JPS633076Y2 - - Google Patents

Description

[Detailed description of the invention] This invention moves the movable iron core using the magnetic field generated when an overcurrent flows through the breaker, more specifically, the coil, and activates the contact tripping mechanism connected to the movable iron core. This invention relates to an electromagnetic tripping device for a breaker.

As shown in Fig. 1, in a conventional breaker of this type, when an overcurrent flows, the magnetic field generated around the coil 1 attracts the movable iron core 4 toward the fixed iron core 2, causing the drive pin 5 to move downward. This actuates the contact tripping mechanism, and since the drive pin 5 and the movable iron core 4 are integrally formed of magnetic material, the wiring inside the breaker does not come into contact with the drive pin 5. In some cases, it may be necessary to insulate with an insulating tube 22 or the like to prevent short circuits, which has the disadvantage of increasing the number of processing steps and the number of materials.
In addition, since relatively high-precision processing is required, it is difficult to process using a construction method that utilizes plastic deformation, and the material is formed by cutting using a lathe. For this reason, cutting waste is generated and there is a lot of material loss.
Moreover, it has the disadvantage that the processing time is long and the cost is high. The present invention has been made in view of the above points, and its purpose is to make the drive pin an insulating material, so that it can be easily processed and provided at a low cost. To provide an electromagnetic tripping device for a breaker which has high magnetic efficiency and a large driving force of a movable iron core.

Hereinafter, the electromagnetic tripping device for a breaker according to the present invention will be described with reference to an embodiment. A coil 1 whose magnetization direction is vertical, a fixed iron core 2 disposed at the lower end of the coil 1, and a coil 1 includes a movable iron core 4 disposed coaxially with the fixed iron core 2 and biased upward by a return spring 3; A fixed iron core 2 protrudes from the coil 1 and has a lower end movable up and down.
The movable iron core 4 moves downward due to the magnetic field generated when an overcurrent flows through the coil 1, and the contact tripping pin 5 is connected to the upper end of the drive pin 5. The contacts 6 and 7 are opened by activating the mechanism, and in this embodiment, a substantially rectangular yoke 10 that closes the upper and lower ends of the coil 1 with a U-shaped member 8 and an I-shaped member 9 is used. An example is shown in which the coil 1 is formed around the coil 1 and used as part of the magnetic path. And this electromagnetic trip device (trip element)
As shown in Figures 2, 3, and 5, a breaker using a contact tripping mechanism has a contact tripping mechanism in the center, and tripping elements and contact blocks are placed on each side of the mechanism. The tripping element is composed of a thermal tripping element made of bimetal 11 and an electromagnetic tripping element having coil 1 as its main component. In the electromagnetic tripping element, a part of the magnetic path is formed by a yoke 10 arranged so as to surround the outer periphery of a coil 1 whose axis is arranged in the vertical direction as shown in FIGS. 4 and 7. At the same time, a cylindrical body 12 made of thermosetting resin is placed inside the coil 1, and a driving pin 5 made of synthetic resin such as urea resin is inserted therethrough and formed integrally with the driving pin 5. A fixed iron core 2 is fixed to the lower side of the movable iron core 4 and the yoke 10, and a restoring spring 3 is disposed between the movable iron core 4 and the fixed iron core 2 and urges the movable iron core 4 upward. The upper end of the drive pin 5 protrudes from the yoke 10 to form an engagement head 13 in the shape of a nail head, and the drive pin 5 passes through the fixed iron core 2.
The lower end of the movable iron core 4 protrudes below the yoke 10 when the movable iron core 4 moves downward due to the excitation of the coil 1. The movable iron core 4 is formed into a cylindrical shape with approximately the same diameter as the inner diameter of the cylindrical body 12, and is movable only in the vertical direction.A part of the upper end protrudes from the yoke 10, and when the coil 1 is excited, the fixed iron core is moved. 2 and closes a magnetic path together with the yoke 10. The upper end of the cylindrical body 12 becomes a narrow diameter part 14 and is inserted into the upper side of the yoke 10, and the step part 1 of each of the movable iron core 4 and the fixed iron core 2
When the movable iron core 4 is pushed upward by the return spring 3 disposed between 5 and 16, the yoke 10
The movable iron core 4 is insulated from the movable iron core 4. The lower end of the bimetal 11 is fixed to a fixed piece 17 extending from the I-shaped member 9 constituting the yoke 10, and the second
One end is connected to the coil 1 of the electromagnetic tripping element, one end of which is connected to the terminal portion 18 on the right side of the figure, through a stranded wire 19, and the other end is electrically connected to a contact 21 through a stranded wire 20. Therefore, if the drive pin 5 is made of metal as in the conventional example shown in FIG.
When the drive pin 5 contacts the pin 9, the bimetal 11 passes from the drive pin 5 through the fixed iron core 2 and the yoke 10.
Since the stranded wire 19 is short-circuited, it is necessary to insert the stranded wire 19 into the insulating tube 22. However, in this embodiment, since the drive pin 5 is molded with synthetic resin, the bimetal 11 is not short-circuited and the stranded wire 19 is inserted into the insulating tube 22. becomes unnecessary. As a result, the unstable drag force caused by the insulating tube 22 on the bimetal 11 disappears, and the thermal strain characteristics of the bimetal 11 can be easily adjusted and stabilized. To explain the contact tripping mechanism, when the breaker is in the on state, as shown in FIGS. 2 and 6, the torsion coil spring 24 attached to the shaft 23 biases the breaker in the clockwise direction in FIG. The lower end engaging protrusion 26 of the trip lever 25 that has been
7 to prevent the upward movement of one end of the latch lever 27, and the movable shaft 3 inserted into the other end of the latch lever 27 by input from the handle 29.
0 is also pressed downward and located at the lower end of the groove 31, and is latched due to the positional relationship between the shafts 32, 33 and the movable shaft 30. The contactor 21 is pushed up by compressing the return spring 35 due to the lowering of the drive rod 34 as the latch lever 27 is lowered, thereby bringing the movable contact 6 into contact with the fixed contact 7. The fixed contact 7 is provided at one end of the terminal plate 36, and the other end of the terminal plate 36 is provided at the terminal portion 3.
7 is connected. Reference numeral 38 denotes an arc traveling plate which induces the arc generated when the fixed contact 7 and the movable contact 6 are opened between the arc traveling plates 38 and interacts with the magnetic field generated around the arc by the arc current. The arc is moved upward and the length of the arc is extended, and the arc is cooled and extinguished by the arc extinguishing grid 39 disposed at the upper end of the arc traveling plate 38. As a result, arc current flows and the circuit is This prevents delays in shutoff.

Next, the operation of the contact tripping mechanism will be explained. When an overcurrent flows while the breaker is in the on state, the bimetal 11 is heated and the curvature of the bimetal 11 presses the engagement surface 40 of the trip lever 25, causing the trip lever 25 to rotate. move. When the engagement protrusion 26 and the engagement portion 28 are disengaged due to this rotation, the engagement portion 28 of the latch lever 27
The spring pressure of the return spring 35 applied to the spring causes the latch lever 27 to spring upward about the movable shaft 30 or the entire latch lever 27, and the spring pressure of the return spring 35 causes the contact 21 to rotate and open. The pole is done. Furthermore, when a large current such as a short circuit current flows, the movable iron core 4 is quickly attracted downward by the magnetic field generated in the coil 1, and the engagement head 13 of the drive pin 5 pushes down the protrusion 41 protruding from the trip lever 25. When the latch lever 27 is disengaged, the lower end of the drive pin 5 directly pushes down one end of the contact 21, moves the other end of the contact 21 on the movable contact 6 side upward, and instantaneously opens the contact. . 42 is the base.

As described above, the present invention has a drive pin made of an insulator molded that is formed integrally with a movable iron core, passes through the movable iron core, and is inserted through a fixed iron core, and protrudes from the coil in this drive pin. The upper end of the contact is the drive part of the contact tripping mechanism, and since the drive pin with the drive part is molded separately from the movable iron core, cutting is not required when manufacturing this drive pin. Not only has it become possible to shorten processing time and increase mass production, but even if there is a wiring part near the upper end of the drive pin that protrudes from the coil, short-circuit accidents due to the drive pin can be avoided. This makes it possible to increase the arrangement density of the breaker parts, and also because the movable iron core is inside the coil together with the fixed iron core, and what protrudes from the coil is the drive pin, which is unrelated to the magnetic circuit. There is no magnetic leakage, the magnetic efficiency is high, and the driving force of the movable iron core is large, ensuring reliable tripping action.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the vicinity of an electromagnetic tripping element used in a conventional breaker, Fig. 2 is a longitudinal cross-sectional view of the present invention, Fig. 3 is a partially cutaway plan view of the same, and Fig. 4 is the same as the above. FIG. 5 is a perspective view of the present invention, and FIG. 6 is an exploded perspective view showing the contact tripping mechanism used in the above.
FIG. 7 is an exploded perspective view showing the tripping element and contact block used in the same device, in which 1 is a coil, 2 is an exploded perspective view, and 1 is a coil;
3 is a fixed iron core, 3 is a return spring, 4 is a movable iron core, 5 is a drive pin, and 6 and 7 are contacts.

Claims (1)

[Scope of utility model registration request] A coil whose magnetization direction is vertical, a fixed iron core placed at the lower end of the coil, and a movable iron core placed coaxially with the fixed iron core inside the coil and urged upward by a return spring. and a drive pin formed of an insulator, which is formed integrally with the movable iron core, passes through the movable iron core, has an upper end protruding from the coil, and a lower end that is vertically movable and inserted through the fixed iron core.
An electromagnetic tripping device for a breaker, in which the upper end of the drive pin that protrudes from the coil serves as the driving part of the contact tripping mechanism.