JP3785679B2 - Circuit breaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit breaker for a circuit protector and the like, and more particularly to a shaft support structure for an operation handle incorporated in a circuit breaker.
[0002]
[Prior art]
First, FIG. 4 shows the overall configuration of the circuit protector described above. In the figure, 1 is a main body case of a circuit breaker made as a resin molded product, and the main body case 1 is connected to a fixed contact 2, a movable contact 3, a movable contact holder 4, and the holder 4. The operation handle 5, the opening / closing spring 6, the locking lever 7, the latch pawl mechanism 8, the electromagnetic solenoid type overcurrent tripping device 9 and the like are incorporated as shown in the figure, and the movable contact holder 4, The operation handle 5, the open / close spring 6 and the locking lever 7 constitute a toggle link type contact opening / closing mechanism, and a handle holder 5a made of sheet metal coupled to the operation handle (the handle itself is a resin molded product) 5 is a main body case 1. Is supported by a support shaft 10 provided on the shaft. Here, although the main body case 1 does not show a detailed structure, the main body case 1 is a case with a split structure in which the cover portion is assembled with the end surface of the case portion. Reference numeral 11 denotes an external connection terminal.
[0003]
The operation of the circuit breaker having such a configuration is well known, and the contact is turned ON / OFF or tripped by a handle operation or an overcurrent tripping operation.
[0004]
[Problems to be solved by the invention]
By the way, with respect to the shaft support structure of the operation handle 5 in the circuit breaker, a pin-shaped support shaft as an independent part is incorporated in the main body case 1 as conventionally disclosed in JP-A-7-57607. It is fixed by means such as caulking between the left and right frame side plates, the holder 5a of the operation handle 5 is pivotally supported on the support shaft, and the frame is press-fitted into the body case 1 for assembly. ing.
[0005]
However, the above-described conventional operation handle shaft support structure requires independent parts such as a pair of left and right frame side plates and shaft support pins in addition to the main body case 1, which increases the number of parts and the number of assembly steps, resulting in high costs. become.
The present invention has been considered in view of the above points, and an object of the present invention is to provide an improved circuit breaker that solves the above-mentioned problems and can reduce the number of parts and the number of assembly steps with respect to the shaft support structure of the operation handle. There is.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a pin-shaped stepped shaft having a large-diameter portion projecting from the inner wall surface of the case portion and a small-diameter portion at the tip of the large-diameter portion is provided. And a hollow shaft portion that protrudes from the inner wall surface of the cover portion and is inserted and coupled to the small diameter portion of the pin-shaped shaft portion, and the pin-shaped shaft portion and the hollow shaft portion are integrated with the case portion and the cover portion, respectively. The outer diameter of the hollow shaft portion is set to be larger than the diameter of the holder shaft hole of the operation handle and the larger diameter portion of the pin-shaped shaft portion, and the holder of the operation handle is moved to the pin-shaped shaft portion. The holder of the operating handle is inserted into the end of the hollow shaft and the case portion by inserting the large handle into the large diameter portion and bringing the tip of the hollow shaft portion into contact with the step portion of the large diameter portion of the pin-shaped shaft portion. It shall be positioned between the wall surface and pivotally supported on the large diameter portion of the pin-shaped shaft portion .
With the above configuration, in the assembly process of the circuit breaker, when the operating handle is inserted into the pin-shaped shaft part that is integrally molded with the case part, the cover part is overlaid on the end surface of the case part, so that the cover part is integrally molded. The hollow shaft portion thus fitted is fitted and coupled to the tip of the pin-shaped shaft portion. As a result, the operation handle is pivotally supported by the support shaft of the doubly supported beam structure having a high bending strength.
[0008]
In addition, by setting the outer diameter of the hollow shaft portion to be larger than that of the pin-shaped shaft portion, an operation handle is provided between the tip of the hollow shaft portion and the inner wall surface of the case portion without requiring a separate positioning part. Can be positioned and pivotally supported.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In the drawings of the embodiments, the same members corresponding to those in FIG.
[Example 1]
1 (a) and 1 (b), a main body case 1 is a combination of a case portion 1a and a cover portion 1b made as a resin molded product, and an operation handle straddling the case portion and the cover portion on the upper surface thereof. The window hole from which 5 protrudes is open. As the shaft support structure of the operation handle 5, the case portion 1a has a pin-shaped stepped shaft portion 1c protruding from the inner wall surface, and the cover portion 1b protrudes from the inner wall surface of the pin-shaped shaft portion. A hollow shaft portion 1d inserted and coupled to the tip is molded integrally with the case portion 1a and the cover portion 1b, respectively.
[0010]
Here, the pin-shaped shaft portion 1c includes a shaft portion (large diameter portion) 1c-1 having an outer diameter φ1 and a tip shaft portion (small diameter portion) 1c-2 having an outer diameter φ2 (φ2 <φ1) extended to the tip side. The length of the shaft portion 1c-1 is set slightly longer than the width dimension A of the holder 5a of the operation handle. On the other hand, a shaft fitting hole corresponding to the outer diameter φ2 of the tip shaft portion 1c-2 is formed in the hollow shaft portion 1d.
When the operation handle 5 is incorporated into the main body case 1, the holder 5a of the operation handle 5 is inserted into the pin-shaped shaft portion 1c formed in the case portion 1a together with other contact opening / closing mechanism components and the like. The cover portion 1b is overlaid on the end surface of the portion 1a. As a result, as shown in FIG. 1 (b), the hollow shaft portion 1d formed in the cover portion 1b is fitted and joined to the tip shaft portion 1c-2 of the pin-shaped shaft portion 1c, and the holder 5a is supported by the double-supported beam structure. It is pivotally supported on the shaft so as to be swingable. According to a trial calculation of the bending strength of the support shaft in this respect, the bending strength is 4 in comparison with the cantilever structure having only the pin-shaped shaft portion 1c by making the support shaft a double-supported beam structure as shown in the figure. Doubled.
[0011]
[Example 2]
Figure 2 shows another embodiment of the present invention having improved Sakiki Example 1. In this embodiment, the outer diameter φ3 of the hollow shaft portion 1d formed integrally with the cover portion 1b is set to the outer diameter φ1 of the pin-shaped shaft portion 1c provided in the case portion 1a, and the holder 5a fitted into the pin-shaped shaft portion. The diameter is set larger than the diameter of the shaft hole.
[0012]
With this configuration, in a state where the operation handle 5 is incorporated in the main body case 1, the handle holder 5a fitted on the shaft of the pin-shaped shaft portion 1c is connected between the tip of the hollow shaft portion 1d and the inner wall surface of the case portion 1a. It is positioned and held in a stable position in between.
Example 3
FIG. 3 shows an application example of the second embodiment described above. The tip shaft portion 1c-2 of the pin shaft portion 1c formed on the case portion 1a is a tapered taper shaft, and the cover portion 1b is correspondingly formed. A conical shaft fitting hole is opened in the hollow shaft portion 1d formed in the above.
[0013]
With this configuration, when the cover portion 1b is overlaid on the case portion 1a of the main body case 1, the pin-shaped shaft portion 1c and the hollow shaft portion 1d can be smoothly fitted using the tapered shaft as a guide.
[0014]
【The invention's effect】
As described above, according to the configuration of the present invention, the following effects can be obtained.
1) Compared with the conventional operation handle shaft support structure, the number of parts and assembly man-hours can be reduced and cost can be reduced.
2) The tip of the pin-shaped shaft protruding from the case portion of the main body case and the hollow shaft protruding from the cover portion are fitted and joined to form a dual-supported beam structure with a high bending strength at the support handle shaft. be able to.
[0015]
3) By setting the outer diameter of the hollow shaft part protruding from the cover part to be larger than the outer diameter of the pin-shaped shaft part protruding from the case part, the operation handle pivotally supported by the pin-shaped shaft part can be stably positioned. Positioning can be maintained.
[Brief description of the drawings]
FIGS. 1A and 1B are configuration diagrams of an embodiment corresponding to Embodiment 1 of the present invention, in which FIG. 1A is an exploded perspective view of essential parts, and FIG. 1B is a cross-sectional view of an operation handle support structure in an assembled state of a main body case; FIG. 2 is a cross-sectional view of an operation handle shaft support structure corresponding to a second embodiment of the present invention. FIG. 3 is a cross-sectional view of an operation handle shaft support structure corresponding to a third embodiment of the present invention. Diagram showing overall configuration 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 1 Main body case 1a Case part 1b Cover part 1c Pin-shaped shaft part 1d Hollow shaft part 5 Operation handle 5a Holder

Claims (1)

A circuit breaker configured by incorporating a contact opening / closing mechanism, an operation handle, and an overcurrent trip device into a main body case of a split structure consisting of a combination of a case portion and a cover portion of a resin molded product, and the holder of the operation handle is a main body In what is supported by the support shaft provided in the case,
The pin-shaped shaft portion protruding from the inner wall surface of the cover portion, a large-diameter portion projecting from the inner wall surface of the case portion, a pin-shaped stepped shaft portion having a small-diameter portion at the tip of the large-diameter portion, The pin-shaped shaft portion and the hollow shaft portion are molded integrally with the case portion and the cover portion, respectively, and the outer diameter of the hollow shaft portion is controlled by an operating handle. The diameter of the holder shaft hole and the larger diameter portion of the pin-shaped shaft portion, the holder of the operation handle is inserted into the larger diameter portion of the pin-shaped shaft portion, and the tip of the hollow shaft portion and the The large diameter portion of the pin-shaped shaft portion is brought into contact with the step portion of the large-diameter portion of the pin-shaped shaft portion, and the holder of the operation handle is positioned between the tip of the hollow shaft portion and the inner wall surface of the case portion. A circuit breaker characterized by being pivotally supported .

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