Large-current high-frequency isolation unit and preparation method thereof

Abstract

The invention discloses a large-current high-frequency isolation unit which comprises an insulating shell, an insulating cover plate, a magnetic core, a coil winding, a wiring threaded column and a wiring nut, the coil winding is wound on the cylindrical magnetic core to form an inductance coil, the inductance coil lies in the insulating shell, the wiring threaded column is rotationally connected in a threaded hole of the insulating shell, and the wiring nut is connected with the wiring threaded column. The leading-out end of the coil winding is carried on the inner end of the wiring threaded column, the wiring nut is spirally connected to the outer end of the wiring threaded column, epoxy resin is encapsulated in the insulating shell, the insulating cover plate covers the upper side of the epoxy resin, and the cured epoxy resin, the insulating shell and the insulating cover plate form an integrated structure. According to the invention, the use requirements of high-current and high-frequency environments are met at the same time, and the problem that the existing inductor product can only meet the use requirements of high current or high frequency is solved.

Description

Technical Field

[0001] The invention relates to a high-current high-frequency isolation unit and a preparation method thereof, belonging to the technical field of high-current high-frequency inductance. Background Art

[0002] Existing filter inductors can only meet the requirements of high-frequency environments or high-current environments, but there is no product that can meet the requirements of both high-frequency and high-current environments. Existing filter inductor toroidal cores generate a lot of heat when the current is too large, and the heat dissipation area is relatively small, which limits the product's overcurrent capability. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a high-current high-frequency isolation unit and a preparation method thereof, which can simultaneously meet the market demand for high-current and high-frequency environments.

[0004] The technical solution adopted by the present invention is: a high-current high-frequency isolation unit, including an insulating shell, an insulating cover, a magnetic core, a coil winding, a terminal thread column and a terminal nut. The coil winding is wound on the cylindrical magnetic core to form an inductor coil, the inductor coil lies flat in the insulating shell, the terminal thread column is rotatably connected in the threaded hole of the insulating shell, the lead end of the coil winding is mounted on the inner end of the terminal thread column, the terminal nut is spirally connected to the outer end of the terminal thread column, epoxy resin is poured in the insulating shell, and the insulating cover is covered on the upper side of the epoxy resin. After the epoxy resin is cured, it forms an integrated structure with the insulating shell and the insulating cover.

[0005] Furthermore, the lead-out end of the coil winding is fixed on the terminal thread column by welding.

[0006] Furthermore, the outer section of the above-mentioned terminal thread column is provided with a hexagonal head abutting against the insulating shell, and the terminal nut is spirally connected to the outside of the hexagonal head.

[0007] Furthermore, mounting holes are arranged on both sides of the bottom of the insulating shell, and the insulating shell can be fixedly connected to the whole machine by passing bolts through the mounting holes.

[0008] Furthermore, the cylindrical magnetic core comprises a first cylindrical magnetic core, a second cylindrical magnetic core and a third cylindrical magnetic core which are fixed in sequence, and annular partitions are arranged at both ends and the middle of the cylindrical magnetic core to form two annular grooves, which are used to wind two coil windings.

[0009] A method for preparing a high-current high-frequency isolation unit, the method comprising the following steps:

[0010] Step 1: Bonding:

[0011] 1.1) Use E107HF epoxy resin to apply a layer of epoxy resin on one end of the cleaned first cylindrical magnetic core; scrape the epoxy resin evenly and spread it on the end of the magnetic core; stack the second cylindrical magnetic core on the cylindrical magnetic core with glue applied and adjust the position of the magnetic cores so that the two magnetic cores are aligned; connect the third cylindrical magnetic core in the same way, so that the three magnetic cores are bonded into one cylindrical magnetic core;

[0012] 1.2) Use high temperature tape to wrap the glue point one or two times to prevent the core from shifting during the baking process and causing the core to be misaligned;

[0013] 1.3) Bonding of partitions: Then put three annular partitions on the one-piece cylindrical magnetic core that has passed the inspection, adjust the position of the partitions on the cylindrical magnetic core, so that two partitions are located at the two ends of the cylindrical magnetic core, and one partition is located in the middle of the magnetic core column, and glue is applied on both sides of each partition so that the glue sticks to the partition and the cylindrical magnetic core to form a cylindrical magnetic core with two annular grooves;

[0014] Step 2: Winding:

[0015] Clamp a section of the coil winding on the winding fixture and press it tightly (about 100mm in length). Hold one end of the cylindrical core tightly with one hand, and wind the coil winding in an annular groove between two partitions on the cylindrical core. Start from the middle of the core to the edge to fold and wind a 41Ts coil winding. After winding, use high-temperature tape to wrap and fix the two lead-out ends of the wound coil. In the same way, in another annular groove, fold and wind another 41Ts coil winding from the middle of the cylindrical core to the edge.

[0016] Step 3: Pre-soldering

[0017] 3.1) Spread out the lead wires of the coil windings, and the lead wire spreading position should be 5mm-10mm beyond the edge of the partition;

[0018] 3.2) After the pre-soldering tin furnace temperature meets the standard, put the product lead into the tin furnace for pre-soldering. When the paint film begins to melt, move the product horizontally to remove the paint film;

[0019] 3.3) Clean the lead-out end of the coil winding and remove foreign matter such as tin beads attached to the coil;

[0020] Step 4: Assembly welding:

[0021] 4.1) Assemble the terminal screw posts into the four holes on the top of the insulating shell, leaving 11mm±0.5mm on the outside of the insulating shell, and then place the lead-out ends of the wound core windings upward and flat into the insulating shell. Adjust the position of the lead-out ends and press the leads down to the edge of the terminal screw posts. The lead length should be flush with the edge of the insulating shell, and the excess wire tails should be cut off;

[0022] 4.2) When winding, the two lead-out terminals near the middle partition are a group of terminals with the same name; cross the terminals with the same name on both sides of the winding and connect them to the wiring threaded posts on the opposite sides respectively. All lead wires must be connected for a complete circle and the lead wires must be close to the shell wall;

[0023] 4.3) Place the connected product terminals on the operating table with the terminals facing upwards, apply a small amount of tin to the soldering iron, and solder each terminal. After soldering, use a toothbrush with anhydrous ethanol to scrub the soldering position and the surrounding area;

[0024] Step 5: Potting:

[0025] Use W-280 potting glue to pour glue from one side of the long side of the insulation shell into the cavity of the insulation shell, and gradually let the glue fill the entire cavity from the other side of the long side.

[0026] In the welding process, a soldering iron at 350°C is used, and the welding time is 5-10S. The lead-out end of the coil winding is wound on the terminal thread column for 3 turns without overlapping. The potting process uses an automatic dispensing machine for dispensing and potting. After dispensing, the baking condition is 130°C for 120 minutes.

[0027] Beneficial effects of the present invention: Compared with the prior art, the cylindrical magnetic core structure of the present invention increases the relative heat dissipation area, improves the rated overcurrent capacity of the product from the heat dissipation aspect, and at the same time meets the use requirements of large current and high frequency environments, solving the problem that existing inductor products can only meet large current or high frequency use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a cross-sectional structural schematic diagram of the present invention;

[0029] Figure 2 It is a left-side structural physical diagram of the present invention;

[0030] Figure 3 It is a front view structure physical diagram of the present invention;

[0031] Figure 4 It is a top view of the structure of the present invention;

[0032] Figure 5 It is a schematic diagram of the circuit principle structure of the present invention;

[0033] Figure 6 Schematic diagram of the magnetic core structure. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0035] Example 1: Figure 1-6As shown, a high-current high-frequency isolation unit includes an insulating shell 1, an insulating cover plate 2, a cylindrical magnetic core 3, a coil winding 4, a terminal thread column 5 and a terminal nut 6. The coil winding 4 is wound on the cylindrical magnetic core 3 to form an inductor coil. The inductor coil lies flat in the insulating shell 1. The terminal thread column 5 is rotatably connected to the threaded hole of the insulating shell 1. The lead end of the coil winding 4 is mounted on the inner end of the terminal thread column 5. The terminal nut 6 is spirally connected to the outer end of the terminal thread column 5. Epoxy resin is poured in the insulating shell 1, and the insulating cover plate 2 is covered on the upper side of the epoxy resin. After the epoxy resin is cured, it forms an integrated structure with the insulating shell 1 and the insulating cover plate 2.

[0036] In order to make the conductive connection more reliable, the lead-out end of the coil winding 4 is fixed to the terminal thread column 5 by welding.

[0037] The outer section of the terminal thread column 5 is provided with a hexagonal head 7 which abuts against the insulating housing 1, and the terminal nut 6 is spirally connected to the outside of the hexagonal head 7, so as to facilitate the connection of the high-frequency isolation unit.

[0038] In order to facilitate the installation of the high-frequency isolation unit, mounting holes 8 are provided on both sides of the bottom of the insulating housing 1 , and the insulating housing 1 can be fixedly connected to the whole machine by passing bolts through the mounting holes 8 .

[0039] The cylindrical magnetic core 3 includes a first cylindrical magnetic core, a second cylindrical magnetic core and a third cylindrical magnetic core which are fixed in sequence. Annular partitions 9 are provided at both ends and the middle of the cylindrical magnetic core 3 to form two annular grooves. The two annular grooves are used to wind two coil windings. The two windings are isolated by partition material, which improves the isolation effect of the product.

[0040] Embodiment 2: A method for preparing a high-current high-frequency isolation unit, the method comprising the following steps:

[0041] Step 1: Bonding:

[0042] 1.1) Use E107HF epoxy resin to apply a layer of epoxy resin on one end of the cleaned first cylindrical magnetic core; scrape the epoxy resin evenly and spread it on the end of the magnetic core; stack the second cylindrical magnetic core on the cylindrical magnetic core with glue applied and adjust the position of the magnetic cores so that the two magnetic cores are aligned; connect the third cylindrical magnetic core in the same way, so that the three magnetic cores are bonded into one cylindrical magnetic core;

[0043] 1.2) Use high temperature tape to wrap the glue point one or two times to prevent the core from shifting during the baking process and causing the core to be misaligned;

[0044] 1.3) Bonding of partitions: Then put three annular partitions on the one-piece cylindrical magnetic core that has passed the inspection, adjust the position of the partitions on the cylindrical magnetic core, so that two partitions are located at the two ends of the cylindrical magnetic core, and one partition is located in the middle of the magnetic core column, and glue is applied on both sides of each partition so that the glue sticks to the partition and the cylindrical magnetic core to form a cylindrical magnetic core with two annular grooves;

[0045] Step 2: Winding:

[0046] Clamp a section of the coil winding on the winding fixture and press it tightly (about 100mm in length). Hold one end of the cylindrical core tightly with one hand, and wind the coil winding in an annular groove between two partitions on the cylindrical core. Start from the middle of the core to the edge to fold and wind a 41Ts coil winding. After winding, use high-temperature tape to wrap and fix the two lead-out ends of the wound coil. In the same way, in another annular groove, fold and wind another 41Ts coil winding from the middle of the cylindrical core to the edge.

[0047] Step 3: Pre-soldering

[0048] 3.1) Spread out the lead wires of the coil windings, and the lead wire spreading position should be 5mm-10mm beyond the edge of the partition;

[0049] 3.2) After the pre-soldering tin furnace temperature meets the standard, put the product lead into the tin furnace for pre-soldering. When the paint film begins to melt, move the product horizontally to remove the paint film;

[0050] 3.3) Clean the lead-out end of the coil winding and remove foreign matter such as tin beads attached to the coil;

[0051] Step 4: Assembly welding:

[0052] 4.1) Assemble the terminal screw posts into the four holes on the top of the insulating shell, leaving 11mm±0.5mm on the outside of the insulating shell, and then place the lead-out ends of the wound core windings upward and flat into the insulating shell. Adjust the position of the lead-out ends and press the leads down to the edge of the terminal screw posts. The lead length should be flush with the edge of the insulating shell, and the excess wire tails should be cut off;

[0053] 4.2) When winding, the two lead-out terminals near the middle partition are a group of terminals with the same name; cross the terminals with the same name on both sides of the winding and connect them to the terminal threaded studs on the opposite side, such as Figure 5 As shown in the schematic diagram, all leads need to be connected in a complete circle and the leads should be close to the shell wall;

[0054] 4.3) Place the connected product terminals on the operating table with the terminals facing upwards, apply a small amount of tin to the soldering iron, and solder each terminal. After soldering, use a toothbrush with anhydrous ethanol to scrub the soldering position and the surrounding area;

[0055] Step 5: Potting:

[0056] Step 6: Test:

[0057] 6.1) Test instrument and frequency: Ls, RDC test instrument: HP4263B or equivalent instrument for testing, test frequency: 100kHz, 1V;

[0058] 6.2) Test method: When testing the RDC value, the fixture clamps the product lead-out terminals with the legs; when measuring the Ls value, connect the right lead-out terminals in series and clamp the two left lead-out terminals.

[0059] Use W-280 potting glue to pour glue from one side of the long side of the insulation shell into the cavity of the insulation shell, and gradually let the glue fill the entire cavity from the other side of the long side.

[0060] Among them, the welding process uses an electric soldering iron at 350℃ and a welding time of 5-10S. The lead-out end of the coil winding is wound on the terminal thread column with 3 non-overlapping turns. The potting process uses an automatic dispensing machine for dispensing and potting. After dispensing, the baking condition is 130℃ for 120 minutes.

[0061] The two windings are isolated by partition materials, which improves the isolation effect of the product, as shown in the following table.

[0062]

[0063] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A high current high frequency isolation unit, characterized in that: The invention comprises an insulating shell (1), an insulating cover plate (2), a cylindrical magnetic core (3), a coil winding (4), a terminal thread column (5) and a terminal nut (6). The coil winding (4) is wound on the cylindrical magnetic core (3) to form an inductor coil. The inductor coil lies flat inside the insulating shell (1). The terminal thread column (5) is rotatably connected to a threaded hole of the insulating shell (1). The lead end of the coil winding (4) is mounted on the inner end of the terminal thread column (5). The terminal nut (6) is spirally connected to the outer end of the terminal thread column (5). Epoxy resin is poured inside the insulating shell (1), and the insulating cover plate (2) is covered on the upper side of the epoxy resin. After the epoxy resin is cured, it forms an integrated structure with the insulating shell (1) and the insulating cover plate (2).

2. A high current high frequency isolation unit according to claim 1, characterized in that: The lead-out end of the coil winding (4) is fixed to the terminal thread column (5) by welding.

3. A high current high frequency isolation unit according to claim 1, characterized in that: The outer section of the terminal thread column (5) is provided with a hexagonal head (7) that abuts against the insulating housing (1), and the terminal nut (6) is spirally connected to the outside of the hexagonal head (7).

4. A high current high frequency isolation unit according to claim 1, characterized in that: Mounting holes (8) are provided on both sides of the bottom of the insulating housing (1), and the insulating housing (1) can be fixedly connected to the entire machine by passing bolts through the mounting holes (8).

5. The high current high frequency isolation unit according to claim 1, characterized in that: The cylindrical magnetic core (3) comprises a first cylindrical magnetic core, a second cylindrical magnetic core and a third cylindrical magnetic core which are fixed in sequence to each other, and an annular partition plate (9) is provided at both ends and the middle of the cylindrical magnetic core (3) to form two annular grooves, and the two annular grooves are used to wind two coil windings.

6. The method for preparing a high current high frequency isolation unit according to claim 1, characterized in that: The method comprises the following steps: Step 1: Bonding: 1.1) Use E107HF epoxy resin to apply a layer of epoxy resin on one end of the cleaned first cylindrical magnetic core; scrape the epoxy resin evenly and spread it on the end of the magnetic core; stack the second cylindrical magnetic core on the cylindrical magnetic core with glue applied and adjust the position of the magnetic cores so that the two magnetic cores are aligned; connect the third cylindrical magnetic core in the same way, so that the three magnetic cores are bonded into one cylindrical magnetic core; 1.2) Use high temperature tape to wrap the glue point one or two times; 1.3) Partition bonding: Then put three annular partitions on the one-piece cylindrical magnetic core that has passed the inspection, adjust the position of the partitions on the cylindrical magnetic core, so that two partitions are located at the two ends of the cylindrical magnetic core, and one partition is located in the middle of the magnetic core column. Glue is applied on both sides of each partition so that the glue sticks to the partition and the cylindrical magnetic core to form a cylindrical magnetic core with two annular grooves; Step 2: Winding: Clamp a section of the coil winding on the winding fixture and press it to fix it (about 100mm in length). Hold one end of the cylindrical core tightly with one hand, and wind the coil winding in an annular groove between two partitions on the cylindrical core. Start from the middle of the core to the edge to fold and wind a 41Ts coil winding. After winding, use high-temperature tape to wrap and fix the two lead-out ends of the wound coil. In the same way, in another annular groove, fold and wind another 41Ts coil winding from the middle of the cylindrical core to the edge. Step 3: Pre-soldering 3.1) Spread out the lead wires of the coil windings, and the lead wire spreading position should exceed the edge of the partition by 5mm-10mm; 3.2) After the pre-soldering tin furnace temperature meets the standard, put the product lead into the tin furnace for pre-soldering. When the paint film begins to melt, move the product horizontally to remove the paint film; 3.3) Clean the lead-out ends of the coil windings; Step 4: Assembly welding: 4.1) Assemble the terminal screw posts into the four holes on the top of the insulating shell, leaving 11mm±0.5mm on the outside of the insulating shell, and then place the lead-out ends of the wound core winding upward and flat into the insulating shell. Adjust the position of the lead-out ends and press the leads down to the edge of the terminal screw posts. The lead length should be flush with the edge of the insulating shell, and the excess wire tails should be cut off; 4.2) When winding, the two lead-out terminals near the middle partition are a group of terminals with the same name; cross the terminals with the same name on both sides of the winding and connect them to the wiring threaded posts on the opposite sides respectively. All lead wires must be connected for a complete circle and the lead wires must be close to the shell wall; 4.3) Place the connected product terminals on the operating table with the terminals facing upwards, apply a small amount of tin to the soldering iron, and solder each terminal. After soldering, use a toothbrush dipped in anhydrous ethanol to scrub the soldering position and the surrounding area; Step 5: Potting: Use W-280 potting glue to pour glue from one side of the long side of the insulation shell into the cavity of the insulation shell, and gradually let the glue fill the entire cavity from the other side of the long side.

7. The method for preparing a high current high frequency isolation unit according to claim 5, characterized in that: In the assembly welding process, a soldering iron at 350°C and a welding time of 5-10S are used. The lead-out end of the coil winding is wound on the terminal thread column with three non-overlapping turns.

8. A method for preparing a high current high frequency isolation unit according to claim 5 or 6, characterized in that: The potting process uses an automatic dispensing machine for dispensing and potting, and the baking condition after dispensing is 130℃ for 120min.

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