Double-cap wire-wound resistor

Abstract

The utility model discloses a double-cap winding resistor which comprises a core rod made of a ceramic material, first metal caps are arranged at two ends of the core rod, two resistance wires which are bidirectionally and reversely spiral are wound on the core rod, and two ends of the two resistance wires are respectively welded on the side walls of the first metal caps to form welding spots which protrude outwards. The first metal cap is provided with a matched second metal cap, the inner wall of the second metal cap is provided with a groove matched with the protruding welding spots, the protruding welding spots are located in the groove and are symmetrically distributed up and down, and the end portion of the second metal cap is provided with a lead. According to the utility model, the problem that the welding point of the resistance wire and the end cap is exposed outside to easily cause desoldering can be effectively avoided, and meanwhile, the problem of inductance effect generated by single spiral winding is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of wire-wound resistors, and particularly relates to a double-cap wire-wound resistor. Background Art

[0002] A resistor is generally directly called a resistance in daily life. A resistor is a current-limiting component. After connecting the resistor to a circuit, the resistance value of the resistor is fixed, generally with two leads. It can limit the magnitude of the current passing through the branch it is connected to. A resistor with an unchangeable resistance value is called a fixed resistor, and a resistor with a variable resistance value is called a potentiometer or variable resistor.

[0003] With the rapid development of technologies such as electronic and electrical products, people's requirements for the use of resistors have increased. The current wire-wound resistor winds the resistance wire around an insulating rod in a certain direction. The resistor wound in a single helix will generate an inductance effect when connected to a circuit, affecting the accuracy. At the same time, the solder joints formed after welding the resistance wire and the end caps are directly exposed outside and are extremely easy to be damaged, resulting in desoldering, thus causing the wire-wound resistor to fail and affecting the normal operation of the circuit. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a double-cap wire-wound resistor, which can effectively avoid the problem that the solder joints of the resistance wire and the end caps are exposed outside and are prone to desoldering, and at the same time solve the problem of the inductance effect generated by single helix winding.

[0005] To solve the above technical problems, the utility model adopts the following scheme:

[0006] A double-cap wire-wound resistor includes a core rod made of ceramic material. First metal caps are provided at both ends of the core rod. Two resistance wires wound in a bidirectional reverse helix are wound on the core rod. The two ends of the two resistance wires are respectively welded to the side walls of the first metal caps and form an outwardly protruding solder joint. A second metal cap adapted to the first metal cap is provided on the first metal cap. The inner wall of the second metal cap has a groove adapted to the protruding solder joint. The protruding solder joint is located in the groove and is symmetrically distributed up and down. Leads are provided at the ends of the second metal cap.

[0007] Due to the adoption of the above technical solution, two resistance wires with a bidirectional anti-helix are wound along the length direction of the mandrel. After the resistance winding, the inductances generated by the two coils cancel each other out, making the entire wound resistance present a non-inductive or slightly inductive state to the external circuit, and the inductance effect is basically eliminated. After the two resistance wires are wound on the mandrel, both ends of the two resistance wires are welded to the outer wall of the first metal cap, and raised solder joints are formed by welding. The symmetrically arranged raised solder joints ensure the uniformity of the current passing through. A groove adapted to the raised solder joint on the first metal cap is provided on the inner wall of the second metal cap. After the second metal cap is connected to the first metal cap, the raised solder joint is located in the groove, realizing the precise connection between the resistance wire and the second metal cap. At the same time, the second metal cap completely wraps and covers the exposed raised solder joint, avoiding the problem that the welding point between the resistance wire and the end cap is easily de-soldered when exposed to the outside.

[0008] Optionally, a card slot adapted to the winding direction of the resistance wire is provided on the mandrel, and the metal wire is embedded in the card slot.

[0009] Optionally, the raised solder joint is arc-shaped.

[0010] Optionally, epoxy paint is coated on the raised solder joint.

[0011] Optionally, both the first metal cap and the second metal cap are cylindrical with a single-sided opening.

[0012] Optionally, both the first metal cap and the second metal cap are iron caps or copper caps.

[0013] Optionally, an insulating layer is wrapped around the outer sides of the first metal cap, the second metal cap and the mandrel.

[0014] The beneficial effects of the present utility model are as follows:

[0015] 1. In the present utility model, two resistance wires with a bidirectional anti-helix are wound along the length direction of the mandrel. After the resistance winding, the inductances generated by the two coils cancel each other out, making the entire wound resistance present a non-inductive or slightly inductive state to the external circuit, and the inductance effect is basically eliminated. After the two resistance wires are wound on the mandrel, both ends of the two resistance wires are welded to the outer wall of the first metal cap, and raised solder joints are formed by welding. The symmetrically arranged raised solder joints ensure the uniformity of the current passing through. A groove adapted to the raised solder joint on the first metal cap is provided on the inner wall of the second metal cap. After the second metal cap is connected to the first metal cap, the raised solder joint is located in the groove, realizing the precise connection between the resistance wire and the second metal cap. At the same time, the second metal cap completely wraps and covers the exposed raised solder joint, avoiding the problem that the welding point between the resistance wire and the end cap is easily de-soldered when exposed to the outside. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a structural schematic diagram of the present utility model;

[0017] Figure 2 It is a schematic diagram of the distribution structure of the card slots on the mandrel.

[0018] Reference numerals: 1 - mandrel, 2 - resistance wire, 3 - first metal cap, 4 - raised solder joint, 5 - groove, 6 - second metal cap, 7 - lead wire, 8 - card slot, 9 - insulating layer. Specific embodiments

[0019] The following combines examples and drawings to further elaborate on the present utility model in detail, but the implementation manners of the present utility model are not limited thereto.

[0020] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "longitudinal", "lateral", "horizontal", "inner", "outer", "front", "rear", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this utility model is usually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present utility model.

[0021] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, terms such as "set", "provided with", "installed", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0022] Example

[0023] A double - cap wound resistor includes a mandrel 1 made of ceramic material. The two ends of the mandrel 1 are provided with first metal caps 3. Two resistance wires 2 wound in a double - reverse helix are wound on the mandrel 1. The two ends of the two resistance wires 2 are respectively welded to the side walls of the first metal caps 3 and form an outward - raised solder joint 4. A second metal cap 6 adapted to the first metal cap 3 is arranged on the first metal cap 3. The inner wall of the second metal cap 6 has a groove 5 adapted to the raised solder joint 4. The raised solder joint 4 is located in the groove 5, and the raised solder joints 4 are symmetrically distributed up and down. The end of the second metal cap 6 is provided with a lead wire 7.

[0024] In this embodiment, as Figure 1As shown, the mandrel 1 is a round rod made of ceramic insulating material. Along its length direction on the mandrel 1, two resistance wires 2 are wound in a two-way anti-helix manner. After the resistance winding, the inductance generated by the two formed coils cancels each other out, making the entire wound resistor present no inductance or micro-inductance to the external circuit, and the inductance effect is basically eliminated. At the same time, winding two resistance wires 2 in a two-way anti-helix manner on the mandrel 1 can ensure the consistency and stability of the resistance value. The two-way anti-helix design can also reduce the heat generated by the resistance when energized and improve the heat dissipation performance of the resistance. After the two resistances are wound on the mandrel 1, both ends of the two resistance wires 2 are welded to the outer wall of the first metal cap 3, and raised solder joints 4 are formed at the welding points. The symmetrically arranged raised solder joints 4 ensure the uniformity of the current when passing through. On the inner wall of the second metal cap 6, there is a groove 5 adapted to the raised solder joint 4 on the first metal cap 3. After the second metal cap 6 is connected to the first metal cap 3, the raised solder joint 4 is located in the groove 5, realizing the precise connection between the resistance wire 2 and the second metal cap 6. At the same time, the second metal cap 6 completely wraps and covers the exposed raised solder, avoiding the problem that the welding point between the resistance wire 2 and the end cap is easily desoldered when exposed.

[0025] Furthermore, a card slot 8 adapted to the winding direction of the resistance wire 2 is provided on the mandrel 1, and the metal wire is embedded in the card slot 8.

[0026] Specifically, as Figure 2As shown, a card slot 8 adapted to the winding direction of the resistance wire 2 is provided on the ceramic mandrel 1. The card slot 8 extends along the axial direction of the mandrel 1, and its shape and size are designed according to the specific specifications of the resistance wire 2. The provision of the card slot 8 enables the resistance wire 2 to be accurately embedded therein, not only ensuring the stable position of the resistance wire 2 on the mandrel 1, but also avoiding the possible displacement or loosening of the resistance wire 2 during the winding process. When the resistance wire 2 is wound, it will be embedded into the card slot 8 in a pre-set direction. This design ensures that the resistance wire 2 can maintain a stable resistance value when energized, and reduces the stress change of the resistance wire 2 caused by temperature change or mechanical vibration. The two bidirectional anti-helical resistance wires 2 can be accurately embedded into the corresponding card slots 8, further enhancing the overall stability and reliability of the resistance. The two ends of the resistance wire 2 are still welded to the side wall of the first metal cap 3 to form outwardly protruding solder joints. The solder joints not only ensure the electrical connection between the resistance wire 2 and the metal cap, but also facilitate the precise docking with the groove 5 of the second metal cap 6 through the protruding design. The groove 5 on the inner wall of the second metal cap 6 is adapted to the protruding solder joint 4, making the entire resistance structure more compact and stable. The double-cap wound resistor with the card slot 8 design has higher stability and reliability. Since the resistance wire 2 is accurately fixed in the card slot 8, the resistance can still maintain good electrical performance and stability even in harsh environments such as high temperature, high humidity, and high corrosion. This kind of resistor is applicable to various circuits that require precise control of the resistance value, especially in occasions with high requirements for the stability and reliability of the resistor, such as automotive electronics, medical equipment, aerospace and other fields. Generally speaking, by providing a card slot 8 on the mandrel 1 that is adapted to the winding direction of the resistance wire 2, the stability and reliability of the double-cap wound resistor are further improved, enabling it to maintain good performance in various complex environments.

[0027] Furthermore, the protruding solder joint 4 is arc-shaped.

[0028] Specifically, such as Figure 1As shown, the arc-shaped raised solder joint 4 has a larger contact area compared to other shapes (such as linear or dot-shaped), which means that the connection between the solder joint and the metal cap is stronger, capable of withstanding greater mechanical stress, improving the vibration and shock resistance of the resistor. The arc-shaped raised solder joint 4 can provide a more uniform and stable electrical connection. Due to the increase in the solder joint area, the current can be more evenly distributed when passing through, reducing local overheating and changes in the resistance value, thereby improving the stability and reliability of the resistor. The arc-shaped raised solder joint 4 can better fit the groove 5 on the inner wall of the second metal cap 6. This design makes it easier to align and fix the resistor during assembly, improving the assembly efficiency and accuracy. At the same time, it forms a limiting and positioning effect on the second metal cap 6, preventing the second metal cap 6 from falling off from the first metal cap 3. The arc-shaped raised solder joint 4 increases the heat dissipation area of the resistor to a certain extent. When the resistor is energized, the generated heat can be more quickly dissipated to the surrounding environment through the solder joint, thereby reducing the operating temperature of the resistor and improving its long-term operating stability. The arc-shaped raised solder joint 4 not only has better functional performance but also is more beautiful and unified in appearance. This design helps with the standardized production and quality control of the resistor, improving the overall quality of the product. In summary, designing the raised solder joint 4 as an arc shape can further enhance the mechanical strength, electrical connection stability, assembly convenience, heat dissipation performance, and aesthetics of the double-cap wound resistor. This design enables the resistor to exhibit better performance and reliability in various application scenarios.

[0029] Further, an epoxy paint is coated on the raised solder joint 4.

[0030] Specifically, epoxy paint is an excellent electrical insulation material. Coating it on the raised solder joint 4 can enhance the electrical insulation between the resistor and the outside world, which helps prevent electrical faults such as current leakage and short circuits, improving the safety of the resistor. Epoxy paint has excellent corrosion resistance and can resist the erosion of various chemical substances. Coating it on the raised solder joint 4 can protect the solder joint from corrosion in environments such as moisture, salt, acids, and alkalis, extending the service life of the resistor. Although epoxy paint itself does not contribute much to mechanical strength, it can enhance the bonding force between the solder joint and the metal cap to a certain extent, which helps resist external mechanical stresses such as vibration and shock, improving the reliability of the resistor.

[0031] Further, both the first metal cap 3 and the second metal cap 6 are cylindrical with a single-sided opening.

[0032] Specifically, the one-sided open cylindrical structure enables the first metal cap 3 and the second metal cap 6 to be easily put on the mandrel 1, facilitating the winding and fixing of the resistance wire 2. At the same time, this structure also makes subsequent installation and disassembly simpler. Since it is a one-sided open cylindrical structure, during assembly, the tightness of the resistance can be improved through close fitting and appropriate fixing measures (such as welding, threaded connection, etc.), which helps prevent external factors such as dust and moisture from entering the resistance interior, ensuring the stability and reliability of the resistance. The one-sided open cylindrical structure endows the metal cap with high mechanical strength, and this structure can effectively resist external mechanical stresses such as vibration and impact, protecting the resistance wire 2 from damage. Although the metal cap itself is not the main heat dissipation component, the one-sided open cylindrical structure can increase the heat dissipation area to a certain extent, which helps dissipate the heat generated inside the resistance to the external environment and reduce the operating temperature of the resistance. The one-sided open cylindrical structure is relatively simple and can be manufactured through processes such as stamping and stretching, which helps reduce production costs and improve production efficiency. In this design, the raised solder joint 4 is usually located on the side wall of the cylinder. Due to the symmetry of the cylindrical structure, the raised solder joint 4 can be more easily aligned and fixed with the groove 5 on the inner wall of the second metal cap 6 to achieve good electrical connection.

[0033] Furthermore, both the first metal cap 3 and the second metal cap 6 are iron caps or copper caps.

[0034] Furthermore, an insulating layer 9 is wrapped around the outer sides of the first metal cap 3, the second metal cap 6, and the mandrel 1.

[0035] Specifically, such as Figure 1As shown, the insulating layer can effectively isolate the conductive part inside the resistor from the external environment, preventing electrical faults such as current leakage and short circuits. This greatly improves the electrical safety of the resistor, making it more reliable when used in various circuits. The insulating layer 9 can protect the metal cap and the core rod 1 inside the resistor from the erosion of the external environment, such as moisture, dust, chemical substances, etc. This helps to extend the service life of the resistor and improve its stability and reliability. Due to the presence of the insulating layer 9, the resistor can be more flexible and convenient during installation and wiring. Users do not need to worry about accidental contact between the resistor and other conductive components, thus reducing the installation difficulty and error rate. The insulating layer 9 is usually of a unified color, such as black or gray, which makes the resistor more beautiful and unified in appearance. In addition, the insulating layer 9 can be added with labels or markings according to needs, facilitating users to identify and manage resistors of different specifications or uses. The design of the insulating layer 9 enables the double-cap wound resistor to adapt to a wider range of application scenarios. Whether in harsh environments such as high temperature, high humidity, and high corrosion, or in circuits that require high-precision electrical control, this resistor can exhibit good performance and stability. By adding the design of the insulating layer 9, the double-cap wound resistor has been significantly improved in terms of performance and reliability, which helps to improve the market competitiveness of the product and meet the needs of more users.

[0036] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Based on the technical essence of the present invention, any simple modifications, equivalent replacements, and improvements made to the above embodiments within the spirit and principles of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A double-capped wirewound resistor, comprising a core rod (1) made of ceramic material, characterized in that: The core rod (1) is provided with a first metal cap (3) at both ends, and two resistance wires (2) are wound on the core rod (1) in a bidirectional reverse spiral. The two ends of the two resistance wires (2) are respectively welded to the side wall of the first metal cap (3) to form an outwardly protruding welding point (4). The first metal cap (3) is provided with a matching second metal cap (6). The inner wall of the second metal cap (6) has a groove (5) that is matched with the protruding welding point (4). The protruding welding point (4) is located in the groove (5). The protruding welding points (4) are symmetrically distributed up and down. A lead wire (7) is provided at the end of the second metal cap (6).

2. A double-capped wirewound resistor according to claim 1, characterized in that: The core rod (1) is provided with a slot (8) adapted to the winding direction of the resistance wire (2), and the metal wire is embedded in the slot (8).

3. A double-cap wirewound resistor according to claim 1, characterized in that: The raised welding point (4) is in an arc shape.

4. A double-capped wirewound resistor according to claim 1, characterized in that: The raised welding points (4) are coated with epoxy paint.

5. A double-capped wirewound resistor according to claim 1, characterized in that: The first metal cap (3) and the second metal cap (6) are both cylindrical in shape with an opening on one side.

6. A double-cap wirewound resistor according to claim 5, characterized in that: The first metal cap (3) and the second metal cap (6) are both iron caps or copper caps.

7. A double-cap wirewound resistor according to claim 1, characterized in that: The first metal cap (3), the second metal cap (6) and the core rod (1) are wrapped with an insulating layer (9) on the outside.

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