JP2017057935A - solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a structure, while securing the suction force between a core of a solenoid valve and a plunger.SOLUTION: A guide pipe 9 is inserted into the inside of a bobbin 3 in which an electromagnetic coil 2 is wound around the outer periphery thereof, and a plunger 13, in which a valve body 14 provided at one end, is inserted into the guide pipe so as to be movable in the axial direction. Further, the solenoid valve includes: an energizing spring 12 for energizing the plunger toward the valve body side; and a core 4 for attracting the plunger from the side opposite to the valve body when electrifying the electromagnetic coil. Then, an end part of the core side of the guide pipe is sealed, the core is placed in close contact with the outside of the sealed end 9a, and the other end of the plunger on the opposite side from the valve body can be brought into contact with the inside of the sealed end. Thus, there is no possibility that the fluid leaks from the sealed end of the guide pipe, and the structure can be simplified by omitting a seal member. And, when energizing the electromagnetic coil, the suction force can be secured by interposing the sealed end between the core and the plunger to minimizing the distance between them.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electromagnetic valve that drives a valve body that opens and closes a fluid passage by using a magnetic force generated by energization of an electromagnetic coil.

  In gas equipment such as a water heater, an electromagnetic valve is used to open and close a passage of fuel gas (fluid) supplied to the burner. In the solenoid valve, a guide pipe is inserted inside a cylindrical bobbin around which an electromagnetic coil is wound, and a plunger is movable in the axial direction in the guide pipe. A valve body for opening and closing the passage is provided. Further, an urging spring that urges the plunger toward the valve body side, a core that attracts the plunger from the side opposite to the valve body inside the bobbin when energizing the electromagnetic coil, and the like are provided.

  When the electromagnetic coil is energized, a magnetic attractive force is generated between the core and the plunger, and the plunger is attracted to the core against the urging force of the urging spring, so that the valve body is separated from the valve seat in the passage. Open the passage. On the other hand, when the energization is stopped, the magnetic attractive force disappears and the plunger is not attracted to the core, and the valve body comes into contact with the valve seat by the urging force of the urging spring to close the passage. The electromagnetic valve operating in this way has a feature that the response speed of opening and closing the passage is faster than an electric valve driven by a motor or the like.

  In such an electromagnetic valve, it has been proposed to insert a core into the guide pipe from the end opposite to the valve body of the guide pipe and fix the core in that state (for example, Patent Document 1). ). By reducing the distance between the core and the plunger when the electromagnetic coil is energized in this way, it becomes easy to obtain a large suction force, and the valve opening state can be stabilized while reliably opening the valve.

JP 2000-205432 A

  However, an electromagnetic valve with the core inserted inward from the end of the guide pipe is advantageous for obtaining an attractive force between the core and the plunger, but fluid may leak from the gap between the core and the guide pipe. In order to prevent this, there is a problem that a seal member such as packing is separately required.

  The present invention has been made in response to the above-described problems in the prior art, and does not require a seal member between the core and the guide pipe while ensuring a suction force between the core and the plunger of the solenoid valve. The purpose is to provide a technique capable of simplifying the structure.

In order to solve the above-described problems, the solenoid valve of the present invention employs the following configuration. That is,
A cylindrical bobbin around which an electromagnetic coil is wound on the outer periphery, a non-magnetic metal guide pipe inserted inside the bobbin, and a valve body for opening and closing a fluid passage are provided at one end, and inside the guide pipe A plunger made of magnetic metal that is movable in the axial direction, a biasing member that biases the plunger toward the valve body side, and opposite to the valve body inside the bobbin when energizing the electromagnetic coil In a solenoid valve comprising a magnetic metal core that attracts the plunger from the side,
The guide pipe has a sealed end in which the end on the core side is sealed integrally with the peripheral surface,
The core is installed in close contact with the outside of the sealed end of the guide pipe,
When the electromagnetic coil is energized, the other end of the plunger opposite to the valve body can be brought into contact with the inside of the sealed end of the guide pipe.

  In such a solenoid valve of the present invention, since the end of the guide pipe on the core side is sealed, there is no risk of fluid leaking from the guide pipe, and a seal member such as packing is omitted to simplify the structure. be able to. When energizing the electromagnetic coil, the suction force can be secured by minimizing the distance between the core and the plunger with the sealed end of the guide pipe interposed therebetween. As a result, it is possible to reliably open the valve and stabilize the valve opening state.

  In the electromagnetic valve of the present invention described above, a cylindrical collar that is inserted between the inner periphery of the bobbin and the outer periphery of the guide pipe and is located on the plunger side of the core is integrated with the core with a magnetic metal material. You may form.

  By providing such a collar, immediately after the start of energization of the electromagnetic coil, first, a magnetic attraction force is generated between the collar and the plunger, and the plunger is drawn into the inside of the collar. The valve opening can be started. In addition, by forming the collar integrally with the core, the flow of magnetic flux (line of magnetic force) from the collar to the core is smoothed, and the attractive force acting on the plunger is increased, and the part is more than the case where it is provided separately. The number of points can be reduced to simplify the structure.

  In addition, in the electromagnetic valve of the present invention, a magnetic metal frame that clamps the bobbin from both sides in the axial direction is provided, and the core is brought into close contact with the frame, and the plunger is inserted into the insertion hole formed in the frame. You may keep it.

  In this way, since the magnetic flux generated by energizing the electromagnetic coil flows from the core through the frame to the plunger, leakage of the magnetic flux can be reduced and the attractive force between the core and the plunger can be increased. it can.

It is sectional drawing which showed the state which decomposed | disassembled the solenoid valve 1 of a present Example. It is sectional drawing which showed the state which assembled the solenoid valve 1 of a present Example. It is sectional drawing which showed the state which supplied with electricity to the electromagnetic coil 2 of the solenoid valve 1 of a present Example. It is sectional drawing which showed the structure of the solenoid valve 1 of a prior art example. It is explanatory drawing which showed the characteristic of the attractive force which acts on the plunger 13 with the solenoid valve 1 of a present Example. It is sectional drawing which showed the structure of the solenoid valve 1 of a modification.

  FIG. 1 is a sectional view showing an exploded state of the electromagnetic valve 1 of the present embodiment. The electromagnetic valve 1 is mounted on a gas device (not shown) such as a water heater, and is used for opening and closing a passage for supplying fuel gas to the burner. In the electromagnetic valve 1 of this embodiment, first, an electromagnetic coil 2 is wound around the outer periphery of a cylindrical bobbin 3 made of a resin material, and is formed integrally with the cylindrical upper collar 5 and a magnetic metal material. A cylindrical core 4, a cylindrical coil spring 6, and a cylindrical lower collar 7 formed of a magnetic metal material are accommodated inside the bobbin 3 and supported by a magnetic metal frame 8. The upper collar 5, the coil spring 6, and the lower collar 7 have the same inner diameter. Moreover, iron, nickel, cobalt, or those alloys can be illustrated as a magnetic metal.

  The frame 8 is formed in a U-shape in which a metal flat plate is bent and an upper plate portion 8a and a lower plate portion 8b are connected by a side plate portion 8c, and the bobbin 3 is formed by the upper plate portion 8a and the lower plate portion 8b. Is clamped from both sides in the central axis direction (vertical direction in the figure). A through hole 8d is formed in the upper plate portion 8a, and a convex portion 4a formed on an end surface (upper surface in the drawing) opposite to the upper collar 5 of the core 4 is fitted into the through hole 8d, so that the frame The bobbin 3 is positioned with respect to 8.

  Further, an insertion hole 8 e having the same diameter as the inner diameter of the lower collar 7 is formed in the lower plate portion 8 b of the frame 8, and a guide is provided from the insertion hole 8 e to the inside of the lower collar 7, the coil spring 6, and the upper collar 5. The pipe 9 is inserted. The guide pipe 9 is formed in a cylindrical shape using a nonmagnetic metal material, and an end portion on the core 4 side is a sealed end 9 a that is sealed integrally with the peripheral surface. Examples of the nonmagnetic metal include copper, aluminum, and brass. On the other hand, on the outer periphery of the portion protruding from the insertion hole 8e of the lower plate portion 8b on the side opposite to the sealed end 9a of the guide pipe 9, an annular packing 10 made of rubber or the like and a fitting formed on the bottom plate 11 The joint hole 11 a is fitted, and the bottom plate 11 is in close contact with the lower plate portion 8 b of the frame 8.

  A cylindrical plunger 13 made of a magnetic metal material is inserted into the guide pipe 9 so as to be movable in the axial direction (vertical direction in the figure). A valve body 14 for opening and closing the fuel gas passage is provided at one end of the plunger 13, and a cylindrical buffer member 15 formed of rubber or the like is provided at the other end opposite to the valve body 14. Embedded. Further, when the plunger 13 is inserted into the guide pipe 9, the plunger 13 is passed inside the conical energizing spring 12 and is energized between the bottom plate 11 and the valve body 14. The plunger 13 is biased toward the valve body 14 by the elastic force of 12 (downward in the figure). The urging spring 12 of this embodiment corresponds to the “urging member” of the present invention.

  FIG. 2 is a cross-sectional view showing a state in which the electromagnetic valve 1 of this embodiment is assembled. In the figure, a state in which the electromagnetic coil 2 is not energized is shown. As shown in the figure, a coil spring 6 is sandwiched between an upper collar 5 and a lower collar 7 formed integrally with the core 4, and the core 4 is an upper plate of the frame 8 by the elastic force of the coil spring 6. The lower collar 7 is pressed against the lower plate portion 8b of the frame 8 by being pressed against the portion 8a. The guide pipe 9 is inserted inside the upper collar 5, and the core 4 is in close contact with the outside of the sealed end 9 a of the guide pipe 9.

  The electromagnetic valve 1 of this embodiment is fixed by screwing or the like so that the opening 21 provided in the middle of the fuel gas (fluid) passage 20 is covered with the bottom plate 11. An annular packing 22 made of rubber or the like is sandwiched between the opening 21 and the bottom plate 11 in order to prevent leakage of fuel gas. Then, since the plunger 13 is urged in a direction (downward in the drawing) from the guide pipe 9 by the urging spring 12, the valve body 14 is pressed against the valve seat 23 provided in the passage 20. The passage 20 is closed.

  FIG. 3 is a cross-sectional view showing a state in which the electromagnetic coil 2 of the electromagnetic valve 1 of this embodiment is energized. When the electromagnetic coil 2 is energized, a magnetic attractive force is generated between the core 4 and the upper collar 5 and the plunger 13, and the plunger 13 is attracted to the core 4 against the urging force of the urging spring 12. As a result, the valve body 14 leaves the valve seat 23 and opens the passage 20.

  In the solenoid valve 1 of the present embodiment, as shown in FIG. 3, the end of the plunger 13 opposite to the valve body 14 (hereinafter, the tip) may abut on the inside of the sealed end 9 a of the guide pipe 9. The passage 20 is fully opened at the abutting position. Further, as described above, the buffer member 15 made of rubber or the like is embedded in the tip of the plunger 13 that contacts the inside of the sealed end 9 a of the guide pipe 9, and the plunger 13 is attracted to the core 4. This reduces the impact when contacting the closed end 9a.

  Thereafter, when energization of the electromagnetic coil 2 is stopped, the magnetic attractive force between the core 4 and the upper collar 5 and the plunger 13 disappears, and the plunger 13 is pulled out from the guide pipe 9 by the biasing force of the biasing spring 12. It is. As a result, as shown in FIG. 2, the valve body 14 is pressed against the valve seat 23 and the passage 20 is closed.

  In the electromagnetic valve 1 of the present embodiment as described above, the structure is simpler than that of the conventional electromagnetic valve 1 while ensuring the magnetic attractive force between the core 4 and the plunger 13 when the electromagnetic coil 2 is energized. Can be achieved. Although this point will be described below, the structure of the electromagnetic valve 1 of the conventional example will be briefly described as a comparison.

  FIG. 4 is a cross-sectional view showing the structure of a conventional solenoid valve 1. In FIG. 4, the periphery of the core 4 is mainly shown, and the urging spring 12 and the valve body 14 are not shown. The illustrated state is a state in which the electromagnetic coil 2 is not energized. In the illustrated solenoid valve 1 of the conventional example, the end portion on the core 4 side of the guide pipe 9 is not sealed but is an open end. The open end contacts the upper plate portion 8a of the frame 8, and the open end. The core 4 is inserted into the guide pipe 9. The core 4 passes the caulking portion 4b protruding from the end surface (upper surface in the drawing) opposite to the plunger 13 side through the through hole 8d formed in the upper plate portion 8a of the frame 8, and the caulking portion 4b. The tip of the is crushed and fixed. Further, the upper collar 5 of the conventional example is provided separately from the core 4 and is inserted between the inner periphery of the bobbin 3 and the outer periphery of the guide pipe 9.

  In such a conventional solenoid valve 1, since the core 4 is inserted inside the guide pipe 9, by reducing the interval between the core 4 and the plunger 13 when energizing the electromagnetic coil 2, It is advantageous for obtaining a large magnetic attractive force. On the other hand, fuel gas may leak from the gap between the core 4 and the guide pipe 9, and an annular packing 30 formed of rubber or the like is sandwiched between the core 4 and the guide pipe 9 in order to prevent leakage. There is a need.

  On the other hand, in the solenoid valve 1 of the present embodiment, as shown in FIG. 2, the end portion on the core 4 side of the guide pipe 9 is a sealed end 9a. Therefore, there is no possibility that the fuel gas leaks from the guide pipe 9, and the packing 30 can be omitted, and the structure can be simplified compared to the conventional solenoid valve 1. Moreover, since the core 4 of this embodiment is pressed against the upper plate portion 8a of the frame 8 by the coil spring 6 inserted between the inner periphery of the bobbin 3 and the outer periphery of the guide pipe 9, the core 4 is The caulking to be fixed to the portion 8a is unnecessary, and the structure of the electromagnetic valve 1 can be further simplified.

  In the electromagnetic valve 1 of the present embodiment, the core 4 is installed in close contact with the outside of the sealed end 9a of the guide pipe 9, and the plunger 13 is at the tip (end opposite to the valve body 14). Is set so as to be able to contact the inside of the closed end 9 a of the guide pipe 9. By doing so, a magnetic attractive force between the core 4 and the plunger 13 can be ensured.

  FIG. 5 is an explanatory diagram showing the characteristics of the attractive force acting on the plunger 13 in the electromagnetic valve 1 of this embodiment. In the graph of FIG. 5, the relationship between the axial attractive force acting on the plunger 13 by energization of the electromagnetic coil 2 and the position of the plunger 13 moving in the guide pipe 9 is indicated by a solid line. The relationship between the urging force (spring load) of the urging spring 12 acting on the plunger 13 and the position of the plunger 13 is indicated by a one-dot chain line.

  In the fully closed position (see FIG. 2) in which the valve body 14 is in contact with the valve seat 23, the core 4 and the plunger 13 are separated from each other, so that the attractive force (magnetic force) is mainly generated by the upper collar 5 and the plunger 13. Occurs between. In the present embodiment, the tip of the plunger 13 is slightly inside the upper collar 5 in the fully closed position, and a suction force sufficiently larger than the spring load is generated. It starts to open when it is pulled in (inside the upper collar 5).

  When the plunger 13 enters the guide pipe 9, the area between the inner periphery of the upper collar 5 and the outer periphery of the plunger 13 is increased by an increase in the facing area between the inner periphery of the upper collar 5 and the outer periphery of the plunger 13 ( That is, since a magnetic force acts on the radial direction of the plunger 13, the axial attractive force of the plunger 13 becomes small. Further, as the plunger 13 enters the guide pipe 9, the urging spring 12 is compressed, so that the spring load increases.

  When the plunger 13 further enters the guide pipe 9, the distance between the core 4 and the plunger 13 is reduced, and a suction force is generated between the core 4 and the tip of the plunger 13. . However, if there is a clearance between the core 4 and the closed end 9a of the guide pipe 9, the suction force between the core 4 and the tip of the plunger 13 is as shown by the broken line in FIG. Without being obtained, the suction force acting in the axial direction of the plunger 13 decreases, and the plunger 13 may stagnate at a position balanced with the spring load. Therefore, in order to fully open the solenoid valve 1, a larger solenoid coil 2 is required, and as a result, the solenoid valve 1 itself becomes large.

  On the other hand, in the electromagnetic valve 1 of the present embodiment, the core 4 is installed in close contact with the outside of the sealed end 9 a of the guide pipe 9, and suction generated between the core 4 and the tip of the plunger 13. Due to the force contribution, the axial suction force acting on the plunger 13 increases as the plunger 13 approaches the core 4. At the fully open position (see FIG. 3) where the tip of the plunger 13 comes into contact with the inside of the sealed end 9a of the guide pipe 9, the distance between the core 4 and the plunger 13 is minimized with the sealed end 9a interposed therebetween. A suction force larger than the spring load can be secured. As a result, the electromagnetic valve 1 can be reliably fully opened and the fully opened state can be stabilized.

  Further, as described above, the core 4 formed integrally with the upper collar 5 is pressed against the upper plate portion 8 a of the frame 8 by the coil spring 6. Thereby, the magnetic flux (line of magnetic force) generated by energizing the electromagnetic coil 2 flows from the core 4 to the plunger 13 through the upper plate portion 8a, the side plate portion 8c, and the lower plate portion 8b of the frame 8, so that the leakage of the magnetic flux The suction force between the core 4 and the plunger 13 can be increased. Further, since the lower collar 7 inserted between the inner periphery of the bobbin 3 and the outer periphery of the guide pipe 9 is pressed against the lower plate portion 8b, the plunger 13 is passed through the lower collar 7 from the lower plate portion 8b. The flow of magnetic flux to can be made smooth. As a result, the suction force between the core 4 and the upper collar 5 and the plunger 13 can be further increased as compared with the case where the lower collar 7 is not provided.

  The electromagnetic valve 1 of the present embodiment described above includes the following modifications. In the following, modifications will be described focusing on differences from the above-described embodiment. In the description of the modified example, the same components as those in the above-described embodiment are denoted by the same reference numerals and the description thereof is omitted.

  FIG. 6 is a cross-sectional view showing the structure of a modified electromagnetic valve 1. In FIG. 6, the periphery of the core 4 is mainly shown, and the urging spring 12 and the valve body 14 are not shown. The illustrated state is a state in which the electromagnetic coil 2 is not energized. In the embodiment described above, the closed end 9a of the guide pipe 9 is formed flat (see FIG. 2). On the other hand, the sealing end 9a of the guide pipe 9 of the modified example is formed with a tapered recess whose diameter is reduced toward the inside of the guide pipe 9 (downward in the drawing). The core 4 is provided with a taper-shaped protruding portion 4c corresponding to the sealed end 9a, and the protruding portion 4c is in close contact with the outside of the sealed end 9a. Furthermore, a tapered recess 13a corresponding to the sealed end 9a is provided at the tip of the plunger 13, and a buffer member 15 is embedded in the bottom surface of the recess 13a. And in the state which the plunger 13 exists in a fully closed position, the front-end | tip part of the protrusion part 4c is located inside the recessed part 13a.

  In the electromagnetic valve 1 of such a modified example, even if the interval in the axial direction (vertical direction in the drawing) between the core 4 and the plunger 13 is the same as that of the electromagnetic valve 1 of the above-described embodiment, Since the shortest distance between the core 4 and the plunger 13 (the distance between the outer periphery of the protruding portion 4 c of the core 4 and the inner periphery of the concave portion 13 a of the plunger 13) is reduced, a suction force is generated between the core 4 and the plunger 13. Can be easily generated, and the axial suction force acting on the plunger 13 can be increased.

  The electromagnetic valve 1 according to this embodiment and the modification has been described above. However, the present invention is not limited to the above-described embodiment and modification, and can be implemented in various modes without departing from the gist thereof. It is.

  For example, in the embodiment described above, the upper collar 5 is formed integrally with the core 4, but the upper collar 5 may be provided separately from the core 4. However, if the upper collar 5 is formed integrally with the core 4 as in the embodiment described above, the flow of magnetic flux from the upper collar 5 to the core 4 is made smooth, and the attractive force acting on the plunger 13 is increased. At the same time, the number of parts can be reduced to simplify the structure.

  In the above-described embodiment, the coil spring 6 is sandwiched between the upper collar 5 and the lower collar 7, and the core 4 is pressed against the upper plate portion 8 a of the frame 8 by the elastic force of the coil spring 6. However, as long as the core 4 is in close contact with the frame 8, the fixing method of the core 4 is not limited to this, and the core 4 may be fixed to the frame 8 by caulking (see FIG. 4). Even in this case, since the magnetic flux flows from the core 4 to the plunger 13 through the frame 8, the attractive force between the core 4 and the plunger 13 can be increased.

1 ... Solenoid valve, 2 ... Electromagnetic coil, 3 ... Bobbin,
4 ... core, 4a ... convex, 5 ... upper collar,
6 ... Coil spring, 7 ... Lower collar, 8 ... Frame,
8a ... Upper plate portion, 8b ... Lower plate portion, 8c ... Side plate portion,
8d ... through hole, 8e ... insertion hole, 9 ... guide pipe,
9a ... sealed end, 10 ... packing, 11 ... bottom plate,
12 ... Biasing spring, 13 ... Plunger, 14 ... Valve body,
15 ... buffer member, 20 ... passage, 21 ... opening,
22 ... packing, 23 ... valve seat, 30 ... packing.

Claims (3)

A cylindrical bobbin around which an electromagnetic coil is wound on the outer periphery, a non-magnetic metal guide pipe inserted inside the bobbin, and a valve body for opening and closing a fluid passage are provided at one end, and inside the guide pipe A plunger made of magnetic metal that is movable in the axial direction, a biasing member that biases the plunger toward the valve body side, and opposite to the valve body inside the bobbin when energizing the electromagnetic coil In a solenoid valve comprising a magnetic metal core that attracts the plunger from the side,
The guide pipe has a sealed end in which the end on the core side is sealed integrally with the peripheral surface,
The core is installed in close contact with the outside of the sealed end of the guide pipe,
When the electromagnetic coil is energized, the other end of the plunger opposite to the valve body can be brought into contact with the inside of the sealed end of the guide pipe. The solenoid valve according to claim 1,
A cylindrical collar that is inserted between the inner periphery of the bobbin and the outer periphery of the guide pipe and is located closer to the plunger than the core is formed integrally with the core from a magnetic metal material. Solenoid valve characterized by. The solenoid valve according to claim 1 or 2,
A magnetic metal frame that clamps the bobbin from both sides in the axial direction;
The core is in close contact with the frame;
The solenoid is characterized in that the plunger is inserted through an insertion hole formed in the frame.

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