JPH11287346A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with the current-carrying in a coil for the purpose of maintaining the open condition of a passage by carrying current in the coil only when a moving iron core is moved. SOLUTION: One end of a cylinder 16 is fixed to a valve body 11, and a stationary iron core 17 is fixed to the other end of the cylinder 16, and a moving iron core 18 is installed in the cylinder 16. An energizing means 21 energizes the moving core 18 in the direction of going apart from the stationary core 17. The cylinder 16 is equipped at the periphery with a coil 22 which generates a magnetic flux to attract the moving core 18 to the stationary core 17 and a magnetic flux to move the former 18 apart from the latter 17 in accordance with the current feeding direction. The cylinder 16 is also equipped at the periphery with a permanent magnet 30 which is magnetized in different polarities about the axial direction and generates a magnetic flux A to attract the moving core 18 to the stationary core 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solenoid valve used for opening and closing a flow path.

[0002]

2. Description of the Related Art Conventionally, a solenoid valve is used for opening and closing a flow path of a refrigerant or the like in a refrigeration cycle, for example.

As shown in FIG. 4, this solenoid has a valve body 1 and an inlet pipe 2 and an outlet pipe 3
Are connected, and a valve seat 4 that connects the inlet pipe 2 and the outlet pipe 3 is formed. One end of a tube 5 is fixed to the valve body 1, a fixed iron core 6 is fixed to the other end of the tube 5, and a movable iron core 7 for opening and closing the valve seat 4 is provided in the tube 5 so as to be movable in the axial direction. ing. A spring 8 for urging the movable core 7 toward the valve seat 4 is provided between the fixed core 6 and the movable core 7, and a magnetic flux for attracting the movable core 7 to the fixed core 6 is provided around the tube 5. A generating coil 9 is provided.

When the coil 9 is not energized, the movable iron core 7 is pushed downward by the bias of the spring 8, and moves.
The leading end of the movable core 7 contacts the valve seat 4 and the inlet pipe 2 and the outlet pipe 3
And shut off.

On the other hand, when the coil 9 is energized, the movable core 7 is attracted to the fixed core 6 and moves upward, and the tip of the movable core 7 separates from the valve seat 4 to separate the inlet pipe 2 and the outlet pipe 3. Communicate.

[0006]

Recently, as the demand for electric power has increased, there has been a demand for electric appliances to save electric power. However, in the conventional solenoid valve, the flow path between the inlet pipe 2 and the outlet pipe 3 has been reduced. In order to maintain the open state, it is necessary to maintain energization of the coil 9, which is uneconomical in terms of power consumption, and selects a material having excellent heat resistance in consideration of the temperature rise of the coil 9. There is a problem that it is necessary and cost increases.

In particular, when the pressure difference between the inlet pipe 2 and the outlet pipe 3 is large due to the use of the alternative refrigerant accompanying the elimination of the specific chlorofluorocarbon gas in the refrigeration cycle, the suction force of the movable iron core 7 for opening the valve seat 4 is also large. Therefore, the power applied to the coil 9 increases, so that power consumption and heat resistance become more problematic, and the coil 9 becomes larger.

The present invention has been made in view of such a point, and energization of the coil is performed only when the movable core moves.
It is an object of the present invention to provide a solenoid valve capable of saving energy, reducing cost, and reducing the size by eliminating the need to energize a coil for maintaining an open state of a flow path.

[0009]

According to a first aspect of the present invention, there is provided a solenoid valve including a valve body having a flow path and a valve seat provided in the middle of the flow path, a cylindrical body having one end fixed to the valve body, A fixed iron core fixed to the other end of the cylindrical body, a movable iron core disposed in the cylindrical body so as to be movable in the axial direction, and opening and closing the valve seat by moving in the axial direction, and moving the movable iron core from the fixed iron core. Urging means for urging in a direction away from the main body;
A coil is provided on the outer periphery of the cylindrical body and generates a magnetic flux for attracting the movable iron core to the fixed iron core and a magnetic flux for moving the movable iron core away from the fixed iron core, in accordance with the direction of electric current. And a permanent magnet which is arranged and magnetized to have a different pole in the axial direction to generate a magnetic flux for attracting the movable iron core to the fixed iron core.

By providing a permanent magnet for generating magnetic flux for attracting the movable core to the fixed core, the coil is energized in a state where the movable core is separated from the fixed core by the biasing means, and the movable core is fixed. When attracted by the iron core, the attracted state is maintained by the magnetic flux action of the permanent magnet. Also, if the coil is energized in the opposite direction while maintaining the attracted state by the magnetic flux action of the permanent magnet, the magnetic flux action of the permanent magnet is canceled and the movable core is separated from the fixed iron core by the urging of the urging means. .

Accordingly, the coil needs to be energized only when the movable iron core is moving, and it is not necessary to energize the coil for maintaining the open state of the flow path. In addition, since the coil is energized only when the movable core is moving, relatively large power can be instantaneously supplied to the coil, and even when the moving load of the movable core is large due to the pressure applied to the valve seat, The channel can be opened and closed with a small coil.

According to a second aspect of the present invention, in the solenoid valve according to the first aspect, the attraction force of the movable core to be attracted to the fixed iron core by the magnetic flux generated by the permanent magnet and the urging force of the urging means are movable. The urging force is set to be larger than the attraction force when the core is separated from the fixed core, and the attraction force is set to be larger than the urging force when the movable core is in contact with the fixed core.

By appropriately setting the attractive force of the movable core to be attracted to the fixed iron core by the magnetic flux generated by the permanent magnet and the urging force of the urging means, the moving state of the movable iron core even when the coil is not energized, that is, Maintain the open / closed state of the valve seat.

According to a third aspect of the present invention, there is provided the solenoid valve according to the first or second aspect, wherein one end of the permanent magnet in the axial direction is supported on the cylindrical body, and a magnetic path between the permanent magnet and the fixed iron core is provided. And a second magnetic body that supports the other end of the permanent magnet in the axial direction with respect to the cylindrical body and forms a magnetic path between the permanent magnet and the movable iron core. Is what you are doing.

The first magnetic body and the second magnetic body allow the magnetic flux of the permanent magnet to effectively act on the movable iron core and the fixed iron core, so that the attracted state by the magnetic flux action of the permanent magnet is reliably maintained.

According to a fourth aspect of the present invention, in the solenoid valve according to the third aspect, the first magnetic body is a coil case for holding a coil, and the second magnetic body is a disk-shaped cylinder at the center. It has a fitting hole fitted to the outside of the body.

By using a coil case as the first magnetic body, or by fitting the fitting hole of the second magnetic body to the outside of the cylindrical body, the permanent magnet can be easily assembled and the configuration can be simplified. .

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a solenoid valve according to the present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 11 denotes a valve body.
An inlet pipe 12 is connected to the side of the valve body 11, an outlet pipe 13 is connected to a lower part of the valve body 11, and a flow path 14 in which the inlet pipe 12 and the outlet pipe 13 communicate with each other is formed inside the valve body 11, A valve seat 15 is formed in the middle of the flow path 14, that is, on the bottom surface in the valve body 11.

A lower end (one end) of a cylindrical tube 16 as a cylindrical body is fitted and tightly fixed to the upper end opening of the flow path of the valve body 11. The tube 16 is made of, for example, a non-magnetic material. A fixed iron core 17 made of a magnetic material is tightly fixed inside the other end of the tube 16.

A movable iron core 18 made of a magnetic material is disposed in the tube 16 so as to be movable in the axial direction. At the lower end of the movable iron core 18, a spherical valve element 19 that opens and closes while being in contact with and separated from the valve seat 15 is attached, and a concave portion 20 is formed at the upper end of the movable iron core 18. Between the concave portion 20 of the movable core 18 and the fixed core 17, a spring as biasing means for biasing the movable core 18 downward away from the fixed core 17, that is, in a direction to close the valve seat 15 with the valve body 19. 21 are arranged.

A coil 22 and a coil case 23 as a first magnetic body holding the coil 22 are attached to the outer periphery of the upper end (the other end) of the tube 16. Lead wires 22a at both ends of the coil 22 are drawn out of the coil case 23. The coil case 23 is formed of a magnetic material,
A peripheral surface portion 24 covering the peripheral surface of the coil 22, an end surface portion 25 covering the lower end surface of the coil 22, and an end surface portion 26 covering the end surfaces of the coil 22 and the fixed iron core 17 are integrally formed. Between the inner circumference of the end face portion 25 and the tube 16, a gap portion 27 for reducing the leakage magnetic flux between the end face portion 25 and the movable core 18 is formed.

The lower end (one end) of the tube 16 close to the valve body 11
A second magnetic body 28 is attached to the outer periphery. The second magnetic body 28 is formed in a disc shape from a magnetic material, and has a fitting hole 29 fitted (joined) to the outer periphery of the tube 16 at the center.
Are formed.

On the outer periphery of the tube 16, there are arranged permanent magnets 30 supported by an end surface 25 of a coil case 23 and a second magnetic body 28, respectively. The permanent magnet 30 is formed in an annular shape, and a gap 27 that reduces leakage magnetic flux between the permanent magnet 30 and the movable iron core 18 is formed between the permanent magnet 30 and the outer periphery of the tube 16.

The permanent magnet 30 is magnetized to have a different polarity in the axial direction.
The 28 side is magnetized to the N-pole, and generates a magnetic flux A for attracting the movable core 18 to the fixed core 17. The attractive force by which the movable core 18 is attracted (adsorbed) to the fixed core 17 by the magnetic flux generated by the permanent magnet 30 and the urging force of the spring 21 are smaller than the attractive force when the movable core 18 is separated from the fixed core 17. The urging force is large, and the suction force is set to be larger than the urging force when the movable iron core 18 is in contact with the fixed iron core 17.

Next, the operation of the present embodiment will be described.

In the closed state shown in FIG. 1, the coil 22 is not energized, and the movable core 18 is urged downward by the bias of the spring 21 away from the fixed core 17, and the valve body 19 is pressed against the valve seat 15. The flow path 14 between the inlet pipe 12 and the outlet pipe 13 is closed.

When the movable core 18 is separated from the fixed core 17, the magnetic flux A of the permanent magnet 30 is transferred from the N pole of the permanent magnet 30 to the second magnetic body 28, the movable core 18, the movable core 18 and the fixed core 17.
Reaches the S pole of the permanent magnet 30 via the fixed iron core 17 and the coil case 23, but is movable by the magnetic flux A generated by the permanent magnet 30 due to the gap between the movable iron core 18 and the fixed iron core 17. The urging force of the spring 21 is greater than the suction force of the core 18 being attracted to the fixed core 17, and the closed state is reliably maintained.

In the closed state, the coil 22 is energized to generate a magnetic flux B (see FIG. 2) in the same direction as the magnetic flux A of the permanent magnet 30. As shown in FIG. 2, due to the action of the magnetic flux B generated by the coil 22, the movable iron core 18 is attracted to the upper fixed iron core 17 to move against the bias of the spring 21, and the valve body 19 is moved. And the flow path 14 between the inlet pipe 12 and the outlet pipe 13 is opened. The upper end face of the movable movable core 18 is joined to the fixed core 17.

The movable core 18 moves instantaneously by the action of the magnetic flux B, and the energization of the coil 22 is stopped when the movement of the movable core 18 is completed. That is, the coil 22 is energized only momentarily.

The upper end surface of the movable movable core 18 is fixed to the fixed core 17.
, The magnetic flux A of the permanent magnet 30 reaches the S pole of the permanent magnet 30 from the N pole of the permanent magnet 30 through the second magnetic body 28, the movable core 18, the fixed core 17, and the coil case 23. Is formed, and the attracting force of the movable core 18 attracted (attached) to the fixed core 17 by the magnetic flux A generated by the permanent magnet 30 is larger than the urging force of the spring 21.
The suction state of 18, ie, the open state is reliably maintained.

As shown in FIG. 3, in the open state, the coil 22 is energized in a direction opposite to that in the above-described open state, and generates a magnetic flux C in a direction opposite to the magnetic flux A of the permanent magnet 30. The magnetic flux C generated by the coil 22 cancels the magnetic flux A generated by the permanent magnet 30, and the action of the magnetic flux C and the bias of the spring 21 cause the movable core 18 to move urged downward away from the fixed core 17. , The valve body 19 is pressed against the valve seat 15 and the inlet pipe 12
And the outlet pipe 13 is closed.

The movable core 18 is instantaneously moved by the action of the magnetic flux C, and the energization of the coil 22 is stopped when the movement of the movable core 18 is completed. That is, the coil 22 is energized only momentarily.

When the movable core 18 separates from the fixed core 17,
The magnetic flux A of the permanent magnet 30 is transferred from the N pole of the permanent magnet 30 through the second magnetic body 28, the movable core 18, the gap between the movable core 18 and the fixed core 17, the fixed core 17, and the coil case 23 to the permanent magnet 30. S
When the magnetic core 18 reaches the pole and the gap between the movable core 18 and the fixed core 17, the biasing force of the spring 21 becomes larger than the attraction force of the movable core 18 attracted to the fixed core 17 by the magnetic flux A generated by the permanent magnet 30. , The closed state is reliably maintained.

As described above, since the permanent magnet 30 which generates the magnetic flux A for attracting the movable core 18 to the fixed core 17 is provided,
When the movable core 18 is separated from the fixed core 17 by the bias of the spring 21, the coil 22 is energized and the movable core 18 is attracted to the fixed core 17, and the attracted state is maintained by the magnetic flux action of the permanent magnet 30. If the coil 22 is energized in the opposite direction in a state where the attracted state is maintained by the magnetic flux action of the permanent magnet 30, the magnetic flux action of the permanent magnet 30 is canceled and the movable iron core 18 is biased by the spring 21. It can be separated from the fixed iron core 17.

Accordingly, the coil 22 is energized by the movable core.
It is sufficient only at the time of movement of 18, and it is not necessary to energize the coil 22 for maintaining the open state of the flow path 14, and it is possible to save energy, and it is not necessary to consider the temperature rise of the coil 22. The material can be selected.

Further, since the coil 22 is energized only when the movable core 18 is moved, a relatively large power can be instantaneously supplied to the coil 22. As described above, even when the moving load of the movable iron core 18 is large due to the pressure applied to the valve seat 15, the small-sized coil 22 can open and close the flow path.

Further, the attraction force of the movable core 18 attracted to the fixed core 17 by the magnetic flux A generated by the permanent magnet 30 and the urging force of the spring 21 cause the movable core 18 to be separated from the fixed core 17. The biasing force is greater than the suction force, and the movable iron core 18
Since the suction force is set to be larger than the urging force in a state where the coil is in contact with the fixed core 17, even when the coil 22 is not energized, the moving state of the movable core 18, that is, the open / close state of the valve seat 15, can be reliably maintained .

Further, the magnetic flux A of the permanent magnet 30 can be effectively applied to the movable iron core 18 and the fixed iron core 17 by the first magnetic material (coil case 23) and the second magnetic material 28. The attraction state by the action of magnetic flux can be reliably maintained.

The coil case 23 is used as the first magnetic material.
The permanent magnet 30 can be easily assembled to the solenoid valve by fitting the fitting hole 29 of the second magnetic body 28 to the outside of the tube 16 by utilizing the method described above.

It should be noted that the present invention is not limited to the form of the solenoid valve of the above-described embodiment, and the same action and effect can be obtained even when applied to various solenoid valves.

[0042]

According to the solenoid valve of the first aspect, since the permanent magnet that generates the magnetic flux for attracting the movable iron core to the fixed iron core is provided, the movable iron core is separated from the fixed iron core by the urging of the urging means. If the coil is energized while the armature is moving and the movable iron core is attracted to the fixed iron core, the attracted state can be maintained by the magnetic flux action of the permanent magnet. When the current is supplied in the opposite direction, the magnetic flux action of the permanent magnet is canceled, and the movable iron core can be separated from the fixed iron core by the urging of the urging means.

Accordingly, the coil needs to be energized only when the movable iron core is moving, so that it is not necessary to energize the coil for maintaining the open state of the flow path, thereby saving energy and increasing the temperature of the coil. Since there is no need to take into account, it is possible to select an inexpensive material.

Further, since the coil needs to be energized only when the movable core moves, relatively large power can be supplied to the coil instantaneously, and the moving load of the movable core is large due to the pressure applied to the valve seat. Even in this case, the flow path can be opened and closed with a small coil.

According to the solenoid valve of the second aspect, in addition to the effect of the solenoid valve of the first aspect,
When the movable core is attracted to the fixed core by the magnetic flux generated by the permanent magnet and the biasing force of the biasing means, the biasing force is greater than the attractive force when the movable core is separated from the fixed core. Since the suction force is set to be larger than the urging force in a state where the coil is in contact with the fixed iron core, the moving state of the movable iron core, that is, the open / close state of the valve seat can be reliably maintained even when the coil is not energized.

According to the solenoid valve of the third aspect, in addition to the effect of the solenoid valve of the first or second aspect, the magnetic flux of the permanent magnet is fixed to the movable iron core and fixed by the first magnetic body and the second magnetic body. It can effectively act on the iron core, and can reliably maintain the attracted state by the magnetic flux action of the permanent magnet.

According to the solenoid valve of the fourth aspect, in addition to the effect of the solenoid valve of the third aspect,
By using a coil case as the first magnetic body and fitting the fitting hole of the second magnetic body to the outside of the cylindrical body, the permanent magnet can be easily assembled to the solenoid valve, and has a simple configuration. it can.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a closed state of a solenoid valve according to an embodiment of the present invention.

FIG. 2 is a sectional view of the solenoid valve in an open state;

FIG. 3 is a cross-sectional view illustrating a case where the solenoid valve is switched from an open state to a closed state.

FIG. 4 is a cross-sectional view of a conventional solenoid valve.

[Explanation of symbols]

 11 Valve body 14 Flow path 15 Valve seat 16 Tube as a cylinder 17 Fixed iron core 18 Movable iron core 21 Spring 22 as a biasing means 22 Coil 23 Coil case as a first magnetic body 28 Second magnetic body 29 Fitting hole 30 permanent magnet

Claims (4)

[Claims] A valve body having a flow path and a valve seat provided in the middle of the flow path; a tubular body having one end fixed to the valve body; a fixed iron core fixed to the other end of the tubular body; A movable core that is arranged movably in the axial direction in the cylindrical body, and that opens and closes the valve seat by moving in the axial direction; a biasing unit that biases the movable core in a direction away from the fixed core; A coil that is disposed on the outer periphery of the cylindrical body and generates a magnetic flux that attracts the movable core to the fixed core and a magnetic flux that separates the movable core from the fixed core in accordance with the direction of current supply; And a permanent magnet which is magnetically polarized in a different direction in the axial direction and generates a magnetic flux for attracting the movable core to the fixed core. 2. The attraction force of the movable iron core being attracted to the fixed iron core by the magnetic flux generated by the permanent magnet and the urging force of the urging means are more than the attraction force in the state where the movable iron core is separated from the fixed iron core. 2. The solenoid valve according to claim 1, wherein the suction force is set to be larger than the urging force when the movable core is in contact with the fixed core. 3. A first magnetic body that supports one end of the permanent magnet in the axial direction with respect to the cylindrical body and forms a magnetic path between the permanent magnet and the fixed iron core; 3. The solenoid valve according to claim 1, further comprising a second magnetic body having an end supported on the cylindrical body and forming a magnetic path between the permanent magnet and the movable iron core. 4. The first magnetic body is a coil case for holding a coil, and the second magnetic body is a disc-shaped and has a fitting hole at a central portion fitted to the outside of the cylindrical body. 4. The solenoid valve according to claim 3, wherein: