JPH0121534Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an adsorption type solenoid that holds the movable yoke to the fixed yoke by configuring a magnetic circuit when the fixed yoke and the movable yoke are in contact with each other. This relates to the suction surface.

BACKGROUND ART Adsorption type solenoids, which hold a movable yoke to a fixed yoke using magnetic flux generated by passing a current through a coil wound around a fixed yoke, are used in various electrically controlled devices.

1A and 1B are a plan view and a side view of a conventionally used suction type solenoid, FIGS. 2A and 2B are explanatory diagrams of the operation when a force is applied to separate the suction surfaces, and 3 The figure shows the suction force when a force is applied perpendicular to the suction surface to separate the suction surfaces.
100, and is a characteristic diagram of the adsorption force when a force is applied at an angle of inclination to the adsorption surface.

In Fig. 1, the solenoid includes a fixed yoke 1 which is U-shaped and has flat suction surfaces 1a and 1b at both ends, a coil 2 wound around the fixed yoke 1, and suction surfaces 1a and 1b of the fixed yoke 1. It consists of a movable yoke 3 provided with a suction surface 3a that makes surface contact. The fixed yoke 1 is fixed to the chassis 5, and the movable yoke 3 is connected to another drive mechanism so that the suction surface 3a can move toward and away from the suction surfaces 1a and 1b of the fixed yoke 1. It will be done.

To explain the operation of such a suction type solenoid, when the movable yoke 3 approaches the fixed yoke 1 and the suction surface 3a contacts the suction surfaces 1a and 1b, or when the coil 2 is energized beforehand, the fixed yoke 1 The movable yoke 3 is attracted to the fixed yoke 1 by a magnetic circuit composed of the movable yoke 3 and the movable yoke 3, and is held in that state.

When both yokes 1 and 3 are in surface contact to form a magnetic circuit in this way, the force acting on the movable yoke 3 is relative to the force F perpendicular to the attraction surfaces 1a and 1b shown in Fig. 2a and b. Maximum adsorption power is demonstrated. However, depending on the mounting position of the movable yoke 3 or other connected components, forces F _A1 and F _A2 tilted in the width direction of the suction surfaces 1a and 1b (Fig. 2 a) are applied to the movable yoke 3.
As shown in curve A in Fig. 3, the larger the inclination angle, the more rapidly the adsorption force weakens, resulting in a force that is inclined in the thickness direction of the adsorption surfaces 1a and 1b (Fig. 2b).
When F _B1 and F _B2 act on the movable yoke 3, the attraction force becomes weaker as shown by curve B in FIG. This is because when the forces F _A1 , F _A2 and F _B1 , F _B2 act on the movable yoke 3, the points P ₁ to _{P 4} serve as fulcrums, and the attraction surface 3a of the movable yoke 3 and the fixed yoke 1 are attracted by the lever principle. The cause is that the surfaces 1a and 1b are separated.

Therefore, in order to increase the suction force, it is necessary to make the force acting on the movable yoke 3 perpendicular to the suction surfaces 1a and 1b. For this purpose, it was necessary to create a perpendicularity between the mounting surfaces of both yokes 1 and 3 and the suction surfaces 1a, 1b, and 3a. Also, when installing it on the chassis 5, it was necessary to check the perpendicularity in the same way. Furthermore, since the suction surfaces 1a, 3a, 1b, and 3a make surface contact to reduce magnetic resistance and increase the suction force, it is necessary to manage the end surfaces of the suction surfaces 1a, 1b, and 3a to prevent burrs and foreign matter from adhering to them. It was hot.
However, the machining accuracy of both yokes 1 and 3, and the chassis 5
Depending on the accuracy of mounting on the
This results in an error in the angle of inclination in degrees, and this structure has the disadvantage of resulting in a solenoid with large variations in adsorption force.

This idea was made in view of the above points, and the suction surface of the movable yoke is a curved surface that bulges in the thickness direction of the yoke, and the suction surfaces of the pair of fixed yokes are flat surfaces, so that the movable yoke and the movable yoke are fixed. The present invention provides a solenoid in which the yokes are in line contact and the attraction force is stable even when a force tilted in the thickness direction, where the attraction force fluctuates greatly, acts on the movable yoke.
This invention will be explained below based on the drawings.

FIG. 4 is a perspective view showing an embodiment of this invention, and FIG. 5 is an explanatory view.

The solenoid of this invention is the same as the conventional solenoid except that the suction surface 4a of the movable yoke 4 is an arcuate curved surface that projects toward the fixed yoke 1 in the thickness direction.

In the solenoid of this invention, the fixed yoke 1 is fixed to the chassis, the movable yoke 3 is connected to another drive mechanism, and the suction surfaces 1a, 1b, 4a of both yokes 1 and 4 are in contact with each other. By doing so, a magnetic circuit is constructed, and by energizing the coil 2, the movable yoke 4 is held on the fixed yoke 1.

However, in this invention, the suction surface 4a is curved in the thickness direction, so that the fixed yoke 4 is tilted by 1 to 3 degrees from the line perpendicular to the suction surfaces 1a and 1b shown by the dashed line and the dashed double dot line in FIG. Even if the movable yoke 3 is attached so that a force acts on it, the fulcrums P ₃ and P ₄ that would pull the movable yoke 3 apart shown in FIG. 2 do not occur. Therefore, the suction surfaces 1a, 1b and the suction surface 4a are in line contact, and the difference in suction force with respect to the inclination angle is reduced as shown by straight line C shown in FIG. Therefore, even if there is an error in the machining accuracy and mounting accuracy of both yokes 1 and 4, a solenoid with more stable suction force than before can be obtained. Furthermore, the operation of the drive mechanism connected to the movable yoke 4 can also be stabilized, and by using the solenoid of this embodiment, it is possible to promote appropriate operation of the equipment. Furthermore, in this invention, by making the suction surface of the movable yoke 4 a curved surface, ease of processing and prevention of quality deterioration can be achieved at the same time. That is, the suction surfaces 1a and 1b of the fixed yoke 1
Even if it is a curved surface, the suction surfaces 1a, 1b and the suction surface 4a
Line contact is achieved, but in this case, if the curvatures of the two suction surfaces 1a and 1b are not the same, suction stability will be impaired and the quality of the solenoid will be degraded. For this reason, the suction surface 1a,
Making the 1b side a curved surface requires high-precision machining and makes it difficult to maintain quality, but by making the suction surface 4a a curved surface, these problems are solved and curved surface machining becomes easy. .

The radius of the arc is determined in consideration of adsorption force, permeance, etc. Moreover, the curved surface does not have to be a circular arc.

As explained above, in the solenoid of this invention, the suction surface of the movable yoke is a curved surface that bulges in the thickness direction of the yoke, and the suction surfaces of the pair of fixed yokes are flat surfaces, so that the movable yoke and the fixed yoke are in line contact. This eliminates the need for strict machining accuracy of each component, eliminates the need for post-assembly adjustments, stabilizes the suction force, and allows manufacturing at low cost. By making the suction surface on the movable yoke side a curved surface, there is also the effect that the curved surface can be easily processed.

[Brief explanation of the drawing]

Figures 1a and b are plan and side views of a conventional solenoid, Figures 2a and b are explanatory diagrams, Figure 3 is a characteristic diagram, and Figure 4 is a perspective view of an embodiment of this invention.
FIG. 5 is an explanatory diagram. In the figure, 1 is a fixed yoke, 1a and 1b are suction surfaces,
2 is a coil, 4 is a movable yoke, and 4a is an attraction surface.

Claims (1)

[Claims for Utility Model Registration] A pair of suction surfaces formed on the open end side of a U-shaped fixed yoke around which a coil is wound and attached to the chassis, and directions in which they approach and separate from the pair of suction surfaces. The movable yoke is movable as shown in FIG. In the solenoid that is held by a fixed yoke, the movable yoke's suction surface is an arcuate curved surface that bulges in the thickness direction of the yoke, and the fixed yoke's pair of suction surfaces are flat surfaces. A solenoid characterized in that when an excitation current is supplied to a coil, an attraction surface of the movable yoke and an attraction surface of the fixed yoke are attracted and held in line contact.