JP2009281472A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small solenoid valve for surely operating for opening-closing with small electric power. <P>SOLUTION: A plate-like valve element 14 is arranged so as to be opposed to U-shaped both extension parts 11a and 11b in a U-shaped yoke 11, and a valve seat 15 is arranged in a fuel passage 8, and a compression coil spring 18 is arranged for energizing the valve element in the valve closing direction, and an interval to the valve element is lengthened in the one extension part 11a wound with an excitation coil 13 more than the other. There is no need to separately arrange the valve element since a movable iron core also serves as the valve element, and the movable iron core is reduced in weight. In the initial stage of current-carrying, the side to the one extension part wound with the excitation coil is attracted first, and the movable iron core loses an interval difference to both extension parts by its attraction operation, and afterwards, attraction is performed without a time difference to both extension parts by being attracted to both extension parts. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a solenoid valve used to open and close a fluid passage.

  2. Description of the Related Art Conventionally, there is a fuel control solenoid valve in which a carburetor and a solenoid valve are integrally combined, and a fuel supply passage to the carburetor is opened and closed by the solenoid valve. Some of the solenoid valves have a configuration in which the solenoid valve is operated by electric power generated by a magnet or power from a battery. For example, an exciting coil is formed on a bobbin formed of a synthetic resin material into a hollow cylindrical shape. Some steel yokes are disposed so as to cover the outer peripheral surface thereof, and a fixed iron core and a movable iron core are coaxially arranged in a hollow cylindrical bobbin (for example, patents). Reference 1).

  The electromagnetic valve is configured, for example, as shown in FIG. In the figure, a yoke 21 is formed from a yoke body 21a formed by bending a steel plate into a U shape (inverted U shape in the figure) and a plate-like yoke lid 21b that closes the opening of the yoke body 21a. The yoke 21 includes a cylindrical bobbin 22 having outward flanges at both ends in the axial direction, and a columnar fixed iron core 23 that is disposed in the bobbin 22 so as to enter the bottom wall portion of the yoke body 21a. And a cylindrical movable iron core 24 disposed coaxially opposite the fixed iron core 23 and provided so as to protrude and retract in the bobbin 22, and coaxially interposed between the fixed iron core 23 and the movable iron core 24. A compression coil spring 25 is incorporated. The bobbin 22 is wound with an exciting coil 26 for magnetically attracting the movable iron core 24 to the fixed iron core 23 in an excited state. In the non-excited state, the movable iron core 24 is a spring biasing force of the compression coil spring 25. Thus, the yoke 21 is projected outward.

  Further, one axial end of the movable iron core 24 protrudes outward (downward in the drawing) from the yoke lid 21b, and a valve body 27 is coupled to the protruding end. The valve body 27 is disposed so as to open and close fluid passages 29 a and 29 b formed in the vaporizer body 28. The fluid passage 29a is connected to a fuel pump (not shown), and the fluid passage 29b communicates with a fuel outlet (not shown) facing the mixture passage. Between both the fluid passages 29a and 29b, the valve seat 30 which connects both the passages 29a and 29b is disposed. The valve seat 30 is opened and closed by the reciprocating motion of the movable iron core 24, that is, the valve body 27, and thus the electromagnetic valve is configured.

In the electromagnetic valve having the above-described structure, the valve seat 30 is fully closed by the valve element 27 when the movable iron core 24 protrudes. Therefore, in order to ensure the expansion / contraction length of the compression coil spring 25 that biases the movable iron core 24 in the non-excited state of the exciting coil 26, and to secure the magnetic flux amount between the iron cores 23 and 24 at the start of suction 24 is formed with a coil spring holding hole 24a that can receive the entire length of the compression coil spring 25 in a compressed state. The coil spring holding hole may be provided in the fixed iron core 23.
JP-A-8-14107

  As described above, since the coil spring holding hole 24a is provided in the movable iron core 24, the entire length of the movable iron core 24 is increased. Furthermore, since the opening of the valve seat 30 is opened and closed by the valve body 27 integral with the movable iron core 24, the straight movement of the movable iron core 24 is required. To achieve this, the length of the movable iron core 24 in the reciprocating direction is increased. . Ensuring this straightness is also necessary when a coil spring holding hole is provided in the fixed iron core 23, and the movable iron core 24 remains long.

  Due to the length of the movable iron core 24, there is a problem that the movable iron core 24 is increased in size and weight. Further, if the movable iron core 24 is heavy, it is disadvantageous for vibration resistance in mounting the engine. For example, in order to prevent the valve element 27 from opening even under high vibration in a closed state, it is necessary to increase the spring force of the compression coil spring 25. The heavier the movable iron core 24, the stronger the spring is biased. There is a need. When the valve is opened, the movable iron core 24 urged by a strong spring force is magnetically attracted, and a large magnetic force (current) is required to operate the valve body 27 in the valve opening direction. There is a problem of increasing the size.

  In order to solve such a problem and realize a solenoid valve that opens and closes reliably even with a small size and low power, in the present invention, a U-shaped fixed iron core and the U-shaped fixed iron core An excitation coil wound around one extension part and a bridged state with respect to both extension parts in the U-shape of the fixed iron core, and both extension ends of the extension parts A movable iron core provided detachably, and a solenoid provided with a spring means for biasing the movable iron core in a direction to separate the movable iron core from the two extending portions of the fixed iron core, the movable iron core comprising the spring means The fluid passage is closed in a state where the fluid passage is energized by and separated from the two extension portions, and the fluid passage is opened in a state where the fluid passage is adsorbed by the excitation coil and is in contact with the extension portions. Displaceable in the contact / separation direction by a part of the fluid passage The distance between the two extending portions of the movable iron core that faces the two extending portions is opposite to the one extending portion around which the exciting coil is wound. It is supposed to be longer than the one against.

  In particular, a bent engagement portion having a bent end portion is provided at a portion facing the other extension portion of the movable iron core, and is separated from the bent engagement portion by a predetermined length in the fully closed state, and It is preferable that an engaging pin made of a magnetic material is provided at a position where the bent engaging portion is engaged when the movable iron core is attracted to and tilted by the one extending portion in the initial stage of energizing the exciting coil. .

  As described above, according to the first aspect of the present invention, the movable iron core disposed in a bridging state between the two extending portions of the U-shaped fixed iron core is biased by the spring means and separated from the two extending portions. Since the fluid passage is closed in the state and acts as a valve body that opens the fluid passage while being attracted to both extension portions by excitation by energization of the excitation coil, the movable iron core is formed in a plate shape In addition, since the movable iron core also serves as the valve body, there is no need to provide a separate valve body, and the weight of the movable iron core can be reduced.

  In addition, the interval between the movable iron core and the two extension portions of the fixed iron core is longer than the other extension portion around which the exciting coil is wound. In this case, one extension part wound with an exciting coil is sucked first, and the suction operation eliminates the gap between the two extension parts, and then the suction part is attracted to both extension parts. Thus, adsorption without time difference is performed on both the extending portions. When the distance between the movable cores with respect to both extending portions of the U-shaped fixed iron core is the same, the movable iron core is first adsorbed by the one having a strong attractive force (the one on which the excitation coil is wound). Since it is adsorbed on the other side, there is a problem that the valve opening operation is in two stages and the stability of the valve opening operation is lacking. On the other hand, the valve opening operation can be stabilized by the above structure.

  According to the second aspect of the present invention, when the movable iron core is attracted and tilted first with respect to the one extending portion wound with the exciting coil, the other extending portion becomes the engaging pin by the tilting. The engaging pin becomes the pivot in the tilting motion of the movable iron core. As a result, the position of the movable iron core is regulated by the engagement pin, so that resistance due to sliding contact when a guide structure such as a guide groove is provided does not occur, and the movable iron core can be tilted, that is, opened by a simple structure. Can be stabilized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic front view showing an entire vaporizer to which the present invention is applied. The carburetor is mounted on, for example, an engine of a two-cycle internal combustion engine, and the throttle valve may be a rotary valve type.

  The carburetor body 1 is formed with an air-fuel mixture passage 1a penetrating in the front and back direction in the figure. In the air-fuel mixture passage 1a, a fuel nozzle 2 that crosses the air-fuel mixture passage 1a in the diameter direction and in the vertical direction in the figure. Is provided. The fuel nozzle 2 is formed in a tube shape, is provided coaxially with the axis of the valve body 3 having a cylindrical shape, and projects into a through hole formed in the radial direction of the valve body 3. A needle-like fuel adjustment valve 4 is integrally attached to the valve body 3 so as to face the fuel nozzle 2 and to change the amount of immersion in the fuel nozzle 2 in accordance with the displacement of the valve body 3 in the axial direction (vertical direction in the figure). ing. Fuel is injected into the air-fuel mixture passage 1a in accordance with the amount of immersion of the fuel adjustment valve 4 with respect to the fuel nozzle 2.

  A fuel control chamber body 5 and an atmospheric pressure chamber body 6 are integrally assembled at the lower part of the carburetor body 1. Between the fuel control chamber body 5 and the atmospheric pressure chamber body 6, the supply pressure of fuel sent from the fuel control chamber (not shown) provided in the fuel control chamber body 5 toward the fuel nozzle 2 is kept constant. A diaphragm (not shown) is provided. Further, the carburetor body 1 is integrally formed with an extending portion 1b extending to one side, and the extending portion 1b is provided with a solenoid valve 7 according to the present invention in parallel with the carburetor body 1. It is attached. A fluid passage 8 extending from the fuel control chamber body 5 to the fuel nozzle 2 is piped via an extending portion 1b, and a portion corresponding to the extending portion 1b in the fluid passage 8 is driven by a fuel control solenoid valve 7. An on-off valve 9 is provided.

  Next, the electromagnetic valve 7 will be described with reference to FIG. The solenoid valve 7 is replaced with a U-shaped (reverse U-shaped in the figure) -shaped yoke 11 as a fixed iron core, and one extending portion 11a in the U-shaped of the yoke 11, and has outward flanges at both axial ends. As a movable iron core arranged so as to be bridged between both ends of the bobbin 12, the exciting coil 13 wound around the body portion between both outward flanges of the bobbin 12, and the both extending portions 11 a and 11 b of the yoke 11. And a long plate-like valve body 14.

  As shown in the drawing, a chamber 8a is formed in the turning portion of the fluid passage 8 provided to turn at the extending portion 1b, and the valve element 14 is received in the chamber 8a. A valve seat 15 is disposed on the side of the chamber 8a that communicates with the fuel control chamber body 5. The valve seat 15 is provided with an axial hole 15 a as a part of the fluid passage 8 opened and closed by the valve body 14.

  The valve seat 15 is formed in a shape having an outward flange 15b at an axially intermediate portion of the cylindrical body, and an O-ring 16 is fitted on the fuel control chamber body 5 side of the outward flange 15b. In addition, the bobbin 12 is formed with a pair of opposing wall portions 12a that rush into the room 8a when attached to the extending portion 1b. The valve seat 15 is positioned and fixed by a pair of opposing wall portions 12a.

  Further, the opposing wall portions 12a are connected to the side of the valve seat 15 at a position facing the other extending portion 11b of the yoke 11 and facing the extending direction of the extending portion 11b with a predetermined interval L1. An engagement pin 17 is provided so as to be attached. A valve body 14 is disposed so as to cross between the other extending portion 11b and the engagement pin 17, and the end of the valve body 14 on the engagement pin 17 side is on the engagement pin 17 side. A bent engagement portion 14a is formed.

  The valve body 14 is spring-biased until it comes into contact with the valve seat 15 by a compression coil spring 18 as a spring means interposed between the valve body 14 and the bobbin 12. With the valve seat 14 in contact, the axial hole 15a of the valve seat 15 is closed. FIG. 2 shows this state, and the electromagnetic valve 7 is fully closed.

  Further, a difference L2 is provided between the length of one extension portion 11a of the yoke 11 and the length of the other extension portion 11b with respect to the extension direction (the urging direction of the compression coil spring 18). Yes.

  The exciting coil 13 is tangled and soldered to the bald pin 19 provided on the flange surface on the side opposite to the room 8a side of the bobbin 12, and the lead coil 20 is soldered to the bald pin 19. Connected to an external power supply circuit (not shown). And in order to protect an electric system, the whole is overmolded so that it may be shown with a dashed-two dotted line.

  The on-off valve operation in the electromagnetic valve 7 configured as described above will be described with reference to FIG. In the initial stage when the exciting coil 13 is energized in the fully closed state of FIG. 2, a large magnetic flux is generated in one extending portion 11 a around which the exciting coil 13 is wound in the yoke 11. Since the magnetic attraction force by 11a is large and the magnetic attraction force by the other extension part 11b is still weak, the valve body 14 which is a movable iron core tilts so that the one extension part 11a side may be largely displaced. Due to the tilting, the bent engagement portion 14a of the valve body 14 is brought into contact with and engaged with the engagement pin 17 as shown in FIG. 3 (a) so that the engagement pin 17 serves as a pivot (rotation center). The valve body 14 can tilt. And one longitudinal direction edge part of the valve body 14 is adsorb | sucked and contact | abutted to the magnetic pole surface of one extension part 11a.

  Thus, since the valve body 14 is attracted and tilted with respect to the one extending portion around which the exciting coil is wound, some kind of guide is necessary to stabilize the tilting motion. When a guide plate that guides both side edges of the valve body 14 is provided, the valve body 14 tilts while slidingly contacting the guide plate, resulting in a large resistance. On the other hand, as described above, the valve body 14 can be tilted with its position being restricted by the engagement pin 17 with a simple structure in which the bent engagement portion 14a is engaged with the engagement pin 17. In this case, the tilting of the valve body 14, that is, the valve opening operation can be stabilized.

  3A, the magnetic attractive force between the other longitudinal end of the valve element 14 and the other extending portion 11b is increased, as shown in FIG. 3B. In addition, the other longitudinal end of the valve element 14 is adsorbed to the magnetic phase of the other extending portion 11b. As a result, the electromagnetic valve 7 is fully opened, and the fuel supplied from the fuel control chamber 5 can flow toward the fuel nozzle 2.

  Since the valve body 14 is thus opened, even if the valve body 14 is freely displaced to some extent without providing a guide portion for guiding the valve body 14 with high accuracy, It will be displaced in a substantially positioned state by contact. The valve body 14 can operate satisfactorily without significantly deviating from the position set in the valve opening operation (contact position to the engagement pin 17).

  Further, the solenoid valve 7 has a structure that opens and closes by tilting the plate-like valve body 14, and since the valve body 14 is a movable iron core, the weight can be greatly reduced when viewed as a whole movable iron core including the valve body. And a large spring force is not required to prevent the valve from opening due to vibration. Therefore, the magnetic attractive force at the time of valve opening may be small, and the electromagnetic valve 7 can be operated with low power by downsizing the exciting coil 13. Thus, reliable vibration resistance of the solenoid valve 7 is ensured, and the solenoid valve 7 as a whole can be reduced in size and weight.

  When the energization of the exciting coil 13 is stopped, the valve body 14 is immediately separated from both the extending portions 11a and 11b of the yoke 11 by the spring biasing force of the compression coil spring 18 and pressed against the valve seat 15. As a result, the fully closed state shown in FIG. 2 is obtained.

  The solenoid valve according to the present invention has an effect of ensuring vibration resistance, reducing the size and weight, and realizing operation with low power, and is installed in a device that requires vibration resistance. Useful as.

It is a schematic front view which shows the whole vaporizer to which this invention was applied. It is a principal part expanded sectional view which shows the structure of a solenoid valve. (A) is a schematic diagram which shows the valve opening state of the valve body of an electricity supply initial stage, (b) is a figure corresponding to (a) which shows a fully open state. It is principal part side sectional drawing which shows the conventional solenoid valve for fuel control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vaporizer body 7 Solenoid valve 8 Fluid passage 9 On-off valve 11 Yoke 11a One extension part 11b The other extension part 12 Bobbin 13 Excitation coil 14 Valve body 15 Valve seat 17 Engagement pin

Claims (2)

A U-shaped fixed iron core, an excitation coil wound around one extension portion of the fixed iron core in the U-shape, and a bridge state with respect to both extension portions of the fixed iron core in the U-shape. A movable iron core that is disposed and provided so as to be able to contact with and separate from both extension ends of the two extension portions, and a spring that urges the movable iron core in a direction to move away from the two extension portions of the fixed core. And a solenoid comprising means,
The movable iron core is urged by the spring means to close the fluid passage in a state where the movable iron core is separated from the two extension portions, and is attracted by the excitation coil and is in contact with the two extension portions. Guided to be displaceable in the contact / separation direction by a part of the fluid passage so as to open the fluid passage;
The distance between the two extending portions of the movable iron core that faces both the extending portions is greater than the one extending portion around which the exciting coil is wound than the other extending portion. A solenoid valve characterized by being lengthened. A bent engagement portion having a bent end is provided at a portion facing the other extension portion of the movable iron core, and
In the fully closed state, the bent engaging portion is engaged with the bent engaging portion by separating the predetermined length from the bent engaging portion and tilting the movable iron core by being attracted to the one extending portion at the initial energization of the exciting coil. The electromagnetic valve according to claim 1, wherein an engagement pin made of a magnetic material is provided at a position where the magnetic valve is placed.

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