JPH0537390Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a compact overcurrent circuit breaker with a simple structure.

[Background Art] This type of overcurrent circuit breaker proposed by the present inventors in Japanese Patent Application No. 120648/1980 has a sliding member A for driving a contact spring as shown in FIG. , a sliding rotating body 32 that presses the contact spring 31
and engages with the bimetal piece 33 to rotate the sliding rotating body 32.
The latch lever 34 that latches the sliding rotor 3
2 is supported by a shaft 35, and a push button part 36 is guided in the front and back direction.Since these parts were separate from each other, the structure still had the disadvantage of being complex and having a large number of parts.

[Purpose of the invention] An object of the invention is to provide an overcurrent circuit breaker with a simpler structure by integrating the above-mentioned separate parts.

[Disclosure of the invention] The overcurrent circuit breaker according to the invention has a long hole in the middle of the sliding body whose rear end serves as a push button that can freely protrude outside the case, and a horizontal shaft inserted through the long hole. The sliding body is pivotally supported so that it can slide back and forth and move up and down, and one end is fixed to the case below the horizontal axis, and the other end is connected to the sliding body in front of the horizontal axis, so that the sliding body can be moved backwards. A contact plate with a rear end fixed to the case and a front end biased upward by a spring is provided. A sliding member is disposed below the sliding member, and as the sliding member advances, the front end of the contact plate is pushed downward to close the contact provided on the lower surface of the front end of the contact plate and the contact fixed to the case.
When both contacts are closed, a reaction force from the contact plate of the sliding body engages with a locking protrusion protruding from the tip of a bimetal piece disposed in a vertical plane parallel to the sliding body. A convex step is provided on the upper surface of the front end of the sliding body to lock the upward rotation by the spring and the backward return by the spring, and the spring force from the contact plate applied upward to the locking projection via the sliding body is transferred to By giving the sliding body itself the freedom to slide back and forth and rotate up and down through the horizontal shaft and long hole, the push button part and the sliding rotating body in the conventional example are integrated. At the same time, the latch lever is omitted, and as a result, the reaction force of the contact plate directly applied to the locking protrusion is offset by the downward spring force of the spring, adjusting the latch load, thereby stabilizing the tripping operation. It has the following.

[Embodiment] FIGS. 1 to 3 show an embodiment of the present invention, in which the rear end of the sliding body 1 is a push button portion 1a that can be pressed from outside the case 5. A long hole 2 is provided in the middle of the moving body 1, and the sliding body 1 is pivotally supported by a horizontal shaft 3 inserted through the long hole 2 so as to be freely slidable back and forth and vertically. Fig. 1 shows the latched state in which the push button part 1a is pushed into the case 5 against the spring 4, which is a tension spring that urges the sliding body 1 backward, and the push button part 1a is shown as a contact plate with the front end tilted upward. A contact spring 6 is disposed below the sliding body 1, and the contact spring 6 is pressed downward as the sliding body 1 moves forward to close the contact springs 13 and 14. The upward rotation due to the reaction force from the spring 6 and the backward return due to the spring 4 are locked by a locking protrusion 8 provided at the tip of the bimetal piece 7. Bimetal piece 7
is disposed in a vertical plane parallel to the sliding body 1, and its plate surface is parallel to the rotating surface of the sliding body 1, and the locking protrusion 8 is moved laterally due to thermal deformation of the bimetal piece 7 due to an overcurrent. When the sliding body 1 retreats to the locking protrusion 8
The engagement state, that is, the latched state, is released, and the contact spring 6 is rotated upward and slid backward to enter the trip state shown in FIG. 3, and the contact spring 6 is returned to its original state.

In FIG. 2, the support fittings 9 have mounting holes 9a, 9.
The rear end of the contact spring 6 is fixed to the contact spring fixing piece 9c, the rear end of the bimetal piece 7 is fixed to the bimetal fixing piece 9d, and the spring is fixed to the spring retaining piece 9e. One end of 4 is attached. The other end of the spring 4 is engaged with a spring engaging pin 10 that projects from the side surface of the sliding body 1, and biases the sliding body 1 diagonally downward. The guard portion 11 is brought into elastic contact with the upper surface of the contact spring 6.

FIG. 3 shows the tripped state, in which the sliding body 1 is disengaged from the locking step 12 on its upper surface and the locking protrusion 8 of the bimetal piece 7, and is moved backward by the restoring force of the spring 4. As a result, the push button portion 1a at the rear end protrudes outward from the case 5, and the sliding body 1
is urged downward by the spring 4, so its tip is located below the locking protrusion 8 of the bimetal piece 7. Therefore, when the push button part 1a is pushed in from this state, the locking protrusion 8 comes into sliding contact with the slope 1b on the upper surface of the tip end of the sliding body 1, and then the locking step part 1
2 and latches the slider 1, resulting in the state shown in Figure 1a.

As mentioned above, in the latched state shown in FIG. 12, but even if some obstacle prevents the push button portion 1a from protruding out of the case 5, the circuit will be interrupted by the trip. It has a so-called trip-free structure.
That is, when the bimetallic piece 7 is heated by an overcurrent and curves in the direction of the arrow in FIG. Then, it rotates in the direction of the arrow in FIG. 1a, and as shown in FIG. 4, contacts 13 and 14 open to interrupt the circuit. Note that the rotation angle of the sliding body 1 at this time is regulated by the engagement between the step portion 15 on the side surface of the tip end of the sliding body 1 and the locking protrusion 8 .

Further, as shown in FIG. 1b, in order to arrange the bimetal piece 7 adjacent to the sliding body 1, the bimetal piece 7 is
The heater 16 is disposed in a through hole 17 provided in the bimetal piece 7 so that the heater 16 and the indirect heater (resistor) 16 do not come into contact with each other. It is connected to the. Further, one end of each of the terminal plate 18 and the terminal plate 19 provided with the fixed contacts 14 protrudes from the front surface of the case 5 and serves as a plug.

Now, in the above-mentioned configuration, as a result of omitting the latch lever 34 of the conventional example, when the reaction force of the contact spring 6 is applied to the locking protrusion 8 as a latch load, the bimetal piece 7 is curved and the locking protrusion 8 is moved laterally. There is a problem in that the frictional force increases when moving backwards, making the operation unstable. Therefore, in this invention, the spring 4
is stretched rearward and downward, so that the downward spring force of the spring 4 cancels out the reaction force of the contact spring 6 applied to the sliding body 1, so that the latch load can be adjusted to an optimal value.

Furthermore, if the sliding body 1 wobbles in the lateral direction, the amount of displacement of the locking protrusion 8 during the tripping operation will not be stable. It is used as a guide member for the sliding body 1.

FIG. 5 shows its structure, in which a semi-cylindrical card portion 11 for pressing the contact spring 6 is protruded from the lower surface of the sliding body 1, and a protrusion is provided at the center of the circumferential surface of the card portion 11. 20 is provided, and this protrusion 20 is inserted into a guide groove 21 provided in the contact spring 6, thereby restricting the lateral rotation of the sliding body 1. Note that the guide groove 21 is formed so that the width of the introduction part 21a in the latter half is slightly wider so that the protrusion 20 can be smoothly introduced at the time of reset.

[Effect of the invention] According to the above-described structure, the sliding body 1 is pivotally supported by the elongated hole 2 and the horizontal shaft 3 so as to be able to slide back and forth and move up and down. The sliding rotating body 32 and the push button part 36 can be integrated,
Moreover, by tensioning the spring 4 toward the rear and downward direction for returning the sliding body 1 to the rear,
The reaction force of the contact spring 6 directly applied to the locking protrusion 8 is offset to stabilize the latch load, thereby making it possible to omit the latch lever 34 in the conventional example, reducing the number of parts and simplifying the structure. This has the advantage that it can be converted into

[Brief explanation of the drawing]

Fig. 1a is a side view showing an embodiment of the overcurrent circuit breaker of the present invention, b is a horizontal sectional view of the same, Fig. 2 is an exploded perspective view of the same, and Fig. 3 is a side view showing the same as the trip state; FIG. 4 is a side view of the main part showing the trip-free state of the same as above, FIG. 5 is a perspective view of the main part of the same as above, and FIG.
The figure is a side view of a conventional example. 1...Sliding body, 1a...Push button part, 2...Long hole,
3...Horizontal shaft, 4...Spring, 5...Case, 6...Contact spring, 7...Bimetal piece, 8...
...locking protrusion, 20... protrusion, 21... guide groove.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A long hole is provided in the middle of a sliding body whose rear end is a push button that can freely protrude outside the case, and a horizontal shaft inserted into the long hole allows the sliding body to slide back and forth. It is pivoted so as to be movable up and down, one end is fixed to the case below the horizontal axis, and the other end is connected to the sliding body in front of the horizontal axis to urge the sliding body backward. A spring, which is a tension spring, biases the front end of the sliding body downward around a horizontal axis, and a contact plate, whose rear end is fixed to the case and whose front end is biased upward, is placed below the sliding body. The front end of the contact plate is pushed downward by the advance of the sliding body to close the contact provided on the lower surface of the front end of the contact plate and the contact fixed to the case, and the two contacts are closed. When the sliding body is in the position, it engages with a locking projection protruding from the tip of a bimetal piece disposed in a vertical plane parallel to the sliding body, causing upward rotation due to the reaction force from the contact plate of the sliding body and backward return due to the spring. A convex stepped portion is provided on the upper surface of the front end of the sliding body to lock the locking projection, and the spring force from the contact plate that is applied upward to the locking protrusion through the sliding body is reduced by the downward component of the spring force of the spring. Overcurrent circuit breaker. (2) Utility model registration claimed in paragraph 1, in which the sliding direction of the sliding body is regulated by inserting a protrusion protruding from the lower surface of the front end of the sliding body into a guide groove provided on the contact plate. overcurrent circuit breaker.