case, the pen tip needs to be replaced, which affects the testing efficiency. If it breaks, the broken pen tip will fly out and damage the target being tested, and may even injure the testing personnel. When testing targets with holes, a cylindrical testing head is used. The size of this testing head is generally smaller than the diameter of the hole, which makes it unable to fit the hole well, increasing the contact resistance and affecting the testing results.

[0036] Based on this, the pen tip portion 220 of the pen 200 of the present invention includes a fixed section 230 and a telescopic section 240, such as Figure 3 As shown, the end of the telescopic section 240 furthest from the fixed section 230 is the pen tip 250. A rubber sleeve 260 is provided on the outer periphery of the telescopic section 240. One end of the rubber sleeve 260 is fixedly connected to the pen tip 250, and the other end of the rubber sleeve 260 is fixedly connected to the fixed section 230. When the pen tip 220 breaks off, the rubber sleeve 260 can retain the broken pen tip 220 inside the rubber sleeve 260, thereby preventing damage to the detection target or injury to the detection personnel when the pen tip 220 breaks off. Furthermore, multiple elastic guide strips 270 are provided on the side wall of the rubber sleeve 260. The elastic guide strips 270 are elastic and conductive, such as... Figure 4 , Figure 6 and Figure 7 As shown, multiple elastic guide strips 270 are parallel to the axis of the rubber sleeve 260, and are evenly distributed along the circumference of the rubber sleeve 260. The two ends of each elastic guide strip 270 are fixedly connected to the pen tip 250 and the fixed section 230, respectively, thus providing electrical conductivity. When the telescopic section 240 of the pen tip 220 is shortened, the multiple elastic guide strips 270 can bend outwards radially along the rubber sleeve 260. Figure 8 and Figure 10 As shown, the degree to which the multiple elastic guide strips 270 bend outward along the radial direction of the rubber sleeve 260 is positively correlated with the diameter of the hole.

[0037] When inspecting a perforated target, the inspector needs to insert the pen tip 250 into the hole and push the fixed section 230 to shorten the telescopic section 240, ensuring that the pen tip 250 can reach the bottom of the hole. When the diameter of the hole is larger, the telescopic section 240 of the pen tip needs to shorten by a greater distance, thereby increasing the degree to which the multiple elastic guide strips 270 bend radially outward along the rubber sleeve 260, and thus allowing the multiple elastic guide strips 270 to abut against the inner wall of the hole. When the diameter of the hole is smaller, the telescopic section 240 of the pen tip needs to shorten by a shorter distance, thereby reducing the degree to which the multiple elastic guide strips 270 bend radially outward along the rubber sleeve 260, thus adapting to smaller hole diameters and ensuring that the multiple elastic guide strips 270 can contact the inner wall of the hole.

[0038] Understandably, compared to only the tip 250 of the pen tip 220 contacting the bottom of the hole, the contact area between the probe 200 and the target is increased by multiple elastic guide strips 270 abutting against the sidewall of the hole. Since the contact resistance is inversely proportional to the size of the contact area, the contact resistance can be effectively reduced when the contact area between the probe 200 and the target is increased, thereby reducing the impact on the detection results and improving the accuracy of the detection results.

[0039] It should be noted that when the tester tilts the pen body 210 of the test pen 200 to test non-perforated targets, the rubber sleeve 260 and multiple elastic guide strips 270 of the pen tip 220 can improve the bending resistance of the pen tip 220. Compared with the pen tip 220 in the prior art that does not have elastic guide strips 270 and rubber sleeves 260, the pen tip 220 of the present invention has stronger bending resistance. In addition, the multiple elastic guide strips 270 are elastic. After the pen tip 220 has been used for a long time, the rubber sleeve 260 and multiple elastic guide strips 270 can restore the areas of the pen tip 220 that are prone to bending, reduce the degree of bending of the pen tip 220 after long-term use, and thus improve the service life of the pen tip 220 to a certain extent.

[0040] Specifically, in this embodiment of the invention, the telescopic section 240 of the pen tip portion 220 includes a guide rod 241 and an elastic element 242. The guide rod 241 is slidably inserted into the fixed section 230, which includes a sleeve. The guide rod 241 is slidably inserted into the sleeve. The elastic element 242 is located between the guide rod 241 and the sleeve of the fixed section 230. The elastic element 242 is a compression spring. Both ends of the elastic element 242 abut against the guide rod 241 and the sleeve, respectively. The elastic element 242 has a tendency to push the guide rod 241 out of the sleeve. The end of the guide rod 241 away from the elastic element 242 is fixedly connected to the pen tip 250. When the inspector inserts the pen tip 250 into the hole, he can push the fixed section 230, so that the guide rod 241 connected to the pen tip 250 moves axially within the sleeve of the fixed section 230 to compress the elastic element 242.

[0041] More specifically, in order to enable the multiple elastic guides 270 to bend outward along the radial direction of the rubber sleeve 260 when the telescopic section 240 of the pen tip 220 is shortened, a sealed cavity 290 is formed between the rubber sleeve 260 and the guide rod 241 in this embodiment. When the guide rod 241 slides axially within the sleeve of the fixed section 230 and shortens, the gas in the sealed cavity 290 is compressed, thereby pushing the rubber sleeve 260 outward to increase its diameter. Furthermore, the sidewall thickness of the rubber sleeve 260 gradually decreases from the sleeve of the fixed section 230 to the pen tip 250. As a result, when the gas inside the sealed cavity 290 is compressed, the rubber sleeve 260 with the thinner sidewall begins to expand outward first, thereby driving the multiple elastic guides 270 to bend outward along the radial direction of the rubber sleeve 260. As the distance of the telescopic section 240 shortens increases, the degree of outward expansion of the rubber sleeve 260 increases, and the expansion position of the rubber sleeve 260 gradually moves towards the position with the thicker sidewall.

[0042] It should be noted that, in this embodiment, a plurality of protrusions 280 are formed on the sidewall of the rubber sleeve 260 facing the axial direction of the rubber sleeve 260, such as... Figure 6 and Figure 7 As shown, multiple elastic guide strips 270 are located within multiple protrusions 280 facing the axial direction of the rubber sleeve 260. When the rubber sleeve 260 begins to expand, its diameter increases, thereby unfolding the protrusions 280. After the protrusions 280 are unfolded, the elastic guide strips 270 inside them are pushed and bent, and gradually exposed to the outer periphery of the rubber sleeve 260. This allows the elastic guide strips 270 to gradually approach the sidewall of the hole to ensure that the elastic guide strips 270 can abut against the sidewall of the hole.

[0043] Understandably, since the sidewall of the rubber sleeve 260 gradually expands from the thinner part to the thicker part, meaning the elastic guide strip 270 gradually protrudes from near the pen tip 250 to near the fixed section 230, and since the elastic guide strip 270 begins to protrude from near the pen tip 250, when the inspector inserts the pen tip 250 into the hole and pushes the fixed section 230, the pen tip 250 abuts against the bottom of the hole. At this time, the rubber sleeve 260 expands from near the pen tip 250 and pushes the elastic guide strip 270 at that position to bend and gradually contact the sidewall of the hole. If the diameter of the hole is small, the area of ​​expansion of the rubber sleeve 260 is small, and the elastic guide strip 270 is not exposed in the area where the rubber sleeve 260 is not expanded, thus providing protection and preventing safety problems caused by accidental contact by the inspector. At the same time, it can reduce the area of ​​the elastic guide strip 270 that comes into contact with the outside air and undergoes an oxidation reaction. The exposed part of the elastic guide strip 270 is located inside the hole. The air inside the hole is discharged from the hole under the expansion of the rubber sleeve 260. The elastic guide strip 270 located outside the hole is covered by the rubber sleeve 260, thereby reducing external corrosion.

[0044] In a further embodiment, the rubber sleeve 260 of the present invention has four protrusions 280 facing the axial direction, and the number of elastic guide strips 270 is four, with the four elastic guide strips 270 respectively located within the four protrusions 280. Of course, there can also be five, six, etc., which are not specifically limited here.

[0045] Specifically, in this embodiment, each of the two probes 200 has a wire 120 connected to its body 210. The other end of the wire 120 is connected to the multimeter body 100, so that current can flow through the probes 200 and the wire 120 through the multimeter body 100, and the display screen 110 on the multimeter body 100 displays the test result.

[0046] Specifically, to facilitate the connection between the pen body 210 and the pen tip 220 of the pen 200, a threaded post 221 is fixedly provided on the end of the fixed section 230 of the pen tip 220 away from the telescopic section 240. The outer circumference of the threaded post 221 is provided with threads, and the pen body 210 is provided with a threaded groove. The threaded post 221 is threaded into the threaded groove, thereby connecting the pen body 210 and the pen tip 220 together, making disassembly more convenient.

[0047] It should be noted that the threaded post 221 is made of conductive material, and it is electrically connected to the four elastic conductors 270 and the pen tip 250, thereby enabling current to be transmitted to the multimeter body 100. Meanwhile, the four elastic conductors 270 are made of stainless steel, which is both elastic and conductive, and also has strong oxidation resistance.

[0048] In a further embodiment, the pen body 210 of the present invention is provided with an anti-slip sleeve 211. The anti-slip sleeve 211 can increase the friction when the tester holds the pen body, and avoid the pen body slipping off due to sweaty hands, oil stains or sudden external force during operation.

[0049] The specific working process of the portable multi-channel polarity testing device provided by the present invention will be described in conjunction with the above embodiments: When performing CT polarity testing, the multimeter body should be set to the DC milliamp or DC microamp range, and a smaller range, such as 10mA, should be selected for higher sensitivity.

[0050] When detecting perforated targets: The two probes 200 of the multimeter body 100 are inserted into the test hole. The tester holds the body 210 of the probe 200 and inserts the tip 250 of the tip 220 into the hole. Then, the body 210 is moved, causing it to push the fixing section 230 of the tip 220. The fixing section 230 pushes the guide rod 241 to compress the elastic element 242, so that the tip 250 on the guide rod 241 can abut against the bottom of the hole, and part of the rubber sleeve 260 of the tip 220 also extends into the hole. As the tester continues to apply force, the elastic element 242 gradually... As the gas inside the sealed cavity 290 of the rubber sleeve 260 on the outer periphery of the guide rod 241 is compressed, the rubber sleeve 260 expands from the thinner part of its sidewall, that is, from the part of the rubber sleeve 260 near the tip 250. The diameter of the rubber sleeve 260 gradually increases, thus opening up the protrusion 280 formed on the sidewall facing the axis of the rubber sleeve 260. The elastic guide strip 270 inside the protrusion 280 gradually protrudes out of the outside of the rubber sleeve 260 and abuts against the inner sidewall of the hole, thereby increasing the contact area between the detection hole and the probe 200 and reducing the influence of contact resistance on the detection result.

[0051] When the diameter of the detection hole is large, the inspector continues to push the pen body 210, increasing the compression of the elastic element 242 by the guide rod 241 of the pen tip 220. At this time, the expansion diameter of the rubber sleeve 260 on the outer periphery of the guide rod 241 is larger, which makes the four elastic guide strips 270 on the side wall of the rubber sleeve 260 bend radially outward toward the rubber sleeve 260. This ensures that the four elastic guide strips 270 can abut against the inner side wall of the detection hole, while the rubber sleeve 260 that does not extend into the detection hole does not expand, thus protecting the part of the elastic guide strips 270 that does not extend into the detection hole, preventing this part from being exposed, and improving the safety of the detection process.

[0052] After the test is completed, the tester pulls the tip 220 of the two test probes 200 out of the hole. The telescopic section 240 of the tip 220 is reset under the action of the elastic element 242, which in turn drives the rubber sleeve 260 and the four elastic guide strips 270 to reset.

[0053] When detecting non-porous targets: The tester tilted the two pen body parts 210 so that the pen tip part 220 tilted simultaneously. The pen tip 250 of the pen tip part 220 tilted to contact the non-perforated target, which can increase the contact area and reduce the contact resistance. At the same time, the rubber sleeve 260 on the outer periphery of the guide rod 241 and the four elastic guide strips 270 can provide the guide rod 241 and the pen tip 250 with a certain degree of bending resistance, thereby ensuring that the guide rod 241 and the pen tip part 220 are not easily bent during long-term use.

[0054] The above description is merely a specific embodiment of the present invention, and the various examples do not constitute a limitation on the substantive content of the present invention.

Claims

1. A portable multi-channel polarity testing device, characterized in that, include: Multimeter body (100), on which a display screen (110) is provided; Two probes (200) are connected to the multimeter body (100). Each probe (200) has a body portion (210) and a tip portion (220). The tip portion (220) includes a fixed section (230) and a telescopic section (240). The end of the telescopic section (240) away from the fixed section (230) is the tip (250). A rubber sleeve (260) is fitted around the telescopic section (240). The two ends of the rubber sleeve (260) are fixedly connected to the tip (250) and the fixed section (230), respectively. Multiple elastic guide strips (270) are provided, with their ends electrically connected to the pen tip (250) and the fixed section (230) respectively. The multiple elastic guide strips (270) are parallel to the axis of the rubber sleeve (260). The multiple elastic guide strips (270) are evenly distributed circumferentially on the sidewall of the rubber sleeve (260). The multiple elastic guide strips (270) are elastic and conductive. The multiple elastic guide strips (270) are configured to bend radially outward along the rubber sleeve (260) when the telescopic section (240) is shortened. The degree to which the multiple elastic guide strips (270) bend radially outward along the rubber sleeve (260) is positively correlated with the diameter of the hole.

2. The portable multi-channel polarity testing device according to claim 1, characterized in that, The telescopic section (240) includes a guide rod (241) and an elastic element (242). The guide rod (241) is slidably inserted into the fixed section (230). The elastic element (242) is located between the guide rod (241) and the fixed section (230). The elastic element (242) has a tendency to push the guide rod (241) out of the fixed section (230).

3. The portable multi-channel polarity testing device according to claim 2, characterized in that, A sealed cavity (290) is formed between the guide rod (241) and the rubber sleeve (260), and the thickness of the rubber sleeve (260) gradually decreases from the fixed section (230) to the pen tip (250).

4. The portable multi-channel polarity testing device according to claim 3, characterized in that, Multiple protrusions (280) facing the axis of the rubber sleeve (260) are formed on the side wall of the rubber sleeve (260). Multiple elastic guides (270) are respectively disposed in the multiple protrusions (280) facing the axis of the rubber sleeve (260). The multiple elastic guides (270) gradually extend out of the outside of the rubber sleeve (260) as the diameter of the rubber sleeve (260) increases.

5. The portable multi-channel polarity testing device according to claim 4, characterized in that, There are four protrusions (280) facing the axis of the rubber sleeve (260), and the number of elastic guide strips (270) is four.

6. The portable multi-channel polarity testing device according to claim 2, characterized in that, The elastic element (242) is a compression spring.

7. The portable multi-channel polarity testing device according to claim 1, characterized in that, A wire (120) is provided between the pen body (210) of the two probes (200) and the multimeter body (100).

8. The portable multi-channel polarity testing device according to claim 1, characterized in that, A threaded post (221) is provided on one end of the fixed section (230) of the pen (200) away from the telescopic section (240), and the threaded post (221) is threadedly connected to the pen body (210).

9. The portable multi-channel polarity testing device according to claim 1, characterized in that, The multiple elastic guide strips (270) are made of stainless steel.

10. The portable multi-channel polarity testing device according to claim 1, characterized in that, The pen body (210) of the pen (200) is provided with an anti-slip sleeve (211).

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