JPH073603Y2 - Plunger solenoid - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention is provided with a movable magnetic core movably in a coil.
The present invention relates to a plunger solenoid in which a movable magnetic core is attracted into the coil by energizing the coil.

"Prior Art" Fig. 4 shows a conventional plunger solenoid.

A coil 12 is wound around the bobbin 11, and a fixed magnetic core 13 is inserted and fixed in one end of the bobbin 11. A movable magnetic core 14 made of, for example, an iron core is inserted into the bobbin 11 from the other end of the bobbin 11 so as to be movable along the axis. A magnetic yoke 15 is provided that passes through the outside of the coil 12 and connects the fixed magnetic core 13 and the vicinity of the peripheral surface of the movable magnetic core 14. The magnetic yoke 15 is composed of, for example, a U-shaped portion 15a and an end plate 15b connecting between both legs of the U-shaped portion 15a. The protrusion of the fixed magnetic core 13 is inserted and caulked and fixed in the hole formed in the intermediate connecting portion of the character portion 15a. A hole 16 through which the movable magnetic core 14 is passed is formed in the end plate 15b. Non-magnetic bearing 17 on the inner surface of bobbin 11
Is embedded.

When a current is passed through the coil 12, the magnetic flux generated therethrough passes through a closed magnetic circuit consisting of the fixed magnetic core 13-magnetic yoke 15-movable magnetic core 14-fixed magnetic core 13, and the movable magnetic core 14 is magnetically attracted to the fixed magnetic core 13. It

[Problems to be Solved by the Invention] By reducing the magnetic gap between the movable magnetic core 14 and the inner peripheral surface of the hole 16 as much as possible, the magnetic resistance against the magnetic flux is reduced. An attractive force acts between the end plate 15b and the end plate 15b, which acts as a resistance against the movement of the movable magnetic core 14 and causes a mechanical loss in the attractive force of the movable magnetic core 14 into the coil 12.

[Means for Solving the Problem] According to the present invention, an auxiliary yoke made of a ring-shaped magnetic body is coaxially attached to the movable magnetic core on the outer surface of the end plate, and the inner diameter of the auxiliary yoke corresponds to that of the hole of the end plate. Larger than diameter. The collar of the magnetic material is fixed to the movable magnetic core, and the outer diameter of this collar is slightly smaller than the inner diameter of the auxiliary yoke.When the movable magnetic core is in contact with the fixed magnetic core, the magnetic gap between the collar and the end plate has Is smaller than the magnetic air gap between the inner peripheral surface of and the outer peripheral surface of the movable magnetic core.

"Embodiment" FIGS. 1 and 2 show the embodiments of the present invention by assigning the same reference numerals to the portions corresponding to those in FIG. In this device, the end plate 15
On the outer surface of b, an auxiliary yoke 21 made of a ring-shaped magnetic material coaxial with the hole 16 is brought into contact with and fixed by, for example, a screw 22. The inner diameter of the auxiliary yoke 21 is larger than the diameter of the hole 16. A collar 23 of a magnetic material is fixed to the movable magnetic core 14. Brim 23
The outer diameter of is smaller than the inner diameter of the auxiliary yoke 21. While the movable magnetic core 14 is in contact with the fixed magnetic core 13, the end plate 15b and the collar 23 are determined from the distance between the inner peripheral surface of the hole 16 and the outer peripheral surface of the movable magnetic core 14.
The distance between the end plate 15b and the brim 23 is smaller.
Make sure that and are in contact with each other.

In this configuration, when a current is applied to the coil 12, the collar 23 is in the initial state and the collar 23 is in the initial state, as shown in FIG. 3A.
On the other hand, it is located on the outer side in the axial direction and is approaching,
The magnetic flux 24 passes through the gap between the auxiliary yoke 21 and the collar 23, and mainly acts to attract the collar 23 into the auxiliary yoke 21 in this gap and to move the movable magnetic core 14 closer to the fixed magnetic core 13. The magnetic attraction between the fixed magnetic core 13 and the movable magnetic core 14 is the same as in the conventional case.

When the brim 23 enters the auxiliary yoke 21, as shown in FIG. 3B, the magnetic flux 24 passes through the gap between the inner peripheral surface of the auxiliary yoke 21 and the outer peripheral surface of the brim 23, and the movable magnetic core is moved in the same manner as in the conventional case. Although it acts to attract 14 in the direction perpendicular to the moving direction, the gap between the end plate 15b and the collar 23 also becomes small, and the magnetic flux also passes through this gap,
The attraction force also acts between the end plate 15b and the brim 23, and the movable magnetic core 14
, The force applied to the movable magnetic core 14 in the direction perpendicular to its moving direction is smaller than in the conventional case. From this point, it is preferable to make the facing area between the end plate 15b and the collar 23 as large as possible.

When the movable magnetic core 14 is further sucked, as shown in FIG. 3C, the distance between the end plate 15b and the collar 23 becomes small, the magnetic flux 24 mainly passes through this distance, and the attractive force between them becomes strong. The force applied to the movable magnetic core 14 in the direction perpendicular to its moving direction becomes almost zero.

[Advantage of the Invention] As described above, according to the present invention, the distance between the inner peripheral surface of the hole 16 and the outer peripheral surface of the movable magnetic core 14 is made larger than before.
By providing the auxiliary yoke 21 and the collar 23, the coil
The magnetic resistance of the magnetic circuit against the magnetic flux generated when a current is applied to 12 is not made larger than before, but the attraction force applied to the movable magnetic core 14 in the direction perpendicular to the moving direction is smaller than before, and it is movable as much. The magnetic core 14 becomes easy to move, and the axial attractive force generated between the auxiliary yoke 21 and the collar 23 and the axial attractive force generated between the end plate 15b and the collar 23 are fixed and movable. In addition to the attractive force between the magnetic core 14,
The suction force is improved as compared with the conventional one. According to the configuration shown in FIG. 1, the moving length of the movable magnetic core is 3 mm and the attraction force is improved by 30% as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
FIG. 3 is a right side view of the drawing, FIG. 3 is a view showing a changing state of a magnetic flux passage between the end plate 15b, the auxiliary yoke 21 and the collar 23 when attracting the movable magnetic core in the embodiment of FIG. 1, and FIG. It is sectional drawing which shows a solenoid.

Claims (1)

[Scope of utility model registration request] 1. A coil, a fixed magnetic core arranged at one end of the coil, a movable magnetic core inserted into the coil from the other end so as to be movable along the axis of the coil, and one end of the fixed magnetic core. A magnetic yoke having an end plate connected to a magnetic core and having the other end facing the other surface of the coil and having a hole through which the movable magnetic core passes, and a magnetic yoke projecting from the outer surface of the end plate of the magnetic yoke. An auxiliary yoke made of a ring-shaped magnetic body having an inner diameter larger than that of the hole and having a coaxial center therewith, and an outer yoke made of a magnetic material having an outer diameter slightly smaller than the inner diameter of the auxiliary yoke and having a diameter larger than the hole, A collar fixed to the movable magnetic core, and, in a state where the movable magnetic core is in contact with the fixed magnetic core, a distance between the end plate and the collar based on a distance between the peripheral surface of the movable magnetic core and the inner surface of the hole. Plunger is characterized by being small Isoprenoid.