JP4633904B2 - Circuit breaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit breaker, and more particularly to an improvement of the switching mechanism.
[0002]
[Prior art]
FIG. 1 is a side sectional view of a conventional circuit breaker, and the circuit breaker is in a closed state. FIG. 2 is a perspective view showing a state in which a movable contact plate is incorporated in the crossbar of the circuit breaker of FIG. FIG. 3 is a side cross-sectional view showing the circuit breaker of FIG. 1 in an open circuit state. FIG. 4 is a side sectional view showing a state where the contact of the circuit breaker of FIG. 1 is welded and tripped.
[0003]
1 to 4, reference numeral 1 denotes a cover, and reference numeral 2 denotes a base, both of which are made of synthetic resin and constitute an insulating casing of a circuit breaker. Reference numeral 3 denotes a handle for opening and closing the contact of the circuit breaker from the outside. Reference numeral 4 denotes a fixed contact plate fixed to the base 2, and a fixed contact 6 is fixed thereto. Reference numeral 7 denotes a movable contact plate, to which a movable contact 8 facing and separating from the fixed contact 6 is fixed.
[0004]
Reference numeral 9 denotes a contact spring, which is mounted between the recess 2 a of the base 2 and the movable contact plate 7 and biases the movable contact plate 7 in the direction of separating from the fixed contact plate 4. Reference numeral 10 denotes a cross bar formed of an insulating material, which is assembled to prevent the movable contact plate 7 from falling off as shown in FIG. 2, and the movable contact 8 is fixed in the groove 2b provided in the base 2. It slides in the direction of contact and separation.
[0005]
Reference numeral 11 denotes a link, one end of which is pivotally supported on the handle 3 by a link shaft 12, and the other end abuts on and away from the upper end surface 10 d of the crossbar 10 by a roller shaft 13. Reference numeral 14 denotes a claw piece, one end of which is pivotally supported by the rotary shaft 15 of the handle 3, and the claw piece tip 14 a abuts the roller shaft 13. Reference numeral 16 denotes an operating plate, which is pivotally supported at a substantially central portion by a shaft 17 and has one end abutting against the claw piece 14a. The handle 3, the link 11, the link shaft 12, the roller shaft 13, the cross bar 10, and the claw piece 14 constitute an opening / closing mechanism. Reference numeral 19 denotes an electromagnet device having a movable iron piece 20. In the state shown in FIG. 1, the handle is in the ON position.
[0006]
In such a conventional circuit breaker, in FIG. 1 where the contacts are closed, if the handle 3 is tilted in the OFF direction (clockwise), the handle 3, the link 11, the link shaft 12 and the roller shaft 13 The constructed link mechanism is bent in a square shape, the crossbar 10 is pushed upward in FIG. 1 together with the movable contact plate 7 by the urging force of the contact spring 9, and the movable contact 8 is separated from the fixed contact 6. The open circuit state shown in FIG. In this state, the handle 3 is in the OFF position.
[0007]
When an abnormal current flows in the circuit in the closed state shown in FIG. 1, the movable iron piece 20 is attracted to the fixed iron core 21 by the electromagnet portion 19, and the movable portion 20 a of the movable iron piece 20 kicks the operating portion 18 of the operating plate 16. The operation plate 16 rotates counterclockwise about the shaft 17, the engagement between the operation plate 16 and the claw piece 14 is released, and the roller shaft 13 is released from the upper end surface 10 d of the cross bar 10. The cross bar 10 is pushed up in the contact opening direction together with the movable contact plate 7 by the urging force of the contact spring 9, and the movable contact 8 is separated from the fixed contact 6. As shown in FIG. 3, the handle 3 and the link mechanism are turned off. It will be in the state position and the automatic trip will be completed.
[0008]
[Problems to be solved by the invention]
The conventional circuit breaker as described above has a separated configuration in which the roller shaft 13 of the opening / closing mechanism portion presses the upper end surface 10d of the crossbar 10 only in the closing direction of the movable contact plate 7 and comes into contact with and separates. is there. Therefore, as shown in FIG. 3, even when an abnormal current is generated and the movable contact 8 and the fixed contact 6 are welded and are in a closed state, the handle 3 moves to the OFF position. Since the handle is in the OFF state, the user misidentifies that the contact is in an open state from the position of the handle, and safety is reduced.
[0009]
An object of the present invention is to obtain a circuit breaker that can prevent misidentification that the movable contact and the fixed contact are in the open state at the time of welding as described above.
[0010]
[Means for Solving the Problems]
The present invention includes a handle that is disposed inside an insulating housing composed of a cover and a base and can be turned on and off from the outside, a fixed contact plate mounted on the base, and the fixed contact plate. A movable contact plate that contacts and separates, and a cross bar that drives the movable contact plate, one of which is a first link pivotally supported by the link shaft support portion of the handle, and the other end of the link is a roller shaft. When there is no current, the roller shaft movement is restricted. When an abnormal current is detected, the roller shaft movement restriction is provided, and when there is no abnormal current, the handlebar is turned on by turning the handle on. In a circuit breaker having a structure in which the movable contact plate is pressed and brought into contact with the fixed contact plate, with the fixed contact of the fixed contact plate and the movable contact of the movable contact plate welded, the engagement portion is released and the roller shaft Push against the crossbar When but which is released, so the handle is stopped at an intermediate position between the ON position and the OFF position without moving from the ON position to the OFF position, the second with the links shaft support crossbar and the handle, the hole at both ends The circuit breaker is characterized in that it is provided with a connecting member in which one or both holes are elongated holes .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. FIG. 5 is an external perspective view of an open circuit breaker, and FIG. 6 is an internal side cross-sectional view showing the circuit breaker in a closed state. FIG. 7 is a sectional side view showing the circuit breaker of FIG. 6 when it is in an open circuit state. FIG. 8 is a side sectional view showing a trip state in a state where the handle of the circuit breaker of FIG. 6 is held in the ON direction. FIG. 9 is a side sectional view showing a trip state in a state where the contacts of the circuit breaker of FIG. 6 are welded. FIG. 10 is a perspective view showing a state in which a movable contact plate is incorporated in the crossbar of the circuit breaker shown in FIG.
5 to 10, reference numerals 1 to 9 and 11 to 20 are the same as those in the conventional apparatus, and the description thereof is omitted. Reference numeral 30 denotes a cross bar for driving the movable contact plate 7, which is formed of an insulating material and has a □ -shaped through hole 30a for preventing and holding the movable contact plate 7 from falling off, as shown in detail in FIG. , A plurality of protrusions 30b that prevent the movable contact plate 7 from coming off and hold it rotatably are formed, and a substantially central portion of each movable contact plate 7 provided to all poles is supported by the protrusion 30b by the movable bearing 7a. ing. 30d is a roller engaging portion with which the roller shaft 13 is engaged. Reference numeral 30e denotes a hook portion for connecting the connecting member 31. Note that the cross bar 30 slides in the groove 2b formed in the base 2 in the direction in which the movable contact 8 contacts and separates from the fixed contact 6, that is, in the vertical direction in FIG. Reference numeral 31 denotes a connecting member for connecting the link shaft 12 and the hooking portion 30e of the crossbar 30. The connecting member 31 has connecting holes at both ends, and the hole 31a at one end holds the handle in an ON state from the outside. Even in this state, when the abnormal current is generated, the long hole is formed so as not to obstruct the opening of the movable contact 8.
[0014]
In this circuit breaker, in FIG. 6 in which the contacts are closed, if the handle 3 is tilted in the OFF direction (clockwise), the link composed of the handle 3, the link 11, the link shaft 12 and the roller shaft 13 is provided. The mechanism is bent in a square shape, the cross bar 30 is pushed upward in FIG. 6 together with the movable contact plate 7 by the urging force of the contact spring 9, and the movable contact 8 is separated from the fixed contact 6, and the opening shown in FIG. It becomes a state.
[0015]
When an abnormal current flows in the circuit in the closed state shown in FIG. 6, the movable iron piece 20 is attracted to the fixed iron core 21 by the electromagnet portion 19, and the operating portion 20 a of the movable iron piece 20 kicks the operating portion 18 of the operating plate 16. The operation plate 16 rotates counterclockwise about the shaft 17, the engagement between the operation plate 16 and the claw piece 14 is released, and the roller shaft 13 is released from the roller contact portion 30 d of the cross bar 30. The crossbar 30 is pushed up in the contact opening direction together with the movable contact plate 7 by the biasing force of the contact spring 9, the movable contact 8 is separated from the fixed contact 6, and the handle 3 and the link mechanism are turned off as shown in FIG. It will be in the state position and complete the automatic trip.
[0016]
Similarly, even when the handle is held in the ON state from the outside, when an abnormal current is generated, the hooking portion 30e of the crossbar 30 passes through the elongated hole 31a of the connecting member 31 as shown in FIG. It moves without obstructing the opening of the movable contact 8 from the position shown in FIG.
[0017]
In FIG. 9, an abnormal current flows in the circuit in the closed state, and the movable contact 8 and the fixed contact are welded. Then, the engagement between the operating plate 16 and the claw piece 14 is released, and the movable contact 8 is moved from the fixed contact 6. The case where it does not separate is shown. In this state, when the engagement between the operating plate 16 and the claw piece 14 is released as shown in FIG. 9, the roller shaft 13 is disengaged from the roller contact portion 30a of the cross bar 30, and the handle 3 is not shown. Driven in the OFF direction (clockwise) by the urging force of the spring, the hook 30e of the cross bar 30 fixed by the welding force of the movable contact 8 and the fixed contact 6 and the link shaft 12 are connected by the connecting member 31. Therefore, the handle 3 cannot move to the OFF position and stops at an intermediate position between the ON position and the OFF position.
[0018]
As a result, it is possible to display the trip state and the contact welding state by the handle 3, and it is possible to prevent the misunderstanding that the circuit is open.
[0019]
11A to 11D are diagrams illustrating only the relationship between the handle 3, the connecting member 31, and the crossbar 30 in FIGS. 6 to 10, and FIG. B) corresponds to FIG. 7, (C) corresponds to FIG. 8, and (D) corresponds to FIG.
[0020]
【The invention's effect】
As described above, according to the present invention, even when the mechanism is tripped due to an abnormality in the electric circuit, if the movable contact and the fixed contact are welded, the handle stops at an intermediate position between ON and OFF. Therefore, it is possible to provide a circuit breaker that can prevent misidentification that the contact is open, and to improve safety.
[Brief description of the drawings]
FIG. 1 is a structural diagram of a conventional circuit breaker in a contact closed state.
FIG. 2 is a combination diagram of a crossbar and a movable contact plate of a conventional circuit breaker.
FIG. 3 is a structural diagram of a conventional circuit breaker in a contact open state.
FIG. 4 is a diagram of a state in which a conventional circuit breaker has tripped due to contact welding.
FIG. 5 is an external view of a circuit breaker.
FIG. 6 is a structural diagram in which the circuit breaker of the present invention is in a contact closed state.
FIG. 7 is a structural diagram of the circuit breaker of the present invention in a contact open state.
FIG. 8 is a diagram when the circuit breaker handle according to the present invention is tripped while being restrained to ON.
FIG. 9 is a diagram when the circuit breaker of the present invention trips in a contact welded state.
FIG. 10 is an explanatory diagram of a combination of a cross bar, a movable contact plate, and a connecting member according to the present invention.
FIG. 11 is a state explanatory diagram of a main part of the present invention.
[Explanation of symbols]
Reference Signs List 1 cover 2 base 3 handle 4 fixed contact plate 6 fixed contact 7 movable contact plate 8 movable contact 9 contact spring 11 link 12 connecting shaft 13 roller shaft 14 claw piece 16 operating plate 20 iron piece 30 crossbar 31 connecting member (second member Link)

Claims (1)

A handle that can be turned on and off from the outside, is installed inside an insulating housing consisting of a cover and a base, a fixed contact plate that is mounted on the base, and a movable contact that contacts and separates from this fixed contact plate A plate and a crossbar for driving the movable contact plate, one of which is a first link pivotally supported by the link shaft support portion of the handle, and the other end of the link is a roller shaft. When the abnormal current is detected, the roller shaft movement is controlled and an engagement part is provided to release the roller shaft movement restriction. When there is no abnormal current, the handle is turned on by the roller shaft holding the crossbar to move the movable contact plate. In a circuit breaker having a structure in which the fixed contact plate is brought into contact with the fixed contact plate, with the fixed contact of the fixed contact plate and the movable contact of the movable contact plate welded, the engagement portion is released and the roller shaft is pushed against the crossbar. Pressure was released It can handle as to stop at an intermediate position between the ON position and the OFF position without moving into the OFF position from the ON position, between the link shaft support crossbar and the handle, there in a second link with a hole at both ends The circuit breaker is characterized in that one or both holes are provided with a connecting member having a long hole .

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