JPH0968287A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve with a low height as a whole, by providing a magnetic line induction tube in the noncontact condition to a fixed iron core, and making a movable iron core movable up and down in the magnetic line induction tube. SOLUTION: A movable iron core 22 moves in a magnetic line induction tube 41 provided at the upper end of an electromagnetic coil 2, and between a fixed iron core provided at the lower end of the electromagnetic coil 2, and the moving movable iron core can be housed in the electromagnetic coil 2 perfectly. On the other hand, the magnetic line induction tube 41 formed of a magnetic body is provided in the form to surround the outer periphery of the movable iron core 22. Even though the movable iron core 22 is made movable in the condition housed in the electromagnetic coil 2 perfectly, a clearance to leak the magnetic lines B in the valve closed condition is not formed in the magnetic passage by the presence of a side wall 411 in the magnetic line induction tube 41, add the cause to leak the magnetic lines B in the valve opening condition is only the clearance S between the movable iron core 22 and the fixed iron core 21. As a result, the leaking of the magnetic lines can be prevented in either condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve, and more particularly to a solenoid valve having a reduced size.

[0002]

2. Description of the Related Art For example, as a solenoid valve for opening and closing a water circuit,
There is known a structure as shown in FIG. 4, which is composed of a valve box (D) and a valve drive device (C) connected to the valve box (D). In the lower part of the valve box (D), a flow path (14) connecting from the inflow port (11) to the discharge port (12) is provided, and the valve seat opening (16) formed in the flow path (14) is On the other hand, a diaphragm-type valve body (15) that moves in and out of contact with the valve is opened and closed.

A valve drive device continuously provided on the valve box (D)
(C) is an output shaft for opening and closing the valve body (15).
(13) is provided, the output shaft (13) is an electromagnetic coil (2)
It is designed to be moved back and forth in the axial direction by the magnetic force of. That is, a cylindrical fixed iron core (21) is fitted and fixed to the opening end of the electromagnetic coil (2) wound in a cylindrical shape on the valve body (15) side, and the inside of the fixed iron core (21) is fixed. The output shaft (13) penetrates slidably. A cylindrical movable iron core (22) is connected to the upper end of the output shaft (13). The upper end of the movable iron core (22) is configured to project further upward than the upper end of the electromagnetic coil (2), and the projecting portion of the movable iron core (22) is an electromagnetic coil. (2) is housed and can move inside a cylindrical cap (26) protruding from an outer cover (25) made of a ferromagnetic material (hereinafter simply referred to as "magnetic material"). .

Incidentally, (31) is a cylinder made of a non-magnetic material, and a screw shaft (32) screwed and fixed to the upper end of the cylinder and the screw shaft.
The cap (26) is fixed on the exterior cover (25) by a cap nut (33) screwed to the tip of the (32). In this structure, when the electromagnetic coil (2) is energized in the valve open state shown in FIG. 4, the magnetic lines of force generated around the electromagnetic coil (2) are formed along the magnetic path (A) shown in the same figure. Be done. That is, the top plate of the box (250) → the movable iron core (22) → the fixed iron core (21) → the closing lid (251) → the outer side plate of the box (250) → the box (25
Lines of magnetic force are formed along the closed magnetic path (A) connected to the top plate of (0). And the movable iron core into and out of which the magnetic field lines come in and out
The attraction force acts between the opposing surfaces of (22) and the fixed core (21), whereby the movable core (22) moves to the fixed core (21) side together with the output shaft (13). Then, the valve body (15) interlocking with the output shaft (13) closes the valve seat opening (16) and maintains the valve closed state.

When the electromagnetic coil (2) is de-energized, the attraction force between the movable iron core (22) and the fixed iron core (21) disappears, and the output shaft (13) is urged by a return spring (not shown). Is moved back to the initial position, which causes the valve body (15)
Is opened. In this structure, the magnetic field lines pass through the almost closed magnetic path (A) formed by the outer cover (25), the movable core (22) and the fixed core (21), so the leakage of magnetic field lines is reduced. , Even if the current supplied to the electromagnetic coil (2) is small, reliable on-off valve operation can be secured.

[0006]

However, in this type of solenoid valve, the movable iron core (22) is formed in the magnetic path (A) regardless of the position of the movable iron core (22) in order to prevent the leakage of magnetic force lines. It is necessary to reduce the number and size of the gaps as much as possible. From this point of view, in the above-mentioned conventional one, the dimensions of the respective parts are set so that the upper end of the movable iron core (22) attracted to the fixed iron core (21) slightly projects from the upper end of the electromagnetic coil (2). Then, the fixed iron core (21) and the movable iron core (22)
When the valve is open, the upper end of the movable iron core (22) inevitably protrudes above the electromagnetic coil (2) by the lifting stroke. Therefore, the cap (26) for accommodating the projecting end of the movable iron core (22) at the highest position is attached to the electromagnetic coil.
Since it is necessary to project from the upper end of (2), there is a disadvantage that the height of the entire solenoid valve increases by the amount of projecting the cap (26).

[0007] The present application has been made in view of such a point,
The invention according to claim 1 is an electromagnetic valve comprising a valve box (D) and a valve drive device (C) connected to the valve box (D), wherein the valve box (D) is the valve drive device. Built-in valve body (15) that opens and closes in conjunction with the output shaft (13) of (C), the valve drive device (C)
Is a cylindrically wound electromagnetic coil (2), an outer cover (25) surrounding the outer surface of the electromagnetic coil (2) and made of a magnetic material, and the cylindrical electromagnetic coil (2 ), The movable iron core (22), the fixed iron core (21) inserted and fixed in the lower end opening of the electromagnetic coil (2), the outer cover (25) and the fixed iron core (21). A solenoid valve, which is equipped with the output shaft (13) movably pierced through and fixed to the movable iron core (22) and a spring for urging the movable iron core (22) upward, is movable. It is an object of the present invention to provide an electromagnetic valve which is short as a whole by making the moving range of the iron core (22) completely within the electromagnetic coil (2).

[0008]

In order to achieve the above-mentioned object, the invention according to claim 1 is that "the electromagnetic coil (2) is inserted and fixed in the upper opening and is in contact with the exterior cover (25). The fixed magnetic core (21) is provided with a magnetic field line guiding cylinder (41) in a non-contact state, and the movable magnetic core is provided inside the magnetic field line guiding cylinder (41).
(22) can move up and down. ”

According to the above means, between the inside of the magnetic force line induction cylinder (41) arranged at the upper end of the electromagnetic coil (2) and the fixed iron core (21) arranged at the lower end of the electromagnetic coil (2). The movable iron core (22) moves, and the moving movable iron core (22) can be completely housed in the electromagnetic coil (2). On the other hand, the magnetic force line guide tube (41) made of a magnetic material is arranged so as to surround the outer circumference of the movable iron core (22). Therefore, the magnetic force lines generated by the electromagnetic coil (2) pass through the top plate of the outer cover (25) → the magnetic force line guide tube (41) → the movable iron core (22) and are fixed from the gap below the movable iron core (22). Enter the iron core (21) and fix the iron core (21) to the outer cover
It is formed in a manner connected to (25). Therefore, the movable iron core (2
In the initial state where 2) is separated from the fixed iron core (21), there is a region where magnetic field lines leak other than the facing gap between the movable iron core (22) and the fixed iron core (21) as in the conventional one described above. Without
The mutual attraction force does not decrease.

Even when the movable iron core (22) and the fixed iron core (21) are attracted to each other, the body portion of the movable iron core (22) has the fixed iron core (21).
It is inserted inside. Therefore, in such a state,
The outer peripheral surface and the inner peripheral surface of the electromagnetic coil (2) are completely surrounded by an outer cover (25) made of a magnetic material, a magnetic force line induction tube (41), a movable iron core (22) and a fixed iron core (21), As with the conventional one, the air gap that causes the leakage of magnetic force lines is not formed in the magnetic circuit, so the movable core (22) and the fixed core (21)
There is no inconvenience that the adsorption power of is reduced.

[0011]

As described above, according to the first aspect of the present invention, the moving movable core (22) is configured to be completely housed in the electromagnetic coil (2). Since the cap (26) is not required, a short solenoid valve can be constructed as a whole.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the valve drive device
The valve box (D) connected to the lower part of (C) has a flow path (14) connecting from the inlet port (11) at one end to the discharge port (12) at the other end, as in the conventional one. Has penetrated. A vertically oriented valve seat opening (16) is formed in the middle of the flow path (14), and a valve mounting hole (1) is formed in the side wall of the main body facing the valve seat opening (16).
0) is bored, and the valve mounting hole (10) is covered with a flexible membrane (150) which constitutes a diaphragm type valve body (15).
Further, a pressing lid (5) for fixing the outer peripheral edge of the valve body (15) is covered above the valve body (15), and this is covered with a screw (51) as a main body.
It is fixed to (1).

Further, the flexible membrane (150) constituting the valve body (15) is made to communicate with the water chambers (159) (158) located above and below the flexible membrane (150), respectively. There is a leak hole (151) for balancing the pressure of these water chambers.
By opening and closing the valve body (15) while maintaining the pressure balance between (159) and (158), the valve body (15) can be opened and closed with a small force. In addition, a shaft body (15) having a pilot hole (153) vertically penetrating the central portion of the valve body (15).
2) is installed in a penetrating state.

The shaft body (152) is connected to a pilot valve holder (54) above the shaft body (152) through a flexible rubber connecting piece (53) bent in a V shape at the center. That is, as shown in FIG. 2, both ends of the connecting piece (53) are flanges formed around the pilot valve holder (54) and the shaft (152).
(543) (155) Engagement groove formed at the base end (544) (156)
These are engaged by being press-fitted into.

The pilot valve holder (54) is formed with a pilot valve accommodating chamber (541) which is opened to the shaft (152) side, and the inner diameter of the inner part of the pilot valve accommodating chamber (541) is restricted. To form a step (542). Then, the pilot valve accommodating chamber (5
41), a spring is attached to the tip side of the pilot valve accommodating chamber (541).
It is loaded with a pilot valve (56) that is urged by (58),
The pilot valve (56) is the pilot valve accommodating chamber (541).
The retaining ring (57) fitted to the inner circumference of the tip of the retainer retains the retaining state.

The pilot valve holder (54) is designed to be lifted and lowered by being guided in a guide tube (50) inserted in the upper end of the pressing lid (5) described above. A spring (52) for opening the valve is interposed between the valve (50) and the flange (546) protruding to the outer periphery of the upper end of the pilot valve holder (54).
Next, the connecting tube (6
The valve drive device (C) connected in series above 1) will be described in detail.

A holding flange (611) for holding a fixed iron core (21) (formed of stainless steel having a property as a magnetic body in the present embodiment) described later is provided on the inner circumference of the upper portion of the connecting tube (61). ) Is projected, and the holding flange (611)
Includes a bottom flange (2
11) is stacked from above. Then, the lower end flange (211) is provided with a closing lid (25
1) Retaining flange under it by the threaded portion (253)
(611) Pressed and fixed on top. An electromagnetic coil (2) wound around a bobbin (28) made of a non-magnetic material (a synthetic resin material is used in this embodiment) is placed on the upper surface of the connection tube (61). At the same time, a sleeve (20) made of a non-magnetic material (a synthetic resin is used in this embodiment) is inserted and fixed in the lower part of the bobbin (28), and further, inside the sleeve (20). The upper part of the fixed iron core (21) is in an inserted state. Further, the electromagnetic coil (2) is a cylindrical box body (250) that opens downward (when the electromagnetic coil (2) is wound in a rectangular tubular shape, it is formed in a rectangular tubular shape) from above. The box body (250) and the closing lid (251) that covers the open part of the box body (250) are made of stainless steel (which may be resin-coated iron or the like) having a magnetic property. There is. Thereby, the electromagnetic coil
The entire outer surface of (2) is substantially surrounded by the magnetic outer cover (25) which is a collection of the box body (250) and the closing lid (251) covering the open end thereof.

Further, the box body (2
A through hole (254) is formed at the center of the upper surface of the magnetic field induction tube (254) inserted into the through hole (254) so as to be in close contact with the inner circumference of the upper portion of the electromagnetic coil (2). A screw shaft (412) protruding from the upper end of 41) is inserted, and a cap nut (43) for fixing the outer cover (25) is screwed onto the tip of the screw shaft (412). . Further, the magnetic force line guiding cylinder (41) is formed in a tubular shape that opens downward, and a movable iron core (22) is accommodated in the magnetic force line guiding cylinder (41) so as to be movable in the axial direction. The magnetic force line guide tube (41) and the movable iron core (22) are made of stainless steel having a magnetic property. A ring (8) made of Teflon corresponding to the friction reducing member according to the invention of claim 3 is loaded in the annular groove (29) provided around the outer periphery near the upper end of the movable iron core (22). , The ring (8) is formed in a C shape having a notch in a part thereof, and the elastic force of the ring (8) induces a magnetic force line guide tube (4).
It is kept pressed against the inner surface of 1). This allows
The frictional resistance when the movable iron core (22) moves with respect to the magnetic force line induction tube (41) is reduced to ensure smooth movement of the magnetic force line induction tube (41), and the relative magnetic force guide tube (41) and the movable iron core (22) slide relative to each other. Generation of iron powder due to movement is suppressed. Further, the large diameter portion (223) at the lower end of the movable iron core (22) projects from the magnetic force line guiding cylinder (41), and the movable iron core (22) has a female screw portion (224) that opens downward. It is provided. And the female screw part (224)
The output shaft (13) is screwed and coupled to the
(13) penetrates the central hole (214) of the fixed iron core (21) therebelow and is screwed into the pilot valve holder (54) further below it.

Next, the operation of the solenoid valve will be described. FIG.
Indicates that the valve is open.
(2) is not energized. Now, when an alternating current is applied to the electromagnetic coil (2) in the valve open state, the electromagnetic coil
Magnetic field lines (B) are formed so as to surround (2). When the electromagnetic coil (2) is wound in a cylindrical shape, the magnetic field lines (B) extend radially from the center when viewed from a plane, and the electromagnetic coil (2) is wound in a rectangular tubular shape. When it is formed, it is formed so as to extend vertically and horizontally from the central portion. Although only the magnetic field lines (B) formed in the right half of the electromagnetic coil (2) are shown in the figure, the magnetic field lines (B) are also shown in the left half of the electromagnetic coil (2) in the figure. Similar magnetic field lines are formed. That is, as shown by the magnetic field lines (B) in the figure,
The magnetic force lines (B) that have entered the magnetic force line guiding cylinder (41) from the top plate of the box (250) are guided to the side of the movable iron core (22) by the side wall portion (411) of the magnetic force line guiding cylinder (41), After that, the magnetic field lines (B) enter the movable iron core (22) and the lower end of the movable iron core (22) → the fixed iron core (21) → the closing lid (251) → the outer peripheral side plate of the box (250) → the upper plate of the box (250) → Magnetic field lines (B) are formed along the magnetic path circulating with the movable iron core (22). In this case, except for the gap (S) formed between the facing surfaces of the movable iron core (22) and the fixed iron core (21), the magnetic field lines are
Since there is no gap that causes leakage of (B), a large electromagnetic attraction force can be secured between the facing surfaces of the movable iron core (22) and the fixed iron core (21).

When the attraction force acts between the fixed iron core (21) and the movable iron core (22), the movable iron core (22) descends together with the output shaft (13), whereby the pilot valve holder (54 )
A pilot valve (56) incorporated therein closes the upper end of the pilot hole (153) of the shaft body (152) facing the pilot valve (56). Then, when the output shaft (13) further descends, the output shaft (13) is pushed down and the flexible film (150) is deformed downward.
The valve body (15) composed of the flexible membrane (150) and the like has a valve seat opening (16).
Is closed and the valve is closed as shown in FIG.

In the above-mentioned valve closed state, the magnetic field lines (B) are
Top plate of 50) → Side wall part (411) of magnetic field induction tube (41) → Movable iron core (22) → Fixed iron core (21) → Closing lid (251) → Outer side plate of box (250) → Box (250) ) Is formed along a completely closed magnetic path connected to the top plate. That is, the magnetic force lines are formed along the closed magnetic path where there is no gap that causes the leakage of the magnetic force lines, whereby the movable iron core (22) and the fixed iron core (21) are attracted and held by a strong force. .

As described above, in the solenoid valve described as the above embodiment, even if the movable iron core (22) is moved while being completely housed in the electromagnetic coil (2), the magnetic force line guide tube (41) The presence of the side wall portion (411) in () does not form a gap in the magnetic path that causes leakage of the magnetic field lines (B) in the valve closed state, and also prevents leakage of the magnetic field lines (B) in the valve opened state. The only cause is the gap (S) between the movable iron core (22) and the fixed iron core (21) .Therefore, it is possible to prevent the leakage of magnetic field lines in both the valve closed state and the valve opened state. I can. As a result, not only is it possible to secure a strong suction force between the movable iron core (22) and the fixed iron core (21), but also it is necessary to provide it on the upper surface of the exterior cover (25) such as the above-mentioned conventional cap (26). You can make things unnecessary.

Next, the valve opening operation of the solenoid valve will be described. In the state shown in FIG. 3, when the electromagnetic coil (2) is demagnetized, the pilot valve holder (5
4) is lifted, whereby the pilot valve (56) is separated from the shaft body (152) and the pilot valve seat (154) at the upper end of the pilot hole (153) is opened. Then, the water pressure on the inlet (11) side, which is in the high pressure state upstream, becomes the leak hole (151).
→ Primary water chamber (159) above flexible membrane (150) → Pilot hole
(153) → The pressure in the water chambers (159) (158) above and below the flexible membrane (150) is balanced by being transmitted to the secondary side water chamber (158) below the flexible membrane (150). Then, the elastic return force of the flexible membrane (150) and the valve opening force transmitted from the spring (52) to the pilot valve holder (54) → connecting piece (53) → shaft body (152) → valve body (15). By the valve body
(15) is moved away from the valve seat opening (16), whereby the valve is opened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a solenoid valve according to an embodiment in an open state.

FIG. 2 is an enlarged view of a connecting portion between a pilot valve holder (54) and a shaft body (152) in the solenoid valve according to the embodiment.

FIG. 3 is a cross-sectional view of a closed state of the solenoid valve according to the embodiment.

FIG. 4 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 (2) ・ ・ ・ Electromagnetic coil (13) ・ ・ ・ Output shaft (15) ・ ・ ・ Valve body (21) ・ ・ ・ Fixed iron core (22) ・ ・ ・ Movable iron core (25) ・ ・ ・ Exterior cover (41 ) ・ ・ ・ Magnetic field induction tube

Claims (3)

[Claims] 1. A solenoid valve comprising a valve box (D) and a valve drive device (C) connected to the valve box (D), wherein the valve box (D) is a solenoid valve of the valve drive device (C). The valve drive device (C) has a built-in valve body (15) that opens and closes in conjunction with the output shaft (13), and the valve drive device (C) includes a cylindrically wound electromagnetic coil (2) and this electromagnetic coil (2). ) An outer cover (25) surrounding the outer surface and made of a magnetic material, a movable iron core (22) housed in the cylindrical electromagnetic coil (2), and the electromagnetic coil.
The fixed iron core (21) inserted and fixed in the lower end opening of (2) slidably penetrates the exterior cover (25) and the fixed iron core (21) and is fixedly connected to the movable iron core (22). Output shaft
(13) and a solenoid valve provided with a spring for urging the movable iron core (22) upward, the solenoid valve being inserted and fixed in the upper opening of the electromagnetic coil (2) and contacting the exterior cover (25). A solenoid valve having a structure in which a magnetic field line guiding cylinder (41) in a non-contact state is provided on the fixed iron core (21), and the movable iron core (22) can move up and down in the magnetic field line guiding cylinder (41). 2. The solenoid valve according to claim 1, wherein a lower portion of the movable core (22) is maintained in a state of protruding from the magnetic force line guide cylinder (41) in the entire movement range of the movable core (22). . 3. The outer circumference of the movable iron core (22) and the magnetic force line guiding cylinder (41).
The solenoid valve according to claim 1 or 2, wherein a friction reducing member for smoothing the relative sliding of the two is interposed at the boundary portion of the electromagnetic valve.