JPS5843882B2 - electromagnet device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a so-called fulcrum type electromagnet device consisting of an excitation coil, an iron core, a yoke, and an armature, which enables the armature to operate proportionally in accordance with the current of the excitation coil. Regarding the new magnetic pole shape.

FIG. 1 shows the most basic conventional fulcrum type electromagnet device, with no current flowing through the excitation coil.

1 is the iron core, 2 is the excitation coil, 3 is the yoke, 4 is the armature, 5
is a return spring, and 6 is a spacer.

This electromagnetic device is often used in electrical relays and the like, and its operation, as is well known, is to instantaneously open and close an armature by turning on and off the current in an exciting coil.

FIG. 2 shows the static attractive force characteristics, that is, the relationship between the stroke and the attractive force when a predetermined constant current is passed through the exciting coil.

Several improvements to this basic electromagnetic device have also been attempted in the past.

For example, in Japanese Utility Model Publication No. 421337, the basic model is in the l-loak dog position, and therefore the suction force at the operation start position is small. It is said that the static characteristics shown in FIG. 4 can be obtained by forming stepped portions A and B in each of the electrodes.

The suction force at the operation start position is large and the operation speed is rapid, and the suction force near the operation completion position is also sufficiently large.

In any case, the armature opens and closes instantaneously, and the improved example can be said to speed up the operation.

The main purpose of the present invention is to enable the armature to operate continuously and reversibly in accordance with the current value of the excitation coil, whereas the conventional example opens and closes the armature instantaneously. The purpose of the present invention is to provide an electromagnetic device with a simple structure and low cost that can provide a suitable stroke and force.

Next, it will be explained that with the structure and characteristics of the conventional example, the movement of the armature proportional to the current of the excitation coil, which is the object of the present invention, cannot be obtained.

FIG. 5 shows actual measurements of the characteristics of the basic fulcrum type electromagnet device shown in FIG.

The excitation coil is 4250 turns, and the thickness of spacer 6 is 2r.
It's rrrn.

Therefore, the point of stroke O is the end face of iron core 1 and armature 4.
There is a magnetic gap of 2rran between the two.

The solid line in Figure 5 shows the static attraction characteristics of the electromagnet, and the current value is 100m.
Shown from A to 160mA.

The broken line is the characteristic of the return spring, and the spring constant is 50 ff/rt.
It is vn.

Po is the force acting on the armature in the direction of the anti-attractive force when no current is flowing through the excitation coil at the initial load.

For example, when an electromagnet device is used as a solenoid valve, the value of Po is a value required as the valve closing pressure in the valve closed state, and varies depending on the equipment to which it is applied, but here it is set to 1002.

In FIG. 5, when the current in the excitation coil is gradually increased, the armature starts to move at a current at a point a where the spring force shown by the broken line intersects Po, that is, a current of a little less than 140 mA.

However, the solid line with a current value of 140 mA and the broken line indicating the spring characteristics are already touching, and even if the current value is 140 mA,
If the point A is exceeded, the balance point between the attractive force and the spring force is lost, and the armature instantly moves to the stroke 70 point.

Points a and b on the graph are a little apart, and it seems that some strokes can be used, but they are extremely close to the 140 mA line, making it unstable and not practical.

Even in the case of an excitation coil current of 120 mA that does not exceed 140 mA, the armature 4 appears to be stable at around the stroke 3.6, but the armature 4
When an external force such as a vibration shock is applied to the coil, the coil current increases to 12
Even if it remains fixed at 0mA, the armature 4 has a stroke of 0.
It has a very unstable so-called unstable point where it moves to a position near 5sn.

In short, it can be seen that in the conventional structure, since the static attraction force characteristic is inversely proportional to the square of the stroke, it is practically difficult to obtain movement of the armature proportional to the current of the excitation coil.

The present invention is based on the fact that, in addition to such conventional product C analysis, the shape of the magnetic pole portion of the iron core was examined to obtain ideal static attraction characteristics for proportional operation of the armature.

FIG. 6 shows an embodiment of the present invention in which no current is flowing through the excitation coil.

1' is an iron core, 2 is an excitation coil, and 3' is a yoke, one end of which is fastened to the iron core 1', and the other end is a knife that supports the armature 4' as a fulcrum.

5' is a spring hook 6' fixed to the armature 4' with a return spring.
and hook it onto the adjustment screw I which is secured by the claw protruding from the yoke 3'.
It is L.

8 and 9 are sui-soba fixed to the iron core 1'.

An important point in this configuration is the relative position between the magnetic pole portion of the iron core 1' and the tip of the armature 4'.

Figure 1 is an explanatory diagram of this part, where the armature 4' is connected to the stopper 9.
Indicates the state in which the object is hit, that is, the operation start position.

At the end of the iron core 1', a magnetic pole face A having an inclination of θ is formed in a line perpendicular to the armature 4'.

As the current of the excitation coil is gradually increased, the armature 4' moves in an arc around the fulcrum C, and the tip moves along the line R, and the distance between the magnetic pole surface A and the tip H of the armature 4' moves in a circular arc around the fulcrum C. The operating gap becomes gradually shorter.

Here, the radius of rotation r of the armature and the inclination θ of the magnetic pole surface A have a large relationship with the attraction characteristics6. Fig. 8 shows an example of actual measurement of the characteristics.

The graph display is the same as that shown in FIG. 5 above, with the solid line representing the static suction characteristic and the broken line representing the spring characteristic.

The coils and springs used are the same as in the conventional example, ie, in FIG.

In FIG. 7, θ is approximately 8 degrees and r is approximately 35 degrees.

As is clear from Fig. 8, the static attraction force characteristics are shown in Fig. 2.

Compared to the conventional examples shown in Figs. 4 and 5, it is flat over the entire stroke, which is ideal for proportional control, and especially in the stroke 1wn.
Characteristics of strong suction force were obtained in the above areas.

The initial load Po explained in the conventional example is 120'? Even if it closes,
Operation starts with a coil current of 100 mA or less, and extremely reliable operation with no unstable points can be obtained over the entire stroke of 4rrrrn.

Even though the armature 4' rotates and the operating gap, that is, the magnetic gap, between the core magnetic pole surface A and the tip B of the armature 4' gradually narrows, the attractive force, that is, the armature 4' Without the sudden increase in the force for further rotation,
The reason why the suction characteristic can be maintained almost constant or even slightly decreased will be explained using FIG. 9, which is a simplified model of FIG. 7.

The armature 4' at the stroke 0 point, that is, the operation start position, is drawn with a solid line.

In this state, the attractive force F in the direction perpendicular to the magnetic pole distance A of the iron core 1'
When the coil current value ■1 that produces o is energized, the armature 4'
The component of force that tries to rotate around the fulcrum C is f.

becomes. In other words, this f. is the attraction force on the vertical axis of the graph in FIG.

When the armature 4' is at the position shown by the two-dot chain line at the same coil current ■1, the air gap between the core magnetic pole surface A and the tip B of the armature 4' becomes shorter, and the gap in the direction perpendicular to the magnetic pole surface A becomes shorter. The suction force is Fl and the above F.

becomes larger than

However, the component force f1 in the direction of rotating the armature 4' is the above f
.

almost the same or slightly smaller.

This is because the armature 4' moves in an arc around the fulcrum C, and as the tip B moves on the line R, the armature 4'
' is approaching in the direction perpendicular to the core magnetic pole face A.

To make it easier to understand, let us take as an example the position of the armature 4' indicated by the broken line, that is, the rotational position perpendicular to the magnetic pole surface A. Since the magnetic gap between the magnetic pole surface A and the tip B is the smallest, , the attractive force F2 in the direction perpendicular to the magnetic pole surface A is maximum.

However, at this time, the component force in the direction of rotating the armature 4' disappears.

In actual use, a stopper 8 is provided as shown in FIGS. 6 and 7 to restrict the operating range before reaching this position.

As described above, according to the electromagnet device of the present invention, the following effects can be obtained.

That is, it consists of an excitation coil, an iron core, a yoke, an armature supported on one end of the yoke, and a biasing member that biases a force in a direction in which the armature is attracted. On the attraction surface of the iron core, when the armature rotates in the core suction direction with respect to the rotational arc tangent of the tip of the armature at the operation start position, there is an air gap between the tip of the armature and the magnetic pole surface of the iron core. The structure is such that an inclined surface that narrows little by little is provided, and a main operating gap is formed between the inclined iron core magnetic pole surface and the tip of the armature, which is large and flat in proportion to the magnitude of the coil current. This has the effect of providing a stable proportional operation according to the coil current, which is efficient and has a wide operating range.

[Brief explanation of the drawing]

Fig. 1 is a side view of a conventional electromagnet device, Fig. 2 is its characteristic diagram, Fig. 3 is an enlarged view of main parts of another conventional example, Fig. 4 is its characteristic diagram, Fig. 5 is an explanatory diagram, Figure 6 is a side view of the electromagnet device according to the embodiment of the present invention, Figure 7 is an enlarged view of its main parts, and Figure 8 is an enlarged view of the main parts.
9 are explanatory diagrams. 1'... Iron core, 2'... Exciting coil,
3'... Yoke, 4'... Contact, A.
...Magnetic pole surface.

Claims (1)

[Claims] 1 Consists of an excitation coil, an iron core, a yoke, an armature supported on a fulcrum at one end of the yoke, and an urging member that applies a force in a direction in which the armature is attracted, and The suction action surface of the iron core is inclined with respect to the rotation arc tangent of the tip of the armature at the operation start position, and the direction of the inclination is such that the tip of the armature is inclined when the armature rotates in the core suction direction. An electromagnet device having a structure in which a main operating gap is formed between the inclined iron core magnetic pole surface and the tip of the armature by providing an inclined surface in a direction in which a gap between the iron core magnetic pole surface and the iron core magnetic pole surface narrows little by little.