JPH0353095Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a solenoid valve, and particularly to a solenoid valve suitable for switching and controlling a flow path of a fluid such as compressed air.

[Conventional technology]

For example, the following structures are generally known as electromagnets used in electromagnetic valves that switch and control pressurized fluid acting on fluid pressure operated devices.

In other words, a solenoid consisting of a conductor wound around a hollow bobbin has a fixed column whose axial displacement is fixed from both ends, and a valve body which is movable in the axial direction and is locked at the outer end. A plunger is inserted and opposed to each other at a predetermined interval, and the plunger is provided with a spring that biases the plunger in a direction to project the plunger to the outside of the solenoid.

When the solenoid is energized, a magnetic field is generated inside the solenoid to generate an attractive force between the opposing fixed column and the plunger,
By displacing the plunger in a direction to draw it into the inside of the solenoid, and when the solenoid is de-energized, the plunger is caused to perform a return operation in which the plunger is projected by the urging force of the spring. The opening/closing operation of the channel is performed by the displacement of the body.

[Problem that the invention attempts to solve]

By the way, in conventional electromagnets with the above structure, the stroke of the plunger is regulated by the contact position with respect to the fixed column, so in order to increase the stroke, the gap between the plunger and the fixed column must be set large. There is a need.

However, in principle, the thrust force obtained from the plunger is inversely proportional to the square of the gap between the plunger and the fixed column, so in order to increase the stroke while maintaining the thrust force at a predetermined value, it is necessary to increase the number of turns of the conductive wire that makes up the solenoid. It is necessary to increase the magnetomotive force of the solenoid by increasing the current value or by increasing the current value, which inevitably leads to problems such as increased external dimensions and power consumption.

An object of the present invention is to provide a solenoid valve equipped with an electromagnet that can increase at least one of the stroke and thrust of a plunger without increasing external dimensions or power consumption.

[Means for solving problems]

The solenoid valve of the present invention includes a solenoid located in a yoke, a plunger inserted into the solenoid so as to be freely displaceable in the axial direction, one end facing the plunger and inserted into the solenoid in the axial direction, and an end face of the solenoid. An electromagnet is constructed of a movable column that can be freely displaced between the yoke and the yoke.

[Effect]

According to the above-described means, the stroke of the plunger is divided into the gap between the plunger and the movable column inside the solenoid and the gap between the movable column and the yoke outside the solenoid, resulting in an increase in external dimensions and power consumption. Without,
At least one of the stroke or thrust of the plunger can be increased.

〔Example〕

FIG. 1 is a sectional view showing an example of a solenoid valve according to an embodiment of the present invention, and FIG. 2 is a sectional view showing an example of an electromagnet used in the solenoid valve of this embodiment.

As shown in FIG. 2, a cylindrical outer yoke 1 constituting an electromagnet M, an upper yoke 2 and a lower yoke 3 respectively fixed to the upper and lower ends of the outer yoke 1
Inside the space surrounded by the bobbin 4a
A solenoid 4 consisting of a conductive wire 4b wound around the bobbin 4a is housed in the lower yoke 3 in a locked state.

In the internal axial direction of the solenoid 4, from both ends,
Plunger 5 made of a magnetic material that can be freely displaced in the axial direction
and movable column 6 are inserted facing each other, and when the solenoid 4 is de-energized, there is a predetermined gap.
_l1 , and one end of the plunger 5 passes through the lower yoke 3 and projects to the outside.

In this case, the movable column 6 is movable in the axial direction of the solenoid 4, and a flange portion 6a having a diameter larger than the inner diameter of the bobbin 4a of the solenoid 4 is integrally formed at the outer end of the movable column 6. It is formed.

Then, the movable column 6
Inward displacement of the bobbin 4a is regulated, and a gap l ₂ is created between the large diameter portion 6a of the movable column 6 and the upper yoke 2 with the large diameter portion 6a in contact with the solenoid 4 side. is formed, and the movable column 6 can be displaced in the axial direction of the solenoid 4 by this gap _l2 .

In addition, the gap l ₁ between the plunger 5 and the movable column 6 inside the solenoid 4 is approximately equal to the gap l ₂ between the large diameter portion 6a of the movable column 6 and the upper yoke 2, and A spring 7 (biasing means) is interposed between the large diameter portion 6a and the upper yoke 2, and the movable column 6 moves in the direction of bringing the large diameter portion 6a into close contact with the end face of the solenoid 4.
That is, it is always biased in the direction of entering the inside of the solenoid 4.

Such a solenoid valve V incorporating an electromagnet M
is shown in FIG.

As shown in the figure, a valve body 8 is attached to the lower yoke 3 side of the electromagnet M, and the outer end of the plunger 5a is accommodated between the valve body 8 and the lower yoke 3. A valve body chamber 8a is formed.

A packing 8b is interposed at the connection between the valve body 8 and the outer yoke 1 so as to surround the valve body chamber 8a, and prevents the fluid inside the valve body chamber 8a from leaking to the outside. .

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

The inner end of the inlet port 9 is opened in a wall surface facing the center of the end surface of the plunger 5a in the fluid chamber 8a, and a valve seat 9a is provided protruding around the opening.

In the large diameter portion of the different diameter hole 5b bored in the axial direction inside the end face of the plunger 5a facing the valve seat 9a,
A valve body 11 is housed so as to be freely displaceable in the axial direction of the plunger 5a, and this valve body 11 is moved outwardly from the end face of the plunger 5a by a valve spring 11a provided in the small diameter portion of the different diameter hole 5b on the back side. It is constantly biased in the direction of protrusion.

Furthermore, an enlarged diameter portion 5 is provided at the outer end of the plunger 5a.
A return spring 12 is provided between the enlarged diameter portion 5c and the end surface of the lower yoke 3 to constantly bias the valve body 11 in the direction of bringing the valve body 11 into close contact with the valve seat 9a via the plunger 5a. Intervention is provided.

The operation of this embodiment will be explained below.

First, when the conductor 4b of the solenoid 4 is not energized, no magnetic field is formed inside the solenoid 4, so no attractive force is generated between the movable column 6 and the plunger 5a, and the return spring 12 The plunger 5a is urged in a direction approaching the valve seat 9a by the urging force, and the valve body 11 accommodated in the end face of the plunger 5a is moved by the valve spring 11a and the return spring 1.
The solenoid valve V is brought into close contact with the valve seat 9a by the urging force of 2, the inlet port 9 and the outlet port 10 are cut off, and the solenoid valve V is in a closed state as shown in FIG.

Next, when the conductor 4b of the solenoid 4 is energized,
A magnetic flux (not shown) is formed inside the solenoid 4 that passes through the movable column 6 and the plunger 5a in the axial direction.

At this time, the plunger 5a is attracted to the movable column 6 whose large diameter portion 6a is locked to the end face of the solenoid 4, thereby preventing the solenoid 4 from moving inward. The movable column 6 and the plunger 5a move by a gap l ₁ in the direction of being drawn into the interior of the movable column 6, and come into contact with the inner end of the movable column 6 and become integrated. Due to the suction force, the upper yoke ₂ is further removed by a gap l2.
In other words, the plunger 5a moves up by a stroke l (=l ₁ −l ₂ ), and stops at a position where the end surface of the large diameter portion 6a of the movable column 6 abuts the upper yoke 2.

In this state, the valve body 11 provided at the outer end of the plunger 5a is moved only by the difference between the sum of gaps l ₁ and l ₂ and the amount of axial displacement within the large diameter portion of the different diameter hole 5b of the plunger 5a. It is separated from the valve seat 9a, the inlet port 9 and the outlet port 10 are in communication via the valve body chamber 8a, and the solenoid valve V is in an open state.

Here, when the displacement of the movable column 6 is fixed and the stroke l of the plunger 5a is achieved only by the gap between the movable column 6 and the plunger 5a, as in a conventional general electromagnet, the plunger 5
Considering the attractive force F acting on a, the magnetic resistance Rg in the gap _l1 between the movable column 6 and the plunger 5a is Rg=1/Pg= _l1 /( _μ0・S)...(1) The suction force F acting on the plunger 5a is expressed as: F=(10 ⁷ /8π)·B ² ·S = (10 ⁷ /8π)·(φ ² /S) (2).

However, Pg: Permeance in the gap l ₁ μ ₀ : Magnetic permeability of air S: Cross-sectional area perpendicular to the magnetic resistance axis B: Magnetic flux density φ: Magnetic flux.

Also, the relationship between magnetic resistance and magnetic flux is φ=(A・T)/R……(3) becomes.

however, R: Magnetic resistance in the entire magnetic circuit A: Current flowing through solenoid 4 T: Number of turns of conductor 4b in solenoid 4 It is.

Here, when R≒Rg, the relationship between the attractive force F and the magnetic circuit is obtained from the above equations (1) to (3) as follows: F=(10 ⁷ /8π)・(φ ² /S) = (10 ⁷ /8π)・(1/S)・(A ²・T ² /Rg ² ) = (10 ⁷ /8π)・(A ²・T ² /S)・ (μ ²・S)/l ² = (10 ⁷・μ ²・A ²・T ² /8π)・ (S/l ² ) ……(4) Furthermore, if we set 10 ⁷・μ ²・A ²・T ² /8π=K, then F=K・(S/l ² ) ...(5) is obtained.

Here, like the electromagnet M of this embodiment, in order to obtain the stroke 1 of the plunger 5a, the stroke 1 is set by the gap between the plunger 5a and the movable column 6.
l ₁ and the gap between the movable column 6 and the upper yoke 2 l ₂
Considering the case where it is equally distributed between the two, that is, l ₁ = l ₂ = (l/2), from the above formula (5), the suction force F generated on the plunger 5a is F = K・(S /l ₁ ² +l ₂ ² )) =K・(S/((l ² /4)+(l ² /4)) =K・(S/(l ² /2)) =2・K・(S /l ² ).

That is, in order to obtain the same stroke l (=l ₁ +l ₂ ) for the plunger 5a, for example, the movable column 6 is fixed to the solenoid 4 as in the conventional case, and the gap between the movable column 6 and the plunger 5a is simply set by l. In this embodiment, twice the suction force F can be obtained on the plunger 5a compared to the case where the setting is made as follows.

This also means that it is possible to double the stroke l while keeping the same attractive force F, i.e. without increasing the number of turns N of the conductor 4b in the solenoid 4 or the current A supplied to the conductor 4b. It means.

Thereby, at least one of the stroke or thrust of the plunger 5a can be increased without increasing the external dimensions or power consumption due to increasing the number of turns of the conductive wire 4b in the solenoid 4.

Further, a spring 7 interposed between the movable column 6 and the upper yoke 2 causes the plunger 5a, which reciprocates in the axial direction inside the solenoid 4, to come into contact with the movable column 6 and the movable column 6 with respect to the upper yoke 2. Since the shock caused when the electromagnet M contacts the electromagnet M is reduced, wear and damage of the movable column 6, the plunger 5a, etc. are reduced, and the life of the electromagnet M can be extended.

It goes without saying that the present invention is not limited to the above-described embodiments, and can be modified in various ways without departing from the spirit thereof.

For example, the electromagnetic valve V using the electromagnet M of this embodiment may have any structure such as a spool valve.

[Effect of idea]

(1) The solenoid valve of the present invention includes a solenoid located in a yoke, a plunger inserted into the solenoid so as to be freely displaceable in the axial direction, and one end facing the plunger and displacing the solenoid in the axial direction. Since the structure includes an electromagnet consisting of a movable column that is inserted and can be freely displaced between the end face of the solenoid and the yoke, the stroke of the plunger is controlled by the gap between the plunger and the movable column inside the solenoid and the solenoid. By distributing the force to the gap between the movable column and the yoke on the outside, at least one of the stroke or thrust of the plunger can be increased without increasing external dimensions or power consumption.

(2) A biasing means for biasing the movable column toward the inside of the solenoid is interposed between the movable column and the upper yoke, so that the movable column of the plunger reciprocates in the axial direction inside the solenoid. Since the impact generated when the movable column contacts the upper yoke and the movable column against the upper yoke is reduced, wear and damage to the movable column and the plunger are reduced, and the life of the electromagnet and, by extension, the electromagnetic valve can be extended.

(3) As a result of (1) above, the applicable uses of solenoid valves and even electromagnets are expanded, and marketability is improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a solenoid valve according to an embodiment of the present invention, and FIG. 2 is a sectional view of an example of an electromagnet used in the solenoid valve of the present invention. 1... Outer yoke, 2... Upper yoke, 3...
Lower yoke, 4...Solenoid, 4a...Bobbin, 4b...Conductor, 5, 5a...Plunger, 5
b... Different diameter hole, 5c... Expanded diameter part, 6... Movable column, 6a... Large diameter part, 7... Spring (biasing means),
8... Valve body, 8a... Valve body chamber, 8b... Packing, 9... Inlet port, 9a... Valve seat, 10...
Outlet port, 11...valve body, 11a...valve spring,
12... Return spring, M... Electromagnet, V... Solenoid valve, l ₁ ... Gap between plunger and movable column, l ₂
...Gap between the movable column and the upper yoke.

Claims (1)

[Claims for Utility Model Registration] (1) A solenoid located in a yoke, a plunger inserted into the solenoid so as to be freely displaceable in the axial direction, and one end facing the plunger and disposed in the solenoid in the axial direction. 1. A solenoid valve comprising an electromagnet including a movable column inserted into the solenoid and displaceable between the end face of the solenoid and the yoke. (2) A flange portion having an outer diameter larger than the inner diameter of the solenoid is integrally formed at the outer end of the movable column, and the flange portion is in contact with each of the end face of the solenoid and the yoke. The solenoid valve according to claim 1, wherein the displacement of the movable column is regulated. (3) A utility model registration characterized in that a biasing means for constantly biasing the movable column toward the inside of the solenoid is provided between the outer end of the movable column and the yoke. A solenoid valve according to claim 1. (4) Utility model registration claim 1, characterized in that the gap between the movable column and the plunger and the gap between the movable column and the yoke inside the solenoid are approximately equal.
Solenoid valve described in section. (5) A valve body that opens and closes a fluid flow path is driven by the plunger, and the valve body is axially inserted into a large diameter part of a hole of different diameters bored in the axial direction at the end of the plunger. A valve spring is disposed in a small diameter portion of the different diameter hole on the back side of the valve body so as to be displaceable in a direction, and a valve spring biases the valve body in a direction to project the valve body from the plunger. A solenoid valve according to claim 4 of the utility model registration claim.