JP2000323323A - Plunger type magnet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase attractive force and effective stroke without increasing ampere-turn. SOLUTION: In a plunger type magnet device, an almost pillar-shaped plunger 1 is movably fitted in a coil 5 surrounded by a square core 2 of one end, a square core 4 of the other end which has a hole into which the plunger 1 is inserted, and a magnetic pole 3 of a side surface is reciprocally driven in the center axis direction of the coil 5. The tip 1a of the plunger 1 attracted by the square core 2 is formed in a cone type, and a conic recessed part 2a is formed on the square core 2 facing the conic tip 1a. A guide ring 6 where notches 7 are formed at proper intervals in the inner peripheral part is arranged in the penetrating hole of the plunger 1 of the square core 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plunger-type magnet device, and more particularly, to an opening / closing operation of a main circuit contact of an automatic switch disposed on a distribution line by utilizing an electromagnetic force obtained by energizing a coil. The present invention relates to a plunger-type magnet device suitable for performing the following.

[0002]

2. Description of the Related Art As a general plunger type magnet apparatus, there is a conventional one shown in FIG. In FIG. 4, 1 is a plunger, 2 is a square iron core, 3 is a side magnetic pole, 4 is a square iron core, and 5 is a coil. In this magnet device, when the coil 5 is energized, the iron core 2, the magnetic pole 3,
A magnetic flux φ is generated in the iron core 4 and the plunger 1, whereby a force F for attracting the plunger 1 downward is generated, and the lower end of the plunger 1 is attracted to the iron core 2. This force F
Since it is inversely proportional to the square of the distance between the lower end of the plunger 1 and the iron core 2, the value becomes larger as the lower end is closer to the iron core 2. Specifically, FIG. 5 shows the relationship between the stroke of the plunger 1 and the load.

[0003] Conventionally, it is attached to an automatic switch,
Some plunger type magnet devices for turning on and off the main circuit contacts are formed, for example, as shown in FIG. In FIG. 6, 5 is a closing coil, 6 is a holding coil, 11 and 12 are iron cores, 14 is a magnetic pole, 15 is a plunger, 16 is a boss, 17 is a magnetic pole, 18 and 19 are collars, 20 is packing, and 21 is a hexagon bolt. It is. Also in this case, the force generated in the plunger 15 has the same characteristics as in FIG.

[0004]

As described above, in this type of magnet device, as shown in FIG.
When the stroke is zero, the load becomes maximum, and the load decreases rapidly as the stroke increases. Therefore, when trying to obtain the required load, it is necessary to design it to be used in a small stroke range, or to increase the ampere turn to compensate for the decrease in load due to the increase in stroke when a certain stroke is required was there. When the number of turns of the coil or the exciting current increases, the size of the magnet device itself or the power supply device increases. Therefore, conventionally, there has been a demand for the development of a magnet device having such characteristics that a required stroke can be obtained with a required load without increasing the number of ampere turns.

[0005]

In order to solve the above-mentioned problems, a first aspect of the present invention is a space surrounded by a rectangular iron core at one end, a rectangular iron core having a plunger insertion hole at the other end, and magnetic poles on side surfaces. A plunger magnet device in which a substantially cylindrical plunger loosely fitted in the coil is reciprocated in the direction of the center axis of the coil. And a conical concave portion is formed in the square iron core at the one end facing the conical convex portion.

According to a second aspect of the present invention, in the first aspect of the present invention, a guide ring having a notch formed at an appropriate interval in an inner peripheral portion is provided in the plunger insertion hole of the rectangular iron core at the other end. And

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an end view of a magnet device according to the present invention. In the drawing, reference numeral 1 denotes a plunger whose tip 1a is formed in a substantially conical shape, and 2 denotes a rectangular iron core, and a contact portion with the plunger 1 is formed with a substantially conical concave portion 2a according to the shape of the tip 1a. . 3 is the side magnetic pole, 4
Is a square iron core having a through hole through which the plunger 1 is inserted;
Is a coil wound in a cylindrical shape, and 6 is a guide ring disposed in a through hole of the square iron core 4.

In this magnet device, when the coil 5 is energized, the iron core 2, the magnetic pole 3, the iron core 4 and the plunger 1
Generates a force F to attract the plunger 1 downward, and the tip 1a of the plunger 1 is attracted to the iron core 2. At this time, the tip 1a of the plunger 1
And the recess 2a of the iron core 2 with which it comes into contact have a conical shape in which they fit together and come into close contact with each other.
The change in the magnetic separation distance (gap) between a and the iron core 2 becomes gentle. As a result, the characteristics of load and stroke
As shown in FIG. 5, even when compared with FIG.
The rate of decrease in load with an increase in stroke becomes gentle. Thereby, without increasing the ampere turn,
It is possible to realize a magnet device having a larger load and stroke than before.

The guide ring 6 disposed in the through hole of the rectangular iron core 4 is formed in the shape shown in FIG. The guide ring 6 is made of a non-magnetic material such as plastic, and has notches 7 formed at equal intervals on the inner periphery. When the guide ring 6 is fitted into the through hole of the iron core 4,
As the outer peripheral portion of the plunger 1 is supported and the plunger 1 reciprocates, as the volume of the space on the tip 1a side increases and decreases, the air in that space passes through the notch 7 of the guide ring 6. It is possible to get in and out. In particular, since the area ratio of the notch 7 to the entire guide ring 6 is large, the resistance when the air to be eliminated passes decreases, and the high-speed operation of the plunger 1 becomes possible.

[0010]

As described above, according to the present invention, a conical convex portion is formed at the end of the plunger on the side to be attracted to the iron core, and a conical concave portion is also formed at the iron core at a position opposed thereto. Thus, when the plunger is operated, the magnetic separation distance (gap) between the plunger and the iron core is shortened, the characteristics are improved, and the size and the performance can be reduced. In addition, the provision of the guide ring facilitates the inflow and outflow of air in the internal closed space due to the reciprocation of the plunger, thereby enabling the plunger to operate at a higher speed.

[Brief description of the drawings]

FIG. 1 is an end view of a magnet device according to the present invention.

FIG. 2 is a diagram showing characteristics of a load and a stroke in FIG. 1;

FIG. 3 is a view showing a shape of a guide ring of FIG. 1;

FIG. 4 is an end view showing a conventional example.

FIG. 5 is a diagram showing characteristics of a conventional example.

FIG. 6 is a partial sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plunger 1a Tip 2 Square iron core 2a Recess 3 Magnetic pole 4 Square iron core 5 Coil 6 Guide ring 7 Notch

Claims (2)

[Claims] A coil is disposed in a space surrounded by a rectangular core at one end, a rectangular core at the other end having a plunger insertion hole, and magnetic poles on side surfaces, and a substantially cylindrical plunger loosely fitted in the coil. A plunger-shaped magnet device that moves back and forth in the direction of the coil center axis, wherein a conical convex portion formed at the end of the plunger attracted to the rectangular iron core at one end; and a rectangular iron core at the one end facing the conical convex portion. And a conical recess formed in the plunger. 2. The magnet device according to claim 1, wherein a guide ring having a notch formed at an appropriate interval in an inner peripheral portion is disposed in the plunger insertion hole of the rectangular iron core at the other end. Shaped magnet device.