Coil assembly for miniature circuit breaker

Abstract

The utility model provides a coil assembly used for a miniature circuit breaker, comprising an iron core sleeve which is a hollow cylinder, and two ends of the cylinder are provided with baffle plates extending outwards; a coil is wound on the column body, and a movable iron core, an ejector rod and a spring are arranged in the column body; the magnet yoke is arranged around the iron core sleeve, the magnet yoke at least comprises four parts, namely a first part, a second part, a bent part and a protruding part, and the protruding part is provided with a hole allowing the ejector rod to pass through. The utility model has the advantages of few parts and simple structure, can realize automatic assembly, and improves the yield.

Description

Technical Field

[0001] The utility model relates to the field of miniature circuit breakers, in particular to a coil assembly for a miniature circuit breaker. Background Art

[0002] The statements in this section are only intended to provide background information related to the present invention to help understand the present invention. Such background information does not necessarily constitute prior art.

[0003] Low-current coil assemblies are essential components for miniature circuit breakers. Existing low-current coil assemblies have numerous parts, requiring numerous riveting points. This leads to high costs and a complex structure, which in turn complicates the assembly process and prevents automated assembly. This further increases assembly costs, reduces production efficiency, and reduces product yield. Therefore, a low-current coil assembly with a simple structure that facilitates automated assembly is needed. Utility Model Content

[0004] Therefore, the purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a coil assembly for a miniature circuit breaker, comprising:

[0005] The core sleeve is a hollow cylinder with baffles extending outward at both ends; a coil is wound around the cylinder, and a moving iron core, a push rod and a spring are arranged inside the cylinder;

[0006] A magnetic yoke is arranged around the core sleeve, and the magnetic yoke includes at least a first part located on a first side of the column and covering the two ends of the column and the coil therebetween, a second part located on a second side of the column opposite to the first side and covering the two ends of the column and the coil therebetween, a bent portion connected to the second part, and a protrusion with one end connected to the bent portion and the other end connected to the first part, and embedded in the interior of the core sleeve column, opposite to the moving iron core and protruding toward the moving iron core, the protrusion having a hole for allowing the push rod to pass through.

[0007] According to the coil assembly for a miniature circuit breaker of the present invention, preferably, the push rod is inserted into the moving iron core and passes through the protruding portion of the magnetic yoke, and can move axially along the core sleeve cylinder under the drive of the moving iron core, and the push rod has a protruding base at the end in contact with the moving iron core.

[0008] According to the coil assembly for a miniature circuit breaker of the present invention, preferably, the spring is sleeved on the push rod, with one end of the spring resting on the protrusion of the magnetic yoke and the other end resting on the base of the push rod.

[0009] According to the coil assembly for a miniature circuit breaker of the present invention, preferably, the first portion, the second portion, the bent portion, and the protruding portion of the magnetic yoke are integrally formed.

[0010] According to the coil assembly for a miniature circuit breaker of the present invention, preferably, the first portion and the second portion of the magnetic yoke cover the baffle.

[0011] According to the coil assembly for a miniature circuit breaker of the present invention, preferably, the material of the magnetic yoke is ferromagnetic material.

[0012] According to the coil assembly for a miniature circuit breaker of the present invention, preferably, the ferromagnetic material is cold-rolled carbon steel.

[0013] According to the coil assembly for a miniature circuit breaker of the present invention, preferably, the baffle extends outward perpendicularly to the side surface of the column.

[0014] According to the coil assembly for a miniature circuit breaker of the present invention, preferably, the height of the baffle is equal to the thickness of the coil.

[0015] According to the coil assembly for a miniature circuit breaker of the present invention, preferably, the height of the baffle is the thickness of the coil plus the radius of the copper wire forming the coil.

[0016] Compared with the prior art, the advantages of the present invention are: fewer parts and lower cost; simple structure, no need for riveting, and automatic assembly, thereby improving assembly efficiency and yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following is a further description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0018] Figure 1 This is a structural schematic diagram of a low-current coil assembly according to one embodiment of the present utility model;

[0019] Figure 2 Schematic diagram of the cross-sectional structure of a low-current coil assembly according to one embodiment of the present utility model;

[0020] Figure 3 Schematic diagram of the structure of a low-current coil assembly according to another embodiment of the present invention;

[0021] Figure 4 Schematic diagram of the cross-sectional structure of a low-current coil assembly according to another embodiment of the present utility model; DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings. It should be noted that the embodiments given in the present invention are only for illustration and do not limit the scope of protection of the present invention.

[0023] The structural diagram and cross-sectional diagram of the low current coil assembly of one embodiment are shown in FIG. Figure 1 and Figure 2 As shown. Figure 1 and Figure 2 It can be seen that the low-current coil assembly of this embodiment includes: a cylindrical core sleeve 1; a coil 2 wound on the core sleeve 1; a plastic frame 11 that partially surrounds the coil 2 to protect the coil and prevent the thin copper wire of the coil from scattering or breaking; an iron frame 12 that serves as a support; a moving iron core 3, a push rod 5, a spring 6, and a static iron core 13 located inside the core sleeve 1; a magnetic yoke 4 attached to two adjacent sides of the iron frame 12, which includes interconnected parts 4b and 4c; a magnetizing sheet 14 located in part 4c of the magnetic yoke 4 for enhancing the magnetic field, and a silver point 7 for connecting to other circuits in the miniature circuit breaker.

[0024] The inventors discovered that Figure 1 and Figure 2 The low-current coil assembly shown above contains many parts, and the assembly process is complicated, making it difficult to achieve automated assembly. Therefore, based on this, the present invention proposes a low-current coil solution with a small number of parts, a simple structure, and the ability to achieve automated assembly.

[0025] like Figure 3 and Figure 4 As shown, the main structure of the low current coil of the present invention is a cylindrical iron core sleeve 1 for winding a coil 2. The column of the iron core sleeve 1 has outwardly extending baffles at both ends to protect the coil 2 from the thin copper wire forming the coil 2 from being scattered or broken. Figure 4 The figure shows baffles 1a and 1a' at the first end of the column and baffles 1b and 1b' at the second end. In one embodiment, the baffles extend outward perpendicularly to the sides of the column. In another embodiment, the baffles are approximately perpendicular to the sides of the column, as long as they can protect the coil 2 from becoming tangled or broken. Figure 4 The baffle positions shown are merely examples. In one embodiment, the baffles at both ends of the column are closed structures surrounding the ends of the column. In another embodiment, the baffles at both ends of the column are intermittent structures surrounding the ends of the column, as long as they can protect the coil 2 from becoming tangled or broken.

[0026] The cross-section of the cylinder can be circular, elliptical, or other suitable shapes. The heights of the baffles 1a, 1a', 1b, and 1b' can be set according to actual needs. In one embodiment, the height of the baffle is equal to the thickness of the coil 2, and the thickness of the coil is equal to the diameter of the copper wire used in the coil multiplied by the number of layers of copper wire. In one embodiment, the height of the baffle is the thickness of the coil plus the radius of the copper wire. Such a height allows the baffle to better protect the coil without increasing the volume of the coil assembly.

[0027] A thin copper wire is tightly wound around the cylindrical core sleeve 1, forming a coil 2. When current flows through the coil 2, a magnetic field is generated inside the core sleeve 1. A moving iron core 3 is located at the first end of the cylindrical core sleeve 1. Under the influence of the magnetic field, the moving iron core 3 can move along the axial direction of the cylindrical core sleeve 1 toward the second end.

[0028] A magnetic yoke 4 surrounds the core housing 1. It concentrates and enhances the magnetic field generated by the coil 2, improving its strength and uniformity. It also serves as an external frame, supporting the coil assembly. The yoke 4 comprises at least a first portion 4a located on the first side of the column, covering the ends (in one embodiment, end baffles 1a and 1b) and the coil therebetween; a second portion 4b located on the second side of the column, opposite the first side, covering the ends (in one embodiment, end baffles 1a' and 1b') and the coil therebetween; a curved portion 4c connected to the second portion 4b; and a protrusion 4d, which is connected at one end to the curved portion 4c and at the other end to the first portion 4a and is embedded within the column of the core housing 1. The protrusion 4d is located at the second end of the column, facing and protruding toward the movable core 3. A predetermined gap is defined between the movable core 3 and the flat top portion of the protrusion 4d of the yoke 4. The protrusion 4d has a hole for the passage of a push rod 5. The curved portion 4c can be shaped like a pistol handle.

[0029] In one embodiment, the yoke 4 is fixed to the core sleeve 1. In one embodiment, the yoke 4 can be fixed to the core sleeve 1 by bonding or riveting. A portion of the rod-shaped push rod 5 is arranged inside the moving iron core 3, with a protruding base at one end in contact with the moving iron core 3 and the other end passing through the protrusion 4d of the moving iron core 3 and the yoke 4. The push rod 5 can move axially along the cylindrical body of the core sleeve 1 under the drive of the moving iron core 3. A spring 6 is also sleeved on the push rod 5, one end of the spring 6 rests on the protrusion 4d of the yoke 4, and the other end rests on the base of the push rod 5.

[0030] The baffle of the core sleeve 1 can protect the coil 2 to prevent the thin copper wire forming the coil 2 from being scattered or broken, and the cylinder for winding the copper wire and the baffle for protecting the copper wire are integrally formed, which is convenient for installation. The core sleeve is made of an insulating, lightweight and strong material, preferably polyamide 66 (PA66). The rated current of the copper wire forming the coil 2 is usually not more than 1 ampere (A), preferably 0.5A, the diameter is usually not more than 0.5 millimeters (mm), preferably 0.26mm, and the number of windings is not more than 300 turns, preferably 225 turns. The coil wound with copper wire within these parameter ranges can take into account weight, heat generation and magnetic field strength, and is more suitable for small current circuit breakers.

[0031] The moving iron core 3 is made of ferromagnetic material, preferably cold-rolled carbon steel (Steel for Cold Commercial, SPCC). The inventors found that the rated current of the low-current coil is low, and the current loss can be met by using ferromagnetic material instead of copper to make the yoke 4. In addition, the magnetic field generated by the coil 2 can be concentrated and enhanced without using the magnetizing sheet 14, thus reducing the number of parts. Figure 1 and Figure 2 The outer iron frame 12 and static iron core 13 in the illustrated embodiment can be integrally formed with the yoke 4, eliminating the need for separate connections such as riveting or welding. The low-current coil of this utility model does not require a magnetizing sheet 14. The core sleeve 1 is integrally formed with the plastic frame 11, and the yoke 4 is integrally formed with the iron frame 12 and static iron core 13. This reduces the number of parts used, facilitating assembly while reducing production costs.

[0032] The push rod 5 moves under the drive of the moving iron core to enable the miniature circuit breaker to be disconnected, so a light, strong and insulating material is selected, preferably PA66.

[0033] In the above embodiment, the arrangement of the moving iron core 3, the push rod 5 and the spring 6 is only an example. In actual application, other arrangements may be used, and the components thereof may be increased or decreased.

[0034] Within the normal operating current range, the spring 6 can prevent the movement of the moving iron core 3, so that the top rod 5 remains stationary, the circuit breaker is closed, and the circuit operates normally. When the current is abnormal and increases to several times the rated current, the magnetic field increases, and the magnetic field force on the moving iron core 3 increases, overcoming the resistance of the spring 6, driving the top rod 5 to move and causing the circuit breaker to disconnect. For example, according to one embodiment of the present invention, it can be selected that when the current is 5-10 times the rated current, the moving iron core 3 can drive the top rod 5 to move, thereby causing the miniature circuit breaker to disconnect. According to another embodiment of the present invention, it can be selected that when the current is 10-20 times the rated current, the moving iron core 3 can drive the top rod 5 to move, thereby causing the miniature circuit breaker to disconnect. The force F on the moving iron core can be calculated according to the following formula, thereby selecting the spring 6.

[0035]

[0036] Among them, I m Indicates the maximum current allowed for operation, in A; W indicates the number of turns of coil 2; S indicates the cross-sectional area of the moving iron core 3, in square centimeters (cm 2 );σ represents the distance of the gap between the moving iron core 3 and the flat top portion of the protrusion 4d of the yoke 4, and the unit is centimeter (cm).

[0037] According to one embodiment of the present invention, in order to facilitate the user to connect the circuit to the coil assembly, a terminal 8 and a screw 9 can also be provided at the output end of the coil 2, and the screw 9 can also be replaced by a bolt. The terminal 8 is formed by bending an elongated conductive metal plate into a semi-enclosed space that is approximately a rectangular parallelepiped. The metal plate constitutes the four metal sides of the rectangular parallelepiped, and the other two opposite sides of the rectangular parallelepiped are empty sides. The screw 9 made of conductive metal rotates through one metal side of the terminal 8 until the tip of the screw 9 can reach the other metal side opposite to the metal side it passes through. The output end of the coil 2 is electrically connected to the terminal 8. The user can place the wire into the terminal 8 through one of the empty sides of the terminal 8, and tighten the screw 8 to compress the wire so that the wire is in close contact with one of the metal sides of the terminal 8, facilitating the flow of current.

[0038] Furthermore, according to one embodiment of the present invention, another elongated conductive metal plate can be used to surround the metal side of the terminal 8 that is in close contact with the wire and then be bent into a semi-enclosed space that is approximately rectangular to form a wire frame 10. The two opposite metal sides of the wire frame 10 can cover the two opposite empty sides of the terminal 8. After the tip of the screw 9 rotates through one metal side of the terminal 8, it can then pass through one metal side of the wire frame 10 and reach the other metal side opposite to the metal side of the terminal 8 it passed through. In this way, two ways of connecting the wires can be provided to the user: one is to clamp the wire between the nut of the screw 9 and the metal side of the terminal 8 closest to the nut, and the other is to clamp the wire between the tip of the screw 9 and one metal side of the wire frame 10.

[0039] According to another embodiment of the present invention, in order to reduce resistance and achieve better electrical connection with other circuits, silver dots 7 are provided on the yoke 4 .

[0040] Through the small current coil assembly of the specific embodiment of the utility model described above, the core sleeve 1 has integrally formed baffles 1a, 1a', 1b, 1b', and the magnetic yoke 4 is integrally formed of ferromagnetic material, and no magnetizing sheet 14 is required. Fewer parts are required and fewer connection points are required, and automated assembly can be achieved, thereby improving efficiency, reducing costs, improving precision and product consistency, and thereby improving product yield.

[0041] Although the present invention has been described through preferred embodiments, the present invention is not limited to the embodiments described herein, and includes various changes and modifications that may be made without departing from the scope of the present invention.

Claims

1. A coil assembly for a miniature circuit breaker, characterized in that: include: The core sleeve (1) is a hollow column with baffles extending outward at both ends of the column; A coil (2) is wound around the column, and a moving iron core (3), a push rod (5) and a spring (6) are arranged inside the column; A magnetic yoke (4) is arranged around the core sleeve (1), the magnetic yoke comprising at least a first portion (4a) located on a first side of the column and covering both ends of the column and the coil therebetween, a second portion (4b) located on a second side of the column opposite to the first side and covering both ends of the column and the coil therebetween, a bent portion (4c) connected to the second portion (4b), and a protruding portion (4d) having one end connected to the bent portion (4c) and the other end connected to the first portion (4a), embedded in the column of the core sleeve (1), opposite to the moving iron core (3) and protruding toward the moving iron core (3), the protruding portion (4d) having a hole through which the push rod (5) can pass.

2. The coil assembly for a miniature circuit breaker according to claim 1, characterized in that: The push rod (5) is inserted into the moving iron core (3) and passes through the protruding portion (4d) of the magnetic yoke (4), and can move along the axial direction of the column of the iron core sleeve (1) under the drive of the moving iron core (3). The push rod (5) has a protruding base at the end in contact with the moving iron core (3).

3. The coil assembly for a miniature circuit breaker according to claim 2, characterized in that: The spring (6) is sleeved on the push rod (5), with one end of the spring resting against the protruding portion (4d) of the magnetic yoke (4) and the other end resting against the base of the push rod (5).

4. The coil assembly for a miniature circuit breaker according to any one of claims 1 to 3, characterized in that: The first part (4a), the second part (4b), the bent part (4c), and the protruding part (4d) of the magnetic yoke (4) are integrally formed.

5. The coil assembly for a miniature circuit breaker according to any one of claims 1 to 3, characterized in that: The first portion (4a) and the second portion (4b) of the yoke cover the baffle.

6. The coil assembly for a miniature circuit breaker according to any one of claims 1 to 3, characterized in that: The material of the magnetic yoke (4) is ferromagnetic material.

7. The coil assembly for a miniature circuit breaker according to claim 6, characterized in that: The ferromagnetic material is cold-rolled carbon steel.

8. The coil assembly for a miniature circuit breaker according to any one of claims 1 to 3, characterized in that: The baffle extends outward perpendicularly to the side surface of the column.

9. The coil assembly for a miniature circuit breaker according to claim 8, characterized in that: The height of the baffles (1a, 1a', 1b, 1b') is equal to the thickness of the coil (2).

10. The coil assembly for a miniature circuit breaker according to claim 8, characterized in that: The height of the baffles (1a, 1a', 1b, 1b') is the thickness of the coil (2) plus the radius of the copper wire forming the coil (2).

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