WO2004053911A1

WO2004053911A1 - Air circuit breaker

Info

Publication number: WO2004053911A1
Application number: PCT/JP2002/012846
Authority: WO
Inventors: Hideya Wakabayashi
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2002-12-09
Filing date: 2002-12-09
Publication date: 2004-06-24
Also published as: TW200410278A; CN1282209C; TW579533B; JP4134987B2; JPWO2004053911A1; CN1615532A; KR100641863B1; KR20040091710A

Abstract

An air circuit breaker in which the size of a spring for closing the air circuit breaker by relieving accumulated pressure is decreased, an excessive stress load is prevented, the mechanical strength lifetime of the closing spring is prolonged, and mis-tripping is prevented by reducing the impact force of a spring at the time of closing. The air circuit breaker comprises a switching mechanism (10) consisting of a toggle link mechanism for turning a contact on/off by opening/closing a mover (3) while oscillating, a closing spring (12) for shifting the mover (3) to turn it on by relieving accumulated pressure and pressing the link joint of the toggle link mechanism, and a spring (18) for urging the mover (3) in an opening direction in an off-state, and imparting a contact pressure between both contacts under on state wherein the pressure contact spring (18) comprises a nonlinear spring. When a nonlinear spring is also employed as the closing spring (12), closing impact force is lessened and mis-tripping can be prevented.

Description

Air circuit breaker Technical field Akira

The present invention relates to an open / close mechanism of an air circuit breaker, and more particularly to an air circuit breaker which is operated by opening force of a panel accumulated when the circuit breaker is turned on.

book

Background art

FIG. 6 is a side cross-sectional view of a conventional air circuit breaker described in, for example, Japanese Patent Application Laid-Open No. HEI 3-2-133434.

In the figure, a housing 1 is formed from an insulating material, and a fixed conductor 2 is attached to the inner bottom of the housing 1. A fixed contact 2a is fixed to one end of the fixed conductor 2, and the other end is led out to the outside of the housing 1 to form a power supply terminal 2b. A movable contact 3a is fixed to the mover 3, and the movable contact 3a is separated from and connected to the fixed contact 2a by the rotation of the mover 3.

The mover 3 is rotatably supported by a contact arm 4, and the contact arm 4 is supported by a contact arm shaft 5 fixed to the housing 1. The mover 3 is connected to the terminal conductor 7 by a flexible conductor 6 so as to be conductive and flexible. The terminal conductor 7 is fixed to the housing 1 and led out to the outside of the housing 1 to form the power supply terminal 7a. Further, the mover 3 is urged in the opening direction by the contact pressure panel 8. The contact arm 4 is connected via a shaft 9 to an opening / closing mechanism 10 comprising a well-known toggle link mechanism. The shaft 9 supports the mover 3 in a swingable manner. The opening / closing mechanism 10 turns the movable element 3 to move the movable contact 3a and the fixed contact 2a apart to turn on / off the energization of the air circuit breaker.

In the normal ON state, the opening / closing mechanism 10 is latched by a latch (not shown) associated with the trip relay section 11 and maintains the ON state. However, when the trip relay section 11 detects an overcurrent or an excessive current due to an accident or the like, the latch is disengaged, and the opening / closing mechanism 10 is turned off.

The OFF operation is driven by the force of the contact pressure panel 8 and the electromagnetic force, but the closing operation is performed by releasing the energy stored in the springs 12. The closing spring 12 is compressed and stored by the pressure storage means of the ratchet cam mechanism 14 by the handle 13 or a motor (not shown).

To close the air circuit breaker, it is necessary to compress the contact pressure spring 8 that urges the mover 3 in the separating direction, move the mover 3, and bring the movable contact 3a into contact with the fixed contact 2a. . Since the contact pressure spring 8 uses a normal coil spring wound at an equal pitch, the amount of movement of the panel end and the generated reaction force are in a proportional relationship. The movable element 3 in the opened state remains at the position where the contact pressure panel 8 is slightly compressed, and a certain amount of pressing force is required at the time of the initial compression movement.

-The todal link in the initial stage of the closing operation is in a state where each link is bent, and the component force in the direction required to shift the mover 3 to the on state among the forces released from the closing springs 12 is small. . For this reason, the input panel 12 is made to be much stronger in order to secure the pressing force at the time of initial movement. Or, it is necessary to install the closing spring 12 in a limited space in order to reduce the size of the air circuit breaker, so the reduced loading panel 1 2 has an excessive stress load and shortens the mechanical strength life There was a problem.

After the contacts are turned on, the release of the input panel 12 is terminated by the collision of the spring pin 15 with the end of the guide hole 16. When the input panel 12 is made strong, the entire mechanism including the housing 1 vibrates due to the impact force at this time, There is also a problem that a latch (not shown) that engages with the release relay section 11 is released and a mistrip that does not turn on the contact occurs.

The present invention has been made in order to solve the above-mentioned problems, and by reducing the size of the input panel of the input operating force source and reducing the stress load, the mechanism life can be stabilized for a long time, and after the contact is turned on. An object of the present invention is to obtain a highly reliable air circuit breaker that maintains the contact pressure between contacts by a contact pressure panel and satisfies the electrical characteristics when energized. Disclosure of the invention

An air circuit breaker according to the present invention includes an opening / closing mechanism including a toggle link mechanism for automatically opening and closing a movable element to which a movable contact is fixed and for turning a movable contact on and off to a fixed contact, and a link node of the toggle link mechanism. A closing spring that presses and moves on by the force of release and a pressure accumulator that stores the closing panel.In the off state, the mover is urged in the direction to separate from the fixed contact.In the on state, the movable contact is fixed. And a contact pressure panel made of a non-linear panel for applying a contact pressure to a contact point. The closing spring is also a non-linear panel. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side sectional view of an air circuit breaker according to the present invention.

FIG. 2 is a side view of the nonlinear contact pressure panel of the present invention.

FIG. 3 is a graph showing the relationship between the input panel, the force of the contact pressure panel, and the stroke according to the first embodiment of the present invention.

FIG. 4 is a side sectional view of an essential part for explaining closing of the air circuit breaker.

FIG. 5 is a graph showing the relationship between the input panel, the force of the contact pressure panel, and the stroke according to Embodiment 2 of the present invention. FIG. 6 is a side sectional view of a conventional air circuit breaker. BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1

Embodiment 1 of the present invention will be described with reference to FIGS.

In the figure, 1 to 7 and 9 to 16 are the same as those of the above-mentioned conventional device, and the description is omitted. The contact pressure spring 18 is a non-linear panel as shown in Fig. 2 and the winding pitch is made unequal, so that the relationship between the compression movement distance and the repulsive force is not proportional as shown in Fig. 3, and the panel constant is Is small at the initial position S of the stroke and increases toward the final position L of the stroke.

Next, the closing operation will be described. In FIG. 4, when the latch of the pressure accumulating arm 20 to which the spring retaining pin 15 for compressing the closing spring 12 is attached is released by the injection command, the pressure accumulating arm 20 is centered on the shaft 21. The pressure accumulating arm 20 is rotated in the counterclockwise direction, and presses the upper joint 10a of the toggle link upward. This pressing force propagates through each member of the toggle link, moves the movable element 3 in the ON direction, and starts compressing the contact pressure spring 18.

The relationship between the forces at this time is, as shown by the vector in FIG. 4, the release spring P1 of the input panel 12 is divided by the todal link into the input component force P2 required to move the mover 3. . This input component force P2 needs to be larger than the total reaction force of the plurality of contact pressure springs 18. Here, as for the contact pressure spring 18, several poles of the air circuit breaker or an integral multiple thereof are arranged in parallel, and usually 3 to 12 pieces are mounted.

By making the contact pressure panel 18 a non-linear panel, the reaction force F at the time of initial operation can be reduced compared to the conventional contact pressure panel 8. Although the reaction force of each contact pressure panel 18 is small, the total reaction force F is several times larger and is reduced accordingly, and the input panel 12 can be made smaller and weaker. Since the contact pressure panel 18 is made a non-linear panel to reduce the reaction force F at the time of the initial movement of the injection, the stress load on the input panel 12 is correspondingly reduced and the mechanical strength life can be extended. Embodiment 2

FIG. 5 is a graph showing a relationship between a force of a closing spring and a contact pressure panel and a stroke according to the second embodiment of the present invention. In the second embodiment, both the contact pressure spring and the input panel are non-linear springs. Note that the mechanism configuration is the same as in FIGS. 1 and 4 of the first embodiment, and a description thereof will be omitted. As shown in FIG. 5, a desired panel force can be obtained at the time of initial operation of the injection and at the completion of the injection by setting the injection spring 12 to a non-linear panel. Then, since the force is reduced in the middle of the stroke, when the closing spring 12 for closing operation is released, when the closing is completed, the energy W that the spring hook pin 15 collides with the end of the guide hole 16 is reduced. It is reduced and the impact force is reduced. As a result, it is possible to prevent the occurrence of mistrip due to the release of the latch (not shown) engaged with the trip relay section 11. 'And, by reducing the reaction force F of the input panel 12, it is also effective in reducing the power consumption when accumulating the input panel 12 with a motor.

In the above description, the non-linear contact pressure panel and the non-linear input spring are coil springs with unequally spaced winding pitches. A spring may be used. Industrial applicability

As described above, the air circuit breaker according to the present invention urges the mover in the direction of separating from the fixed contact in the off state, and fixes the movable contact in the on state. Since the contact pressure panel that applies contact pressure to the contact is a non-linear panel, the input panel of the input operating force source can be made smaller and the stress load can be reduced, and the long life of the input panel mechanism can be stabilized. Peel off.

Also, by using a non-linear spring for the input panel, the input panel is released and the collision energy at the completion of input is reduced, the impact force is reduced, and the occurrence of mistrip due to the latch disengagement due to the impact can be reduced. Is prevented. This is also effective in reducing the power consumption of the motor that accumulates pressure in the input panel.

Claims

The scope of the claims

1. A mover with a movable contact opposite to the fixed contact fixed to the conductor, and a movable link that swings and opens and closes the mover to turn the movable contact on and off to the fixed contact. An opening / closing mechanism, an input panel for pressing the link node of the toggle link mechanism by a biasing force to turn on the movable element, pressure accumulating means for accumulating the input spring, and the movable element in an off state. And a contact pressure spring for applying a contact pressure to the fixed contact when the movable contact is in the on state, wherein the contact pressure panel is An air circuit breaker characterized by a non-linear panel.

2. The air circuit breaker according to claim 1, wherein the input panel is a non-linear panel.