JPH0643993Y2 - Circuit breaker - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial field of application) The present invention relates to a circuit breaker and a circuit breaker having an improved support structure for a trip rod.

(Prior Art) In the conventional circuit breaker and circuit breaker, as shown in FIG. 5, the trip rod 5 of the trip device 4 is attached to the device frame 3 of the switchgear 2 mounted in the main body case 1 by the metal pin 6. It is rotatably supported.

(Problems to be Solved by the Invention) However, according to the above-described conventional configuration, the trip rod 5 has a long axial length because it is necessary to correspond to each phase of the main circuit. Since the length of the trip rod 5 must be adjusted, the device frame 3 becomes large. Further, the pin 6 is required to rotatably support the trip rod 5, and in the hole of the plastic trip rod 5 into which the pin 6 is inserted, the pin 6 is formed of a metal pipe to form the pin 6. Since it is necessary to improve the slidability with respect to the trip rod 5, the trip rod 5 must be produced by combining a plurality of parts made of different materials, which increases the production cost of the trip rod. Moreover, if the metal rod is integrated with the trip rod 5 by insert molding, or if the hole for inserting and fixing the metal pipe into the trip rod 5 is simultaneously formed, the structure of the forming die becomes complicated. It becomes a factor of increasing the manufacturing cost of the rod 5.

The present invention has been made in view of the above circumstances, and an object thereof is to make it possible to reduce the size of a device frame of an opening / closing device and to enable a trip rod to smoothly rotate even though it has a simple support structure. It is an object of the present invention to provide a circuit and a circuit breaker that can be supported and can be configured with a trip rod made of a single component to reduce the manufacturing cost.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the circuit and disconnector of the present invention are
The trip mechanism is operated in response to the current flowing through the main circuit, and the trip rod is rotated to cause the switchgear to perform the trip operation. The trip mechanism is housed in the case together with the trip rod. In this case, a recess is formed on the inner surface of the case, and the rotary shaft of the trip rod is inserted into the recess, and the outer surface of the rotary shaft on the pressing direction side by the spring member for returning the trip rod and the outer surface thereof. A supporting recess that becomes narrower toward the back is formed on one of the inner surfaces of the case facing each other, and a supporting protrusion that is inserted into this supporting recess is provided on the other side, and the tip of this supporting protrusion is The rotation shaft is rotatably supported by the contact between the portion and the bottom of the support recess.

(Operation) The rotating shaft of the trip rod is assembled to the case by inserting the end portion thereof into the recess. Moreover, since the rotating shaft is supported by the contact between the supporting convex portion and the supporting concave portion in a small area, the rotating shaft smoothly rotates. Therefore, a pin for supporting the trip rod is not necessary, and the trip rod can be composed of a single component. Further, since the frame of the opening / closing device does not have to match the axial length of the trip rod, it can be downsized.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

First, in FIGS. 3 and 4, reference numeral 11 denotes a plastic insulating case as a case in which a thermo-electromagnetic trip device 12 is housed and arranged, which is composed of a base 13 and a cover 14. It is arranged in a main body case (not shown) of a circuit for phase alternating current or a circuit breaker. A trip rod 15 of a trip device 12 is rotatably supported at a central portion of a base 13 of the insulating case 11 about a rotary shaft 16, and an outer surface of one side of the base 13 has a main circuit. A device frame 18 of an opening / closing device 17 for opening and closing a contact (not shown) provided in the above is attached. As is well known, the opening / closing device 17 includes a catch receiver 20 that locks the catch 19, and a latch 21 that locks the catch receiver 20. The latch 21 contacts the engaging portion 15a of the trip rod 15 in FIG. In this state, the unillustrated contactor is kept in contact. When the trip rod 15 rotates counterclockwise as indicated by arrow A in FIG. 3 against the spring force of the compression coil spring 22 as a return spring, the engaging portion 15a is disengaged from the latch 21. The opening / closing device 17 is configured to perform a tripping operation to open the contactor. Also the base
A conductor 23 connected to each phase of the main circuit is attached to the inner lower portion of the base 13, and three inverted U-shaped frames 24 are located above the conductor 23 on the inner upper portion of the base 13. Installed.

On the other hand, the thermo-electromagnetic trip device 12 bimetal
25 are provided in a one-to-one relationship with each phase of the main circuit. That is, the bimetal 25 as the tripping mechanism part is
Attached to each conductor 23, an overcurrent flows in the main circuit
When the heat is generated, the heat deforms in the direction of arrow B to rotate the trip rod 15 in the direction of arrow A, whereby the opening / closing device 17 is pulled out and operated. An adjusting screw 26 for adjusting the distance to the trip rod 15 is screwed onto the upper end of the bimetal 25.

As is well known, the electromagnet of the thermal-electromagnetic trip device 12 is composed of a fixed iron core 27 and a movable iron piece 28, and is provided in a one-to-one relationship with each phase of the main circuit. That is, the fixed iron core 27 is attached to each conductor 23 as a coil, and the movable iron piece 28 corresponding to the tripping mechanism portion is rotatably attached to each frame 24. Also each frame 24
An interlocking piece 29 that rotates in association with each movable iron core 28 is attached to the, and these interlocking pieces 29 are connected by a connecting pin 30. The movable iron piece 28 is always rotated in the clockwise direction indicated by an arrow C in FIG. 3 by a tension coil spring 31 stretched between a hooking piece 28a formed by cutting and raising in an intermediate portion and an upper portion of the frame 24. It is urged dynamically, and as a result, the lower end portion is always kept away from the fixed iron core 27. When a fault current flows through the conductor 23, the movable iron piece 28
Is rotated in the direction opposite to the arrow C by the electromagnetic force of the fixed iron core 27 to rotate the trip rod 15 in the direction of the arrow A, whereby the opening / closing device 17 is pulled out and operated. Reference numeral 32 is an operation member for adjusting the magnitude of the tripping current by adjusting the gap between the fixed iron core 27 and the movable iron piece 28. This is an operation member on the upper surface of the central frame of the three frames 24. It is rotatably attached.

Here, the support structure of the rotary shaft 16 of the trip rod 15 will be described with reference to FIGS. 1 and 2. That is, substantially U-shaped cutouts 13a that open to the cover 14 side are formed on the inner surface sides of the left and right sides of the base 13. Also cover 1
Shallow U-shaped notches 14a corresponding to the notches 13a of the base 13 are formed on the inner surfaces of the left and right sides of the base plate 4. When the cover 14 is assembled to the base 13, both cutouts 13a
And 14a form a square-shaped recess 33. On the other hand, the rotating shaft 16 is formed in a rectangular shape whose cross section is one size smaller than the recess 33. Then, the left and right ends of the rotating shaft 16 are formed in the base 13 in the previous step of assembling the cover 14 to the base 13.
The cover 14 is inserted into the notch 13a from the side of the cover 14, and the cover 14 is assembled thereafter to be in a state of being prevented from being pulled out.

Then, of the outer surface of the rotating shaft 16, a compression coil spring
A support concave portion 34 having a substantially V-shaped groove shape is formed at a desired position on the surface (left surface in FIG. 3) on the cover 14 side which is the pressing direction side by 22. On the other hand, in the portion of the inner surface of the cover 14 facing the support recess 34, a support protrusion 35 in the form of a substantially V-shaped plate whose thickness decreases toward the tip is integrally provided. . This support protrusion
The cover 35 is inserted into the support recess 34 by assembling the cover 14 to the base 13. Then, the trip rod 15 is pressed toward the cover 14 side by the compression coil spring 22, so that the tip end portion of the support convex portion 35 and the bottom portion of the support concave portion 34 come into contact with each other, whereby the trip rod 15 is lined. It is rotatably supported by the support convex portion 35 in a contact state. In this case, the width of the support concave portion 34 is set larger than the thickness of the support convex portion 35, and in FIG. 3, a relatively large gap is generated between the upper surface of the support convex portion 35 and the inner upper surface of the support concave portion 34. ing. The gap allows the trip rod 15 to rotate in the arrow A direction. The rotation limit position of the trip rod 15 in the direction opposite to the arrow A is regulated by the upper portion of the rotation shaft 16 contacting the inner upper surface of the recess 33.

On the other hand, the insert pieces 24a are provided on the upper surfaces of the three frames 24.
Are integrally extended, and locking claws 24b are stamped and formed on the insertion piece 24a. And this frame 24 is the insertion piece 24
Insert a into the deep groove 13b formed in the base 13 and engage the locking claw 24b.
It is attached to the base 13 by preventing it from coming off. When mounting the frame 24, the rotary shaft 16 is notched 13
It is done after inserting into a and before assembling the cover. By mounting the frame 24, the rotation shaft 16 is prevented from coming off from the notch 13a until the cover 14 is assembled.

According to the support structure of the rotating shaft 16 as described above, since the rotating shaft 16 is supported by the insulating case 11, even if the axial length of the trip rod 15 is long, the device of the opening / closing mechanism 17 is provided. Unlike the conventional case in which the trip rod 15 is supported by the frame 18, it is not necessary to match the device frame 18 with the axial length of the trip rod 15, and the device frame 18 can be downsized. Moreover, the rotation of the rotation shaft 16 in the arrow A direction and the counter arrow A direction is
Since it is performed centering on the linear contact portion between the bottom of the support recess 34 and the tip of the support protrusion 35, the frictional resistance that adversely affects the rotating operation is small, and the support structure is simple, The smooth rotation of the trip rod 15 is ensured. For this reason, unlike the conventional case, a metal pin for supporting the trip rod 15 is not required, so that it is not necessary to provide the trip rod 15 with a metal pipe for inserting the pin. Therefore, since the trip rod 15 does not have to be composed of a plurality of parts made of different materials, the trip rod 15 can be integrally formed of plastic including the rotating shaft 16 and the molding die can be simplified. The manufacturing can be facilitated.

In the above embodiment, the supporting recess is formed on the rotating shaft and the supporting protrusion is provided on the inner surface of the cover. However, conversely, the supporting protrusion is provided on the rotating shaft, and the supporting recess is formed on the inner surface of the cover. It may be done. Further, the supporting concave portion and the supporting convex portion may be formed in a conical shape.

[Effects of the Invention] As described above, according to the circuit and breaker of the present invention, since the pivot shaft is supported by the case in which the tripping mechanism is disposed, the device frame of the switchgear is tripped. It is not necessary to match the axial length of the rod, and the device frame can be downsized. Moreover, since the rotating shaft is rotatably supported by the contact portion having a small area between the bottom portion of the supporting concave portion and the tip portion of the supporting convex portion, the trip rod can be smoothly rotated while having a simple structure. As a result, it is not necessary to provide a metal pipe on the trip rod for smoothing the turning, and the trip rod can be made up of a single component, so that the production can be facilitated. It has an excellent effect.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view of an essential part, and FIG. 2 is a longitudinal sectional view of the essential part shown in a state before attachment of a cover, 3 and 4 are a side view and a front view of the trip device, and FIG. 5 is a side view showing a conventional circuit breaker and a circuit breaker partially broken away. In the figure, 11 is an insulating case, 12 is a thermal-electromagnetic trip device, 13 is a base, 14 is a cover, 15 is a trip rod, 16 is a rotating shaft, 17 is an opening / closing device, and 22 is a compression coil. Spring (return spring), 25 is bimetal (tripping mechanism),
27 is a fixed iron core, 28 is a movable iron piece (tripping mechanism portion), 33 is a concave portion, 34 is a supporting concave portion, and 35 is a supporting convex portion.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A trip mechanism, which operates in response to an electric current flowing through a main circuit, pivots a trip rod to cause a switchgear to perform a trip operation. The trip mechanism is tripped. In a case that is housed in a case together with a rod, a recess is formed on the inner surface of the case, and the rotary shaft of the trip rod is inserted into the recess, and a spring member for returning the trip rod is provided on the outer surface of the rotary shaft. A supporting recess that narrows inward is formed on either one of the outer surface on the pressing direction side and the inner surface of the case facing the outer surface, and the supporting projection protruding into the supporting recess is projected on the other. A circuit or disconnector characterized in that the pivot shaft is rotatably supported by abutting the tip of the support protrusion and the bottom of the support recess.