JPH0715849B2 - AC electromagnet - Google Patents

Description

TECHNICAL FIELD The present invention relates to an alternating current electromagnet, and more particularly to a technique suitable for reducing the power consumption and downsizing of the alternating current electromagnet.

[Conventional technology]

For example, in an electromagnetic valve used in a fluid pressure circuit or the like, an AC electromagnet is generally used to drive a valve body from the viewpoint of easy availability of a power source and components.

By the way, in electromagnets used for such applications, in order to reduce noise and pulsation of attractive force due to beating during operation, the fixed column and valve element that are installed facing each other inside the solenoid are driven. It is known to attach a rake coil to the opposite end of a plunger or the like.

[Problems to be solved by the invention]

In the conventional design of the shading coil, the ratio of the area inside the shading coil to the area outside the shading coil is theoretically estimated, and even the factor that determines the performance is not clear.

In particular, when one side of the plunger is displaced in the axial direction by the biasing force of the spring, it is necessary to set the magnetomotive force of the solenoid larger so that the minimum value of the pulsating suction force exceeds the biasing force of the spring. Therefore, the pulsation of the suction force causes the solenoid, that is, the solenoid valve as a whole to become large in size and to increase the power consumption.

Therefore, it is an object of the present invention to provide an electromagnet capable of increasing the minimum value of the pulsating attraction force to reduce power consumption and size.

[Means for solving problems]

The AC electromagnet of the present invention includes a solenoid to which AC power is applied, a fixed column having one end inserted into the solenoid, and a plunger which is inserted into the solenoid so as to face the fixed column and is axially displaceable. And a ring-shaped decoupling coil disposed in a groove formed at at least one of the fixed column and the opposite end of the plunger, the axial direction of which is set in the passage direction of the magnetic flux, and the axial length dimension of the decoupling coil. Has a structure in which the width dimension in the radial direction is set to 3 times or more and 15 times or less.

[Action]

An experiment was conducted on the factors that determine the performance of the shading coil, and it was found that the volume of the shading coil is important.

That is, according to the study by the present inventors, in an annular shading coil whose axial direction is set in the magnetic flux passing direction, the axial length dimension of the shading coil is 3 times or more and 15 times the radial width dimension. It has been clarified that the minimum value of the pulsating suction force can be maximized by setting the ratio to the following, preferably about 10 times.

As a result, it is not necessary to set the magnetomotive force of the solenoid to an unnecessarily large value for the purpose of, for example, making the minimum value of the pulsating suction force exceed the urging force of the spring that drives the plunger. Further, it is possible to realize miniaturization by reducing the number of turns of the solenoid conductor wire.

[Embodiment 1] FIG. 1 is an enlarged sectional view showing a main part of an AC electromagnet according to an embodiment of the present invention, and FIG. 2 shows an AC electromagnetic valve equipped with the AC electromagnet of the present embodiment. It is sectional drawing which shows an example.

As shown in FIG. 2, the alternating current electromagnetic valve includes an alternating current electromagnet M.
And a valve body V.

First, in the AC electromagnet M, the upper yoke 2 and the lower yoke 3 are provided at the upper and lower ends of the outer yoke 1 made of a magnetic material, and the space surrounded by the outer yoke 1, the upper yoke 2, and the lower yoke 3 is formed. Inside, a solenoid 5 composed of a conductor wire (not shown) wound around the bobbin 4 is housed.

A plunger 6 made of a magnetic material that is displaceable in the axial direction and a fixed column 7 having an outer end fixed to the upper yoke 2 are inserted in the axial direction of the solenoid 5 so as to face each other. The outer end portion of the penetrating through the lower yoke 3 projects.

A groove portion 7a having a circular section in the axial direction is bored at an end of the fixed column 7 facing the plunger 6, and a shading coil S is coaxially attached to the fixed column 7 inside the groove 7a. ing.

In this case, as shown in an enlarged view in FIG. 1, the axial length dimension L of the shading coil S is substantially equal to the radial width dimension W.
It is set to be 10 times.

On the other hand, the valve body V is connected to the lower yoke 3 side, and a valve body chamber 8 for accommodating the protruding end of the plunger 6 is formed between the valve body V and the lower yoke 3. There is.

A packing 8a is provided at a connecting portion between the valve body V and the lower yoke 3 so as to surround the valve body chamber 8 to prevent fluid inside the valve body chamber 8 from leaking to the outside. There is.

An inlet port 9 and an outlet port 10 communicating with the valve body chamber 8 are formed inside the valve body V.

The inner end of the inlet port 9 is opened in the wall surface of the fluid chamber 8 facing the center of the end face of the plunger 6, and a valve seat 9a is provided around the opening.

Inside the end face of the plunger 6 facing the valve seat 9a, a different diameter hole 6a is bored in the axial direction.

A valve body 11 having a different diameter is housed in the large diameter portion of the different diameter hole 6a so as to be displaceable in the axial direction of the plunger 6.
Is a valve spring 11a provided in the small diameter portion of the different diameter hole 6a on the rear side.
Thus, the end surface of the plunger 6 is constantly biased in the direction of approaching the valve seat 9a.

The axial displacement of the valve element 11 housed in the different diameter hole 6a of the plunger 6 is set smaller than the stroke of the plunger 6, that is, the gap between the plunger 6 and the fixed column 7, and the plunger 6 is fixed. The valve body 11 is disengaged from the valve seat 9a by being displaced to the position where it abuts on the column 7.

Further, an enlarged diameter portion 6b is formed on the outer end portion of the plunger 6, and a valve body 11 is provided between the enlarged diameter portion 6b and the end surface of the lower yoke 3 via the plunger 6. A return spring 12 that constantly urges in the direction of closely contacting with is provided.

The operation of this embodiment will be described below.

First, in a state where the solenoid 5 is not energized, a magnetic field is not formed inside the solenoid 5, so that no attraction force is generated between the fixed column 7 and the plunger 6, and the plunger 6 is urged by the urging force of the return spring 12. Is urged toward the valve seat 9a and is housed in the end face of the plunger 6
The valve spring 11a and the return spring 12 bias the valve seat 11a against the valve seat 9a so that the inlet port 9 and the outlet port 10 are shut off and the solenoid valve is closed as shown in FIG.

Next, when the solenoid 5 is energized from an AC power supply (not shown), the AC current is passed inside the solenoid 5 through the inside and outside of the shading coil S mounted on the fixed column 7 to penetrate the plunger 6 in the axial direction. A magnetic flux that changes with time depending on the frequency of the power supply is formed.

Therefore, as shown in FIG. 3 (b), the suction force F pulsating between the maximum value F _P and the minimum value F _V acts on the fixed column 7 and the plunger 6, and the suction force By F, the plunger 6 is attracted and moved toward the fixed column 7 against the biasing force of the return spring 12, the valve body 11 housed in the plunger 6 is separated from the valve seat 9a, and the inlet port 9 is fluidized. Fluid such as compressed air, which is communicated with the outlet port 10 via the chamber 8 and acts on the inlet port 9, is supplied to the outlet port 10 side.

In order to drive the valve body 11 by the plunger 6 which is displaced against the biasing force of the return spring 12, the minimum value F _V of the pulsating suction force F is made larger than the biasing force of the return spring 12. However, in this embodiment, since the axial length L of the shading coil S is set to be 10 times the radial width W, the suction power is the same with the same AC power. The minimum value F _V of F can be maximized.

That is, as shown in FIG. 3 (a), when the ratio L / W of the axial length dimension L and the radial width dimension W of the shading coil S is approximately 10, the pulsating suction force F It has been found that the minimum value F _V is the maximum.

Thus, for example, the magnetomotive force of the solenoid 5 needs to be set larger than necessary for the purpose of, for example, making the minimum value F _V of the pulsating suction force F exceed the urging force of the return spring 12 that drives the plunger 6. Therefore, it is possible to realize the downsizing by reducing the power consumption and the number of windings of the conducting wire of the solenoid 5.

Further, the ratio L / W of the length dimension L and the width dimension W may be practically 3 or more and 15 or less, and particularly, if set in the range of 5 or more and 15 or less, good performance can be obtained. It turns out that you can.

[Embodiment 2] FIG. 4 is an enlarged sectional view showing a main part of an AC electromagnet M which is another embodiment of the present invention.

In the case of this embodiment, the shading coils S ₁ and S ₂ are separately arranged in the groove portion 7a formed in the fixed column 7 and the groove portion 6c formed in the plunger 6, and the shading coils S ₁ and S ₂ are arranged.
The sum of the lengths L ₁ and L ₂ in the respective axial directions is approximately 10 times the width W in the radial direction.

Therefore, as in the case of the first embodiment, the fixed column 7
Therefore, the minimum value F _V of the suction force F acting on the plunger 6 can be maximized, and the depth dimension of the groove portion 7a and the groove portion 6c to be formed in both the fixed column 7 and the plunger 6 can be reduced. There is an effect that the groove portions 7a and 6c can be easily formed.

[Embodiment 3] FIG. 5 is an enlarged sectional view showing a main part of an AC electromagnet M which is still another embodiment of the present invention.

In the case of the third embodiment, a different diameter hole 7b is formed coaxially in the axial direction at the opposite end of the fixed column 7, and a pin 7c is press-fitted into the small diameter portion of the different diameter hole 7b. The shading coil S is attached to the groove portion 7d formed by the outer circumference of the pin 7c and the inner circumference of the large diameter portion of the different diameter hole 7b.

Also in this case, as in the case of the second embodiment, there is an effect that the groove portion 7d for accommodating the elongated shading coil S can be easily formed in the fixed column 7.

[Embodiment 4] FIG. 6 is an enlarged cross-sectional view showing a main part of an AC electromagnet M which is still another embodiment of the present invention.

In the case of the fourth embodiment, the reduced diameter portion 7e is coaxially formed at the end portion of the fixed column 7 facing the plunger 6, and the fixed column 7 is press-fitted into the pipe body 7f to form the pipe body 7f. The shading coil S is attached to the groove portion 7g constituted by the inner periphery of the above and the outer periphery of the reduced diameter portion 7e.

Also in the case of the present embodiment, as in the case of the third embodiment, there is an effect that the groove portion 7g for accommodating the shading coil S can be easily formed.

〔The invention's effect〕

(1). A solenoid to which AC power is applied, a fixed column having one end inserted into the solenoid, a plunger inserted into the solenoid so as to face the fixed column, and axially displaceable, and the fixed column. And an annular shading coil disposed in a groove formed on at least one of the opposite ends of the plunger and having an axial direction set in the magnetic flux passage direction, and the axial length dimension of the shading coil is a diameter. Since it is set to be 3 times or more and 15 times or less of the width dimension in the direction, for example, by making the axial length dimension of the shading coil approximately 10 times the radial dimension, the pulsating suction force can be reduced. The minimum value can be maximized.

As a result, it is not necessary to set the magnetomotive force of the solenoid to an unnecessarily large value for the purpose of, for example, making the minimum value of the pulsating suction force exceed the urging force of the spring that drives the plunger. Miniaturization can be realized by reducing the number of turns of the solenoid conductor wire.

(2). Since the shading coils are distributed and provided on both the fixed column and the plunger, the depth of the groove portion to be formed on both the fixed column and the plunger becomes small, and the machining becomes easier.

(3). At the end of the fixed column facing the plunger,
Different diameter holes are bored coaxially in the axial direction, and the pin is press-fitted into the small diameter part of the different diameter hole, and in the groove formed by the outer circumference of the pin and the inner circumference of the large diameter part of the different diameter hole. By mounting the shading coil, it is possible to easily form the groove portion as compared with the case of directly processing.

(4). At the end of the fixed column facing the plunger,
Since the reduced diameter portion is formed coaxially, the fixed column is press-fitted into the pipe body, and the kumadori coil is attached to the groove portion formed by the inner periphery of the pipe body and the outer periphery of the reduced diameter portion, thereby directly It is possible to easily form the groove portion as compared with the case where the groove portion is processed.

(5). As a result of the above items (1) to (4), it is possible to realize downsizing of an AC electromagnetic valve equipped with an AC electromagnet and reduction of manufacturing cost.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view showing a main part of an AC electromagnet which is an embodiment of the present invention, FIG. 2 is a cross-sectional view showing an example of an AC electromagnetic valve equipped with the AC electromagnet of the present invention, and FIG. FIG. 4 is a diagram for explaining the operation of one embodiment of the present invention, FIG. 4 is an enlarged cross-sectional view showing a main part of an AC electromagnet which is Embodiment 2 of the present invention, and FIG. 5 is an AC which is Embodiment 3 of the present invention. FIG. 6 is an enlarged cross-sectional view showing the main parts of the electromagnet, and FIG. 6 is an enlarged cross-sectional view showing the main parts of the AC electromagnet that is Embodiment 4 of the present invention. 1 ... Outer yoke, 2 ... Upper yoke, 3 ... Lower yoke, 4 ... Bobbin, 5 ... Solenoid, 6 ... Plunger, 6a ... Different diameter hole, 6b ... Expanded portion, 6c ... … Groove, 7 ……
Fixed column, 7a ... groove, 7b ... different diameter hole, 7c ... pin,
7d ... groove, 7e ... reduced diameter, 7f ... tube, 7g ... groove,
8 ... Valve chamber, 8a ... Packing, 9 ... Inlet port, 9a
…… Valve seat, 10 …… Outlet port, 11 …… Valve disc, 11a …… Valve spring, 12 …… Return spring, S …… Kumae coil, M …… AC electromagnet, V …… Valve body, L, L ₁ , L ₂ …… Length of the shading coil, W …… Width of the shading coil.

Claims (6)

[Claims] 1. A solenoid to which AC power is applied, a fixed column having one end inserted into the solenoid, and a plunger which is inserted into the solenoid so as to face the fixed column and is displaceable in the axial direction. And an annular decoupling coil disposed in a groove formed in at least one opposing end of the fixed column and the plunger, the axial direction of which is set in the passage direction of the magnetic flux, in the axial direction of the decoupling coil. An alternating-current electromagnet having a length dimension set to be 3 times or more and 15 times or less the width dimension in the radial direction. 2. The AC electromagnet according to claim 1, wherein the length dimension in the axial direction of the shading coil is set to be approximately 10 times the width dimension in the radial direction. 3. The AC electromagnet according to claim 1, wherein the shading coils are provided in a distributed manner on both the fixed column and the plunger. 4. A different diameter hole is coaxially bored at an end of the fixed column facing the plunger, and a pin is press-fitted into a small diameter portion of the different diameter hole. 2. The AC electromagnet according to claim 1, wherein the shading coil is mounted in a groove portion formed by the outer circumference of the pin and the inner circumference of the large diameter portion of the different diameter hole. 5. A reduced diameter portion is coaxially formed at an end of the fixed column facing the plunger, and
The fixed column is press-fitted into a tubular body, and the kumad coil is attached to a groove portion formed by an inner circumference of the tubular body and an outer circumference of the reduced diameter portion. AC electromagnet described. 6. The AC electromagnet according to claim 1, which is mounted on an AC electromagnetic valve.