JP7816116B2 - circuit breaker - Google Patents

Description

The present invention relates to a circuit breaker.

Patent Document 1 discloses a structure in which a pin prevents the movable contact from rotating when the contacts are opened by current-limiting interruption. The pin, which functions as a stopper, is located radially inward of the movable contact.

Japanese Patent Application Laid-Open No. 2006-49091

In a structure in which the movable contactor is held in place during current-limiting interruption by only a pin located radially inward of the movable contact, contact with the pin can cause the tip of the movable contactor to deform in the opening direction, potentially resulting in a reduction in the amount of contact wipe.
An object of the present invention is to suppress deformation of a moving contact in a circuit breaker during current-limiting interruption.

A circuit breaker according to one aspect of the present invention comprises a movable contactor, a main stopper, and an auxiliary stopper. The movable contactor has a movable contact on the radially outer side and is closed and opened by rotation. When opening the contact by current-limiting interruption, the main stopper contacts the movable contactor radially inward of the movable contact to prevent rotation. When the movable contactor contacts the main stopper and attempts to deform in the opening direction, the auxiliary stopper contacts the movable contactor radially outward of the main stopper.

According to the present invention, when the contacts are opened by current-limiting interruption, if the movable contactor attempts to deform due to contact with the main stopper, it comes into contact with the auxiliary stopper, thereby suppressing deformation of the movable contactor.

FIG. 2 is a cross-sectional view of a circuit breaker. FIG. 10 is a diagram showing one of the movable contacts of the R phase and the T phase. FIG. FIG. FIG. 10 is a diagram showing the handle and lever fitted together. FIG. FIG. 10 is a view showing a handle of a second embodiment. FIG. 10 is a view showing a lever according to a second embodiment. FIG. 10 is a cross-sectional view of a circuit breaker according to a second embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Note that the drawings are schematic and may differ from the actual product. Furthermore, the following embodiments exemplify devices and methods that embody the technical concepts of the present invention, and are not intended to limit the configuration to those described below. In other words, the technical concepts of the present invention can be modified in various ways within the technical scope set forth in the claims.

First Embodiment
"composition"
In the following description, the three mutually orthogonal directions will be referred to as the vertical direction, the width direction, and the depth direction for the sake of convenience.
FIG. 1 is a cross-sectional view of a circuit breaker 11 .
The diagram shows a cross section of the circuit breaker 11 taken along the vertical and depth directions through the center of its width as viewed from one side in the width direction, with minor components omitted for ease of explanation. The circuit breaker 11 is also called a no-fuse breaker, and can open and close a circuit in normal use by manual or electrical operation, and automatically breaks the circuit when it detects an abnormal overcurrent due to an overload or short circuit, protecting it from damage due to the overcurrent. The circuit breaker 11 includes a movable contact 12, a handle 13, and a lever 14.

The movable contactor 12 is a rod-shaped conductor, and has a movable contact 21 provided on the radially outer side thereof. The movable contactor 12 is rotatably supported by a rotation shaft 22 extending in the width direction. The movable contactor 12 closes when the movable contact 21 comes into contact with a fixed contact (not shown), and opens when it separates. When viewed from one side in the width direction, rotation counterclockwise is the closing direction, and rotation clockwise is the opening direction. There are three poles, and the three movable contactors 12 are arranged side by side in the width direction, one for each pole.
The handle 13 is a resin part that is manually operated by the user.
The lever 14 is fixed to the back side of the handle 13 and is rotatably supported by a rotation shaft 15 extending in the width direction. The lever 14 is a metal part that rotates when the handle 13 is manually operated and transmits a driving force to the movable contact 12 via a toggle link mechanism (not shown) to close and open the contact.

When a short circuit occurs, the movable contact 12 opens by jumping up due to electromagnetic repulsion, resulting in current-limiting interruption. The principle behind the generation of electromagnetic repulsion is that current concentration and diffusion occur at the contact points between the contacts, and currents flowing in opposite directions generate electromagnetic repulsion that tries to separate them.
The circuit breaker 11 is equipped with a main stopper 17. The main stopper 17 is a metal pin extending in the width direction, and both ends of the pin are connected to the frame of the switching mechanism. The main stopper 17 stops the rotation of the S-phase movable contactor 12 at the open position when the movable contactor 12 jumps up due to current-limiting interruption. The main stopper 17 is provided at a position radially inward of the movable contact 21 so as to contact the movable contactor 12. A raised portion 23 is formed on the movable contactor 12 at a position where the main stopper 17 contacts. The raised portion 23 has a substantially triangular shape when viewed in the width direction, and is formed so that the force received from the main stopper 17 is directed radially outward when the main stopper 17 contacts the inclined surface on the radially inner side. The main stopper 17 is provided only on the middle S-phase of the three phases, where the lever 14 is located.

FIG. 2 is a diagram showing one of the movable contacts 12 of the R phase and the T phase.
Here, one of the movable contacts 12 of the R-phase and T-phase, both of which have no lever 14 among the three phases, is shown as viewed from one side in the width direction. The circuit breaker 11 is provided with a stopper 18 to stop the rotation of the R-phase and T-phase movable contacts 12 at the open position when the movable contacts 12 jump up due to current-limiting interruption. The stopper 18 is formed on the back side of the housing cover (not shown) and contacts the movable contact 12 on the radially outer side. Since the S-phase has a handle 13 and it is not possible to provide the stopper 18 on the back side of the housing cover, the main stopper 17 is provided radially inward of the movable contact 21 as described above.

FIG. 3 is a diagram showing the handle 13. As shown in FIG.
1A shows the handle 13 as viewed from the rear in the depth direction, one side in the vertical direction, and the other side in the width direction, and FIG. 1B shows the handle 13 as viewed from the rear in the depth direction, the other side in the vertical direction, and the other side in the width direction. The handle 13 includes a ceiling portion 31, an outer front wall portion 32, and a pair of side walls 33.
The ceiling portion 31 is formed along the approximate vertical and width directions, and the inner peripheral surface facing the depth direction is formed in a flat shape, while the outer peripheral surface facing the front in the depth direction is formed in an arch shape that is convex toward the front in the depth direction when viewed from the width direction.
The outer front wall portion 32 extends from one end of the ceiling portion 31 in the substantially vertical direction toward the back in the substantially depth direction, and is formed in a flat shape along the width direction and the substantially depth direction.

The side wall portions 33 extend from both widthwise ends of the ceiling portion 31 toward the rear in the depth direction, and are formed in a planar shape along the vertical and depth directions.
A notch 34 is formed in the center in the width direction and on the innermost edge in the depth direction of the outer front wall 32. The notch 34 is formed in the shape of a shallow, wide groove that is recessed toward the front in the depth direction.
A rib-like protrusion 35 that protrudes inward in the width direction and extends substantially in the depth direction is formed on the inner peripheral surface of the side wall 33. The protrusion 35 is formed at a position spaced apart in the vertical direction from the outer front wall 32. The protrusion 35 extends over the entire side wall 33 from the rear to the front in the depth direction.

FIG. 4 is a diagram showing the lever 14. As shown in FIG.
1A shows the lever 14 as viewed from the front in the depth direction, one side in the vertical direction, and one side in the width direction, and FIG. 1B shows the lever 14 as viewed from one side in the width direction. The lever 14 is formed by pressing, and includes a ceiling portion 41, an inner front wall portion 42, and a pair of side walls 43.
The ceiling portion 41 is formed in a flat shape along the approximate vertical and width directions.
The inner front wall 42 extends from one end of the ceiling 41 in the substantially vertical direction toward the rear in the substantially depth direction, and is formed in a flat shape along the width and depth directions. The thickness of the inner front wall 42 corresponds to the gap between the outer front wall 32 and the protrusion 35 of the handle 13 when viewed from the width direction.

The side wall portions 43 extend from both ends of the ceiling portion 41 in the width direction toward the back in the depth direction, and are formed in a planar shape along the vertical and depth directions.
A protrusion 44 is formed on the inner front wall 42 at the center in the width direction and at the innermost edge in the depth direction. The protrusion 44 is formed as a short, wide piece that protrudes toward one side in the vertical direction. The width of the protrusion 44 is smaller than the width of the notch 34 and larger than the width of the movable contact 12.
The inner front wall 42 and the side wall 43 each extend independently from the ceiling 41, with both widthwise ends of the inner front wall 42 and one generally vertical end of the side wall 43 separated from each other. The gap between the inner front wall 42 and the side wall 43, as viewed in the widthwise direction, corresponds to the generally vertical dimension of the protrusion 35 of the handle 13.

FIG. 5 shows the handle 13 and the lever 14 in a fitted state.
1A shows the fitted handle 13 and lever 14 as viewed from approximately the front in the depth direction, one side in the vertical direction, and one side in the width direction. FIG. 1B shows the fitted handle 13 and lever 14 as viewed from approximately the rear in the depth direction, the other side in the vertical direction, and the other side in the width direction. By fitting the lever 14 behind the handle 13, the ceiling 41 overlaps the ceiling 31, the inner front wall 42 overlaps the outer front wall 32, both widthwise ends of the inner front wall 42 fit between the outer front wall 32 and the protrusion 35, and the protrusion 44 protrudes from the notch 34.

Returning to the explanation of Figure 1, the circuit breaker 11 is equipped with an auxiliary stopper 47. The auxiliary stopper 47 is composed of a protrusion 44 that protrudes from the lever 14 toward the radially outer portion of the movable contactor 12 that is opening. When the movable contactor 12 contacts the main stopper 17 and attempts to deform in the opening direction, the auxiliary stopper 47 contacts the movable contactor 12 radially outer than the main stopper 17. The protrusion 44 is positioned so that a slight gap is formed between the tip of the protrusion 44 and the movable contactor 12 when the movable contactor 12 contacts the main stopper 17. The tip surface of the protrusion 44 is arranged to face and approximately parallel to the radially outer end face of the movable contactor 12 that is opening. Therefore, when the movable contactor 12 jumps up due to current-limiting interruption and the S-phase movable contactor 12 contacts the main stopper 17 and attempts to deform in the opening direction, the auxiliary stopper 47 makes surface contact with the movable contactor 12 radially outer than the main stopper 17. The auxiliary stopper 47 is attached to the lever 14 and is therefore only provided on the S-phase of the three phases.

<<Action and Effect>>
Next, the main effects of the first embodiment will be described.
The circuit breaker 11 includes a movable contactor 12, a main stopper 17, and an auxiliary stopper 47. The movable contactor 12 has a movable contact 21 provided radially outward, and is closed and opened by rotation. When opening the contact by current-limiting interruption, the main stopper 17 comes into contact with the movable contactor 12 radially inward of the movable contact 21 to prevent rotation. When the movable contactor 12 comes into contact with the main stopper 17 and attempts to deform in the opening direction, the auxiliary stopper 47 comes into contact with the movable contactor 12 radially outward of the main stopper 17. This suppresses deformation of the movable contactor 12 and prevents a decrease in the contact wipe amount.

The circuit breaker 11 comprises a handle 13 and a lever 14. The lever 14 is fixed to the handle 13 and rotates when the handle 13 is operated, transmitting a driving force to the movable contact 12 to close and open the contact. The auxiliary stopper 47 is composed of a protrusion 44 that protrudes from the lever 14 toward the radially outer portion of the movable contact 12 that opens the contact. As a result, when opening the contact by current-limiting interruption, if the movable contact 12 attempts to deform due to contact with the main stopper 17, it comes into contact with the auxiliary stopper 47, thereby suppressing deformation of the movable contact 12. As the lever 14 is made of metal, sufficient strength can be ensured.

The lever 14 has an inner front wall 42 facing radially outward from the movable contact 12 to be opened, and a protrusion 44 is formed on the inner front wall 42. The handle 13 has an outer front wall 32 that overlaps the outer peripheral surface of the inner front wall 42 and faces radially outward from the movable contact 12 to be opened, and a notch 34 is formed in the outer front wall 32 through which the protrusion 44 protrudes. This allows the protrusion 44 to protrude as far radially outward as possible from the movable contact 12 to be opened, avoiding interference with the outer front wall 32. This effectively suppresses deformation of the movable contact 12 in the opening direction. The protrusion 44 is formed on the inner front wall 42 and is a partial extension of the inner front wall 42, so the lever 14 with the protrusion 44 can be easily molded by press working. Because the handle 13 is made of resin, the notch 34 can be easily molded by simply inserting a mold insert into a conventional injection molding die.

The handle 13 is formed with a side wall 33, and the side wall 33 is formed with a protrusion 35 that supports the rear side of the inner front wall 42. As a result, when the movable contact 12 comes into contact with the jump-up auxiliary stopper 47, the load applied to the inner front wall 42 can be borne by the protrusion 35 of the handle 13, thereby preventing the inner front wall 42 from deforming.
The auxiliary stopper 47 is disposed at a position where a gap is formed between the movable contactor 12 and the main stopper 17 when the movable contactor 12 comes into contact with the main stopper 17. This allows the main stopper 17 to basically stop the movable contactor 12 that jumps up due to current-limiting interruption. This prevents vibrations from being transmitted to the handle 13 via the lever 14.
The main stopper 17 and the auxiliary stopper 47 are provided in the S phase where the handle 13 is located. As a result, even in the S phase where the stopper 18 cannot be provided on the back side of the housing cover, like the R phase and T phase, the main stopper 17 and the auxiliary stopper 47 can reliably stop the rotation of the movable contact 12 at the open position.

Next, a comparative example will be described.
FIG. 6 is a diagram showing a comparative example.
The comparative example has a structure in which the lever does not have the auxiliary stopper 47 described above. Since the basic configuration is similar to that of the first embodiment, detailed description of the common configuration will be omitted. The circuit breaker 51 includes a handle 53 and a lever 54. The handle 53 includes a ceiling portion 61, an outer front wall portion 62, and a pair of side walls 63, but does not include the notch 34 or protrusion 35 described above. The lever 54 includes a ceiling portion 71, an inner front wall portion 72, and a pair of side walls 73, but does not include the protrusion 44 described above. Therefore, the comparative example does not include the auxiliary stopper 47, and the movable contact 12 is restrained during current-limiting interruption only by the main stopper 17 located radially inward of the movable contact 21. In this structure, the tip of the movable contact 12 may deform in the opening direction due to contact with the main stopper 17, potentially resulting in a reduction in the contact wipe amount.

Second Embodiment
"composition"
The second embodiment shows another aspect of the auxiliary stopper. The same reference numerals are used to designate parts that are common to the first embodiment, and detailed descriptions thereof will be omitted.
FIG. 7 is a view showing a handle 13 according to the second embodiment.
1A shows the handle 13 as viewed from the front in the approximate depth direction, one side in the approximate vertical direction, and one side in the width direction, while 1B shows the handle 13 as viewed from the rear in the approximate depth direction. The aforementioned notch 34 and protrusion 35 are omitted here. The outer front wall 32 has two rib-like protrusions 36 formed in the center of the width direction, which protrude toward one side in the approximate vertical direction and extend in the approximate depth direction. The protrusions 36 extend across the entire outer front wall 32 from the rear to the front in the approximate depth direction. The two protrusions 36 are spaced apart in the width direction, with the distance between their outward-facing end faces in the width direction being greater than the width dimension of the movable contact 12 and the distance between their inward-facing end faces in the width direction being smaller than the width dimension of the movable contact 12. The protrusions 36 have rounded corners at the rear in the approximate depth direction by R-chamfering.

FIG. 8 is a view showing the lever 14 of the second embodiment.
In the figure, (a) shows the lever 14 as viewed from the front in the depth direction, from one side in the vertical direction, and from one side in the width direction, and (b) shows the lever 14 as viewed from one side in the width direction. In this figure, the protrusion 44 described above is omitted.
FIG. 9 is a cross-sectional view of a circuit breaker 11 according to the second embodiment.
The circuit breaker 11 is equipped with an auxiliary stopper 37. The auxiliary stopper 37 is composed of a protrusion 36 that protrudes from the handle 13 toward a radially outer portion of the movable contactor 12 that is to be opened. When the movable contactor 12 contacts the main stopper 17 and attempts to deform in the opening direction, the auxiliary stopper 37 contacts the movable contactor 12 radially outer than the main stopper 17. The protrusion 36 is positioned so that a gap is formed between the inner corner of the protrusion 36 and the movable contactor 12 when the movable contactor 12 contacts the main stopper 17. Therefore, when the movable contactor 12 jumps up due to current-limiting interruption and the S-phase movable contactor 12 contacts the main stopper 17 and attempts to deform in the opening direction, the auxiliary stopper 37 contacts the movable contactor 12 radially outer than the main stopper 17. Because the auxiliary stopper 37 is attached to the handle 13, it is provided only for the S-phase of the three phases.

<<Action and Effect>>
Next, the main effects of the second embodiment will be described.
The circuit breaker 11 includes a handle 13 and a lever 14. The lever 14 is fixed to the handle 13 and rotates when the handle 13 is operated, transmitting a driving force to the movable contact 12 to close and open the contact. The auxiliary stopper 37 is composed of a protrusion 36 that protrudes from the handle 13 toward a radially outer portion of the movable contact 12 that opens the contact. As a result, when opening the contact by current-limiting interruption, if the movable contact 12 tries to deform due to contact with the main stopper 17, it comes into contact with the auxiliary stopper 37, thereby preventing deformation of the movable contact 12.

The handle 13 has an outer front wall 32 facing radially outward from the movable contact 12 to be opened, and a protrusion 36 is formed on the outer front wall 32. This allows the protrusion 36 to protrude as far radially outward as possible from the movable contact 12 to be opened. This effectively prevents deformation of the movable contact 12 in the opening direction. Because the handle 13 is made of resin, the protrusion 36 can be easily molded simply by modifying a conventional injection molding die. By providing two narrow protrusions 36 instead of one wide protrusion 36, molding defects such as sink marks and voids can be prevented.
Other effects brought about by the common configuration are the same as those of the first embodiment described above.

<<Variation>>
In the second embodiment, the outer front wall 32 and the protrusion 36 are integrally molded. However, the present invention is not limited to this. The outer front wall 32 and the protrusion 36 may be formed as separate parts. For example, two protrusions 36 may be formed on one substrate, and recesses into which the substrates fit may be formed on the outer front wall 32, which are then fitted together and bonded. This allows the protrusion 36 to be easily provided on the handle 13 without requiring major design changes from the conventional structure.

In the second embodiment, the corners at the rear of the protrusion 36 in the depth direction are rounded by R-chamfering, but this is not limited to this. That is, the corners at the rear of the protrusion 36 in the depth direction may be chamfered in a flat shape so as to face substantially parallel to the radially outer end face of the opening movable contact 12. This allows the movable contact 12 to come into surface contact with the movable contact 12 radially outside the main stopper 17 when it comes into contact with the main stopper 17 and attempts to deform in the opening direction. In this way, by increasing the contact area, the load can be distributed and borne.

The above description has been given with reference to a limited number of embodiments, but the scope of the invention is not limited to these, and modifications of the embodiments based on the above disclosure will be obvious to those skilled in the art.

DESCRIPTION OF SYMBOLS 11...circuit breaker, 12...movable contactor, 13...handle, 14...lever, 15...rotating shaft, 17...main stopper, 18...stopper, 21...movable contact, 22...rotating shaft, 23...raised portion, 31...ceiling portion, 32...outer front wall portion, 33...side wall portion, 34...notch portion, 35...projection portion, 36...projection portion, 37...auxiliary stopper, 41...ceiling portion, 42...inner front wall portion, 43...side wall portion, 44...projection portion, 47...auxiliary stopper, 51...circuit breaker, 53...handle, 54...lever, 61...ceiling portion, 62...outer front wall portion, 63...side wall portion, 71...ceiling portion, 72...inner front wall portion, 73...side wall portion

Claims (8)

A movable contactor is provided on the radially outer side and is closed and opened by rotation;
a main stopper that contacts the movable contactor radially inward of the movable contact to prevent rotation when the contacts are opened by current-limiting interruption;
an auxiliary stopper that comes into contact with the movable contact at a position radially outside the main stopper when the movable contact comes into contact with the main stopper and attempts to deform in the opening direction. The handle and
a lever fixed to the handle, which rotates when the handle is operated, and transmits a driving force to the movable contact to close and open the contact,
2. The circuit breaker according to claim 1, wherein the auxiliary stopper is formed by a protruding portion that protrudes from the lever toward a radially outer portion of the movable contact that is to be opened. The lever has an inner front wall portion facing radially outward of the movable contact that opens, and the protrusion portion is formed on the inner front wall portion,
3. The circuit breaker according to claim 2, wherein the handle has an outer front wall portion that overlaps the outer peripheral surface of the inner front wall portion and faces radially outward of the movable contact that opens, and the outer front wall portion has a notch that allows the protrusion to protrude. The circuit breaker described in claim 3, characterized in that the handle has a side wall portion formed thereon, and the side wall portion has a protrusion portion formed thereon that supports the rear side of the inner front wall portion. The handle and
a lever fixed to the handle, which rotates when the handle is operated, and transmits a driving force to the movable contact to close and open the contact,
2. The circuit breaker according to claim 1, wherein the auxiliary stopper is formed of a protruding portion that protrudes from the handle toward a radially outer portion of the movable contact that is to be opened. The circuit breaker of claim 5, characterized in that the handle has an outer front wall portion facing radially outward of the movable contact that opens, and the protrusion is formed on the outer front wall portion. The circuit breaker of claim 1, characterized in that the auxiliary stopper is positioned so that a gap is created between the movable contactor and the main stopper when the movable contactor contacts the main stopper. 2. The circuit breaker according to claim 1, wherein the main stopper and the auxiliary stopper are provided for the phase in which the handle is located.