JPS5934041Y2 - circuit break - Google Patents

Description

[Detailed description of the invention] This invention relates to a circuit breaker, and in particular, in a circuit breaker where a stop such as a hook is integrated with a trip lever, a locked piece such as a trip lever and a locking piece that receives it. The object of this invention is to enable adjustment of the amount of engagement between the locking pieces without affecting the stopping position of the locking piece.

Conventionally, this type of circuit breaker, which automatically opens by the operation of an overcurrent response device, reduces the acting force of the contact spring and operating spring in a normal closed circuit state with a link or lever, and connects a locked piece such as a trip lever with a hook. The receiver is stopped by engaging the locking pieces with each other, and in response to an overcurrent, etc., the locking pieces are rotated to release the engagement with the locked piece, and the locked piece rotates. and the operating spring is shortened,
It is common practice to disconnect the contacts by opening them.

In order to design the overcurrent response device to be compact, it is desirable that the overcurrent response device be able to operate with as little force as possible in such cases, and for this purpose, the acting force generated from the contact spring and operation spring should be reduced as much as possible. An important point is how to reduce the frictional rotational resistance of the locked piece by transmitting the force to the locked piece such as the trip lever and the pressing force generated between the locked piece and the locking piece.

At the same time, in order to reduce the force exerted by the overcurrent response device, it is necessary to reduce the amount of work required to release the locking piece.

That is, it is necessary to reduce the travel distance (or angle) required for frictional rotation low resistance lock release.

Now, let F be the acting force on the locking part of a locked piece such as a trip lever, assume that the friction coefficient μ of the locking part that occurs in a normal closed circuit state is constant, and apply the force from the axis of the locking piece to the engagement surface. If the radius of engagement is r, the travel distance required for release is S, and the rotation angle required for release is θ, then the amount of work required to release the engagement is expressed as μFS or μFrθ (where S and rθ).

In order to make the overcurrent response device a small force due to the release torque required for the locking piece, μFr must first be made as small as possible so that the output of the overcurrent response device can overcome this force.

However, since it is assumed that μ and F are constant, it is effective to reduce r.

For this purpose, the locking piece is a round bar shaft with a small diameter, and a semicircular notch is rotated about the center axis of the round bar, and the notch engages with the piece to be locked. It has been adopted.

Also, from this purpose, it is natural that θ should be smaller than c and pJl.

However, if both r and θ are made small, S will naturally become small from the above equation.

However, due to looseness in the shafts of each element and slight sag in the locking surfaces, the engagement becomes unstable and comes off due to shock during insertion.

Therefore, even if r can be made small, θ cannot be made very small.

That is, θ must be set to a certain large value and determined from S or rθ to the extent that a stable engagement can be maintained in practice.

The value of this S is 0.2 to 0.3 m for small circuit breakers.
A common limit is to choose m.

However, in order to maintain this degree of engagement, adjustments must be made for all products due to manufacturing errors in the locking piece, the locked piece, and their support devices.

This adjustment work can be performed by changing the normal stopping position of the tripping rod, but this will result in instability in quality since the distance between the tripping rod and the overcurrent response device will vary depending on the product.

Therefore, this invention eliminates the above-mentioned drawbacks by changing the amount of engagement between the locked piece and the locking piece that rotates together with the tripping rod to affect the stopping position of the outer rod. The present invention is characterized in that it includes an adjusting device that can adjust the amount of engagement by rotating the locking piece in the shape of a round bar, and fix it in that position.

FIG. 1 is a side sectional view of a three-bar type circuit breaker in a closed circuit state showing an embodiment of this invention, and shows the circuit breaker with the operating mechanism of the switching contact device connected to its center pole. There is.

In the figure, the circuit breaker has a molded base 1 and a molded cover 2 made of an insulating material as outer coverings, and is provided with external connection terminals 3, 3', and one end of a power supply side contact terminal 4. External connection terminal 3 is connected to
A fixed connector 5 is fixed to the other end.

The movable contact rod 7 has a movable contact 6 at a position corresponding to the fixed contact 5, is rotatably supported by a contact holder 9 by a shaft 8, and has one end connected to a flexible conductor 10.
It is connected to the intermediate connector 11 by.

The lower end of the bimetal 12, which is the tripping element of the overcurrent response device, is connected to the intermediate connector 11 through the intermediate connector 11', and the upper end is connected to one end of the load-side conductive terminal 14 via the flexible conductor 13.・In addition, this load side conductive terminal 14
The other end is connected to an external connection terminal 3'.

The intermediate connectors 11, 11' are integrally electrically connected to each other by an intermediate connecting terminal 15.

The adjustment screw 16 is attached to the upper end of the bimetal 12 and corresponds to the tripping rod 17, so that the opposing gap with the tripping rod 17 can be adjusted.

A fixed core 18 of the electromagnetic tripping device surrounding the bimetal 12 in a U-shape is supported by a fixed core support plate 19.

The movable iron piece 20 of the electromagnetic tripping device is provided so as to correspond to the fixed iron core 18, and operates the lower end of the tripping rod 17 when the movable iron piece 20 is attracted to the fixed iron core 18.

Further, as clearly shown in FIG. 2, the round rod-shaped hook 21 has an engaging portion 21a cut into a half-moon shape, and is rotatably supported by a fixed frame 24 at both end shaft portions.

A tripping rod connecting fitting 17a, which is integrally attached to the tripping rod 17, is rotatably supported coaxially with both end shaft portions of the hook 21.

Note that the tripping rod connecting fitting 17a is not necessarily coaxial with the axis of the hook 21, but may be rotatably supported on the fixed frame coaxially with the axis of the hook 21.

The operating mechanism and release device of the movable contact device consisting of the movable contact rod 7 having the movable contact 6 are attached to the mold cover 2.
an operating handle 2 made of an insulating material and protruding outward from the
2, and an inverted U-shaped opening/closing lever 23 fixed to this operating handle 22, and the lower end of this opening/closing lever 23 is rotatably supported on an opening/closing lever shaft 25 fixed to a fixed frame 24. ing.

One end of the trip lever 26 is rotatably supported by a trip lever shaft 27 bridged over the fixed frame 24, and a claw portion 26a at the other end is releasably engaged with an engaging portion 21a cut out in the hook 21. are doing.

Further, the trip lever 26 is formed with a toggle link striking member 26b extending below the trip lever shaft 27 and bent in the lateral direction, corresponding to the toggle link 29.

The pair of toggle links 28 and 29 are rotatably connected at one end by a connecting shaft 3o, and the toggle links 28 and 29 are
The other end is attached to the upper center end of the trip lever 26 by a toggle link attachment shaft 31.

A toggle link connecting shaft 3 is attached to the lower edge of the trip lever 26.
A locking pawl 26c is provided to restrict the movement of the
The opening distance between the movable contact 6 and the fixed contact 5 during normal opening and automatic opening can be varied.

The end of the contact holder 9 is connected to an opening/closing arm 32 made of an insulating material that is linked to a movable contact device of the other pole, and the movable contact preliminary 7 is opened/closed by an operating mechanism using the axis 33 of the opening/closing arm 32 as a fulcrum. It can be rotated into position.

The contact spring 34 has the function of always biasing the movable contact preliminary line 7 in the direction of closing the circuit.

Further, the operating spring 35 is connected to a pair of toggle links 28.
29 and the upper end of the opening/closing lever 23.

An adjustment device 36 that adjusts the amount of engagement between the hook 21 and the claw portion 26a of the trip lever 26 of the releasable device is connected to the hook 21.
A connection plate 37 integrally connected at the center to the notched engagement portion 21a, an engagement adjustment screw 38 provided at one end of this connection plate 37, and a lever connection by pulling out this engagement adjustment screw 38. The connecting plate 37 is in contact with the upper end protrusion 17b of the metal fitting 17a.
A tripping lever return spring 39 installed between the other end and the spring support 24a provided on the fixed frame 24
A clockwise rotational force is applied so that the tripping rod 17 always engages with a stopper piece 24b provided on the fixed frame 24.

The amount of engagement between the claw portion 26a of the trip lever 26 and the hook 21 is adjusted by determining the position of the tripping rod 17, and as shown in FIGS. If the gap is set to dimension A and the amount of engagement between the trip lever 26 and the hook 21 is B as shown in FIG. 3, then when the engagement adjustment screw 38 is rotated in the loosening direction, The hook 21 is rotated clockwise via the connecting plate 37, so that the hook 26 of the trip lever 26 is rotated clockwise.
The amount of engagement between A and the hook 21 is B as shown in FIG.
′ is increased.

Also, if the engagement adjustment screw 38 is rotated to tighten it,
The hook 26 is rotated counterclockwise via the connection plate 37, and the amount of engagement between the trip lever 26 and the hook 21 is reduced.

In this way, the amount of engagement between the trip lever 26 and the hook 21 can be adjusted using the engagement adjustment screw 38.

Next, to explain the opening/closing operation of the circuit breaker of this invention constructed in this way, in the closed circuit state shown in FIG. Inverted, the pair of toggle links 28 and 29 are bent into an inverted dogleg shape in FIG.
The movable contact 6 is rotated clockwise around the axis 33 of the trip lever 26 as a fulcrum, and the connecting shaft 30 of the toggle link 28°29 is locked by a locking pawl 26c provided at the lower edge of the trip lever 26, and the movable contact 6 is fixed. The circuit is opened from the contact 5.

Regarding the automatic opening operation, if an overload current flows in a closed circuit state as shown in FIG.
rotates the tripping rod 17 in the counterclockwise direction, or the fixed iron core 18 for removing the electromagnetic train is excited and attracts the movable iron piece 20, so that the tripping rod 17 is tripped and the rod connecting fitting 17a
is rotated counterclockwise together with the hook 21, and the hook 2
1 disengages from the claw portion 26a at the tip of the trip lever 26, and the trip lever 26 rotates counterclockwise about the rotation shaft 27 by the action of the operation spring 35.
By bending the toggle links 28 and 29 into an inverted dogleg shape, the movable contact preliminary line 7 is pulled up, and the movable contact 6 is separated from the stator contact 5 and opened to the automatic release position, creating a so-called structure in which rows can be removed freely. ing.

As mentioned above, in automatic opening of this type of circuit breaker, the large rotational force of the trip lever 26 is supported by the hook 21 to reduce the force in order to trip the releasable device with a small amount of energy from the overcurrent response device. The amount of engagement between the claw portion 26a of the trip lever 26 and the hook 21 needs to be extremely small, but this amount of engagement is determined by the combination of various parts due to the structure. It usually varies from one unit to another due to variations in the accuracy of the engagement, and if the engagement amount is small, vibrations will be applied to the engagement part due to the impact of opening and closing, resulting in disengagement and a so-called opening/closing trip.

For this purpose, it is necessary to adjust the amount of engagement between the trip lever 26 and the hook 21, and in the conventional hook in which the tripping rod is integrally supported, the amount of engagement between the trip lever and the hook can be adjusted. If you try to do so, the tripping rod itself will rotate and the relative relationship between the tripping rod and the tripping element will change, for example, the tripping rod 17 and the bimetal adjustment screw 16 shown in Figure 3-4.
Since the A dimension between
Therefore, it was necessary to correct the change.

This invention uses a movable contact device and a toggle link 28°29
an operating mechanism for opening and closing the movable contact device, a releasable device having a trip lever 26 and a hook 21 for automatically opening the movable contact device, and a mechanism for disengaging the trip lever 26 and the hook 21. A tripping rod that is supported by a fixed frame coaxially or coaxially with the axis of the hook 21 and rotates together with the hook 21 via an engagement adjustment screw 38 by a tripping element 12.16 that responds to an overcurrent. 1
7, an adjusting device is provided which can adjust the amount of engagement between the trip lever 21 and the hook 21 by rotating only the round bar-shaped hook 21 without changing the stopping position of the trip lever 17. Therefore, only the amount of engagement between the trip lever 26 and the hook 21 can be adjusted independently without changing the relative relationship between the tripping rod 17 and the tripping element, that is, the position of the tripping rod 17. The amount of engagement between the trip lever 26 and the hook 21, which is caused by errors in each assembly component that has a large effect on the important tripping operation of this type of circuit breaker, does not affect other parts. This is very beneficial because it can be easily adjusted to prevent it.

[Brief explanation of drawings]

Figures 1 to 4 show an embodiment of this invention. Figure 1 is a side view of the circuit breaker in the closed state, Figure 2 is a perspective view of the main parts, and Figures 3 and 4 are in the engaged state. FIG. In the figure, 1: mold base, 2: mold cover 3.3'
: External connection terminal, 5: Fixed connector, 6: Movable contact, 9
: contact holder, 12: bimetal, 17: tripping rod, 17a: tripping rod connection fitting, 18: fixed iron core, 2
0: Movable iron piece, 21: Hook, 21a: Engagement part, 22:
Operation handle, 23: Opening/closing lever, 26: Trip lever, 26a: Claw portion, 27: Trip lever shaft, 28.29
: Toggle link, 30: Connection shaft, 32: Opening/closing arm,
34: Contact spring, 35: Operation spring,
36: Adjustment device, 37: Connection plate, 38: Engagement adjustment screw,
39: Trip rod return spring.

Claims (1)

[Scope of utility model registration request] A movable contact device, a trip lever having a toggle link and rotatable so as to automatically open the movable contact device, and a notch engaging portion that engages with a claw portion of the trip lever and is fixed. A round rod-shaped hook rotatably supported on a frame, a tripping rod connecting fitting rotatably supported on a fixed frame coaxially with the hook, and integrally formed with the tripping rod connecting fitting. A tripping rod whose rotation on one side is limited by a stopper, and an engagement adjustment screw attached to the hook and provided at one end are in contact with a part of the tripping rod connecting fitting and are installed at the other end. a connection plate that biases the trip lever toward the stopper by a trip lever return spring; and a tripping element that responds to an overcurrent so as to rotate the trip lever and disengage the trip lever from the hook. The amount of engagement between the claw portion of the top lever and the notch engagement portion of the hook can be adjusted by rotating the hook using the engagement adjustment screw without changing the stop position of the lever. A circuit breaker characterized by being able to