Horizontal flow divider

Abstract

The horizontal shunt comprises a manganese-copper plate, red copper plates are welded on two sides of the manganese-copper plate, a first through hole is formed in the red copper plate close to the manganese-copper plate, a second through hole is formed in the red copper plate far away from the manganese-copper plate, and a pressing rivet nut fixed in the first through hole is arranged at the position, corresponding to the first through hole, of the upper side of each manganese-copper plate; l-shaped through grooves are formed in the positions, corresponding to the first through holes, of the red copper plates, and the projection shapes of the through grooves in the two red copper plates are in central symmetry along the horizontal center point of the manganese-copper plate and are asymmetric along the left-right center line of the manganese-copper plate; a pressing rivet bolt is fixed in each second through hole in a pressing rivet mode, and a screw rod of each pressing rivet bolt vertically extends upwards and exceeds the corresponding second through hole. The upper side of the red copper plate is provided with an annular recess corresponding to the joint of the second through hole and the screw. The pressure riveting nut is preset to prevent a wire from being touched by mistake, the resistance temperature coefficient of the shunt is reduced through the slotting design, and the pressure riveting screw is preset to solve the problem that the bolt head cannot be fixed due to limited space when the shunt is used.

Description

Technical Field

[0001] The utility model relates to a horizontal shunt. Background Art

[0002] A shunt is an essential component in intelligent circuit breakers, power supplies, disconnectors, and test instruments. For its mechanical structure, refer to Chinese Patent CN208270633U. Generally, a manganese copper plate is used as the resistance material, and copper plates are welded on both sides of the manganese copper plate for current access, and sampling is performed near the manganese copper plate. In the prior art, wiring holes for current access are provided on the outer sides where the two copper plates are far from each other, and threaded holes for sampling are provided near the manganese copper plate. The problems existing in the prior art are as follows:

[0003] 1. Since the closer the threaded hole for sampling is to the manganese copper plate, the lower the temperature drift and the smaller the error, when manufacturing the shunt, it is generally set as close as possible to the manganese copper plate. However, during sampling, the exposed part of the wire and the conductive joint at the end of the wire are very likely to accidentally touch the manganese copper plate, resulting in a change in resistance value. To solve this problem, the prior art generally leaves a sufficient safety distance between the threaded hole and the manganese copper plate, which affects the measurement accuracy.

[0004] 2. The hardness of copper is limited. When tapping threads on copper to make threaded holes, the service life of the thread is limited, and it is easy to be scrapped due to thread slipping, resulting in an increase in the rejection rate.

[0005] 3. When different users sample, the shapes and sizes of the conductive joints at the ends of the wires are different. If they are directly attached to the copper plate for contact sampling, the measured resistance values will be different due to different contact areas between the conductive joints and the copper plate, and it is impossible to ensure the consistency between the test results during the production stage and the resistance values measured during actual use by users.

[0006] 4. The temperature coefficient of resistance (TCR) is an important indicator of the shunt. The smaller the TCR of the shunt, the higher its accuracy. However, limited by the existing material technology and manufacturing process, it is very difficult to further reduce the TCR of the shunt.

[0007] 5. The shunt needs to be connected to a pressure plate to access current, and there are also wiring holes on the pressure plate. The shunt and the pressure plate are fixed by screwing with bolts and nuts. When the shunt and the pressure plate are screwed and tightened with bolts and nuts, generally, the bolt head needs to be fixed first, and then the nut is rotated. However, the installation position space of the shunt is limited, and there are often no conditions to fix the bolt head, so it is difficult to complete the tightening operation during use. Moreover, due to the low strength of copper itself, it is easy to deform, and the bolt is prone to relative rotation with the copper plate in the traditional pre-set bolt method. Summary of the Utility Model

[0008] The technical problem to be solved by the present utility model is to provide a horizontal shunt, which is preset with press riveting nuts to prevent the exposed part of the wire and the conductive joint from accidentally touching the manganese copper plate, and has a high consistency of sampling resistance value. Through a special slotting design, the resistance temperature coefficient of the shunt is greatly reduced. A screw is preset at the current connection hole through a press riveting process, solving the problem that the bolt head cannot be fixed due to limited space during the use of the traditional shunt.

[0009] To solve the above technical problems, the present utility model provides a horizontal shunt, which includes a rectangular manganese copper plate arranged horizontally. Rectangular copper plates are symmetrically welded to both the left and right sides of the manganese copper plate and are arranged horizontally. The two copper plates have the same size and are flush with the front and back sides of the manganese copper plate. Along the left-right direction and close to the manganese copper plate, the two copper plates are symmetrically provided with first through holes vertically penetrating the copper plates. Along the left-right direction and away from the manganese copper plate, the two copper plates are symmetrically provided with second through holes vertically penetrating the copper plates;

[0010] At the upper side position of each copper plate and corresponding to the first through hole, a press riveting nut fixed to the first through hole is provided;

[0011] At the positions of the two copper plates corresponding to the first through holes, through slots vertically penetrating the copper plates are provided. The vertical projection of the through slot is L-shaped, and the L shape includes a long horizontal side and a vertical side. The length direction of the horizontal side of the L shape is left-right, and the length direction of the vertical side of the L shape is front-back. The concave side of the L-shaped through slot faces the corresponding first through hole. The vertical projections of the through slots on the two copper plates are centrosymmetric about the horizontal center point of the manganese copper plate and are not symmetric about the left-right center line of the manganese copper plate;

[0012] A press riveting bolt is press riveted and fixed in each second through hole. The press riveting head of the press riveting bolt is matched with the second through hole. The lower side of the press riveting head of the press riveting bolt is flush with the lower side of the copper plate, and the screw of the press riveting bolt extends vertically upward and exceeds the second through hole;

[0013] At the upper side position of the copper plate and corresponding to the connection of each second through hole and the screw, an annular recess surrounding the second through hole is provided.

[0014] For the sake of simplicity in explaining the problem, hereinafter, a horizontal shunt described in the present utility model is simply referred to as this shunt.

[0015] The method for presetting the screw of this shunt includes the following steps:

[0016] (1) Prepare a press riveting machine. A relief hole matching the screw of the press riveting bolt is provided on the punch of the press riveting machine. The bottom die of the press riveting machine is a flat bottom die. An annular boss surrounding the relief hole is provided at the position of the punch of the press riveting machine corresponding to the relief hole;

[0017] (2) Prepare the splitter body that has been processed and has a screw that is ready for use;

[0018] (3) The screw of the rivet bolt to be riveted is passed from bottom to top through the corresponding second through hole of the diverter copper plate, so that the rivet head of the rivet bolt is pre-positioned on the lower side of the corresponding second through hole of the copper plate;

[0019] (4) The diverter body and the preassembled rivet bolts are transferred to the bottom die of the rivet machine. After adjusting to the target position, the rivet machine is started. The punch of the rivet machine is pressed down. The rivet head of the rivet nut cooperates with the second through hole under the extrusion force and is flush with the bottom of the copper plate after riveting. At the same time, the annular boss on the punch of the rivet machine forms an annular recess at the upper position of the copper plate corresponding to the connection between the second through hole and the screw.

[0020] Advantages of this shunt:

[0021] 1. The use of pressure riveting nuts can make the sampling point infinitely close to the joint between the manganese copper plate and the copper plate, thereby obtaining a smaller temperature drift performance. During sampling, the conductive joint only contacts the upper side of the pressure riveting nut and does not contact the manganese copper plate;

[0022] 2. The rivet nut is generally made of stainless steel. Compared with copper, it has higher hardness, longer thread life, and is not easy to slip, which extends the service life of the diverter.

[0023] 3. During sampling, the conductive joint only contacts the upper side of the rivet nut, and the upper side area of ​​the rivet nut is certain. When conductive joints of different shapes and sizes contact the upper side of the rivet nut, the actual contact area is always constant (the conductive joint generally completely covers the rivet nut during use). This ensures that the resistance value measured by the user in actual use is highly consistent with the test result of the shunt when it leaves the factory.

[0024] 4. By making grooves near the first through hole of the copper plate, the entire shunt obtains an extremely low resistance temperature coefficient, which greatly improves its accuracy. In addition, the presence of the grooves increases the heat exchange area between the shunt as a whole and the air, and also provides excellent heat dissipation.

[0025] 5. By presetting the screw at the second through hole through the riveting process, the problem that the bolt head cannot be fixed due to limited space when using the traditional diverter is solved. And because it comes with a screw, the convenience of using the diverter is increased. In addition, the method of presetting the screw is simple and easy to process. By setting a boss structure on the riveting machine, a ring-shaped recess is formed at the second through hole of the copper plate, so that the copper at this location enters the screw thread after deformation, preventing the riveting bolt and the copper plate from rotating relative to each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present shunt.

[0027] Figure 2 is Figure 1 A partial enlarged view of part A.

[0028] Figure 3 is the engineering drawing of experimental group 1.

[0029] Figure 4 is the engineering drawing of experimental group 2.

[0030] Figure 5 is the engineering drawing of experimental group 3.

[0031] Figure 6 is the engineering drawing of experimental group 4.

[0032] Figure 7 is the engineering drawing of the control group. Detailed implementation manner

[0033] See Figure 1 and Figure 2 , a horizontal diverter, comprising a rectangular manganese copper plate 1 arranged horizontally. Horizontally arranged rectangular copper plates 2 are symmetrically welded to both the left and right sides of the manganese copper plate 1. The two copper plates 2 are of the same size and are flush with the front and rear sides of the manganese copper plate 1. At positions where the two copper plates 2 are close to the manganese copper plate 1 in the left - right direction, first through - holes 21 penetrating the copper plates 2 vertically are symmetrically provided. At positions where the two copper plates 2 are far from the manganese copper plate 1 in the left - right direction, second through - holes 22 penetrating the copper plates 2 vertically are symmetrically provided;

[0034] At the upper side position of each copper plate 2 corresponding to the first through - hole 21, a rivet nut 3 fixed to the first through - hole 21 is provided;

[0035] At the positions of the two copper plates 2 corresponding to the first through - holes 21, through - slots 4 penetrating the copper plates 2 vertically are provided. The vertical projection of the through - slot 4 is L - shaped. The L - shape includes a long horizontal side and a vertical side. The length direction of the horizontal side of the L - shape is left - right, and the length direction of the vertical side of the L - shape is front - rear. The concave side of the L - shape of the through - slot 4 faces the corresponding first through - hole 21. The vertical projections of the through - slots 4 on the two copper plates 2 are centrosymmetric about the horizontal center point of the manganese copper plate 1 and are not symmetric about the center line of the manganese copper plate 1 in the left - right direction;

[0036] A rivet bolt 5 is press - riveted and fixed in each second through - hole 22. The riveting head of the rivet bolt 5 is matched with the second through - hole 22. The lower side of the riveting head of the rivet bolt 5 is flush with the lower side of the copper plate 2. The screw rod of the rivet bolt 5 extends vertically upward and exceeds the second through - hole 22;

[0037] At the upper side position of the copper plate 2, a circular recess 51 is provided around each second through hole 22 corresponding to the connection with the screw.

[0038] For the sake of simplicity in explaining the problem, hereinafter, a horizontal shunt described in the present utility model will be simply referred to as this shunt.

[0039] The method for presetting the screw of this shunt includes the following steps:

[0040] (1) Prepare a riveting machine. A relief hole matching the screw of the riveting bolt 5 is provided on the punch of the riveting machine. The bottom die of the riveting machine is a flat bottom die. A circular boss is provided around the relief hole at the position of the punch of the riveting machine.

[0041] (2) Prepare the shunt body that has been processed and is ready for screw presetting for standby.

[0042] (3) Pass the screw of the riveting bolt 5 to be riveted from bottom to top through the corresponding second through hole 22 of the shunt copper plate 2, so that the riveting head of the riveting bolt 5 is positioned and pre-assembled on the lower side of the corresponding second through hole 22 of the copper plate 2.

[0043] (4) Transfer the shunt body and the pre-assembled riveting bolt 5 to the bottom die of the riveting machine. After adjusting to the target position, start the riveting machine. The punch of the riveting machine presses down. The riveting head of the riveting nut 3 cooperates with the second through hole 22 under the action of the extrusion force and is flush with the bottom of the copper plate 2 after riveting. At the same time, the circular boss on the punch of the riveting machine forms a circular recess 51 at the connection between the second through hole 22 and the screw on the upper side position of the copper plate 2.

[0044] The advantages of this shunt:

[0045] 1. Using the riveting nut 3 can make the sampling point infinitely close to the connection between the manganese copper plate 1 and the copper plate 2, thus obtaining a smaller temperature drift performance. During sampling, the conductive joint only contacts the upper side of the riveting nut 3 and will not contact the manganese copper plate 1.

[0046] 2. The riveting nut 3 is generally made of stainless steel. Compared with copper, it has higher hardness, longer thread life, is not prone to thread slipping, and extends the service life of the shunt.

[0047] 3. Since during sampling, the conductive joint only contacts the upper side of the riveting nut 3, and the area of the upper side of the riveting nut 3 is certain, when conductive joints of different shapes and sizes contact the upper side of the riveting nut 3, the actual contact area is always constant (when in use, the conductive joint generally completely covers the riveting nut 3). In this way, it can ensure that the measured resistance value during actual use by the user is highly consistent with the test result when the shunt leaves the factory.

[0048] 4. By grooving near the first through-hole 21 of the copper plate 2, the entire shunt obtains an extremely low resistance temperature coefficient, greatly improving its accuracy. Moreover, due to the existence of the groove, the heat exchange area between the overall shunt and the air is increased, and excellent heat dissipation is also provided.

[0049] 5. By presetting a screw at the second through-hole 22 through a press riveting process, the problem that the bolt head cannot be fixed due to space limitation during the use of the traditional shunt is solved. Moreover, due to the self-provided screw, the convenience of using the shunt is increased. And the method steps of presetting the screw are simple and the processing is convenient. By setting a boss structure on the press riveting machine to form an annular indentation 51 at the second through-hole 22 of the copper plate 2, the deformed copper at this place enters the thread, preventing the press riveted bolt 5 from rotating relative to the copper plate 2.

[0050] To prove that the grooving method provided in this application can indeed greatly reduce the resistance temperature coefficient of the shunt and improve the accuracy, the following comparative experiments are given:

[0051] Test environment: The indoor temperature of the temperature test environment is 24.7°C - 24.8°C, and the humidity is 35% - 38%.

[0052] Experimental groups:

[0053] Experimental group 1, see Figure 3 , the structure adopts a conventional horizontal shunt structure, uses a manganese copper plate as the resistance material, welds copper plates on both sides of the manganese copper plate for connecting current, and symmetrically arranges wiring holes vertically penetrating the copper plates at both sides of the two copper plates away from the manganese copper plate in the left-right direction. Symmetrically arranged through-holes vertically penetrating the corresponding copper plates are provided at both sides of the two copper plates close to the manganese copper plate in the left-right direction. A press riveting nut fixed in the through-hole is provided at the position corresponding to the through-hole on the upper side of the manganese copper plate as a sampling unit. Symmetrically arranged through-grooves vertically penetrating the copper plates are provided at the positions corresponding to the sampling unit on both copper plates. The shapes of the through-grooves on the two copper plates are U-shaped that are symmetric left and right and open towards each other. For specific parameters, see the drawing marks.

[0054] Experimental group 2, see Figure 4, the structure adopts a conventional horizontal shunt structure. Manganese copper plates are used as resistance materials. Copper plates are welded on both sides of the manganese copper plate for current access. On both sides of the manganese copper plate, symmetrically arranged wiring holes penetrating the copper plates vertically are provided at positions far from the manganese copper plate in the left-right direction. On both sides of the manganese copper plate, symmetrically arranged through holes penetrating the corresponding copper plates vertically are provided at positions close to the manganese copper plate in the left-right direction. At the positions corresponding to the through holes on the upper side of the manganese copper plate, rivet nuts fixed in the through holes are provided. As the sampling unit, at the positions corresponding to the sampling unit on both copper plates, through grooves penetrating the copper plates vertically are provided. The shapes of the through grooves on the two copper plates are such that the projection of the through groove described in this application along the vertical direction is L-shaped. The L shape includes a long horizontal side and a vertical side. The length direction of the horizontal side of the L shape is in the left-right direction, and the length direction of the vertical side of the L shape is in the front-back direction. The concave side of the 4L-shaped through groove faces the corresponding sampling unit. The projections of the through grooves on the two copper plates along the vertical direction are centrosymmetric about the horizontal center point of the manganese copper plate and are not symmetric about the center line of the manganese copper plate in the left-right direction. Specific parameters are shown in the drawing marks.

[0055] Experimental group 3, see Figure 5 , the structure adopts a conventional horizontal shunt structure. Manganese copper plates are used as resistance materials. Copper plates are welded on both sides of the manganese copper plate for current access. On both sides of the manganese copper plate, symmetrically arranged wiring holes penetrating the copper plates vertically are provided at positions far from the manganese copper plate in the left-right direction. On both sides of the manganese copper plate, symmetrically arranged through holes penetrating the corresponding copper plates vertically are provided at positions close to the manganese copper plate in the left-right direction. At the positions corresponding to the through holes on the upper side of the manganese copper plate, rivet nuts fixed in the through holes are provided. As the sampling unit, at the positions corresponding to the sampling unit on both copper plates, through grooves penetrating the copper plates vertically are provided. The shapes of the through grooves on the two copper plates are long strips symmetrically arranged in the front-back direction in the left-right direction. Specific parameters are shown in the drawing marks.

[0056] Experimental group 4, see Figure 6 , the structure adopts a conventional horizontal shunt structure. Manganese copper plates are used as resistance materials. Copper plates are welded on both sides of the manganese copper plate for current access. On both sides of the manganese copper plate, symmetrically arranged wiring holes penetrating the copper plates vertically are provided at positions far from the manganese copper plate in the left-right direction. On both sides of the manganese copper plate, symmetrically arranged through holes penetrating the corresponding copper plates vertically are provided at positions close to the manganese copper plate in the left-right direction. At the positions corresponding to the through holes on the upper side of the manganese copper plate, rivet nuts fixed in the through holes are provided. As the sampling unit, at the positions corresponding to the sampling unit on both copper plates, two through grooves penetrating the copper plates vertically are respectively provided. The shapes of the through grooves are long strips in the left-right direction. The two through grooves on each copper plate are symmetrically distributed before and after the rivet nut, and the through grooves on the two copper plates are symmetrically arranged in the left-right direction. Specific parameters are shown in the drawing marks.

[0057] Control group, see Figure 7, the structure adopts a conventional horizontal shunt structure, uses manganese copper plate as the resistance material, welds copper plates on both sides of the manganese copper plate for connecting current, symmetrically arranges wiring holes vertically penetrating the copper plates at positions far from the manganese copper plate in the left-right direction on both copper plates, symmetrically arranges through holes vertically penetrating the corresponding copper plates at positions close to the manganese copper plate in the left-right direction on both copper plates, and riveting nuts fixed in the through holes are arranged at positions corresponding to the through holes on the upper side of the manganese copper plate. As the sampling unit, there are no slots on both copper plates, and the specific parameters are shown in the drawing marks.

[0058] For the above experimental group and control group, the shunt body structure and the sampling unit are the same, only the presence or absence of slots and the slotting methods are different. Next, TCR tests are carried out on four experimental groups and one control group respectively. The test process is as follows: 1. Place the product to be tested in a high and low temperature chamber, adjust the temperature from 20°C to 60°C, at intervals of 10°C; 2. Record the values and calculate the TCR value based on 20°C as the reference.

[0059] The test equipment is shown in the following table:

[0060]

[0061] For Experimental Group 1, the TCR test results are shown in Table 1:

[0062] Table 1

[0063] Serial number Experimental temperature (°C) Measured resistance (mΩ) TCR ppm Accuracy (%) 1 20 0.150160 0.0000 0.1067 2 30 0.150102 -38.6255 0.0680 3 40 0.150066 -31.2999 0.0440 4 50 0.150028 -29.3021 0.0187 5 60 0.149956 -33.9638 -0.0293

[0064] For Experimental Group 2, the TCR test results are shown in Table 2:

[0065] Table 2

[0066] Serial number Experimental temperature (°C) Measured resistance (mΩ) TCR ppm Accuracy (%) 1 20 0.149907 0.0000 -0.0620 2 30 0.149897 -6.6708 -0.0687 3 40 0.149935 9.3391 -0.0433 4 50 0.149942 7.7826 -0.0387 5 60 0.149940 5.5034 -0.0400

[0067] For Experimental Group 3, the TCR test results are shown in Table 3:

[0068] Table 3

[0069] Serial number Experimental temperature (°C) Measured resistance (mΩ) TCR ppm Accuracy (%) 1 20 0.150160 0.0000 0.1067 2 30 0.150102 -38.6255 0.0680 3 40 0.150066 -31.2999 0.0440 4 50 0.150028 -29.3021 0.0187 5 60 0.149956 -33.9638 -0.0293

[0070] For Experimental Group 4, the TCR test results are shown in Table 4:

[0071] Table 4

[0072] Serial number Experimental temperature (°C) Measured resistance (mΩ) TCR ppm Accuracy (%) 1 20 0.149990 0.0000 -0.0067 2 30 0.150070 53.3369 0.0467 3 40 0.150136 48.6699 0.0907 4 50 0.150167 39.3360 0.1113 5 60 0.150170 30.0020 0.1133

[0073] For the control group, the TCR test results are shown in Table 5:

[0074] Table 5

[0075] Serial number Experimental temperature (°C) Measured resistance (mΩ) TCR ppm Accuracy (%) 1 20 0.149740 0.0000 -0.1733 2 30 0.149831 60.7720 -0.1127 3 40 0.149880 46.7477 -0.0800 4 50 0.149902 36.0625 -0.0653 5 60 0.149930 31.7217 -0.0467

[0076] From the above experimental data, it can be seen that the resistance value of experimental group 2 changes minimally with temperature. The grooving method provided by this application can indeed significantly reduce the temperature coefficient of resistance of the shunt and improve the accuracy.

Claims

1. A horizontal flow divider, comprising a horizontally arranged rectangular manganese copper plate, with horizontally arranged rectangular copper plates symmetrically welded on both sides of the manganese copper plate, the two copper plates having the same size and being flush with the front and rear sides of the manganese copper plate, the two copper plates being symmetrically provided with first through holes penetrating the copper plates in the vertical direction near the manganese copper plates in the left and right directions, and the two copper plates being symmetrically provided with second through holes penetrating the copper plates in the vertical direction away from the manganese copper plates in the left and right directions, characterized in that: A rivet nut fixed to the first through hole is provided at a position on the upper side of each copper plate corresponding to the first through hole; The positions of the two copper plates corresponding to the first through holes are both provided with through grooves penetrating the copper plates in the vertical direction, the projection of the through grooves in the vertical direction is L-shaped, the L-shape includes a long horizontal side and a vertical side, the length direction of the horizontal side of the L-shape is left-right, the length direction of the vertical side of the L-shape is front-back, the concave side of the L-shaped through groove is directly opposite to the first through hole on the corresponding side, the projections of the through grooves on the two copper plates in the vertical direction are centrally symmetrical along the horizontal center point of the manganese copper plate, and are asymmetrical along the left-right center line of the manganese copper plate; A rivet bolt is fixed by pressure riveting in each second through hole, the rivet head of the rivet bolt matches with the second through hole, the lower side of the rivet head of the rivet bolt is flush with the lower side of the copper plate, and the screw rod of the rivet bolt extends vertically upward and exceeds the second through hole; An annular recess arranged around the second through hole is provided at the upper side of the copper plate corresponding to the connection between each second through hole and the screw rod.

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