JPH027443Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of an electromagnet that is installed in an electromagnetic contactor and attracts a movable iron core that opens and closes a contactor.

Conventionally, there has been a device of this type as shown in FIG. In the figure, 1 is a mounting base made of a magnetic material such as an iron plate, and 2 is a fixed iron core, which is fixed to the mounting base 1 by caulking or the like. 3 is a yoke plate fixed to the mounting base 1; 4 is a resin-molded coil frame around which the operating coil 5 is wound; the coil frame 4 is disposed around the fixed iron core 2; It is clamped between the mounting base 1 and the yoke plate 3. Reference numeral 6 denotes a movable core that is attracted to the fixed core 2 and moved by the excitation of the operating coil 5, and this movable core 6 is connected to a crossbar 7 that opens and closes the contact portion (not shown) of the electromagnetic contactor. has been done. Reference numeral 8 denotes a guide member for guiding the movable iron core 6, which is held between the yoke plate 3 and the coil frame 4 and faces the circumference of the movable iron core 6 with a slight gap therebetween. Note that FIG. 2 is a perspective view showing this guide member 8. As shown in FIG.

By the way, an electromagnetic contactor is generally installed at a mounting part such as a switchboard so that the movable core 6 of the electromagnet moves horizontally, and the center of gravity position w of the movable core 6 held and guided by the guide member 8 is Since it is located inside the guide member 8 (on the fixed core 2 side), the movable core 6 moves with its tip 6a tilted downward and in point contact with the inner circumferential surface of the coil frame 4. Therefore, during this movement, the sliding friction resistance increases, and the abrasion powder of the coil frame 4 generated by this contact sliding adheres to the contacts of the electromagnetic contactor, especially the contact portions, causing poor contact. There were flaws. Further, the resin-molded coil frame 4 is thermally deformed due to heat generated by the operating coil 5, and the clearance between the coil frame 4 and the movable core 6 becomes smaller, and the coil frame 4 eventually pinches the movable core 6. There was a risk that a pressure situation would occur.

Therefore, in order to prevent such defects, a guide member made of synthetic resin is installed inside the coil frame.
An improved technique in which the circumferential surface of the movable core is guided by this guide member is described in Japanese Patent Application Laid-open No. 113067/1983, and a guide sheet made of synthetic resin is provided inside the coil frame for the same purpose. An improved technique in which a part of this sheet is brought into sliding contact with a movable iron core to guide the movable iron core is described in Japanese Utility Model Application Publication No. 55-9514.

However, the guide members and guide sheets of each of the improved techniques described above are only disposed inside the coil frame, and are not fixed in position with respect to the fixed iron core. For this reason, if the assembly position of the coil frame relative to the fixed core is misaligned, the movable core will be misaligned, resulting in a tilt. In addition, the guide member and the guide sheet are only provided on the coil frame, and when the coil frame deforms, they deform along with the deformation, causing the problem that the movable iron core is guided at an angle, similar to the above. .

The purpose of this invention is to eliminate such conventional drawbacks, and to provide an electromagnet in which the movable core does not come into contact with the coil frame, and the coil frame can be prevented from being deformed due to thermal contraction.

In order to achieve the above object, this invention has a fixed core and a search space for a movable core that is attracted to the fixed core. a first guide member that is disposed in a fixed state and guides the circumferential surface of the movable core that has been penetrated into the search through space; It has a narrow guide surface that slides on the circumferential surface of the tip end of the iron core, and a second guide member made of a material that has a smaller thermal deformation rate and greater rigidity than the coil frame. .

An embodiment of this invention will be described below with reference to FIGS. 3 and 4. 3 is a sectional view of the electromagnet, and FIG. 4 is a half sectional view of the guide portion.

In the figure, the same reference numerals as in FIG. 1 indicate the same or corresponding parts, so the explanation will be omitted. A cylindrical first guide member 8 guides the circumferential surface of the movable core 6, and faces the movable core 6 with a slight gap. Reference numeral 9 denotes a cylindrical second guide member that guides the vicinity of the tip 6a beyond the center of gravity W of the movable iron core 6, and this second guide member 9 is made of a material that is not easily deformed by heat, such as a non-magnetic metal. It is disposed and held in a space between a fitting part 2a provided on the fixed core 2 and an engaging part 4a provided on the coil frame 4. Further, in the second guide member 9 shown in FIG. 4, 9a is a fitting surface with the fixed iron core 2;
9b is the engagement surface with the coil frame 4, 9c is the movable iron core 6
It is a guide surface that guides you.

Next, the operation of this electromagnet will be explained. When a voltage is applied to the operating coil 5, an absorbing force acts and the movable core is attracted to the fixed core 2, and the crossbar 7 moves together with this to open and close the contacts of the electromagnetic contactor. Note that when the application of the voltage is stopped, a trip spring (not shown) causes the movable iron core 6 to
returns to its predetermined position.

At this time, the movable core 6 of the electromagnet is guided by the first guide member 8 and the second guide member 9, so that the movable core 6 moves smoothly, and the movable core 6, especially The tip portion 6a does not come into contact with the coil frame 4, and therefore generation of abrasion powder of the coil frame 4 is prevented. Further, since the inner peripheral portion of the coil frame 4 is in close contact with the second guide member 9, deformation due to heat contraction is prevented by the second guide member 9, and the coil frame 4 comes into contact with the movable iron core 6. can be prevented from happening. That is, since the second guide member 9 is formed of a material having a smaller coefficient of thermal deformation and greater rigidity than the coil frame, the second guide member 9 itself undergoes less thermal deformation, and moreover, the second guide member 9 Since the second guide member 9 is fitted and fixed to the fixed iron core 2, the second guide member 9 can suppress deformation of the coil frame 4 due to thermal contraction. Therefore, the operating coil 5 will not be separated from the coil frame 4 due to contraction of the coil frame 4.

In addition, since the two peripheral surfaces of the movable core 6 are guided by the first guide member 8 and the second guide member 9, which have a small contact area, the movable core can move smoothly and stably. It will be done.

Furthermore, even if the assembly position of the coil frame 4 is slightly misaligned due to variations during assembly, the second guide member 9 and the fixed core 2 will not be misaligned, so the movable core 6 can be guided at an angle. do not have.

Note that by providing a slight gap between the first guide member 8 and the movable iron core 6, this first
Even if the assembly position of the guide member 8 deviates, as long as it is within an allowable range, guiding of the movable iron core 6 will not be hindered.

As described above, this invention not only prevents contact between the movable core and the coil frame, but also allows the movable core to move without being seriously affected by thermal contraction of the coil frame or variations in the assembly position of the coil frame. The iron core can be smoothly and stably moved toward the fixed iron core.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional electromagnet, Fig. 2 is a perspective view showing a guide member portion in Fig. 1, Fig. 3 is a sectional view showing an electromagnet according to an embodiment of this invention, and Fig. 4 is a sectional view showing a conventional electromagnet. FIG. 4 is a half sectional view showing the second guide member portion in FIG. 3; In the figures, the same reference numerals indicate the same or equivalent parts, 2 is a fixed core, 4 is a coil frame, 5 is an operating coil, 6 is a movable core, 8 is a first guide member, and 9 is a second guide member. .

Claims (1)

[Claims for Utility Model Registration] (1) A coil frame having a fixed core, a search space for a movable core attracted to the fixed core, and around which an operating coil is wound, and the above-mentioned space of the coil frame. a first guide member fixedly disposed in the search-through space and guiding the circumferential surface of the movable core penetrated into the search-through space; an electromagnet comprising: a second guide member having a narrow guide surface in sliding contact with the circumferential surface of the distal end of the movable core, and made of a material having a smaller coefficient of thermal deformation and greater rigidity than the coil frame; (2) The electromagnet according to claim 1, wherein the second guide member is provided in a fitted manner on the outside of the fixed iron core. (3) The electromagnet according to claim 1 or 2, wherein the first guide member and the second guide member are formed in a cylindrical shape.