A shielding head structure and a clamp meter for this structure

Abstract

This application relates to the field of multimeters, and particularly to a shielding head structure for a clamp meter, which includes two groups of first shells and second shells for clamping an iron core. Both the first shell and the second shell are made of magnetic conductive materials. A first shielding layer is provided on the inner side of the first shell, and a second shielding layer is provided on the inner side of the second shell. The iron core is clamped between the first shielding layer and the second shielding layer. A connection structure is provided between the first shell and the second shell, and heat dissipation structures are provided on the outer sides of both the first shell and the second shell. Through the above solution, the phenomenon of magnetic leakage is reduced, and the detection accuracy is improved.

Description

Technical Field

[0001] This application relates to the field of meters, and in particular to a shielding head structure and a clamp meter for this structure. Background Art

[0002] A clamp multimeter is a commonly used electrical measuring device that can quickly and accurately measure the current value of alternating current without cutting off the current, and is widely used. The current clamp multimeter has a structure including a measuring device and a housing. The measuring device is encapsulated in the housing. For the occasion of measuring alternating current, the measuring device is composed of an electromagnetic ammeter, a through-core current transformer, a knob, and a wrench. The core of the through-core current transformer is made into a movable opening, and the wrench is used to open and close the core so that the wire to be measured can pass through. The secondary winding of the through-core current transformer is wound around the core and connected to the electromagnetic ammeter. The primary winding of the through-core current transformer is the wire to be measured passing through its center. The knob is a range selection switch. When measuring current, first select an appropriate range, press the wrench to open the jaws, place the wire to be measured in the middle of the through-core current transformer, and then close the jaws. When there is an alternating current passing through the wire to be measured, the magnetic flux of the alternating current induces a current in the secondary winding of the through-core current transformer. This current passes through the coil of the electromagnetic ammeter, causing the pointer to deflect and indicating the measured current value on the dial scale.

[0003] In view of the above related technologies, it is known that the test voltage or current reaches the test purpose through magnetic induction. The existing method of adding a shielding housing on the outside of the core to reduce magnetic leakage to improve the detection accuracy still has a certain magnetic leakage phenomenon, and the shielding effect is not good. Summary of the Invention

[0004] In order to improve the detection accuracy and further reduce the magnetic leakage phenomenon, this application provides a shielding head structure and a clamp meter for this structure.

[0005] In a first aspect, this application provides a shielding head structure for a clamp meter, adopting the following technical solution:

[0006] A shielding head structure for a clamp meter includes two groups of first shells and a second shell for clamping the core. Both the first shell and the second shell are made of magnetic conductive materials. A first shielding layer is provided on the inner side of the first shell, and a second shielding layer is provided on the inner side of the second shell. The core is clamped between the first shielding layer and the second shielding layer. A connection structure is provided between the first shell and the second shell, and heat dissipation structures are provided on the outer sides of both the first shell and the second shell.

[0007] By adopting the above technical solution, the iron core is clamped between the first shell and the second shell. Under the action of the connection structure, the first shell and the second shell are connected to each other to form a shielding head. The first shielding layer and the second shielding layer make the shielding performance of the first shell and the second shell better, reduce the phenomenon of magnetic leakage, and improve the detection accuracy.

[0008] Optionally, the first shielding layer and the second shielding layer are made of the same material, and both are magnetic conductive materials. The cross-sectional shape of the first shielding layer is the same as that of the first shell, and the cross-sectional shape of the second shielding layer is the same as that of the second shell.

[0009] By adopting the above technical solution, the first shielding layer improves the shielding ability of the first shell, and the second shielding layer improves the shielding ability of the second shell.

[0010] Optionally, the heat dissipation structure includes a mounting cover fixedly formed on the outer sides of the first shell and the second shell, and a coolant filled in the mounting cover. Nano-scale magnetic particles are mixed in the coolant, and the coolant and the nano-scale magnetic particles are mixed to form a magnetic fluid with magnetism.

[0011] By adopting the above technical solution, during the process of testing the current value or voltage value of the wire, the magnetic field generated by the current flowing through the wire stirs the magnetic fluid. Since the magnetic fluid has a cooling performance, the coolant reciprocally stirs in the mounting shell, realizing the cooling and heat dissipation of the outer walls of the first shell and the second shell, thereby slowing down the influence of temperature on the magnetic conductivity of the iron core.

[0012] Optionally, a plurality of first heat dissipation grooves are evenly spaced on the outer side of the mounting cover, and the inner wall of the first heat dissipation groove is arc-shaped.

[0013] By adopting the above technical solution, the first heat dissipation grooves increase the heat dissipation area of the mounting cover and reduce the influence of temperature on the magnetic conductivity.

[0014] Optionally, the connection structure includes a plurality of receiving grooves evenly formed on the inner wall of the first shielding layer, and protrusions evenly formed on the outer side of the second shell. The protrusions are snap-fitted in the receiving grooves. When the first shell and the second shell are snap-fitted to form a single shielding head, a plurality of first connection pieces are formed at one end of the shielding head, and a plurality of second connection pieces that cooperate with the first connection pieces are formed at the other end of the shielding head.

[0015] By adopting the above technical solution, the first shell and the second shell are snapped together, so that the protrusions are snap-fitted in the corresponding receiving grooves, and thus the iron core is clamped between the first shell and the second shell to form the required shielding head. During actual use, the two shielding heads are arranged crosswise and rotatably connected. At the free ends of the two shielding heads, the first connection pieces at one end are attached to the second connection pieces at the other end, so that the two shielding heads form a closed magnetic circle.

[0016] Optionally, the first housing is a semi-circular ring. An embedding groove is provided on the inner ring side of the first housing. A plurality of semi-circular magnetic rings are coaxially arranged on the inner ring side of the first housing. Embedding grooves are also provided on the concave sides of the semi-circular magnetic rings. Connecting blocks for embedding in the embedding grooves are fixed on the convex sides of the semi-circular magnetic rings. The plurality of semi-circular magnetic rings are all coaxially arranged, and the diameters of the plurality of semi-circular magnetic rings gradually decrease in the direction towards the center of the first housing.

[0017] By adopting the above technical solution, the corresponding number of semi-circular magnetic rings can be added to the inner ring side of the first housing according to the diameter of the wire harness to be measured until the wire harness is clamped between the two semi-circular magnetic rings with the smallest diameters, thereby reducing the distance between the semi-circular magnetic rings and the wire harness, further reducing the phenomenon of magnetic leakage, and ensuring the detection accuracy.

[0018] Optionally, a plurality of second heat dissipation grooves are provided on both outer sides of the semi-circular magnetic ring, and the inner wall of the second heat dissipation groove is arc-shaped.

[0019] By adopting the above technical solution, the heat dissipation area of the semi-circular magnetic ring is increased, the influence of temperature on the magnetic conduction ability is reduced, and the detection accuracy is improved.

[0020] In a second aspect, the present application provides a clamp meter, adopting the following technical solution:

[0021] A clamp meter includes a meter body, and the meter body adopts the shielding head structure as described in any one of claims 1-7.

[0022] By adopting the above technical solution, the detection of the clamp meter is made more accurate.

[0023] In summary, the present application includes at least one of the following beneficial technical effects:

[0024] 1. The first shielding layer and the second shielding layer make the shielding performance of the first housing and the second housing better, reduce the phenomenon of magnetic leakage, and improve the detection accuracy.

[0025] 2. The ferrofluid has a cooling performance, so that the coolant reciprocally stirs in the installation housing, realizing the cooling and heat dissipation of the outer walls of the first housing and the second housing, thereby slowing down the influence of temperature on the magnetic conduction ability of the iron core.

[0026] 3. According to the diameter of the wire harness to be measured, the corresponding number of semi-circular magnetic rings is added to the inner ring side of the first housing until the wire harness is clamped between the two semi-circular magnetic rings with the smallest diameters, thereby reducing the distance between the semi-circular magnetic rings and the wire harness, further reducing the phenomenon of magnetic leakage, and ensuring the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of Embodiment 1.

[0028] Figure 2 It is an exploded view of the overall structure of the first embodiment.

[0029] Figure 3 It is a cross-sectional view of the mounting cover in the first embodiment.

[0030] Figure 4 It is a schematic diagram of the overall structure of the second embodiment.

[0031] Reference numerals: 1, first shell; 2, second shell; 3, first shielding layer; 4, second shielding layer; 5, connection structure; 6, heat dissipation structure; 7, mounting cover; 8, magnetic fluid; 9, first heat dissipation groove; 10, receiving groove; 11, protrusion; 12, first connecting piece; 13, second connecting piece; 14, embedding groove; 15, semi-circular magnetic ring; 16, connecting block; 17, second heat dissipation groove; 18, meter body. Detailed implementation manners

[0032] The following further elaborates on this application Figures 1-4 in conjunction with the attached drawings.

[0033] Embodiment 1: The embodiment of this application discloses a shielding head structure for a clamp meter.

[0034] Referring to Figure 1 , a shielding head structure for a clamp meter includes a first shell 1 and a second shell 2. The first shell 1 and the second shell 2 are adapted to each other. In the actual use environment, the arc-shaped iron core is pre-held in the first shell 1, and then the second shell 2 is covered on the first shell 1 to form the required single shielding head.

[0035] Referring to Figure 1 and Figure 2 , during the actual installation process, in order to facilitate the assembly of the first shell 1 and the second shell 2, a connection structure 5 is provided between the first shell 1 and the second shell 2. The connection structure 5 includes a receiving groove 10 and a protrusion 11. A plurality of receiving grooves 10 are evenly spaced on the inner wall of the first shielding layer 3, and protrusions 11 adapted to the receiving grooves 10 are evenly formed on the outer side of the second shell 2. During the installation process, the outer side of the second shell 2 is attached to the inner side of the first shielding layer 3, so that the protrusions 11 are snapped into the receiving grooves 10, and thus it is difficult for the first shell 1 and the second shell 2 to separate.

[0036] Referring to Figure 1, To further improve the shielding performance of the first shell 1 and the second shell 2, a first shielding layer 3 is provided on the inner wall of the first shell 1, and a second shielding layer 4 is provided on the inner side of the second shell 2. Both the first shielding layer 3 and the second shielding layer 4 are made of magnetic conductive materials, and the first shell 1 and the second shell 2 are also made of magnetic conductive materials. The magnetic conductive material is preferably iron or iron doped with nickel. Since the magnetic resistance of iron is less than that of air, during the process of testing the wire, the closed circular magnetic field generated by the wire will be conducted along the magnetic conductive material to the induction coil. The induction coil conducts the magnetic field through the iron core to generate an induced current, thereby detecting the magnitude of the current in the wire.

[0037] Refer to Figure 1 , To ensure the convenience of the processing technology, the materials of the first shielding layer 3 and the second shielding layer 4 are set to be the same, and the cross-sectional shape of the first shielding layer 3 is the same as the cross-sectional shape of the first shell 1, and the cross-sectional shape of the second shielding layer 4 is the same as the cross-sectional shape of the second shell 2. During actual use, the first shielding layer 3 is snap-fitted and fixed in the inner cavity of the first shell 1, and the second shielding layer 4 is snap-fitted and fixed in the inner cavity of the second shell 2.

[0038] Refer to Figure 1 , When the first shell 1 and the second shell 2 are snap-fitted to form a shielding head, a number of first connection pieces 12 are fixedly formed at one end of the shielding head, and a number of second connection pieces 13 are formed and arranged at the other end of the shielding head. During actual detection, two shielding heads are required for each detection table. The two shielding heads are cross-set and rotatably connected to each other, so that the first connection pieces 12 of one shielding head are mutually attached and cooperated with the second connection pieces 13 of the other shielding head. Both the first connection pieces 12 and the second connection pieces 13 are also made of iron-based magnetic conductive materials, so that the two shielding heads form a closed magnetic conductive ring.

[0039] Refer to Figure 1 and Figure 3 , To further improve the accuracy of the multimeter detection and reduce the magnetic leakage phenomenon, heat dissipation structures 6 are provided on the outer sides of both the first shell 1 and the second shell 2. Since temperature is extremely likely to affect the magnetic conductivity of the iron core, to improve the magnetic conductivity of the iron core, the heat dissipation structure 6 includes an installation cover 7 and a coolant. There are two installation covers 7. One installation cover 7 is fixed on the side of the first shell 1 facing away from the second shell 2, and the other installation cover 7 is fixed on the side of the second shell 2 facing away from the first shell 1. The coolant is installed in the inner cavity of the installation cover 7. To make the coolant stir and cool in the installation cover 7, nano-scale magnetic particles are mixed in the coolant, and the mixing ratio of the coolant to the nano-scale magnetic particles is 2:1, and finally a magnetic fluid 8 with cooling performance is formed by mixing.

[0040] Refer to Figure 1 and Figure 3, during the process of detecting the electrical performance of the wire, the closed-loop circular magnetic field generated by the current flowing through the wire stirs the magnetorheological fluid 8, causing the coolant to flow within the installation housing, thereby further enhancing the heat dissipation of the first housing 1 and the second housing 2. To further improve the heat dissipation performance of the first housing 1 and the second housing 2, a number of first heat dissipation grooves 9 are evenly spaced on the outer side of the installation cover 7, and the inner wall of the first heat dissipation groove 9 is arc-shaped, and the first heat dissipation groove 9 increases the heat dissipation area of the installation cover 7.

[0041] Refer to Figure 1 , to further reduce the magnetic leakage phenomenon, the first housing 1 is set as a semi-circular ring, and a groove 14 with a dovetail-shaped cross-section is provided on the inner ring side of the first housing 1. A number of semi-circular magnetic rings 15 are coaxially arranged on the inner ring side of the first housing 1, and the number of semi-circular magnetic rings 15 are all coaxially arranged, and the diameters of the number of semi-circular magnetic rings 15 gradually decrease along the direction close to the wire.

[0042] Refer to Figure 1 , to fix the semi-circular magnetic ring 15 on the side wall of the first housing 1, a connecting block 16 for being embedded in the groove 14 is fixed on the convex side of the semi-circular magnetic ring 15, and the shape of the connecting block 16 is dovetail-shaped, thereby realizing the coaxial fixation of the semi-circular magnetic ring 15 on the inner side of the first housing 1. To set a semi-circular magnetic ring 15 with a smaller radius on the inner side of the semi-circular magnetic ring 15, a groove 14 with a dovetail-shaped cross-section is also provided on the concave side of the semi-circular magnetic ring 15, so that multiple semi-circular magnetic rings 15 can be stacked.

[0043] Refer to Figure 1 , to reduce the influence of temperature on the magnetic conductivity of the semi-circular magnetic ring 15, a number of second heat dissipation grooves 17 are provided on the side wall of the semi-circular ring, and the inner wall of the second heat dissipation groove 17 is arc-shaped, and the second heat dissipation groove 17 increases the heat dissipation area of the semi-circular magnetic ring 15, ensuring the magnetic conductivity of the semi-circular ring.

[0044] In the first embodiment of the present application, the implementation principle of a shielding head structure for a clamp meter is as follows: during the installation process, the second housing 2 is snap-fitted on the first housing 1, so that the iron core is clamped between the first housing 1 and the second housing 2, and thus the three form a single shielding head.

[0045] Embodiment 2: The embodiment of the present application discloses a clamp meter.

[0046] Refer to Figure 4 , a clamp meter includes a meter body 18, and the meter body 18 adopts the shielding head structure described in the first embodiment above. By using the above shielding head structure, the detection accuracy of the entire meter body 18 is improved.

[0047] In the second embodiment of the present application, the implementation principle of a shielding head structure for a clamp meter is as follows: Two shielding heads are cross-mounted on the head of the meter body 18, and the two shielding heads are rotatably connected to each other. During the testing process, the first connecting piece 12 at one end is in contact with the second connecting piece 13 at the other end, so that the two shielding heads form a closed ring-shaped magnetic conductor. During the testing process, the ring-shaped closed magnetic field generated by the wire harness is transmitted along the two shielding heads to the induction coil of the meter body 18, thereby realizing the test of the electrical performance of the wire harness.

[0048] The above are all the preferred embodiments of the present application, and the protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A shielding head structure for a clamp meter, comprising two groups of first shells (1) and second shells (2) for clamping an iron core, Characterized in that: Both the first shell (1) and the second shell (2) are made of magnetic conductive materials. A first shielding layer (3) is arranged on the inner side of the first shell (1), and a second shielding layer (4) is arranged on the inner side of the second shell (2). The iron core is clamped between the first shielding layer (3) and the second shielding layer (4). A connection structure (5) is arranged between the first shell (1) and the second shell (2), and heat dissipation structures (6) are arranged on the outer sides of both the first shell (1) and the second shell (2); The first shell (1) is a semi-circular ring. An embedding groove (14) is formed on the inner ring side of the first shell (1). A plurality of semi-circular magnetic rings (15) are coaxially arranged on the inner ring side of the first shell (1). Embedding grooves (14) are also formed on the concave sides of the semi-circular magnetic rings (15). Connection blocks (16) for being embedded in the embedding grooves (14) are fixed on the convex sides of the semi-circular magnetic rings (15). A plurality of the semi-circular magnetic rings (15) are all coaxially arranged, and the diameters of the plurality of semi-circular magnetic rings (15) are sequentially decreasing towards the direction close to the center of the first shell (1).

2. A shielding head structure for a clamp meter according to claim 1, Characterized in that: The first shielding layer (3) and the second shielding layer (4) are made of the same material and are both magnetic conductive materials. The cross-sectional shape of the first shielding layer (3) is the same as that of the first shell (1), and the cross-sectional shape of the second shielding layer (4) is the same as that of the second shell (2).

3. A shielding head structure for a clamp meter according to claim 1, Characterized in that: The heat dissipation structure (6) includes a mounting cover (7) fixedly formed on the outer sides of the first shell (1) and the second shell (2), and a coolant filled in the mounting cover (7). Nano-scale magnetic particles are mixed in the coolant, and the coolant and the nano-scale magnetic particles are mixed to form a magnetic fluid (8) with magnetism.

4. A shielding head structure for a clamp meter according to claim 3, Characterized in that: A plurality of first heat dissipation grooves (9) are evenly spaced and formed on the outer side of the mounting cover (7), and the inner walls of the first heat dissipation grooves (9) are arc-shaped.

5. A shielding head structure for a clamp meter according to claim 1, Characterized in that: The connection structure (5) includes a plurality of receiving grooves (10) evenly spaced and formed on the inner wall of the first shielding layer (3), and protrusions (11) evenly spaced and formed on the outer side of the second shell (2). The protrusions (11) are clamped in the receiving grooves (10). When the first shell (1) and the second shell (2) are mutually clamped to form a single shielding head, a plurality of first connection pieces (12) are formed at one end of the shielding head, and a plurality of second connection pieces (13) for cooperating with the first connection pieces (12) are formed at the other end of the shielding head.

6. A shielding head structure for a clamp meter according to claim 1, Characterized in that: A plurality of second heat dissipation grooves (17) are formed on the outer sides of both sides of the semi-circular magnetic ring (15), and the inner walls of the second heat dissipation grooves (17) are arc-shaped.

7. A clamp meter, comprising a meter body (18), characterized in that: the meter body (18) adopts the shielding head structure according to any one of claims 1-6.

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