JPH0436566B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a solenoid in which a plunger freely movably fitted into a center hole of a coil is attracted in one direction by energization of the coil.

Prior Art and Problems to be Solved by the Invention Conventionally, there are two types of such solenoids: a so-called leakage type and a core type. A short magnetic tube and a long magnetic tube are respectively fitted from both ends of the center hole, leaving a predetermined gap at the abutting part of both magnetic tubes, and a magnetic material is inserted into the long magnetic tube. It has a structure in which a plunger is inserted into it so that it can slide freely.
The plunger is attracted toward the short magnetic tube due to the interaction between the magnetic flux generated by the energization of the coil and passing through the thick parts of both magnetic tubes and the magnetic flux passing inside the plunger.On the other hand, the core type In this method, a non-magnetic tube is fitted into the center hole of a coil which is also fitted into the external iron core, and a plunger made of a magnetic material is slidably inserted into the non-magnetic tube, and the coil is magnetized by energization. It has a structure in which the core is fitted to the end of a non-magnetic tube, and when the coil is energized, the plunger is attracted to the magnetized core. When driving an opening/closing valve in which the valve body, which opens and closes the valve opening provided in the valve opening, is biased in the valve closing direction by the elasticity of a spring, the plunger, which is moved by the energization of the coil, presses the valve body against the biasing force of the spring. The on-off valve is attached to the on-off valve body in such a way that it is driven in the valve opening direction against the
When the valve body is in the state where the valve opening is closed, back pressure is acting on the valve body or it is stuck, so a large starting force is required at the moment the valve opening is opened, and the valve body is closed. Since the elasticity of the spring increases as the valve moves away from the valve opening, the driving force of the valve needs to increase in proportion to the distance traveled by the valve in order to move the valve element away from the valve port sufficiently. However, in a leakage type solenoid, the suction force with respect to the stroke of the plunger when the coil is energized has the characteristic shown by the solid line a in Figure 3, and when the valve body is in the position where the valve port is closed, the suction force is relatively large. A force is generated, but it increases as the plunger moves, and once it reaches a peak value, it gradually decreases, and when the valve body fully opens the valve port, it is smaller than when it was started, and the core This type of solenoid has the characteristic shown by the broken line b in the same figure, in which the suction force increases as the plunger moves, but the suction force is extremely small at startup. Even with this type of solenoid, it was not possible to obtain the characteristics required to drive the opening/closing valve, and conventionally it was possible to increase the overall attraction force over the entire stroke by making the coil larger or increasing the energizing current. This not only made the solenoid large and heavy, but also consumed a lot of power, making it uneconomical.

Means for Solving the Problems The present invention provides, as a means for solving the above-mentioned problems, a coil in the center hole of the coil fitted in the external core.
A magnetic tube with a non-magnetic part interposed in a part in the axial direction is fitted, and a plunger made of a magnetic material is slidably fitted into the magnetic tube, so that the magnetism generated by energization of the coil is generated. In a solenoid that attracts the plunger in one direction by the interaction between the magnetic flux passing through the thick part of the tube and the magnetic flux passing through the inside of the plunger, the front side in the direction of movement of the plunger due to energization of the coil of the magnetic tube. A core is fitted to the end of the plunger, which magnetizes when the coil is energized and attracts the plunger.

Effects and Effects of the Invention The solenoid of the present invention has the above configuration, and when the coil is energized, the attraction force of the plunger is generated due to the interaction between the magnetic flux that is generated and passes through the thick part of the magnetic tube and the magnetic flux that passes through the inside of the plunger. , the attraction force of the plunger due to the magnetization of the core is generated at the same time,
Therefore, it is possible to obtain characteristics that combine the characteristics of a conventional so-called leakage type solenoid, which generates a large suction force at startup, and the characteristics of a core type solenoid, in which the suction force increases as the plunger moves. Therefore, even a small coil with low power consumption generates a large suction force at startup, and the suction force increases as the plunger moves, making it suitable for driving the opening of a fluid on-off valve, for example. be.

Embodiment Hereinafter, an embodiment in which the present invention is applied to an on-off valve for water will be described based on the accompanying drawings.

In FIG. 1, reference numeral 1 denotes the body of a pilot-operated on-off valve, in which a diaphragm-shaped valve body for opening and closing the valve port 5 is located above the valve port 5 provided between the inlet 2 and the outlet 3. 6 is installed, and this valve body 6
A communication pipe 7 whose upper end is a valve seat 9 is inserted through the center of the valve body 6 to form a pilot valve 10 that communicates with and shuts off the pilot chamber 8 above the valve body 6 and the secondary side. A through hole 1 communicating between the pilot chamber 8 and the primary side is provided in a portion corresponding to the outside of the valve port 5.
1 is transparent, and a solenoid 12 for opening and closing the pilot valve 10 is mounted on the upper surface of the body 1 in correspondence with the upper part of the valve body 6.

This solenoid 12 is connected to a device hole 14 which is opened and formed in the upper surface of the body 1 above the valve body 6.
An external iron core 16 having a U-shaped cross section is placed on the upper surface of a synthetic resin base 15 that is tightly fitted into the base body 15, and a mounting plate 16a on the lower surface integrally molded thereon is fixed to the upper surface of the body 1 with screws 17. So, the base 15
The diaphragm 6a of the valve body 6
It is installed airtight by pressing down on the periphery of the
A recess is formed on the lower surface of the base body 15 to partition the pilot chamber 8, and a cylinder 20 is formed in the center of the upper surface and projects in alignment with the center hole 18. around and external core 16
A coil 22 wound around a bobbin 21 is fitted with a gap between the center hole of the bobbin 21 and the cylindrical body 20, and the lower end of the outer core 16 is inserted into the gap. A magnetic tube 24 is fitted with a predetermined gap between the magnetic tube 23 fitted into the center hole at the lower end and the upper edge of the magnetic tube 23, and the bobbin 21 of the upper magnetic tube 24
Around the upper end protruding from the bobbin 21 and the upper surface plate 16b of the external iron core 16, there are several magnetic plates 2 having a square planar shape and a center hole 25.
6 are stacked with their center holes 25 fitted around the magnetic tube 24, and rectangular permanent magnets 27 are fitted between both sides of these magnetic plates 26 and the inside of the external core 16, respectively. On the other hand, the cylindrical body 20
A plunger 28 made of a magnetic material and having a valve body 30 attached to its lower end that moves toward and away from the valve seat 9 of the pilot valve 10 is fitted into the plunger 28 so as to freely slide therein. Occlusion plate 3
A core 32 is fitted inside the plunger 1, and the plunger 28 is urged downward by the elasticity of a return spring 33 installed between the core 32 and the plunger 28.
The lower end of the valve body 30 is normally in contact with the valve seat 9 of the pilot valve 10 to close the pilot valve 10, and the valve body 6 is urged downward to close the valve port 5.

This embodiment has the above-mentioned configuration, and when the coil 22 is energized, a magnetic flux is generated and passes through the thick parts of the upper and lower magnetic tubes 23 and 24, and the plunger 2
Plunger 2 due to interaction with magnetic flux passing through 8
8 and the attraction force of the plunger 28 due to magnetization of the core 32 are generated at the same time. Therefore, the stroke-attraction force curve of the plunger 28 caused by these forces is similar to the characteristics of a conventional leakage type solenoid. The dashed-dotted line c in Figure 2 looks like the characteristic curve of a core type solenoid is superimposed on the curve.
In this embodiment, the attraction force of the plunger due to the self-holding permanent magnet 27 attached around the upper magnetic tube 24 corresponding to the core 32 is
4 and the core 32 are both magnetized by the permanent magnet 27, the characteristics are shown by the two-dot chain line d in FIG. The curve indicated by the solid line e shows the final stroke-attractive force characteristic of the solenoid 12 of this embodiment, and as is clear from this characteristic curve e, when the valve body 6 closes the valve port 5, the coil 22 When energized, an extremely large suction force is generated, and as the plunger 28 moves upward, the suction force increases.For this reason, the valve element 30 at the lower end of the plunger 28 may become stuck to the valve of the pilot valve 10. Even if it sticks to the seat 9, it can be reliably separated by energizing the coil 22, and even if the spring constant of the spring 33 is set large to improve valve closing performance, the plunger 28 can be pulled away from the core 32. The valve port 5 can be opened wide by reliably suctioning until the coil 22 is energized, and the valve port 5 can be opened wide.In addition, in this embodiment, since the valve port 5 is of a self-holding type, the valve port 5 is opened by energizing the coil 22. Even when the coil 22 is de-energized, the plunger 28 is held attracted to the core 32 by the magnetic force of the permanent magnet 27, thereby reducing power consumption when the valve is opened. However, since the suction force that attracts and holds the plunger 28 after the coil 22 is de-energized is extremely large as shown by the two-dot chain line d in FIG. 2, the spring constant of the spring 33 is large. The plunger 28 can be held in a state where it is reliably attracted to the core 32 against the urging force of the coil 2.
Valve port 5 may be damaged due to large vibrations after energization of 2 is cut off.
There is no risk of it being closed. In addition, when closing the valve port 5 held in the open state to close the valve, it is sufficient to once energize the coil 22 with a current of the opposite polarity.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a graph showing the stroke-suction force characteristics of the solenoid plunger according to the present invention, and FIG. 3 is a graph showing the conventional stroke-suction force characteristics. be. 12... Solenoid, 16... External iron core, 22
... Coil, 23, 24 ... Magnetic tube, 27
...Permanent magnet, 28...Plunger, 32...Core.

[Claims]

1. In a stationary induction device in which the main body of the induction device is housed in a tank, a side plate that forms the four sides of the tank and is bent inward, covers these side plates from the outside, and has a side end that is connected to the side plate. A stationary induction device characterized by comprising a sound insulating plate fixed to the side end of the stationary induction device. 2. The stationary guidance device according to claim 1, wherein the side plate is bent into an arc shape. 3. The stationary guidance device according to claim 1, wherein the side plate is bent into a dogleg shape.