JPS6213554B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-speed electromagnetic valve for supplying fluid in pulses for use in a plasma engine, a plasma gun device of a nuclear fusion plasma generator, or the like.

[Conventional technology]

Several MW of discharge power is required to convert the supplied gas into plasma with high efficiency. However, continuous electrical input of several MW results in huge power consumption, so it is economical to input discharge power into the discharge section in pulses to generate plasma. In particular, a plasma engine is used as a propulsion source in space, and the power of the plasma engine is provided by fuel cells and solar cells. It is necessary to perform a pulse operation in which the electric power stored in the electric power is input to the discharge section in a pulsed manner by switching as necessary. Furthermore, the power level of such fuel cells is expected to be around 100KW to 200KW even if we wait until the end of this century, and it is expected that the reality of pulse operation will not change for the time being.

Therefore, in the plasma engine and plasma gun device described above, a high-speed electromagnetic valve is essential for supplying gas in pulses in synchronization with the discharge power.

FIG. 1 shows a high-speed electromagnetic valve used in a plasma engine, in which a valve stem 1 having a conical tip is brought into close contact with a valve seat 2 and separated from it. An iron core 3 is fixed to the base end of the valve stem 1, and the valve stem 1 is integrated with the iron core 3 and is urged toward the valve seat 2 by a spring 4, and a coil 7 is attached around the iron core 3. is provided, and when the coil 7 is energized, the iron core 3 is excited and attracted together with the valve stem 1 in a direction away from the valve seat 2, and a propellant supply channel 5 is bored in the valve seat 2. The propellant (supply gas for turning into plasma) is supplied from the supply path 5 to the discharge section through the communication path 6 and the gap between the valve stem 1 and the valve seat 2. .

Thus, when the coil 7 is energized in a pulsed manner, the valve stem 1 and the valve seat 2 are brought into close contact with each other and separated, and the propellant can be supplied in a pulsed manner.

[Problem that the invention seeks to solve]

In such a high-speed solenoid valve, both the valve stem 1 and the valve seat 2 are made of metal, and in order to ensure the desired sealing performance, the urging force of the spring 4 must be strong to some extent, and the iron core 3 must be The moving parts have a large mass because they move as one unit. Therefore, the responsiveness is poor and the second
As shown in the figure, it takes approximately 5 msec to rise, and the supply pulse width also exceeds 10 msec. The vertical axis in the figure shows the flow rate.

Further, since the valve stem 1 and the valve seat 2 are in contact with each other on an inclined surface, there is a possibility of slippage when they come into close contact with each other and then separate, and wear due to frequent opening and closing must be taken into account.
Further, since both 1 and 2 are in metal contact, if foreign matter such as fine metal powder is caught between them, the sealing performance will be extremely poor, so the environment in which they are used must be extremely clean.

Furthermore, in order to actually operate the plasma engine, the pulse width of propellant supply is less than 10 msec and can be varied within the range of 0.5 msec to 10 msec.
10 Requires durability over ⁷ times.

Due to these circumstances, the above-mentioned high-speed solenoid valves do not have sufficient performance to actually operate plasma engines, and in order to put plasma engines into practical use, it is essential to develop high-performance high-speed solenoid valves. It is.

[Means for solving problems]

The present invention has been made in view of the above circumstances, and includes a coil housing that is airtightly attached to an orifice support plate on which an orifice is projected and a stopper is provided, a space is formed around the orifice, and a coil is attached to the coil housing. A valve stem made of light metal and having a seat formed on the side opposite to the orifice is fitted into the coil unit, and is slidably provided so as to come into contact with the stopper, and a spring is attached to the side of the support plate opposite to the orifice of the coil housing. The storage cylinder is airtightly mounted, and a spring provided in the storage cylinder urges the valve stem toward the orifice side, and the inside of the storage cylinder is communicated with a propellant supply source, and the valve stem is connected to the vicinity of the tip from the catch side. A conduit is drilled to reach the orifice, the conduit is communicated with the space around the orifice, and an elastic material is provided at the tip of the valve stem to come into contact with the orifice tip. When power is supplied to the coil unit in pulses, the receiver The eddy current is excited, and the seat momentarily separates from the coil unit, and the orifice opens due to the separation of the seat, that is, the movement of the valve stem, and the propellant filled around the orifice flows through the valve stem, including the spring. It is supplied only for a certain period of time determined by the movement of the seat.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows a high speed solenoid valve according to the invention.

The solenoid valve case 10 mainly contains the spring storage cylinder 1.
1, coil housing 12, orifice support plate 1
3.

The spring storage cylinder 11 is provided with a bearing portion 15 communicating with the spring chamber 14, and a spring reaction force receiver 17 having a propellant supply channel 16 bored in the center is slidably and airtightly fitted into the bearing portion 15. , the rotation is stopped using the key 18. A spring seat 1 is provided at one end of the reaction force receiver 17 exposed to the spring chamber 14.
9, and the other end that can protrude from the bearing part 15 has a stepped shape.

Further, a screw 20 is carved on the outer surface of the bearing portion 15, and a lock nut 21 and a cap nut 22 are respectively screwed onto the screw 20, and the cap nut 22 is passed through the stepped-shaped narrow diameter portion.

A coil unit 25 consisting of a wire rod 24 wound around a winding frame 23 is fitted into the coil housing 12, and the coil unit 25 is assembled by fixing the spring storage cylinder 11 to the coil housing 12 with bolts 26. Spring storage tube 1
1 and the flange 27 provided on the coil housing 12
It seems like they are being held in between. Here, an O-ring 28 is sandwiched between the spring storage tube 11 and the coil unit 25 and between the coil unit 25 and the collar 27 to make them airtight.

A bearing bush 2 is installed in the center of the coil unit 25.
9, and a valve stem 30 made of a light metal material such as aluminum is slidably inserted into the bearing bush 29.
One end of the valve stem 30 projects into the spring chamber 14, and the spring seat 19 is attached to the one end.
A catch seat 31 facing the spring seat 19 is formed.
A spring 32 is inserted in a compressed state between the seat 31 and the seat 31. In addition, a guide path 33, which is a blind hole, is bored in the valve stem 30 from the spring chamber 14 side.
The tip of the valve stem 30 is communicated with the outside through a required number of horizontal holes 34, and a recess is provided at the tip of the valve stem 30, and an elastic material 35 such as rubber is fitted into the recess.

Coil housing 12 of orifice support plate 13
A cylindrical fitting part 36 that fits into the coil housing 12 is provided protrudingly on the side, and an orifice 3 is provided in the center.
7 is provided protrudingly, and a connecting pipe 38 communicating with the orifice 37 is provided on the side opposite to the coil housing 12. A stopper 39 that contacts the peripheral edge of the tip of the valve stem 30 is fixed around the orifice 37, and a through hole 40 is bored in the stopper 39 to form a space 4 in which the fitting portion 36 is formed.
1 and a space 42 surrounded by the orifice 37 and the stopper 39 are brought into communication.

Orifice support plate 13 and coil housing 12
The fitting portion 36 is hermetically fitted to the coil housing 12, and the coil housing 12 is fastened with a bolt 43.

In the above configuration, the valve stem 30 has a spring 32
The valve stem 30 is biased toward the orifice 37 side, and the peripheral edge of the tip of the valve stem 30 is in contact with the stopper 39, and the elastic agent 35
The orifice 37 is closed in a slightly bent state.

Next, valve operation will be explained.

Supply path 1 connected to a propellant supply source (not shown)
The propellant supplied into the spring chamber 14 through the passage 33 and the horizontal hole 34 enters the space 41.
and further fills the space 42 through the through hole 40.

When power is supplied to the coil unit 25 in a pulsed manner in such a state, an eddy current is excited in the seat 31 of the valve stem 30 while the power is being supplied, and a repulsive force is generated against the coil unit 25, causing the valve stem 30 to move away from the orifice 37. They instantly separate and become open. In the non-power supply state following the power supply state, the valve stem 30/including the spring 32 system
The seat 31 returns to the closed state after a certain period of time determined by the movement of the movable part.

Thus, when power is continuously supplied in a pulsed manner, the valve opens and closes in accordance with the shape of the pulse.

In the above configuration, the propellant is filled up to the area around the orifice 37, so there is no fluid delay associated with the opening/closing operation, and since the valve stem 30 is made of a light alloy, it has a small mass and low inertia. Furthermore, since the orifice 37 is closed by slightly bending the elastic material 35, the sealing performance is good, and even if fine metal powder etc. are inserted, the sealing performance is not seriously affected, and the spring 3
The urging force of 2 can be made weak, and the valve stem 30 can be moved easily. Furthermore, the valve stem 30 has a structure in which it comes into contact with the stopper 39, so that the elastic material 35 does not bend properly and deteriorate, and since the orifice 37 has no sliding parts, damage due to wear is avoided, and the stopper 39 is a softer material than the valve stem 30, so the valve stem 3
0 itself is not damaged.

FIG. 4 shows the propellant discharge state of the high-speed electromagnetic valve according to the above configuration.

As is clear from FIG. 4, the response is extremely good, and short-term pulsed supply of 0.5 msec or less is also possible. Further, by loosening the lock nut 21 and turning the cap nut 22 to change the compression state of the spring 32, the pulse width of the propellant discharge can be changed. Note that the pulse width can be similarly changed by changing the power supply conditions.

It goes without saying that various modifications may be made without departing from the spirit of the present invention, such as the propellant being supplied directly to the space 41.

〔Effect of the invention〕

As described above, the present invention provides a high-performance, high-speed solenoid valve that can significantly reduce the weight of the valve stem, which is a moving part, has extremely good responsiveness, and does not deteriorate in sealing performance even when operated for a long time. be able to.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a conventional high-speed solenoid valve, Figure 2 is a characteristic diagram of the high-speed solenoid valve, Figure 3 is a sectional view of the high-speed solenoid valve according to the present invention, and Figure 4 is a characteristic diagram of the solenoid valve. It is. 10 is a solenoid valve case, 25 is a coil unit,
30 is a valve stem, 32 is a spring, 35 is an elastic material,
37 is an orifice, and 39 is a stopper.

Claims (1)

[Claims] 1. A coil housing is airtightly mounted on an orifice support plate having a protruding orifice and a stopper, forming a space around the orifice, and a coil unit is fitted into the coil housing. A valve stem having a seat formed on the side opposite to the orifice is slidably provided so as to come into contact with the stopper, and a spring storage tube is airtightly attached to the side of the support plate opposite to the orifice of the coil housing, and provided in the storage tube. A spring urges the valve stem toward the orifice and communicates the inside of the storage cylinder with a propellant supply source, and a conduit is bored in the valve stem that reaches near the tip from the seat side, and the conduit is connected to the orifice. A high-speed solenoid valve that communicates with the surrounding space and is characterized by having an elastic material provided at the tip of the valve stem that comes into contact with the tip of an orifice.