JPH04107808U - Electromagnetic trip device for circuit breakers - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to an electromagnetic tripping device for a circuit breaker with a large rated current value.

B. Prior Art Conventionally, in this type of electromagnetic tripping device for a circuit breaker, one with a large rated current value is equipped with a fixed iron piece 2 at the top and a magnetic plunger 3 inside, as shown in Figure 8. An excitation coil 7 made of polyester copper wire is wound around the outer periphery of a non-magnetic container 1 having a brake oil 4b and a compression spring 4a, and as shown in FIG. Then, the ends of both electrical annealed copper wires 6 are spot welded to the movable contact 11 and the load terminal 12, respectively, and the excitation coil 7 is connected to the movable contact 11 and the load terminal 12 via the electrical annealed copper wire 6. was connected to. (P is the welding point) When the plunger 3 is energized, it is magnetized and moves toward the fixed iron piece 2, and the movable iron piece 9 provided at the upper end of the support plate 8, which has an L-shaped cross section and holds the cylinder 1, moves to the fixed iron piece. 2, and the excitation coil 7
When the movable iron piece 9 is demagnetized, the tension spring 10 causes the movable iron piece 9 to separate from the fixed iron piece 2. The rated current and trip current of the circuit breaker are determined by the number of turns and the diameter of the copper wire used in the excitation coil 7.

C. The problem that the invention aims to solve is the conventional circuit breaker with a large rated current value (
Electromagnetic tripping devices (approximately 50 A or more) require a pitch-wound coil with a large wire diameter, but in order to ensure the pitch-wound shape, soft electrical annealed copper wire is not suitable, so polyester copper wire etc. had to use. However, polyester copper wire and the like are hard and difficult to deform, and therefore pitch winding cannot be easily performed, resulting in a decrease in work efficiency.

In addition, in order to connect the excitation coil made of polyester copper wire to the movable contact and the load terminal via the electrical annealed copper wire, spot welding had to be performed at four locations, which was extremely complicated and troublesome. Since the rated current value is large, the number of turns of the coil is small, and there is a disadvantage that a dedicated spacer 40 is required for positioning the coil.

D. Means for Solving the Problems In view of the above-mentioned state of the prior art, the present invention provides an electromagnetic tripping device that allows the use of electrical annealed copper wire, has easy winding work for the excitation coil, and requires less welding work. The structure includes a cylindrical body having a fixed iron piece at the top of the opening, a braking member inside and a plunger that can be moved up and down against the braking member, and a coil guide member fitted outside the cylindrical body. , an excitation coil wound around the coil guide member, a support plate having an L-shaped cross section to which the cylinder is fixed to the bottom plate, and a support plate provided rotatably in the direction of the fixed iron piece at the upper end of the side surface of the support plate. The movable iron piece is provided with a movable iron piece, and an urging member that urges the movable iron piece in a direction in which the movable iron piece is separated from the fixed iron piece.

Preferably, the coil guide member is a bobbin having a spiral rib formed on the outer periphery of the hollow shaft, and further, the coil guide members project horizontally in the radial direction while changing directions by a predetermined angle. The bobbin is formed by providing guide rods at equal intervals and in a stepped manner around the outer periphery of a hollow shaft, and the bobbin is provided with a cylindrical container for accommodating the guide rods.

E) An excitation coil is easily formed by fitting a bobbin as a coil guide member onto the working cylinder and winding a copper wire along the spiral rib or guide rod of the bobbin.

When the current is within the rated value, the plunger is pushed to the bottom of the cylinder by the braking member, and because the magnetic gap is large, the movable iron piece is not attracted to the fixed iron piece.

When the overcurrent continues to flow, the magnetomotive force of the excitation coil increases, and the leakage magnetic flux causes the plunger to move to one side of the fixed iron against the braking member, and when the plunger is attracted to the fixed iron piece, a magnetic gap is created. becomes smaller, and the movable iron piece is attracted to the fixed iron piece, tripping the circuit breaker.

When a large current such as a short circuit current flows, leakage magnetic flux increases rapidly, so the movable iron piece is instantly attracted to the fixed iron piece and trips the circuit breaker without waiting for the plunger to move.

F. Embodiment An embodiment of the electromagnetic tripping device for a circuit breaker according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an electromagnetic tripping device incorporated in a circuit breaker, and FIG. 2 is a partially sectional side view of the electromagnetic tripping device.

Reference numeral 1 denotes a container as a cylindrical body made of a non-magnetic material, and a fixed iron piece 2 is provided at the top of the opening, and a plunger 3 made of a magnetic material is housed in the inner bottom of the container 1. A compression spring 4a as a braking member is provided between the iron piece 2 and a braking oil 4 as a braking member.
b is injected, and both move plunger 3 to container 1.
is biased towards the bottom of the

Fully electromagnetic circuit breakers use the same electromagnet to interrupt overcurrents and short-circuit currents, so there is a time limit until the current reaches a certain value, and when it exceeds it, it must be interrupted immediately. To obtain the timed characteristic, brake oil and a compression spring are placed in a container and used as described above.

3(a) to (c) are shown in the container 1.
As shown, a bobbin 5 made of an insulating material and having spiral ribs 5b at equal intervals is fitted around the outer periphery of a hollow shaft 5a, and an annealed copper wire 6 for electrical use is attached to the bobbin 5 along the spiral ribs 5b. It is wound to form an excitation coil 7. In this way, since the excitation coil 7 is formed along the spiral rib 5b, it is possible to secure a pitch-wound shape with the electric annealed copper wire 6 for use in a circuit breaker with a large rated current value. Since the wire 6 is used, the winding operation is also easy.

Furthermore, Fig. 4 (a), (b) and Fig. 5 (a)
, (b) respectively show modified embodiments of the coil guide member, in which the upper plate 5 of the bobbin 5 is
An insertion hole 5d for terminal treatment of the electrical annealed copper wire 6 is bored in c.

Further, the container 1 is welded to the bottom plate part 8a of a support plate 8 having an L-shaped cross section, and a movable iron piece 9 is attached to the upper end of the side plate part 8b of the support plate 8 so as to be rotatable in the direction of the fixed iron piece 2. . A tension spring 10 is stretched between the rear part of the movable iron piece 9 and the side plate portion 8b of the support plate 8, and biases the movable iron piece 9 in a direction to move away from the fixed iron piece 2.

Both ends of the electrical annealed copper wire 6 are connected to movable contacts 1, respectively.
1 and the load terminal 12 (P is the welding point). In this way, the electrical annealed copper wire 6
Since spot welding can be performed directly on the movable contact 11 and the load terminal 12, only two welding locations are required, and the assembly work is simple.

The electromagnetic tripping device configured as described above operates as follows. That is, when the current flowing between the movable contact 11 and the load terminal 12 is within the rated value, the plunger 3 is pushed to the bottom of the container 1 by the compression spring 4a and is not attracted to the fixed iron piece 2, so that the magnetic gap is This is so large that the movable iron piece 9 is not attracted to the fixed iron piece 2.

However, when the overcurrent continues to flow, the magnetomotive force of the exciting coil 7 increases, and the plunger 3 inside the cylinder 1 moves toward the fixed iron piece 2 against the compression spring 4a and the brake oil 4b due to the leakage magnetic flux. However, when the plunger 3 is attracted to the fixed iron piece 2, the magnetic gap becomes smaller, and the movable iron piece 9 is attracted to the fixed iron piece 2, tripping the circuit breaker. At this time, a time delay operation is performed due to the viscous resistance of the brake oil 4b in the container 1. The characteristic of time-delayed operation is that as the current increases, the electromagnetic attractive force becomes stronger, and the operation time becomes shorter.

When a large current such as a short circuit current flows, the leakage magnetic flux increases rapidly, so the movable iron piece 9
without waiting for the plunger 3 to move, is instantly attracted to the fixed iron piece 2 and trips the circuit breaker.

When the current is cut off, the magnetomotive force of the excitation coil 7 disappears, the plunger 3 returns to its original position due to the urging force of the compression spring 4a and the braking oil 4b, and the movable iron piece 9 is moved to the fixed iron piece by the tension spring 10. 2 and return to the original position.

FIG. 6 shows another embodiment of the electromagnetic tripping device according to the present invention. That is, mutually 90
The bobbin 20 has eight guide rods 21, 21, . It is something that you have. The mounting position of the guide rod on the outer periphery of the hollow shaft 5a and the number of guide rods to be installed are not limited to those described above, and can be changed as appropriate within the scope of achieving the object of the present invention.

Moreover, FIGS. 7(a) to (c) relate to the present invention. That is, a cylindrical container 31 made of an insulating material that houses the bobbin 30 and protects the bobbin 30 and the electrical annealed copper wire (not shown) wound around the bobbin 30;
1 is provided with an introduction hole 32 for introducing an electrical annealed copper wire into the bottom thereof, and has the same functions and effects as each of the above embodiments in addition to the protective function and effect.

G. Effects of the invention As explained above, the electromagnetic tripping device for a circuit breaker according to the invention includes a coil guide member fitted onto a cylinder and an excitation coil wound around the coil guide member. Therefore, for circuit breakers with large rated current values, it is possible to secure a pitch-wound shape with electrical annealed copper wire, and it is easy to wind the excitation coil and requires less spot welding work, making it extremely easy to use. It is rich in sexuality. An electromagnetic tripping device using a bobbin provided with a guide rod or a bobbin provided with a cylindrical container for storing the bobbin also provides the above-mentioned effects.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the electromagnetic tripping device according to the present invention incorporated into a circuit breaker, Fig. 2 is a partially sectional side view of the electromagnetic tripping device, and Figs. 3a, b, and c are respectively A plan view, a front view, and a bottom view of the bobbin. FIGS. 4a and 4b are a plan view and a front view of a modified example of the bobbin, respectively. FIGS. 4 a and b are a plan view and a front view of a modified example of the bobbin, respectively. , Fig. 6 is an explanatory diagram of another embodiment of the coil guide member, Fig. 4 a, b, and c are respectively a plan view, a front view, and a bottom view of a modified embodiment of the bobbin, and Fig. 8 is a part of the conventional example. The cross-sectional side view and FIG. 9 are exploded perspective views of the main parts thereof. 1... Container, 2... Fixed iron piece, 3... Plunger, 4a... Compression spring, 4b... Braking oil, 5...
...Bobbin, 5a...Hollow shaft, 5b...Rib, 5c
... Upper plate, 5d ... Insertion hole, 6 ... Soft copper wire for electricity, 7 ... Excitation coil, 8 ... Support plate, 9 ... Movable iron piece, 10 ... Tension spring, 11 ... Movable contact, 12... Load terminal, 20, 30... Bobbin, 21... Guide rod, 31... Cylindrical container, 32...
Introduction hole.

Correction Heisei 3.2.1
The brief description of the drawing has been amended as follows. "Figure 4" on page 12, line 11 of the specification is changed to "Figure 5"
and correct it. "Figure 4" on page 12, line 13 of the specification is changed to "Figure 7"
and correct it.

Claims (4)

[Scope of utility model registration request] Claim 1: A cylindrical body having a fixed iron piece at the top of the opening, a braking member inside and a plunger that can be moved up and down against the braking member, a coil guide member fitted onto the outside of the cylindrical body, and a coil thereof. An excitation coil wound around a guide member, a support plate having an L-shaped cross section to which the cylinder is fixed to the bottom plate, and a movable iron piece provided at the upper end of the side plate part of the support plate so as to be rotatable in the direction of the fixed iron piece. and a biasing member that biases the movable iron piece in a direction to separate the movable iron piece from the fixed iron piece. 2. The electromagnetic tripping device for a circuit breaker according to claim 1, wherein the coil guide member is a bobbin having a spiral rib formed on the outer periphery of a hollow shaft. 3. The coil guide member is a bobbin in which guide rods, which project horizontally in the radial direction and whose orientations change each other by a predetermined angle, are provided on the outer periphery of a hollow shaft at equal intervals and in a step-like manner. The electromagnetic tripping device for a circuit breaker according to claim 1. 4. The electromagnetic tripping device for a circuit breaker according to claim 2, wherein the bobbin includes a cylindrical container for accommodating the bobbin.