JP2024046344A - Circuit Breakers - Google Patents

Abstract

[Problem] To improve the transmission efficiency from a rotating link to a movable holder when a contact portion comes into contact in a circuit breaker. [Solution] A movable holder (12) opens and closes a contact portion (24) by rotating. A connecting shaft (13) is supported by the movable holder (12). A guide groove (26) that fits into the connecting shaft (13) is formed in a rotating link (14), and when a driving force for opening and closing the contact portion (24) is transmitted and the rotating link rotates, the movable holder (12) is rotated via the connecting shaft (13). In the course of the operation from the open state to the closed state, an angle θ between a straight line connecting the rotation center of the movable holder (12) and the connecting shaft (13) and the extension direction of the guide groove (26) falls within a predetermined small angle range. [Selected Figure] Figure 3

Description

The present invention relates to a circuit breaker.

An elongated hole formed in the rotating link fits into the connecting shaft of the movable holder, and when the rotating link rotates, the contact portion is opened and closed by rotating the movable holder via the connecting shaft. There is a circuit breaker. In order to improve the transmission efficiency from the rotation link to the movable holder, for example, in Patent Document 1, the angle θ between the straight line connecting the center of the movable holder and the connecting shaft and the direction in which the elongated hole extends is set to 45 degrees or less. It is set as follows. Furthermore, the transmission efficiency is set to reach its peak when the contact portion begins to close.

Patent No. 5255731

If the peak of the transmission efficiency from the rotating link to the movable holder is set when the contact portion starts to close, the transmission efficiency will decrease in the closing process thereafter, resulting in a decrease in the contact pressure.
An object of the present invention is to improve the efficiency of transmission from a rotating link to a movable holder when contact portions come into contact with each other in a circuit breaker.

A circuit breaker according to one aspect of the present invention includes a movable holder, a connection shaft, and a rotation link. The movable holder opens and closes the contact portion by rotation. The connecting shaft is supported by a movable holder. The rotation link is formed with a guide groove that fits into the connection shaft, and when the rotation link is rotated by transmitting the driving force for opening and closing the contact portion, the movable holder is rotated via the connection shaft. During the operation from the open state to the closed state, the angle between the straight line connecting the rotation center of the movable holder and the connecting shaft and the direction in which the guide groove extends falls within a predetermined small angle range.

According to the present invention, during the operation from the open state to the closed state, the angle between the straight line connecting the rotation center of the movable holder and the connecting shaft and the direction in which the guide groove extends is within a predetermined small angle range. Therefore, the transmission efficiency when the contact portions make contact can be improved.

1 is a schematic diagram of a circuit breaker in an open state; FIG. FIG. 2 is a schematic diagram of a circuit breaker in a closed state. It is a figure which shows operation|movement of the rotation link in 1st embodiment. 1 is a graph showing the relationship between angle and transmission efficiency. 13A to 13C are diagrams illustrating the operation of a rotating link in the second embodiment.

Embodiments of the present invention will be described below based on the drawings. Note that each drawing is schematic and may differ from the actual drawing. Furthermore, the following embodiments are intended to exemplify devices and methods for embodying the technical idea of the present invention, and the configuration is not limited to the following. That is, the technical idea of the present invention can be modified in various ways within the technical scope described in the claims.

《First embodiment》
"composition"
In the following description, for convenience, three mutually orthogonal directions are referred to as a vertical direction, a width direction, and a depth direction.
FIG. 1 is a schematic diagram of a circuit breaker 11 in an open state.
Here, the state where the circuit breaker 11 is viewed from one side in the width direction is shown, and in order to simplify the explanation, non-main components are omitted, and some main components are partially transparent or simplified. I draw it in various ways. The circuit breaker 11 is also called a no-fuse breaker, and can open and close a circuit in normal use manually or by electrical operation, and automatically closes the circuit when an abnormal overcurrent is detected due to an overload or short circuit. This protects the circuit from damage caused by overcurrent. The circuit breaker 11 includes a movable holder 12, a connection shaft 13, a rotation link 14, a toggle mechanism 15, and an operating handle 16 as an opening/closing mechanism. Since the tripping device has a common structure, a detailed explanation will be omitted.

The movable holder 12 is formed in a substantially cylindrical shape with the width direction as the axial direction, can rotate between a closed position and an open position around the rotation center Pc, and supports the movable contact 21. The movable contact 21 is a rod-shaped conductor, and is provided so as to pass through the movable holder 12 through the rotation center Pc when viewed from the vertical direction, and a movable contact 22 is provided on each of the two ends protruding from the movable holder 12. When the movable contact 21 rotates together with the movable holder 12, the movable contact 22 comes into contact with and separates from the fixed contact 23. Each fixed contact 23 is fixed to a fixed contact (not shown). The fixed contact 23 and the movable contact 22 constitute a contact portion 24, and the movable holder 12 and the movable contact 21 open and close the contact portion 24 by rotating. The movable holder 12, the movable contact 21, and the fixed contact (not shown) are arranged in the width direction for each pole. The movable holders 12 of each pole lined up in the width direction are connected to each other and held in a rotatable state in a case (not shown).

When viewed from one side in the width direction, the direction in which the movable holder 12 and the movable contact 21 rotate clockwise is defined as a closing direction, and the direction in which they rotate counterclockwise is defined as an opening direction. The movable contactor 21 is inserted through the movable holder 12 and is biased toward the movable holder 12 in the closing direction by a torsion coil spring (not shown). When the movable holder 12 is in the off position, the movable contact 22 is spaced apart from the fixed contact 23. When the movable holder 12 rotates from the off position in the closing direction, the movable contact 22 begins to contact the fixed contact 23. When the movable holder 12 further rotates in the closing direction while resisting the repulsive force of the torsion coil spring, the movable contact 22 is further pressed against the fixed contact 23 to reach the on position. In the process of the movable holder 12 rotating in the closing direction, the amount by which the movable holder 12 rotates in the direction of further pressing from the position where the movable contact 22 starts contacting the fixed contact 23 becomes the wipe amount.

The connecting shaft 13 is cylindrical and extends in the width direction, and is inserted into and supported by the outer wall of the movable holder 12 on the outer side in the width direction. The connecting shaft 13 is an eccentric shaft that is parallel to the axis of the movable holder 12 and is located away from the rotation center Pc when viewed from the width direction. Therefore, when the movable holder 12 rotates, the center of the connecting shaft 13 when viewed from the width direction displaces while tracing a circular orbit Ts with the rotation center Pc as its axis, as shown by the dotted line. The connecting shaft 13 is provided only on one movable holder 12 located in the center in the width direction, and one is provided on each side of the movable holder 12 in the width direction.

As shown by the thick solid line, the rotation link 14 has a plate shape extending in the vertical direction and the depth direction, has an external shape extending in the vertical direction when viewed from the width direction, and fits into the connecting shaft 13. A guide groove 26 is formed. The guide groove 26 is an elongated hole that penetrates the rotation link 14 in the width direction and extends linearly when viewed from the width direction, and the width of the groove in the short direction corresponds to the outer diameter dimension of the connecting shaft 13. ing. The other side of the rotation link 14 in the vertical direction is supported by a case (not shown) by a support shaft Ac extending in the width direction. The rotation link 14 has one vertical side connected to the toggle mechanism 15, and rotates about the support shaft Ac when a driving force for opening and closing the contact portion 24 is transmitted from the toggle mechanism 15. At this time, the movable holder 12 is rotated by displacing the connecting shaft 13 by the guide groove 26. Similar to the connection shaft 13, the rotation links 14 are provided one each on both sides of the movable holder 12 in the width direction, and are connected to each other.

The toggle mechanism 15 includes a lower toggle 31 and an upper toggle 32. The lower toggle 31 has a plate shape extending in the vertical direction and the depth direction, and is formed in a substantially L-shape when viewed from the width direction. The upper toggle 32 has a plate shape along the vertical direction and the depth direction, and extends substantially linearly when viewed from the width direction. The lower toggle 31 and the upper toggle 32 are rotatably connected by a toggle pin 33 extending in the width direction. The upper toggle 32 is connected to a latch mechanism (not shown), and is not a main component in this embodiment, so it is virtually shown with a two-dot chain line. Similar to the connection shaft 13, the toggle mechanisms 15 are provided one on each side of the movable holder 12 in the width direction, and are connected to each other.

The operating handle 16 can rotate around a rotation center (not shown) to switch the circuit breaker 11 on and off, and only one is provided in the center of the width of the circuit breaker 11. The operating handle 16 has a handle on the front side facing the front in the depth direction, and an attachment part 35 is formed on the back side facing the back in the depth direction. A tension coil spring 36 is attached to the attachment part 35 and the toggle pin 33. The tension coil spring 36 pulls the toggle pin 33 towards the attachment part 35, and operates the toggle mechanism 15 via the toggle pin 33 in response to the rotation of the operating handle 16.

Here, the basic operation of the circuit breaker 11 will be described.
First, when the operating handle 16 is in the OFF position, as shown in Fig. 1, the toggle mechanism 15 is bent, so that one side of the rotating link 14 is lifted toward the front side in the depth direction. At this time, the connecting shaft 13 engaged with the guide groove 26 rotates the movable holder 12 in the opening direction, and the contact portion 24 is opened, resulting in an open state.
FIG. 2 is a schematic diagram of a circuit breaker in a closed state.
When the operating handle 16 is switched to the on position, the toggle mechanism 15 extends and pushes one side of the rotating link 14 downward in the depth direction. At this time, the connecting shaft 13 engaged with the guide groove 26 rotates the movable holder 12 in the closing direction, thereby closing the contact portion 24 to enter a closed state.

Next, the driving force transmitted from the rotation link 14 to the movable holder 12 will be explained.
FIG. 3 is a diagram showing the operation of the rotation link 14 in the first embodiment.
(a) in the figure shows the locus of the rotation link 14 from the open state to the closed state. (b) in the figure shows an enlarged view of the guide groove 26 and the connecting shaft 13 in (a). Here, the straight line connecting the rotation center Pc of the movable holder 12 and the connecting shaft 13 is Ls, the center line in the direction in which the guide groove 26 extends is Lg, and the angle between the straight line Ls and the center line Lg is θ. . When in the open state, θ=α, θ=0 during operation from the open state to the closed state, and θ=β when in the closed state. Here, when viewed from one side in the width direction, the angular difference when the straight line Ls is in the counterclockwise direction with respect to the center line Lg is taken as a negative value, and the angular difference when it is in the clockwise direction is taken as a positive value. do. Therefore, α is a negative value and β is a positive value. When the rotation link 14 rotates in the closing direction, a driving force perpendicular to the center line Lg is transmitted to the connection shaft 13 from the guide groove 26, as shown by the thick solid arrow. When θ=0, the force that the connecting shaft 13 receives from the guide groove 26 becomes a tangent to the circular orbit Ts in the connecting shaft 13, and the tangent line is perpendicular to the radius passing through the point of contact with the circular orbit Ts. Therefore, when θ=0, the transmission efficiency η of the driving force from the rotation link 14 to the movable holder 12 becomes the highest.

FIG. 4 is a graph showing the relationship between angle θ and transmission efficiency η.
Here, the horizontal axis is the angle θ, and the vertical axis is the transmission efficiency η. As the absolute value of the angle θ approaches 0 degrees, the transmission efficiency η increases exponentially, and when the angle θ becomes 0 degrees, the transmission efficiency η reaches a peak of 1.0. Based on this characteristic, the range of the angle θ from the required transmission efficiency η is set. In the embodiment, the angle θ is set to fall within a predetermined small angle range when the movable contact 22 contacts the fixed contact 23 while operating from the open state to the closed state. The small angle range is set to -8 degrees or more and +8 degrees or less (|θ|≦8 degrees) in order to make the transmission efficiency η 0.99 or more. In addition, the angle θ is set to be within a predetermined tolerance range in all sections where the circuit moves from the open state to the closed state. The allowable range is set to -25 degrees or more and +25 degrees or less (|θ|≦25 degrees) in order to make the transmission efficiency η 0.9 or more.

<Action and Effect>
Next, main effects of the first embodiment will be described.
The circuit breaker 11 includes a movable holder 12, a connecting shaft 13, and a rotating link 14. The movable holder 12 opens and closes a contact portion 24 by rotating. The connecting shaft 13 is supported by the movable holder 12. The rotating link 14 is formed with a guide groove 26 that fits into the connecting shaft 13, and rotates the movable holder 12 via the connecting shaft 13 when a driving force for opening and closing the contact portion 24 is transmitted and the rotating link 14 rotates. In the middle of the operation from the open state to the closed state, an angle θ between a straight line connecting the rotation center of the movable holder 12 and the connecting shaft 13 and a direction in which the guide groove 26 extends falls within a predetermined small angle range. This improves the transmission efficiency η when the contact portion 24 comes into contact, and suppresses a decrease in contact pressure.

In the circuit breaker 11, the absolute value of the angle θ is smallest when the movable contact 22 comes into contact with the fixed contact 23. In the movable holder 12, the rotation resistance is largest when the movable contact 22 comes into contact with the fixed contact 23 in the process of rotating in the closing direction. Therefore, by making the transmission efficiency η the highest when the movable contact 22 comes into contact with the fixed contact 23, a stable and reliable closing operation can be achieved.
The guide groove 26 extends linearly, which makes it easier to design and process the guide groove 26 in the rotating link 14.

The small angle range is -8 degrees or more and +8 degrees or less. This makes it possible to achieve a transmission efficiency η of 0.99 or more during the operation from the open state to the closed state.
A tolerance range larger than the small angle range is predetermined, so that the angle θ is always within the tolerance range. As a result, a constant transmission efficiency η can be achieved in all sections where the circuit operates from the open state to the closed state.
The permissible range is -25 degrees or more and +25 degrees or less. Thereby, it is possible to achieve a transmission efficiency η of 0.9 or more in all sections operating from the open state to the closed state.

Next, a comparative example will be explained.
In the comparative example, the angle θ is set to 45 degrees or less, and the transmission efficiency η is set to reach its peak when the contact portion 24 begins to close. The maximum frictional force occurs when the movable holder 12 starts rotating in the closing direction from a stationary state. Therefore, by setting the transmission efficiency η to reach its peak when the contact portion 24 starts to close, the movable holder 12 can start moving smoothly. However, the rotational resistance of the movable holder 12 is greatest when the movable contact 22 contacts the fixed contact 23 during the process of rotation in the closing direction. Therefore, if the transmission efficiency η is set to reach a peak when the contact portion 24 begins to close, the transmission efficiency will decrease in the subsequent closing process, leading to a decrease in contact pressure. .

Second Embodiment
"composition"
The second embodiment shows another aspect regarding the shape of the guide groove 26. The same reference numerals are used for the parts common to the first embodiment, and detailed description thereof will be omitted.
FIG. 5 is a diagram showing the operation of the rotating link 14 in the second embodiment.
FIG. 1A shows the path of the rotating link 14 from the open state to the closed state. FIG. 1B shows an enlarged view of the guide groove 26 and the connecting shaft 13 in FIG. 1A. The guide groove 26 extends in a curved shape so that the angle θ is always kept within a small angle range. That is, in the process of moving from the open state to the closed state, the angle θ is always approximately 0 degrees. Therefore, the transmission efficiency η of the driving force from the rotating link 14 to the movable holder 12 is always maintained at a peak value.

<Action and Effect>
Next, the main effects of the second embodiment will be described.
The guide groove 26 extends in a curved shape so that the angle θ is always kept within a small angle range. As a result, in the process of moving from the open state to the closed state, the transmission efficiency η of the driving force from the rotating link 14 to the movable holder 12 always maintains a peak value, thereby achieving a stable and reliable closing operation.
Other advantageous effects brought about by the common configuration are similar to those of the first embodiment described above.

Although the embodiments have been described above with reference to a limited number of embodiments, the scope of rights is not limited thereto, 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 holder, 13... Connection shaft, 14... Rotating link, 15... Toggle mechanism, 16... Operation handle, 21... Movable contact, 22... Movable contact, 23... Fixed contact, 24... Contact part, 26...Guide groove, 31...Lower toggle, 32...Upper toggle, 33...Toggle pin, 35...Attachment part, 36...Tension coil spring

Claims (7)

a movable holder that opens and closes the contact portion by rotating;
A connecting shaft supported by the movable holder;
a rotating link having a guide groove formed in the connecting shaft and configured to rotate the movable holder via the connecting shaft when a driving force for opening and closing the contact portion is transmitted thereto and the movable holder rotates,
a circuit breaker, characterized in that, during operation from an open state to a closed state, an angle formed by a straight line connecting the rotation center of the movable holder and the connecting shaft and a direction in which the guide groove extends falls within a predetermined small angle range. The circuit breaker according to claim 1, wherein the angle is the smallest when the movable contact contacts the fixed contact. The circuit breaker according to claim 1, wherein the guide groove extends linearly. The circuit breaker according to claim 1, characterized in that the guide groove extends in a curved shape so that the angle always remains within the small angle range. The circuit breaker according to claim 1, wherein the small angle range is from -8 degrees to +8 degrees. A tolerance range larger than the small angle range is determined in advance,
The circuit breaker of claim 1, wherein the angle always falls within the tolerance range. The circuit breaker according to claim 6, characterized in that the tolerance range is -25 degrees or more and +25 degrees or less.

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