JPH04208504A - Electromagnet - Google Patents

Abstract

PURPOSE:To simplify structure, to reduce cost and to operate an electromagnet safely by mounting two-piece yokes, to which a non-magnetic substance is fast stuck and held, and forming a pair of magnetic poles to the yokes. CONSTITUTION:Since the yoke 14 of an electromagnet 10 is divided into two sections and each of the yoke 14 forms a pair of magnetic poles adjacent to an armature 6, a magnetic path is formed between the electromagnet 10 and the armature 6, and the coil sections 12 of the electromagnet 10 can be disposed outside a valve body without using a bellows. Accordingly, a flow rate can be controlled by small currents while the exposure of the coil sections 12 to a fluid atmosphere is prevented easily even when a seal section is reduced, and safety at a time when a fluid having combustibility and corrosiveness is employed is improved at low cost.

Description

[Detailed Description of the Invention] [Industrial Application Fields] The present invention is suitable for electromagnetic application equipment such as solenoid valves and electromagnetic actuators used in special environments such as flammable or corrosive environments or in vacuum. Regarding electromagnets.

[Prior Art] As an example of such an electromagnet-applied device, a conventionally used flow control valve is shown in FIGS. 3 and 4. Third
The flow control valve shown in the figure is a so-called plunger type.
A coil bobbin 21 around which a solenoid 20 is wound is attached to a core 22 by a fastening member such as a bolt (not shown),
The core 22 and the body 23 are also joined by a fastening member such as a bolt (not shown). Further, an armature 24 having a shaft that is slidable along the center hole of the coil bobbin 21,
It is biased toward the nozzle 26 by a compression spring 25 .

Note that the core 22 and armature 24 are made of magnetic material. When current is applied to the solenoid 20 in this flow control valve, a magnetic path is formed in the direction of the arrow in the figure, and the armature 24 is attracted against the compression coil spring 25, but by changing the current value, The gap between the armature 24 and the nozzle 26 changes, and fluid flows from inside the nozzle 26 into the space surrounded by the body 23 and the core 22.

In addition, in the flow control valve shown in FIG. 4, the armature 40 is pulled in the direction of the nozzle 42 by the force of the bellows 41 to retract, and the electromagnet has a coil 44 wound around a core 43.
It has a structure in which it is mounted inside the yoke 45. Note that the armature 40, core 43, and yoke 45 are made of magnetic material.

In this flow control valve, by passing current through the coil 44, a magnetic path is formed in the direction of the arrow in the figure, and by changing the current value, the gap between the armature 40 and the nozzle 42 is changed, and from the nozzle 42 to The fluid flow rate flowing into the bellows 41 is controlled.

[Problem to be solved by the invention] When using electromagnet-applied equipment such as solenoid valves and electromagnetic actuators in flammable or corrosive environments or in vacuum, if the coil is exposed to these environments, the coating of the electromagnet may be damaged. It may corrode or obstruct the vacuum, and in some cases there is a risk of fire or explosion. Therefore, it is necessary to isolate the coil from these atmospheres.

For example, in the flow control valve shown in FIG. 3, the space surrounded by the core 22 and the body 23 is filled with fluid, but the coil pobbin 21 and the core 22 are connected to O2 so that the solenoid 20 is not exposed to the atmosphere of this fluid. The body 23 and the core 22 are also hermetically joined by an O-ring 29. Therefore, O-ring grooves must be formed in the body 23, coil bobbin 21, and core 22, which makes assembly difficult, resulting in high cost and large size.

In addition, in the flow control valve shown in FIG. 4, the nozzle 42 is located inside the bellows 41, so the coil 44 is not exposed to the fluid atmosphere, but since the bellows 41 is used, it is expensive and the flow control valve is Therefore, the disadvantage is that the current flowing through the coil also increases.

The present invention was devised to eliminate the above-mentioned drawbacks of the prior art, and has a simple and inexpensive structure without exposing the coil to flammable or corrosive environments or environments such as vacuum. The purpose is to provide electromagnets that operate safely.

[Means for Solving the Problems] In order to solve the above problems, the electromagnet of the present invention has a two-part yoke that tightly sandwiches a non-magnetic material, and the yoke forms a pair of magnetic poles. By dividing the yoke into two parts and tightly sandwiching a non-magnetic material, the coil part is isolated from a harmful atmosphere, and it also functions as an electromagnet.

[Function] In the electromagnet of the present invention, the yoke is divided into two parts, each of which forms a pair of magnetic poles with a non-magnetic material tightly sandwiched between them, so that the coil part can be isolated in a different environment from the yoke. However, a magnetic path is formed and it acts as an electromagnet.

[Example] An example in which the electromagnet of the present invention is used in a flow control valve will be described with reference to FIGS. 1 and 2.

FIG. 1 is a sectional view taken along line CC in FIG. 2 of an embodiment of a flow control valve using an electromagnet of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. 1. The valve body is valve body block B
1 and a valve body block B2, the valve body block B2
A fluid flow path 1 is formed on the upper surface of the holder, and extends from left to right in FIG. The valve body block B1 and the valve body block B2 are airtightly connected by enclosing an O-ring 2 and fastening a bolt 3. Valve block B
A leaf spring 4 is supported in a cantilever manner by a bolt 5 in the fluid passage 1 of No. 2, and an armature 6 is attached to the tip of the leaf spring 4. The leaf spring 4 and the armature 6 constitute a flapper 7. A nozzle 8 is attached to the valve body block B, and the tip of the nozzle 8 is disposed close to the upper surface of the leaf spring 4. The electromagnet 10 that attracts the flapper 7 has a pair of coils 12 wound around the flange 11 in the same direction.
is held between the plate 13 and the yoke 14, and the pole piece 15 is passed through and fastened to the valve body block B2. At that time, the valve body block B2 is inserted through the O-ring 16.
is hermetically sealed by the yoke 14, so that the coil 12 is completely isolated from the fluid atmosphere. Also,
The yoke 14 has a three-layer structure sandwiched between an insulating plate 17 made of copper or the like for shielding magnetism. Note that the portions of the pole piece 15, plate 13, and yoke 14 other than the insulating plate 17 are made of magnetic material.

Next, to explain the operation of this flow control valve, when a power supply (not shown) sends current in opposite directions to the left and right coils 12, a magnetic path is formed in the direction of the arrow in FIG. It gets sucked in. As a result, the gap between the leaf spring 4 and the nozzle 8 widens, and the amount of fluid ejected from the nozzle 8 into the fluid passage 1 increases. The amount of fluid ejected changes depending on the amount of current flowing through the coil 12. The fluid ejected into the fluid passage 1 flows out through the discharge passage 17.

In the above embodiment, the insulating plate 17 is soldered, but a rubber sheet or the like may be attached. Also, although two coils are used, one may be used. In addition, we have described a flapper in which the armature is attached to a cantilever-supported leaf spring, but what kind of shape can the armature be elastically supported by an elastic body such as a spring, such as a flapper in which the armature is attached to a coil spring? You may also use a flapper.

Further, the flow control valve using the electromagnet of the present invention has the following effects. In other words, the yoke of the electromagnet is divided into two parts, each forming a pair of magnetic poles close to the armature, so a magnetic path is formed between the electromagnet and the armature, without using a bellows. It becomes possible to arrange the coil portion of the electromagnet outside the valve body. As a result, it is possible to control the flow rate with a small amount of current, and even with fewer seals, it is easier to prevent the coil part from being exposed to the fluid atmosphere, making it easier to prevent the use of flammable or corrosive fluids. Safety can be improved at low cost.

In addition, although the above-mentioned example explained the case where the electromagnet of this invention was used for a flow control valve, for example, a stage is attached to an armature, the stage is housed in a vacuum chamber,
It is also possible to use the electromagnet of the present invention as an actuator for driving a stage or as a solenoid valve for switching the flow path of a conductive fluid, so that the coil part and the yoke cannot be placed in the same environment. It is used in all types of electromagnet application equipment.

[Effects of the Invention] The electromagnet of the present invention has the following effects. That is,
In the electromagnet of the present invention, the yoke is divided into two parts, each of which forms a pair of magnetic poles with a non-magnetic material tightly sandwiched between them, so even if the coil part is isolated in a different environment from the yoke, it will remain magnetic. A channel is formed and acts as an electromagnet. Moreover,
The coil is not exposed to flammable or corrosive environments or vacuum environments, the coil is protected from harmful environments in the vicinity of the yoke, and the structure is simple, inexpensive, and operates safely.

[Brief explanation of the drawing]

1 and 2 show an embodiment of a flow control valve using an electromagnet of the present invention, FIG. 1 is a sectional view taken along the line C-C in FIG. 2, and FIG. 2 is a sectional view taken along the line A-A in FIG. FIG. Figure 3 is a sectional view showing a flow control valve using a conventional electromagnet.
FIG. 4 is a sectional view showing another conventional flow control valve using an electromagnet. Bl, B2: Valve body block, 4: Leaf spring 6: Armature, 7: Flapper 8: Nozzle, 10: Electromagnet, 12: Coil 14: Yoke, 17: Insulating plate 2'3 Y Figure 10 Electromagnetic force 2 Figure 17. 4 points; 16 /37° Lehr'! 10 layers h'fh Figure 3

Claims (1)

[Claims] An electromagnet comprising a two-part yoke that tightly sandwiches a non-magnetic material, the yoke forming a pair of magnetic poles.