A high pressure air tight test bench

Abstract

The present application relates to airtight test bench technical field, specifically, it is a kind of high-pressure airtight test bench.It includes tooling table, tooling table surface is equipped with test host and tooling part, tooling part includes protective shell, protective shell top is equipped with air cylinder, air cylinder end portion piston rod penetrates protective shell and is equipped with moving plate in end portion, placing seat below is equipped with rotating assembly, rotating assembly is used to drive placing seat to rotate, pedestal both sides are equipped with moving assembly, the present application is driven tooth plate to move up along vertical direction by control electric telescopic rod, make tooth plate remove the limiting of tooth block, by energization to the electrically conductive winding group that is wound on the surface of iron core inside electromagnet, so that electromagnet is magnetically attracted to iron block, iron block is driven long rod to electromagnet direction by magnetic attraction force and approaches, so that the slide rod slides in the inner wall of cylinder, the clamping plate that is equipped with the end of slide rod moves in the direction of separation, so as to facilitate the rapid feeding of test box, improve the test speed of the airtightness of test box.

Description

Technical Field

[0001] This invention relates to the field of airtightness testing bench technology, and more specifically, to a high-pressure airtightness testing bench. Background Technology

[0002] Sealed containers are widely used in modern industrial production and daily life. Taking canned food containers as an example, they play a crucial role in many fields such as food, pharmaceuticals, and chemical raw materials. To ensure the airtightness of the containers, airtightness testing benches are now commonly used to test them. There are many existing technologies for airtightness testing benches, such as: Chinese Patent Publication No. CN215639932U discloses a high-pressure airtightness testing bench for easy product testing. The bench includes a base, with cabinets fixedly connected to the four lower corners of the base. Movable devices are fixedly connected to the four corners of the cabinets. A control board is fixedly connected to the upper left side of the base, with a control key fixedly connected to the center of the front end of the control board. A regulating valve is fixedly connected to the lower front end of the control board. A base plate is fixedly connected to the upper right side of the base, with support columns fixedly connected to the four upper corners of the base plate. A horizontal plate is fixedly connected to the upper ends of the four support columns, with a pressing device fixedly connected to the center of the upper end of the horizontal plate. A connecting device is fixedly connected to the center of the upper end of the base plate. This patent, by incorporating movable devices throughout the entire device, facilitates its movement, achieves rapid fixation, enhances stability, and has value for widespread application.

[0003] However, some problems still exist in actual use: 1. In traditional airtightness testing benches, operators need to manually place the test box in the working area. During this process, it is difficult to maintain absolute precision due to manual operation. In addition, the space between the test box and the surrounding components of the working area is tight, and even slight carelessness can easily cause the test box to collide with the surrounding structure. Once the test box is deformed or damaged due to collision, it is very likely to change its original sealing performance, which will seriously interfere with the subsequent airtightness test results, making the test data unable to truly reflect the actual airtightness of the product. 2. Currently, most air tightness testing benches adopt a single-test mode, which means that the air tightness of a product is judged based on the result of a single test. However, this method has great limitations. During the test, it may be affected by a variety of uncontrollable factors such as instantaneous environmental fluctuations and random equipment errors, which makes the result of a single test significantly random.

[0004] In view of this, we propose a high-pressure airtightness test bench. Summary of the Invention

[0005] The purpose of this invention is to provide a high-pressure airtightness testing bench to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides a high-pressure airtightness testing bench, comprising a tooling table. The tooling table surface is provided with a testing host and a tooling section. The tooling section includes a protective shell. A cylinder is located at the top of the protective shell. A piston rod at the end of the cylinder penetrates the protective shell and has a movable plate at its end. A testing head is located at the bottom of the movable plate. A platform is located below the testing head. A placement seat is located on the surface of the platform. A limiting groove is located at the bottom of the placement seat. A rotating assembly is located below the placement seat. The rotating assembly is used to drive the placement seat to rotate. The rotating assembly includes a rotating motor located at the bottom of the platform. A transmission belt assembly is located at the output end of the rotating motor. The transmission belt assembly consists of two transmission wheels and a friction belt. A support column is located at the top of the transmission wheel on the side away from the rotating motor. The support column penetrates the platform and is fixed to the bottom of the placement seat. Moving components are located on both sides of the platform. A clamping component is located at the end of the moving component. The clamping component is used to clamp and load the test box.

[0007] As a further improvement to this technical solution, the surface of the pedestal is provided with a limiting post, which is adapted to the limiting groove provided at the bottom of the placement seat, and the interior of the placement seat is provided with an anti-slip pad.

[0008] As a further improvement to this technical solution, the moving component includes guide rails on both sides of the base, each guide rail surface is provided with a movable seat, and the movable seat is provided with a vertical plate on its side. The movable seat drives the vertical plate to move axially on the guide rail surface.

[0009] As a further improvement to this technical solution, a servo motor is provided at the top of the upright plate, a lead screw is provided at the end of the output shaft of the servo motor, a movable frame is provided on the surface of the lead screw, and when the lead screw rotates, it drives the movable frame on its surface to move in the vertical direction, and a clamping component is provided at the end of the movable frame.

[0010] As a further improvement to this technical solution, an electromagnet is provided inside the movable frame, and the electromagnet is composed of an iron core and an externally wound conductive winding.

[0011] As a further improvement to this technical solution, the clamping assembly includes a cylindrical column disposed at the end of the movable frame, a sliding rod slidably disposed on the inner wall of the cylindrical column, a compression spring disposed between the cylindrical column and the sliding rod, a clamping plate disposed at the end of the sliding rod, the clamping plate being arc-shaped and fitting against the outer surface of the test box.

[0012] As a further improvement to this technical solution, a groove is provided on the surface of the column, and a toothed block is provided at the end of the slide rod. When the slide rod moves, it drives the toothed block to slide in the groove.

[0013] As a further improvement to this technical solution, the top of the upright plate is provided with an electric telescopic rod, and the end of the electric telescopic rod is provided with a toothed plate. The toothed plate is adapted to the toothed block, and the toothed plate is controlled to move in the vertical direction to limit and fix the toothed block.

[0014] As a further improvement to this technical solution, a long rod is provided at the end of the slide bar away from the clamping plate. The long rod is made of plastic, and the end of the long rod passes through the column and is provided with an iron block. The iron block is on the same axis as the center of the electromagnet.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In this high-pressure airtightness test bench, the telescopic rod at the end of the electric telescopic rod drives the toothed plate to move downward in the vertical direction. When the toothed plate moves to the toothed block, it is fixed, thereby limiting the sliding rod and preventing the sliding rod from sliding on the inner wall of the column when the test box moves. This improves the stability of the clamping plate, allows the test box to be quickly clamped and moved to the placement seat for testing, thereby increasing the testing speed.

[0016] 2. In this high-pressure airtightness test bench, when the test box moves above the placement seat, the output of the servo motor drives the lead screw to rotate. When the lead screw rotates, the moving frame moves vertically, thereby causing the clamping assembly at the end of the moving frame to move the test box into the placement seat. When the test is completed, the moving seat is controlled to slide on the guide rail surface, so that the upright plate moves away from the surface of the placement seat. The cylinder is controlled to drive the moving plate to move vertically, so that the test head at the bottom of the moving plate performs the airtightness test on the test box. This avoids manual placement of the test box, reduces the instability of manual placement, and avoids the test box from colliding with the placement seat and deforming, which would affect the test results.

[0017] 3. In this high-pressure airtightness testing bench, the toothed plate is moved vertically by controlling the electric telescopic rod, so that the toothed plate releases the tooth block from its limit. By energizing the conductive winding wound inside the electromagnet on the surface of the iron core, the electromagnet magnetically attracts the iron block. The iron block is attracted by the magnetic force and moves the long rod closer to the electromagnet, so that the slide rod slides on the inner wall of the column. The clamping plate at the end of the slide rod moves in a disjointed direction, so that the clamping plate is away from the surface of the test box, which facilitates the rapid loading and unloading of the test box and improves the speed of testing the airtightness of the test box. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the tooling structure of the present invention; Figure 3 This is a schematic diagram of the protective component structure of the present invention; Figure 4 This is a schematic diagram of the mechanical clamping arm structure of the present invention; Figure 5 This is a schematic diagram of the protective component structure of the present invention; Figure 6 This is a cross-sectional view of the adjustment component of the present invention; Figure 7 This is a schematic diagram of the mobile component structure of the present invention; Figure 8 This is a cross-sectional view of the movable component of the present invention.

[0019] The meanings of the labels in the diagram are as follows: 100. Tooling table; 101. Testing host; 102. Tooling department; 200. Protective housing; 201. Cylinder; 202. Moving plate; 203. Test head; 204. Base; 205. Placement seat; 206. Anti-slip mat; 300. Rotating assembly; 301. Rotating motor; 302. Transmission belt assembly; 303. Support column; 304. Limiting column; 400. Moving component; 401. Guide rail; 402. Moving base; 403. Vertical plate; 404. Servo motor; 405. Lead screw; 406. Moving frame; 407. Electromagnet; 500. Clamping assembly; 501. Column; 502. Slide rod; 503. Compression spring; 504. Clamping plate; 505. Tooth block; 506. Electric telescopic rod; 507. Tooth plate; 508. Long rod; 509. Iron block. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] The purpose of this embodiment is to provide a high-pressure airtightness testing bench, see reference. Figures 1-8As shown, the device includes a tooling table 100, on which a test host 101 and a tooling part 102 are provided. The tooling part 102 includes a protective shell 200, a cylinder 201 on the top of the protective shell 200, a piston rod at the end of the cylinder 201 passing through the protective shell 200 and having a moving plate 202 at the end, a test head 203 at the bottom of the moving plate 202, a platform 204 below the test head 203, a placement seat 205 on the surface of the platform 204, a limiting groove at the bottom of the placement seat 205, a rotating component 300 below the placement seat 205 for driving the placement seat 205 to rotate, moving components 400 on both sides of the platform 204, and a clamping component 500 at the end of the moving component 400 for clamping and feeding the test box.

[0023] To enhance the reliability of test results upon completion of the test box test, the rotating assembly 300 includes a rotating motor 301 located at the bottom of the platform 204. The output end of the rotating motor 301 has a transmission belt assembly 302, which consists of two drive pulleys and a friction belt. A support column 303 is located on the top of the drive pulleys on the side furthest from the rotating motor 301. The support column 303 passes through the platform 204 and is fixed to the bottom of the placement seat 205. By controlling the output shaft of the rotating motor 301, the transmission belt assembly 302 is driven to rotate. When the transmission belt assembly 302 rotates, it drives the support column 303 to rotate coaxially. The rotation of the support column 303, in turn, drives the placement seat 205 to rotate, causing the test box placed inside the placement seat 205 to rotate. When the placement seat 205 rotates the test box to a random angle and stops, the piston rod at the end of the control cylinder 201 drives the moving plate 202 to move vertically. When the moving plate 202 moves, it drives the test head 203 to the top of the test box for sealing and testing. This reduces the need for manual adjustment of the test box position and improves testing efficiency. Through multiple tests, the performance change trend of the test box during long-term use can be observed. For example, as the number of tests increases, it can be observed whether the airtightness of the test box gradually decreases or whether other potential problems occur, such as material fatigue or aging of seals. This helps to discover potential long-term reliability problems of the test box in advance and provides a basis for product improvement and maintenance.

[0024] To improve the stability of the placement seat 205 during rotation, the surface of the base 204 is provided with limiting posts 304, which are adapted to the limiting grooves provided at the bottom of the placement seat 205. The placement seat 205 is provided with anti-slip pads 206. When the placement seat 205 drives the test box to rotate, the limiting grooves provided at the bottom of the placement seat 205 rotate to the top of the limiting posts 304. Since the limiting posts 304 are arranged in a ring array, the stability of the rotation of the placement seat 205 is improved, so that the placement seat 205 maintains stability when driving the test box to rotate.

[0025] When placing the test box, since the placement seat 205 is inside the protective shell 200, the test box is prone to collision with the side wall of the placement seat 205 during placement. Because the test box is thin, it is easily deformed upon collision, affecting the test results. This necessitates replacement and retesting, leading to low efficiency. Therefore, the moving component 400 includes guide rails 401 on both sides of the platform 204. Each guide rail 401 has a moving seat 402 on its surface, and the moving seat 402 has a vertical plate 403 on its side. The moving base 402 drives the upright plate 403 to move axially on the surface of the guide rail 401. A servo motor 404 is mounted on the top of the upright plate 403. A lead screw 405 is mounted at the end of the output shaft of the servo motor 404. A moving frame 406 is mounted on the surface of the lead screw 405. When the lead screw 405 rotates, it drives the moving frame 406 to move vertically. A clamping assembly 500 is mounted at the end of the moving frame 406. The test box is clamped and fixed between the clamping assemblies 500. To move the test box to a suitable location... When the test box is placed on the placement seat 205, the movable seat 402 is controlled to slide axially on the surface of the guide rail 401. When the movable seat 402 moves, it drives the upright plate 403 to move. When the test box moves above the placement seat 205, the output end of the servo motor 404 is controlled to drive the lead screw 405 to rotate. When the lead screw 405 rotates, the movable frame 406 moves vertically, thereby causing the clamping assembly 500 at the end of the movable frame 406 to move the test box into the placement seat 205. When the test box is tested, the movable seat 402 is controlled to slide on the surface of the guide rail 401, so that the upright plate 403 moves away from the surface of the placement seat 205. The cylinder 201 is controlled to drive the movable plate 202 to move vertically, so that the test head 203 at the bottom of the movable plate 202 can perform airtightness testing on the test box. This avoids manual placement of the test box, reducing the instability of manual placement and preventing the test box from colliding with the placement seat 205 and deforming, which would affect the test results. It also reduces the labor intensity of the test personnel.

[0026] To facilitate quick clamping of the test box and improve testing speed during the airtightness test, the clamping assembly 500 includes a cylindrical tube 501 located at the end of the movable frame 406. A sliding rod 502 is slidably mounted on the inner wall of the cylindrical tube 501. A compression spring 503 is positioned between the cylindrical tube 501 and the sliding rod 502. A clamping plate 504, arc-shaped, is located at the end of the sliding rod 502 and fits against the outer surface of the test box. By pressing the clamping plate 504, the sliding rod 502 slides against the inner wall of the cylindrical tube 501, simultaneously compressing the compression spring 503. Increasing the diameter distance between the slide bars 502 facilitates the placement of the test box. When the test box is placed between the clamping plates 504, the pressure on the clamping plates 504 is stopped. The slide bars 502 are subjected to the restoring force of the compression spring 503, causing the relative movement between the clamping plates 504 to clamp and fix the side wall of the test box. Since the surface of the clamping plates 504 is arc-shaped and fits against the outer wall of the test box, the pressure on the test box is reduced, preventing the test box from deforming during the clamping process. This allows the test box to be quickly clamped and moved to the placement seat 205 for testing, thereby improving the testing speed.

[0027] During the clamping and limiting of the test box, when the clamping plate 504 moves, in order to prevent the sliding rod 502 from sliding against the inner wall of the column cylinder 501 and causing the clamping plate 504 to loosen its grip on the test box, resulting in the test box falling and being damaged, a sliding groove is provided on the surface of the column cylinder 501, and a toothed block 505 is provided at the end of the sliding rod 502. When the sliding rod 502 moves, it drives the toothed block 505 to slide in the sliding groove. An electric telescopic rod 506 is provided at the top of the upright plate 403, and a toothed plate 507 is provided at the end of the telescopic rod 506. The toothed plate 507 and the toothed block The 505 adapter controls the toothed plate 507 to move vertically and limit and fix the toothed block 505. When the clamping plate 504 limits the test box, the telescopic rod at the end of the electric telescopic rod 506 drives the toothed plate 507 to move vertically downward. When the toothed plate 507 moves to the toothed block 505, it fixes it, thereby limiting the slide rod 502 and preventing the slide rod 502 from sliding on the inner wall of the column cylinder 501 when the test box moves. This improves the stability of the clamping plate 504 and prevents the test box from falling and being damaged during movement.

[0028] When the test box moves above the placement seat 205, a long rod 508 is provided at the end of the slide rod 502 away from the clamping plate 504 for easy and quick unloading. The long rod 508 is made of plastic, and its end passes through the column cylinder 501 and has an iron block 509 at its end. The iron block 509 is on the same axis as the center of the electromagnet 407. The electromagnet 407 is located inside the moving frame 406. The electromagnet 407 is composed of an iron core and a conductive winding wound around it. By controlling the rotation of the lead screw 405, the moving frame 406 on its surface moves downward in a vertical direction, thereby moving the test box fixed between the clamping plates 504 into the placement seat 205. By controlling the electric telescopic rod 506 to move the toothed plate 507 vertically, the toothed plate 507 releases the restriction on the toothed block 505. By energizing the conductive winding wound inside the electromagnet 407 on the surface of the iron core, the electromagnet 407 generates magnetism, thereby magnetically attracting the iron block 509. The iron block 509, under the magnetic attraction force, moves the long rod 508 closer to the electromagnet 407, thereby causing the slide rod 502 to slide on the inner wall of the column cylinder 501. This causes the clamping plate 504 at the end of the slide rod 502 to move in a disjointed direction, moving the clamping plate 504 away from the surface of the test box, thus facilitating the rapid loading and unloading of the test box and improving the testing speed of the airtightness of the test box.

[0029] In practical use, the clamping plates 504 are pressed, causing the sliding rods 502 to slide against the inner wall of the cylinder 501 while simultaneously compressing the compression spring 503. This increases the diameter distance between the sliding rods 502, facilitating the placement of the test box. When the test box is placed between the clamping plates 504, the pressing of the clamping plates 504 is stopped. The sliding rods 502 are then subjected to the restoring force of the compression spring 503, causing the relative movement between the clamping plates 504 to clamp and fix the side wall of the test box. Because the surface of the clamping plates 504 is arc-shaped and fits against the outer wall of the test box, from... This reduces the squeezing force on the test box and prevents the test box from deforming during clamping. By controlling the telescopic rod at the end of the electric telescopic rod 506, the toothed plate 507 moves downward in the vertical direction. When the toothed plate 507 moves to the toothed block 505, it is fixed, thereby limiting the slide rod 502 and preventing the slide rod 502 from sliding on the inner wall of the column cylinder 501 when the test box moves. This improves the clamping stability of the clamping plate 504, makes it easier to quickly clamp the test box and move it to the placement seat 205 for placement and testing, thereby increasing the testing speed. The control movable seat 402 slides axially on the surface of the guide rail 401. When the movable seat 402 moves, it drives the upright plate 403 to move. When the test box moves above the placement seat 205, the control servo motor 404 output drives the lead screw 405 to rotate. When the lead screw 405 rotates, it causes the movable frame 406 to move vertically. This causes the clamping component 500 at the end of the movable frame 406 to move the test box into the placement seat 205. When the test box is tested, the control movable seat 402 slides on the surface of the guide rail 401, causing the upright plate 403 to move away from the surface of the placement seat 205. The control cylinder 201 drives the movable plate 202 to move vertically, so that the test head 203 at the bottom of the movable plate 202 can perform airtightness testing on the test box. This avoids manual placement of the test box, reducing the instability of manual placement and preventing the test box from colliding with the placement seat 205 and deforming, which would affect the test results. It also reduces the labor intensity of the test personnel. By controlling the electric telescopic rod 506 to move the toothed plate 507 vertically, the toothed plate 507 releases the toothed block 505 from its limit. By energizing the conductive winding wound inside the electromagnet 407 on the surface of the iron core, the electromagnet 407 generates magnetism, thereby magnetically attracting the iron block 509. The iron block 509, under the magnetic attraction force, moves the long rod 508 closer to the electromagnet 407, thereby causing the slide rod 502 to slide on the inner wall of the column cylinder 501. This causes the clamping plate 504 at the end of the slide rod 502 to move in a disjointed direction, moving the clamping plate 504 away from the surface of the test box, thus facilitating the rapid loading and unloading of the test box and improving the speed of testing the airtightness of the test box. By controlling the output shaft of the rotating motor 301 to drive the transmission belt assembly 302 to rotate, the transmission belt assembly 302 drives the support column 303 to rotate coaxially. When the support column 303 rotates, it drives the placement seat 205 to rotate, causing the test box placed inside the placement seat 205 to rotate. When the placement seat 205 drives the test box to rotate to a random angle and stop, the piston rod at the end of the cylinder 201 is controlled to drive the moving plate 202 to move in the vertical direction. When the moving plate 202 moves, it drives the test head 203 to move to the top of the test box for sealing and testing. This reduces the need for manual adjustment of the test box position, improves testing efficiency, and provides a basis for product improvement and maintenance.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-pressure airtightness testing bench, characterized in that: The system includes a tooling table. The surface of the tooling table is equipped with a testing main unit and a tooling section. The tooling section includes a protective shell. A cylinder is located at the top of the protective shell. A piston rod at the end of the cylinder passes through the protective shell and has a movable plate at its end. A testing head is located at the bottom of the movable plate. A base is located below the testing head. A placement seat is located on the surface of the base. A limiting groove is located at the bottom of the placement seat. A rotating assembly is located below the placement seat. The rotating assembly is used to drive the placement seat to rotate. The rotating assembly includes a rotating motor located at the bottom of the base. A transmission belt assembly is located at the output end of the rotating motor. The transmission belt assembly includes two transmission pulleys and a friction belt, wherein the belt is located away from the rotating pulley. A support column is provided on the top of the transmission wheel on one side of the motor. The support column passes through the platform and is fixed to the bottom of the placement seat. Moving components are provided on both sides of the platform. The moving components include guide rails on both sides of the platform. Moving seats are provided on the surface of the guide rails. Vertical plates are provided on the sides of the moving seats. The moving seats drive the vertical plates to move axially on the guide rail surfaces. A servo motor is provided on the top of the vertical plates. A lead screw is provided at the end of the output shaft of the servo motor. A moving frame is provided on the surface of the lead screw. When the lead screw rotates, it drives the moving frame on its surface to move vertically. A clamping component is provided at the end of the moving frame. The clamping component is used to clamp and feed the test box. The clamping assembly includes a cylindrical column at the end of the movable frame. A sliding rod is slidably mounted on the inner wall of the cylindrical column. A compression spring is provided between the cylindrical column and the sliding rod. A clamping plate is provided at the end of the sliding rod. The clamping plate is arc-shaped and fits against the outer surface of the test box. A groove is formed on the surface of the cylindrical column. A toothed block is provided at the end of the sliding rod. When the sliding rod moves, it drives the toothed block to slide in the groove. An electric telescopic rod is provided at the top of the upright plate. A toothed plate is provided at the end of the electric telescopic rod. The toothed plate is adapted to the toothed block. The toothed plate is controlled to move vertically to limit and fix the toothed block. A long rod is provided at the end of the sliding rod away from the clamping plate. The long rod is made of plastic. The end of the long rod passes through the cylindrical column and has an iron block at the end. The iron block is on the same axis as the center of the electromagnet.

2. The high-pressure airtightness testing bench according to claim 1, characterized in that: The surface of the pedestal is provided with a limiting post, which is adapted to the limiting groove provided at the bottom of the placement seat, and the interior of the placement seat is provided with an anti-slip pad.

3. The high-pressure airtightness testing bench according to claim 1, characterized in that: The movable frame is equipped with an electromagnet, which is composed of an iron core and an externally wound conductive winding.

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