JPH0253901B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a circuit breaker that cuts off power supply from a power source to a load when an excessive current flows to the load side.

[Background Art] FIG. 1 is a front view showing the internal configuration of a conventional general circuit breaker. In the figure, A and B indicate terminal fittings, which are interposed in the current path from the power source to the load. When the current flowing through the load is excessive, the plunger in the detection coil HA moves downward, and the rod 2 and head HO of the plunger move downward. As a result, the interlocking arm rotates, the tripping mechanism t operates, and the movable contact t and the fixed contact t are pulled out. A handle is used to manually turn on and off the movable contact and the fixed contact. Reference numeral 1 is an arc extinguishing device designed to extinguish the arc generated when the movable contact 1 and the fixed contact 1 are opened and separated.

FIGS. 2a and 2b are diagrams showing the relationship between the interlocking arm and the head portion of the plunger in the conventional example. Figure a shows a normal state in which the plunger is not attracted to the detection coil, and Figure b shows a state in which the plunger is attracted to the detection coil during an overcurrent. As is clear from the above figures, since the head of the plunger contacts the interlocking arm at the corner, the plunger swings left and right during suction operation, which may adversely affect the characteristics. Ta. In addition, after the plunger suction operation, the opposite corner of the head comes into contact with the interlocking arm as shown in Fig. 2b, so there is a problem that the rotation toward the interlocking arm is not smooth. It was hot.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and its purpose is to provide a sensor that is attracted by a detection coil when there is an abnormality in the power supply from the power source to the load. It is an object of the present invention to provide a circuit breaker that prevents swinging of a plunger and allows smooth rotation of an interlocking arm.

[Disclosure of the Invention] The configuration of the present invention will be described below with reference to illustrated embodiments. FIG. 3 is a front view showing the internal structure of a circuit breaker according to an embodiment of the present invention, and FIG. 4 is a diagram showing the components of this circuit breaker. Also the fifth
The figure is a sectional view of the circuit breaker shown in FIG. 3, and FIGS. 6 to 8 show the circuit breaker when its contacts are closed, when an overcurrent interrupts, and when a short circuit current interrupts, respectively. FIG. In addition, FIGS. 9 to 11 are lines AA and B- in FIG. 3, respectively.
It is a sectional view cut along the B line and the C-C line,
FIG. 12 and FIG. 13 are a plan view and a side view, respectively, of the present circuit breaker. A feature of the present invention is that, as shown in the above figures, of the engaging portions between the interlocking arm 71 and the head portion 11 of the plunger 10, the interlocking arm 71 is formed into an arc shape. . In each of the above figures, a protective sensor 1 for detecting overcurrent or short-circuit current includes a magnetic yoke 2 having a substantially rectangular cross section and a long cylinder 3. The cylinder 3 has a lower cylinder body 4 made of a non-magnetic material, preferably brass, with an open upper end, and an upper cylinder body 4 made of a non-magnetic material, preferably plastic, with open ends and a slightly larger diameter than the lower cylinder body 4. A cylinder body 5 is provided, and the opening at the upper end of the lower cylinder body 4 and the opening of the upper cylinder body 5 include both cylinder bodies 4,
A magnetic head 6 is fitted so as to connect the two magnetic heads 5 to each other. Further, a viscous fluid, preferably silicone oil, is sealed in the lower cylinder body 4, and a magnetic oil plunger 7 and a coil spring 8 that normally biases the oil plunger 7 toward the inner surface of the lower end of the lower cylinder body 4. is accommodated, and this lower cylinder body 4 is connected to the yoke 2.
It passes through the center of the lower side 9, a part of which protrudes downward, and is fixed to the lower side 9. Furthermore, the upper cylinder body 5 is provided with a plunger 10 made of a magnetic material.
is installed inside the plunger 10, and the plunger 10 has a head portion 1.
A rod portion 12 to which a rod portion 1 is fixed is integrally provided, and the rod portion 12 is provided so as to be able to extend outward from the tapered upper end portion of the upper cylinder body 5. The tapered upper end of the upper cylinder body 5 is fitted into a round hole having a lip 13a in the upper side 13 of the yoke 2 and is fixed.

Further, a detection coil 14 is wound around the cylinder 3 over substantially the entire longitudinal direction thereof, and the extraction ends 15 and 16 of the detection coil 14 are wound around the cylinder 3 over substantially the entire length thereof.
One side extends substantially horizontally through one side 17 of the yoke 2 and is connected to a lead wire 18 having sufficient flexibility, and the other side is led out from the open side of the yoke 2 and extends downward. It is bent and fixed to the terminal fitting 19 of the circuit breaker. Further, the plunger 10 is normally applied with the spring force of a coil spring, which will be described later, so as to be displaced upward, and the plunger 10 is provided so that the upper surface of the plunger 10 is in contact with the upper inner surface of the upper cylinder body 5 under normal conditions.

A frame 20 for supporting a manual opening/closing mechanism including a contact tripping mechanism T is integrally provided at the upper end of the side portion 17 of the yoke 2. frame 20
short frame portions 2 extending perpendicularly and parallel to each other;
1 and a long frame portion 22. The short frame portion 21 has an ear portion 23 at the tip, shaft holes 24 and 25 at the upper corner near the rear edge, and a shaft hole 26 near the rear edge below the shaft hole 25. It is set up. On the other hand, the long frame part 22 has a shaft hole 28 in the enlarged part 27 provided at a position corresponding to the ear part 23 of the short frame part 21, and corresponds to the shaft holes 25 and 26 of the short frame part 21 near the rear edge. Shaft holes 29 and 30 are bored at the respective positions. Further, an inverted L-shaped sliding window 31 is formed in the long frame portion 22 with an arcuate edge 32 on one side, and the tip is bent at a substantially right angle. Further, a locking portion 34 is provided on the upper edge of the bent portion 33, and a small disk-shaped arc running ear portion 35 is provided extending horizontally on the lower edge.

Cylindrical lower part 3 of the handle 36 of the manual opening/closing mechanism
7 has a shaft hole 38 drilled in its center, and an enlarged portion 40 having a through hole 39 protruding from a part of its circumferential surface. The handle 36 has short and long shafts 4 held in shaft holes 24 and 28 of the long frame parts 21 and 22.
1 into the shaft hole 38, the frame 20
Rotatably supported. Further, one leg portion 43 of a U-shaped link pin 42 is inserted into the through hole 39 of the enlarged portion 27, and the free end of the leg portion 43 is connected to the L-shaped sliding window of the long frame portion 22. 31 and is movable along the arcuate edge 32. The other leg side 44 of the link pin 42 is inserted into shaft holes 48 and 49 of ears 46 and 47 provided opposite to the link arm 45, and its free end is loosely engaged with the sliding window 31, It is disposed movably within the other side.

The link arm 45 itself has an inverted U-shaped base 50 when viewed from the end surface, and the base 50 has an insertion window 51.
is formed. Further, the ear portions 4 extend vertically and parallel to each other downward from the front end of the base portion 50.
Arm portions 52, 5 with 6, 47 projecting upward
3 are integrally extended, and the arm portions 52,
Shaft holes 54 and 55 are bored at the tip of the shaft 53, respectively. Further, from the lower edge of one arm part 52, a kick tongue part 56 is bent in an L-shape and slightly inclined upward with respect to the vertical direction, and from the upper edge thereof, a kicking tongue part 56 is bent in an L-shape. A curved, substantially horizontally extending stop ear 57 is provided. A support shaft 58 is held in the shaft holes 54 and 55 at the tips of both the arm parts 52 and 53, and the support shaft 58 is connected to the detection coil 14.
It is inserted into the shaft hole 60 of the chevron-shaped movable contact 59 connected to one end via the lead wire 18,
As a result, the movable contact 5 is connected to the link arm 45.
9 is pivoted. Shaft hole 60 of the movable contactor 59
An enlarged portion 62 having a locking hole 61 is provided above to protrude upward, and a movable contact 63 preferably made of a highly conductive contact material is fixed to the lower edge of the tip.

The movable contact 63 of the movable contact 59 is arranged so as to be able to come into contact with a fixed contact 65 attached to a fixed contact 64 disposed below the movable contact 59 and preferably made of a highly conductive material. The fixed contact 64 itself has an arc running part 67 that extends downward from one leg of the U-shaped part 66 on which the fixed contact 65 is fixed and faces the arc running ear part 35 of the frame 20. A connecting portion 69 extends from the other leg of the U-shaped portion 66 and is bent into an L-shape and integrated with the terminal fitting 68 .

Further, to describe the contact tripping mechanism T in detail, an interlocking arm 71 of the contact tripping mechanism T is pivotally supported on a support shaft 70 held in the shaft holes 25 and 29 of the frame 20. The interlocking arm 71 includes a base 73 having an arcuate end portion with a notch 72 that engages the head portion 11 of the protection sensor 1.
A pair of arm portions 74, 75 extend perpendicularly and parallel to each other from the front end of the arm portions 74, 75.
The support shaft 70 is inserted through the shaft holes 76 and 77 bored in the shaft 75, and the interlocking arm 71 is pivotally supported on the frame 20 as described above. Further, one arm portion 74 is bent into an L-shape and extends downward, and when the interlocking arm 71 rotates, a kicking tongue portion 5 of the link arm 45 is provided.
A kicking leg portion 78 that can hit a ball with a 6 is protruded.
Further, the support shaft 70 has an L-shaped latch fitting 79 that operates integrally with the interlocking arm 71 when viewed from the side.
is pivotally supported through shaft holes 80 and 81, one side of the latch fitting 79 is provided as an arm portion 82 that can come into contact with the lower surface of the base 73 of the interlocking arm 71, and the other side extends downward and is connected to the link arm. A hook part 83 that is inserted into the entry window 51 of No. 45 and is locked to the edge thereof.
The foot portion 84 is provided as a foot portion 84 having a diameter.

On the other hand, a coil spring 85 is wound around the support shaft 41 of the handle 36, and the coil spring 85 is guided by the semi-annular guide 36a of the lower part 37 of the handle 36, and one end of the coil spring 85 is attached to the sliding window 31. It is locked to the corner edge, and the other end is locked to the leg side 43 of a U-shaped link pin 42, which constantly applies a rotational force to the handle 36 in the direction of opening and opening of the contact. Also, a return spring 86 is attached to the locking portion 34 at the tip of the long frame portion 22 of the frame 20.
One end of the return spring 86 is locked, and the other end of the return spring 86 is engaged in the locking hole 61 of the movable contact 59, so that a force is always applied to the movable contact 59 in the direction of separating it from the fixed contact 64. giving. Furthermore, an interlocking arm spring 87 is attached to the support shaft 70 of the interlocking arm 71.
In addition, a latch spring 88 is wound around the latch spring 88.
One end of the interlocking arm spring 87 is attached to the lower surface of the base 73 of the interlocking arm 71, and the other end is attached to the frame 20.
The interlocking arm 71 is always locked to the locking shaft 89 held in the shaft holes 26, 30 of the plunger 10.
is biased in the direction of pulling up. Further, one end of the latch spring 88 is latched to the latching shaft 89, and the other end is latched to a suitable position of the frame 20, for example, to the edge of a round hole 90 in the long frame portion 22, so that the latch fitting 79 is always connected to the link arm 45. It functions so that it can be locked.

An arc extinguishing device 91 is disposed between the arc running ear portion 35 of the frame 20 and the arc running portion 67 of the fixed contact 64. The arc extinguisher 91 has a movable contact 59
A large number of deion grids 9 are provided with recesses 92 through which the tips of the deion grids 9 can pass, and are spaced apart from each other with small gaps.
3. In addition, the deion grid 93
The group is held by both side plates 94 and 95, and has an end plate 96 fixed to the side plates 94 and 95 at its edge.
and are provided. An arc gas outflow window 97 is formed in the end plate 96, and a direct release prevention plate portion 98 is provided at the center of the outflow window 97 at a location corresponding to the recess 92 of the deion grid 93.

Furthermore, the operation of this circuit breaker will be explained. Now the third
When the handle 36 of the manual opening/closing mechanism is rotated clockwise in the figure or FIG. The other leg side 44 is located above the other side of the sliding window 31, and the return spring 86
The spring force is also applied, and the link arm 45 and the movable contact 59 are moved upward. Therefore, the movable contact 59
The movable contact 63 of the fixed contact 65 of the fixed contact 64
In other words, the contacts are in an open state. In this case, the link arm 45 is prevented from moving upward more than necessary by a protrusion (not shown) of the casing. On the other hand, the handle 36 is moved from the position shown in FIG. 3 or 5 to the position shown in FIG.
If the coil spring 85 and the return spring 86 are rotated against the spring force of the coil spring 85 and the return spring 86,
The position of one leg side 43 of the link pin 42 inserted into the through hole 39 of the enlarged part 40 of the lower handle 37 crosses the line connecting the spindle 41 of the handle and the other leg side 44 of the link pin 42. At this time, the handle 36 overcomes the spring force of the coil spring 85 and the return spring 86, and is stopped and held at the counterclockwise rotating position. As a result, one leg side 43 of the link pin 42 is attached to the arcuate edge 3 of the sliding window 31.
2, the other leg side 44 reaches the lower part of the other side of the sliding window 31. That is, the link pin 42 is substantially vertical, and the link arm 4
The hook part 83 of the latch fitting 79 is attached to the edge of the access window 51 of No. 5.
Since the link arm 45 and the movable contact 59 connected to the link arm 45 via the support shaft 58 move downward and tilt forward, the movable contact 63 contacts the fixed contact 65. , that is, the contacts are in a closed state. In this case, the electric path includes the terminal fitting 19, the detection coil 14, the lead wire 18, the movable contact 59,
Movable contact 63, fixed contact 65, fixed contact 64,
It is formed by a terminal fitting 68.

In addition, when the contacts in Fig. 6 are closed, excessive current
For example, when a current 1.15 times the rated current continues to flow, the magnetic head 6 is excited via the detection coil 14 in the protection sensor 1, and the oil plunger 7 is activated by the viscosity of the oil sealed in the coil spring 8 and the lower cylinder body 4. It is relatively slowly attracted to the magnetic head 6 while resisting. This provides a time delay effect and does not respond to an excessive current flowing for a relatively short period of time, such as a starting current, even if it is detected.
When the oil plunger 7 is attracted to the magnetic head 6, the permeance of the magnetic circuit via the yoke 2 increases, and the plunger 10, which is always placed in the upward movement position, is moved to the seventh position by the interlocking arm spring 87 via the interlocking arm 71. It is attracted to the magnetic head as shown in the figure. Accordingly, the interlocking arm 71 and the latch metal fitting 79 rotate around the support shaft 70, and the latch metal fitting 79 rotates around the support shaft 70.
The hook part 83 of 9 is the locking window 51 of the link arm 45.
It comes off the edge, and the kicking leg 78 of the interlocking arm 71 hits the kicking tongue 56 of the link arm 45. Therefore, this impact applies a strong starting force to the link arm 45, and also causes the link arm 45 to
The rotational force of link arm 4 is rapidly increased, and link arm 4
Together with the tensile force of the return spring 86 which is engaged with the movable contact 59 connected to the fixed contact 64, the movable contact 59 is rapidly separated from the fixed contact 64. At this time, the arc is driven toward the arc extinguishing device 91 by the electromagnetic driving force generated by the current flowing through the movable contact 59, and is extinguished. and movable contact 5
9 is moved upward, the upper tip of the movable contact 59 is located very close to the frame 20, and after the contact is opened, the movable contact 59 is moved through the frame 20 having the arc running ear portion 35 and the yoke 2 integrated with the frame 20. An electrical path can then be formed. Arc gas generated during arc extinguishing is discharged to the outside from a discharge window 97 formed in an end plate 96 of an arc extinguisher 91 through a long hole 100 in a casing 99. The casing 99 consists of a pair of casing halves 101 and 102, and has an elongated hole 100.
Since the direct discharge prevention plate 98 is attached to the discharge window 97 in alignment with the longitudinal direction of the casing, the arc gas bypasses the direct discharge prevention plate 98 without being directly discharged to the outside.

Further, when the contact shown in FIG. 6 is closed, when a short circuit current, for example, a current two or three times the rated current flows, the excitation force by the detection coil 14 is extremely large, so that only the plunger 10 immediately connects to the magnetic head. 6, it starts to be absorbed. At this time, the interlocking arm 71 and the latch fitting 79 rotate around the support shaft 70, and the hook part 83 of the latch fitting 79 is disengaged from the edge of the locking window 51 of the link arm 45, and the kicking leg part 78 of the interlocking arm 71 is rotated. link arm 45
Only the kicking tongue 56 is hit. Therefore, as described above, a strong starting force is applied to the link arm 45 by this impact, and the movable contact 59 is rapidly separated from the fixed contact 64 as shown in FIG. Other actions are the same as when overcurrent is detected.

Note that the detection coil is not limited to being excited by overcurrent or short-circuit current, and may be excited by the output of the earth leakage detection circuit.

[Effects of the Invention] The present invention is constructed as described above, and includes a detection coil that attracts the plunger when there is an abnormality in the power supply from the power source to the load, and a coil that is connected to the head of the plunger that protrudes outside the detection coil. The moving end is engaged,
a rotatable interlocking arm, the rotary end of which is disposed substantially perpendicular to the direction of suction operation of the plunger;
In a circuit breaker, the head of the plunger and the interlocking arm have a circular arc shape, and the circuit breaker has a contact tripping mechanism that opens the contacts and cuts off the power supply from the power source to the load when the interlocking arm rotates due to suction of the plunger. Since the arc-shaped part of the interlocking arm is in contact with the head of the plunger, the arc-shaped part of the interlocking arm rotates smoothly with respect to the head of the plunger, and the interlocking arm can be smoothly rotated during the suction operation of the plunger. Since the plunger does not swing in a direction perpendicular to the suction direction, the risk of adversely affecting the circuit breaking characteristics is eliminated.Moreover, since an arc-shaped portion is formed on the interlocking arm side, This is preferable from the manufacturing point of view because the arc-shaped portion can be easily formed on the arm by sheet metal processing.Furthermore, since the arc-shaped portion is provided on the interlocking arm, the arc-shaped portion can be somewhat elastically deformed, making it easier to move from the plunger to the interlocking arm. It can transmit power smoothly.

[Brief explanation of the drawing]

Figure 1 is a front view showing the internal structure of a conventional general circuit breaker, Figures 2a and b are diagrams showing the relationship between the interlocking arm and the head of the plunger in the conventional example above, and Figure 3 is a front view showing the internal configuration of a conventional general circuit breaker. FIG. 4 is a front view showing the internal structure of a circuit breaker according to an embodiment of the present invention, FIG. Figures 6 to 8 are
9 to 11 are cross-sectional views of the same circuit breaker when the contacts are closed, when the overcurrent is cut off, and when the short circuit current is cut off, respectively. Cross-sectional views taken along lines A, B-B, and C-C, FIGS. 12 and 13
The figures are a plan view and a side view of the above circuit breaker, respectively. 10 is a plunger, 11 is a head portion, 14 is a detection coil, 63 is a movable contact, 65 is a fixed contact, 7
1 is an interlocking arm, and T is a contact tripping mechanism.

Claims (1)

[Claims] 1. A detection coil that attracts a plunger when there is an abnormality in the power supply from a power source to a load, and a rotating end that is engaged with the head of the plunger that protrudes outside the detection coil, and this rotating end is connected to the plunger. A rotatable interlocking arm arranged approximately perpendicular to the direction of suction operation, and a contact tripping mechanism that opens the contact and cuts off the power supply from the power source to the load when the interlocking arm rotates due to the suction of the plunger. In the circuit breaker, the plunger has a swollen head portion, a notch is provided at the rotating end of the interlocking arm to engage the head portion of the plunger, and the portion formed with this notch is connected to the head portion. 1. A circuit breaker characterized by being formed in an arc shape such that the surface on the side that comes into contact with the section is a convex surface.