Magnetic control mechanism with opening spring protection

Abstract

The utility model relates to a magnetic control mechanism with opening spring protection, which comprises a static iron core, a movable iron core and an opening spring, the movable iron core and the static iron core are axially distributed, the opposite surfaces of the movable iron core and the static iron core are respectively provided with an axial iron core inner hole, a protective sleeve is arranged in the iron core inner hole, the opening spring is arranged between the movable iron core and the static iron core, and the movable iron core and the static iron core are arranged in the protective sleeve. Two ends of the protective sleeve respectively extend into corresponding iron core inner holes, the protective sleeve is made of proper materials such as engineering plastics and is in interference fit with the corresponding iron core inner holes, the outer diameter of the protective sleeve in a free state is slightly larger than the inner diameter of the corresponding iron core inner holes, an outer chamfer is arranged at the outer end of the protective sleeve, and a reducing annular step is arranged on the inner wall of the outer end of the protective sleeve. According to the utility model, the friction between the opening spring and the movable and static iron cores can be effectively avoided or reduced, so that the interference of chippings and impurities generated by abrasion on the closing maintenance of the circuit breaker can be prevented or reduced.

Description

Technical Field

[0001] The utility model relates to a magnetic control mechanism provided with a gate opening spring protection. Background Art

[0002] The existing magnetic control mechanism (a semi-hard magnetic operating mechanism that can be used for circuit breakers) is mainly composed of a static iron core, a moving iron core and a trip spring. The moving iron core and the static iron core are axially distributed, and the driving shaft used to drive the moving contact of the circuit breaker is fixedly connected to the moving iron core and is located at the axis position of the moving and static iron cores. The trip spring is sleeved on the driving shaft, and the two ends are respectively against / connected to the moving iron core and the static iron core, pushing the moving and static iron cores apart from each other, and driving the circuit breaker to trip through the driving shaft. When the excitation coil (or mechanism coil) of the magnetic control mechanism is energized, the moving and static iron cores are attracted to each other, and the circuit breaker is driven to close through the driving shaft. After closing, the moving and static iron cores are kept in the attracted state by the residual magnetism, and then the closing is maintained without power. Because the circuit breaker using the magnetic control mechanism has excellent characteristics such as low energy consumption, small size, fast and accurate action, small dispersion, and wide temperature range, it has gradually been recognized and popularized by industry technicians.

[0003] The basic working principle of the magnetic control mechanism is: by injecting a positive excitation current into the mechanism coil, the moving iron core and the static iron core are attracted to form a closed magnetic line of force. After the excitation current is removed, the magnetic control mechanism relies on the residual magnetism to keep the circuit breaker in the closed position. At this time, the characteristics of the magnetic control mechanism are similar to those of a permanent magnet mechanism. When opening is required, a reverse excitation current (referred to as reverse current) is given to the mechanism coil. The magnetic control mechanism is demagnetized under the action of the reverse electromagnetic force and the opening operation is achieved by relying on the opening spring. Therefore, a sufficiently large residual holding force of the magnetic control circuit breaker is a reliable guarantee for maintaining the magnetic control circuit breaker in the closed position.

[0004] An inner hole for accommodating the opening spring and allowing the opening spring to work is provided in the control mechanism. The two ends of the inner hole are inner holes (which can be called iron core inner holes) respectively provided in the center of the opposite surfaces (attractive surfaces) of the moving iron core and the static iron core. The two ends of the opening spring are located in the corresponding inner holes and abut against the bottom surface of the inner holes. It is found in practice that during the opening and closing operation of the magnetic control mechanism, the outer threaded (shaped) surface of the opening spring will collide and rub against the inner surface of the inner hole of the magnetic control mechanism (especially the inner surface of the corresponding inner hole of the moving iron core and the static iron core). Even if the outer diameter of the spring is smaller than the inner hole diameter of the magnetic control mechanism in the design process, friction between the opening spring and the corresponding inner hole wall is still inevitable in actual work. With the increase in the number of operations, the wear will increase, and the debris and impurities generated by the wear will inevitably enter between the attraction surfaces of the moving and static iron cores, so that the residual holding force of the magnetic control mechanism in the closed state is insufficient, which will lead to the circuit breaker being opened by mistake. Once this phenomenon occurs, the consequences are serious. Utility Model Content

[0005] The utility model aims to provide a magnetic control mechanism with a trip spring protection to avoid or reduce the friction between the trip spring and the dynamic and static iron cores, thereby preventing or reducing the obstruction of the circuit breaker closing maintenance caused by debris and impurities generated by wear.

[0006] The technical solution of the utility model is: a magnetic control mechanism with a trip spring protection, including a static iron core, a moving iron core and a trip spring, the moving iron core and the static iron core are distributed axially (in the axial direction of the moving iron core and the static iron core), and an axial (the depth direction is axial) iron core inner hole is provided on the opposite surfaces (attraction surfaces) of the two (for example, the center of the mating surface), the trip spring is located between the moving iron core and the static iron core, and a protective sleeve (or spring protective sleeve) is provided in the iron core inner hole, and the two ends of the trip spring are respectively extended into the protective sleeves of the corresponding iron core inner holes, and the ends thereof can usually be abutted against the iron core inner hole, and can also be fixedly connected to the iron core inner hole or interact with the corresponding iron core in other ways.

[0007] Preferably, the protective sleeve is installed on the corresponding inner hole of the iron core in an interference fit manner, and the outer wall of the protective sleeve is in pressure contact with the hole wall of the inner hole of the iron core.

[0008] Preferably, the protective cover is made of engineering plastic.

[0009] Furthermore, the material of the protective cover is nylon, ABS, POM or polytetrafluoro.

[0010] Preferably, the inner hole of the iron core is provided with a bottom surface or an inner annular step (or step), and the corresponding end portion of the opening spring abuts against the bottom surface of the inner hole of the iron core or the end surface (perpendicular to the axial direction) of the inner annular step.

[0011] Typically, the protective sleeve is in a cylindrical shape.

[0012] Typically, the core inner hole is a circular hole, the protective sleeve is cylindrical and has an outer diameter in a free state slightly larger than the inner diameter of the corresponding core inner hole (having an interference fit relative to the inner diameter of the core inner hole).

[0013] Typically, the inner diameter of the protective sleeve is not less than the outer diameter of the corresponding portion / area on the opening spring.

[0014] Preferably, an outer end of the protective sleeve is provided with an outer chamfer (an oblique chamfer structure located on the outer side).

[0015] Furthermore, the outer chamfer angle of the outer end of the protective sleeve may be 15 degrees to 75 degrees.

[0016] Preferably, an annular step with a reduced diameter (the inner diameter on the axial outer side is smaller than the inner diameter on the axial inner side) is provided on the inner wall of the outer end of the protective sleeve.

[0017] The beneficial effects of the utility model are as follows: by adding a protective cover to the inner hole wall of the moving and static iron core of the magnetic control mechanism, a good protective effect is achieved, and the spring and the hole wall cannot directly rub against each other, thereby avoiding or significantly reducing the generation of debris, which helps to maintain the closing holding force of the magnetic control mechanism and improve the closing reliability of the circuit breaker. Since the protective cover is made of engineering plastics such as nylon, ABS, POM or polytetrafluoroethylene, it will not generate debris due to collision, effectively avoiding the defect of the core material being not resistant to collision, which is conducive to preventing the influence of debris on the closing holding force; since the outer end of the protective cover is provided with an outer chamfer structure, it is convenient to embed it on the inner hole of the iron core; since a reduced diameter annular step is provided on the inner wall of the outer end of the protective cover, the assembly type can push the protective cover into the bottom of the inner hole of the iron core by a clamping column tool (in a columnar shape) against the end face 35 of the step, which facilitates the assembly operation and helps to ensure that the assembly is in place. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is an exploded view of the magnetic control mechanism involving the protective cover;

[0019] Figure 2 It is a schematic diagram of the structure of the protective cover;

[0020] Figure 3 It is a cross-sectional view (longitudinal section) of the protective cover. DETAILED DESCRIPTION

[0021] See also Figure 1-Figure 3 The magnetic control mechanism with the opening spring protection is mainly composed of the moving iron core 5 of the magnetic control mechanism, the protective cover (spring protection cover) 4 of the inner hole of the moving core, the opening spring 3, the protective cover (spring protection cover) 2 of the inner hole of the static core and the static iron core 1. The protective covers on each side (the protective cover of the inner hole of the moving core and the protective covers of the inner holes of the moving and static iron cores) are tightly embedded in the inner holes of the moving and static iron cores respectively through the tooling, and then the opening spring is placed in the inner hole. The opening spring is no longer in direct contact with the inner hole wall of the iron core. Then, the other components are assembled together through other fixing parts of the magnetic control mechanism according to the existing method to form a magnetic control mechanism.

[0022] The overall structure of the protective sleeve is a cylindrical thin-walled sleeve. The wall thickness can be set according to demand, such as 0.3mm or 0.5mm, etc. The inner diameter of the sleeve cannot be smaller than the outer diameter of the opening spring.

[0023] The height (axial dimension) of the protective sleeve may be slightly lower than the height of the corresponding inner hole of the core.

[0024] The outer surface of the end of the protective sleeve inserted into the inner hole of the iron core has a certain chamfer 43 to facilitate embedding into the inner hole of the iron core for positioning. The chamfer angle can be set to 15 degrees to 75 degrees according to the situation.

[0025] At the same time, an annular step is provided on the inner wall (inner surface) of the end so that the protective sleeve can be pushed into the bottom of the inner hole of the iron core by the step clamping column tooling against the end surface 45 of the step.

[0026] The material of the protective cover can be nylon, ABS, POM, polytetrafluoroethylene or other engineering plastics or other suitable materials.

[0027] The outer diameter of the protective sleeve (in the free state) can be slightly larger than the inner diameter of the corresponding inner hole of the core to achieve the required interference fit.

[0028] Unless otherwise specified or when one preferred or optional technical means is a further limitation of another technical means, the preferred and optional technical means disclosed in the present utility model can be arbitrarily combined to form several different specific implementation methods.

Claims

1. A magnetic control mechanism with a trip spring protection, comprising a static iron core, a moving iron core and a trip spring, wherein the moving iron core and the static iron core are axially distributed, and an axial iron core inner hole is provided on the opposite surfaces of the two, and the trip spring is located between the moving iron core and the static iron core, and is characterized in that A protective sleeve is arranged in the inner hole of the iron core, and two ends of the opening spring extend into the protective sleeves corresponding to the inner hole of the iron core respectively.

2. The magnetic control mechanism with opening spring protection as claimed in claim 1, characterized in that The protective sleeve is installed on the corresponding inner hole of the iron core in an interference fit manner.

3. The magnetic control mechanism with opening spring protection as claimed in claim 2, characterized in that The material of the protective cover is engineering plastic.

4. The magnetic control mechanism with opening spring protection as claimed in claim 3, characterized in that The material of the protective cover is nylon, ABS, POM or polytetrafluoroethylene.

5. The magnetic control mechanism with opening spring protection according to any one of claims 1 to 4, characterized in that The inner hole of the iron core is provided with a bottom surface or an inner annular step, and the corresponding end portions of the opening spring abut against the bottom surface of the inner hole of the iron core or the end surface of the inner annular step.

6. The magnetic control mechanism with opening spring protection according to any one of claims 1 to 4, characterized in that The protective sleeve is in a cylindrical shape.

7. The magnetic control mechanism with opening spring protection as claimed in claim 6, characterized in that The inner hole of the iron core is a circular hole, the protective sleeve is cylindrical and its outer diameter in a free state is slightly larger than the inner diameter of the corresponding inner hole of the iron core.

8. The magnetic control mechanism with opening spring protection according to any one of claims 1 to 4, characterized in that The outer end of the protective sleeve is provided with an outer chamfer.

9. The magnetic control mechanism with opening spring protection as claimed in claim 8, characterized in that The outer chamfer angle of the outer end of the protective sleeve is 15 degrees to 75 degrees.

10. The magnetic control mechanism with opening spring protection according to any one of claims 1 to 4, characterized in that An annular step with a reduced diameter is arranged on the inner wall of the outer end of the protective sleeve.

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