JPS6345039Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil-immersed solenoid, and more particularly to an improvement in the yoke of the solenoid.

An oil-immersed solenoid has a plunger made of a magnetic material movably disposed within a plunger guide that is normally airtight to the outside, and a coil winding is applied to the outside of the plunger guide. The coil winding is surrounded by a yoke that forms a magnetic path. In order to reduce magnetic resistance within the yoke and reduce magnetic loss in such a solenoid, a so-called wound core, which is made by winding thin steel plates in multiple layers, is used for the yoke.

However, due to manufacturing problems, the wall thickness of this wound core is constant, and it is difficult to obtain a core with a desired thickness depending on the type of solenoid. In addition, it is essential that a gap be created between the plunger guide and the hole for inserting the plunger guide formed in the yoke due to the machining process, and this gap increases magnetic resistance, resulting in an increase in power consumption.

In order to solve these problems, the applicant devised an "oil-immersed solenoid" in Utility Model Application No. 98738 filed in 1982. This invention is characterized by the provision of an auxiliary yoke adjacent to the yoke on the outer periphery of the plunger guide.However, if the yoke is a wound core type in which a thin steel plate is wound, the part through which the plunger guide is inserted is is relatively weak in terms of the axial force of the plunger guide,
During molding, as shown in FIG. 1, the upper wall c and/or lower wall c' in which the plunger insertion hole b of the yoke a is formed may deform into a convex or concave shape in the axial direction. . Even if a flat auxiliary yoke d is provided adjacent to a yoke deformed in this way, a gap e will be formed between the yoke and the auxiliary yoke, increasing magnetic resistance and reducing the effect of providing the auxiliary yoke. There may be problems with storage.

An object of the present invention is to prevent a gap from forming between the yoke and the auxiliary yoke in a solenoid in which the auxiliary yoke is provided adjacent to the yoke.

This invention is an oil-immersed solenoid in which the yoke that forms the magnetic path is composed of a wound core made of thin steel plates wound in multiple layers, and an auxiliary yoke is provided adjacent to the yoke. It is distinctive in that it is formed slightly shifted in the axial direction.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, an embodiment of the invention is shown. In the figure, 1 is a tubular plunger guide, 2 is a plunger made of a magnetic material that is movably inserted into the plunger guide 1, 3 is a fixed iron core made of a magnetic material that is fitted and fixed to one end of the plunger guide 1; 4 is a stopper member fitted and fixed to the other end of the plunger guide 1, 5 is a coil winding provided around the outer periphery of the plunger guide, and 6 is a yoke surrounding the coil winding.

The yoke 6 is composed of a so-called wound core formed by winding a thin steel plate such as a silicon steel plate in multiple layers, and the plunger guide 1 and fixed core are inserted into insertion holes 7 and 7a formed in the yoke 6. ing.

A plunger guide 1 is located adjacent to the outside (upper side in the figure) of one of the yoke 6 and adjacent to the yoke.
An annular auxiliary yoke 10 of a desired thickness is provided to surround the yoke. The auxiliary yoke 10 is formed by stacking rings made of thin steel plates such as silicon steel plates in multiple layers. The auxiliary yoke 10 may be formed into a complete ring shape, but as shown in FIG. Magnetic properties can be improved.

In this case, if the inner periphery (around the insertion hole 7) of the wall 61 of the yoke 6 (the side where the auxiliary yoke is provided adjacently) is convexly shifted in the axial direction of the plunger guide with respect to the outer periphery, the auxiliary yoke 1
As shown in FIGS. 2 and 4, the wall 61 is formed in advance in an umbrella shape, that is, so that the inner circumference is slightly offset from the outer circumference in the axial direction.
The convex surface 62 of the auxiliary yoke 10 is aligned with the concave surface of the auxiliary yoke 10 (or vice versa). In this way, it is possible to eliminate the gap that would occur if the auxiliary yoke were flat.

In the solenoid described above, when the coil winding 5 is energized, the magnetic flux generated by the coil winding is transferred from the plunger 2 to the fixed core 3 to the yoke 6.
→Flows through the closed loop of plunger 2, and
is attracted to the fixed iron core and presses the rod 9, but
In this case, the area of the surface of the yoke 6 facing the plunger (the surface of the insertion hole 7) is substantially increased by the action of the auxiliary yoke 10, and part of the magnetic flux is transferred from the yoke 6 to the plunger 2 via the auxiliary yoke 10. As a result, the magnetic resistance at the insertion hole 7 is reduced accordingly. Moreover, since there is almost no gap between the yoke and the auxiliary yoke, there is no reduction in magnetic efficiency.

The auxiliary yoke 10 may be placed outside the yoke 6 as shown in FIG. 2, but may also be placed inside the yoke 6 as shown in FIG.
As shown in the figure, both the inner and outer sides of the yoke 6 may be used.

In FIG. 7, an auxiliary yoke 10 without slits is shown.
The relationship between the thickness t of the auxiliary yoke, the solenoid excitation current (shown by a solid line) and the power consumption (shown by a broken line) when the auxiliary yoke is attached to the outside of the yoke 6 is shown. As is clear from this graph, the provision of the auxiliary yoke reduces the excitation current and power consumption.

In addition, as a result of testing the variations in current values for a large number of solenoids assembled using an auxiliary yoke pre-formed in the shape of an umbrella as in the present invention and a solenoid assembled using a flat auxiliary yoke, The results were as shown in Figure 8. As is clear from this figure, the variation width δ between the maximum and minimum values is greater when using the auxiliary yoke of the present invention (indicated by ◎) than when using a flat auxiliary yoke (indicated by ). It is clear that there are few

As is clear from the above explanation, by providing the auxiliary yoke in the solenoid of the present invention, not only the magnetic effect is improved and the holding current and power consumption can be reduced, but also the vicinity of the plunger guide insertion hole of the yoke can be made concave or convex. Even when deformed, a gap between the yoke and the auxiliary yoke can be prevented, magnetic resistance can be reduced, and efficiency can be further improved.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the gap generated between the yoke and the auxiliary yoke, Fig. 2 is a sectional view of an embodiment of the oil-immersed solenoid according to the present invention, and Fig. 3 is a diagram taken along the line - in Fig. 2. FIG. 4 is a sectional view of the auxiliary yoke, FIGS. 5 and 6 are sectional views showing modified examples of the arrangement of the auxiliary yoke, and FIG. 7 is a sectional view of the auxiliary yoke. Figure 8 shows the relationship between the thickness, excitation current, and power consumption. Figure 8 shows the range of current value variation among many products for solenoids using the auxiliary yoke of the present invention and solenoids using a flat auxiliary yoke. FIG. 1: Plunger guide, 2: Plunger, 5:
Coil winding, 6: Yoke, 10: Auxiliary yoke, 1
1: Slits.

Claims (1)

[Scope of utility model registration request] a plunger guide, a plunger movably inserted into the plunger guide, a coil winding provided outside the plunger guide, and a yoke surrounding the coil winding and forming a magnetic path. In an oil-immersed solenoid, the yoke is composed of a wound core made of a thin steel plate wound in multiple layers, and an auxiliary yoke is provided adjacent to the yoke around the plunger guide. An oil-immersed solenoid characterized by its inner periphery being slightly shifted in the axial direction with respect to the outer periphery.