JPH0426773Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a gas control valve that uses a gas governor and an electromagnetic device to safely and accurately control the combustion output of gas over a wide range, and in particular has a small hysteresis characteristic. Regarding valves with proportional control with closing function.

[Prior Art] A conventional gas proportional control valve consists of a gas governor that uses a diaphragm to catch fluctuations in gas pressure, and an electromagnetic device that externally controls the movement of the diaphragm using magnetic force, as shown in Figure 4. A magnetic body 52 is attached to the diaphragm 51, and this magnetic body is made to respond to the iron core 54 of the corresponding electromagnetic device 53.
The iron core 54 is set in a hollow vertical hole 56 of an electromagnetic coil 55 so as to be vertically adjustable by screwing a screw 57, and the control characteristics are adjusted by the distance between the adjustable iron core and the magnet body. Then, when the power is not energized, the magnet body 52 is connected to the iron core 5.
4 and closes the valve port 58 with the valve body 59. However, when the fixed position of the iron core 54 changes up or down due to adjustment, the distance to the magnet body is not constant, causing fluctuations in the adsorption force, and therefore variations in the ability of the valve body 59 to close the valve port 58. There is a problem.

Further, if there is resistance when the valve element moves from the closed state to the open operation, it becomes a load, which affects the control characteristics and increases the hysteresis width, which becomes a problem in actual use. Therefore, conventionally,
To improve the hysteresis width, apply grease or oil to the sliding part between the valve body and valve seat, or add a dither signal to the current applied to the coil to constantly apply minute vibrations to the valve body. The following methods are being taken.
However, grease and oil do not have long-term guarantees, and there is a problem in that they tend to become sticky at the applied area and attract dirt and dust, which can lead to leaks. Furthermore, when vibration is applied by adding a dither signal, there are problems in terms of durability and cost because it is done constantly.

[Technical Problem] Therefore, in the present invention, it is possible to adjust the control characteristics of the electromagnetic force on the magnet, and
The technical problem is to make the movement of the sliding part of the valve body smooth, reduce the hysteresis characteristic, and effectively prevent sticking.

[Technical means] In order to solve the above technical problems, the present invention has the following features:
A diaphragm 1 that is displaced by gas pressure; a valve body 9 that is directly connected to the diaphragm 1 and opens and closes a valve port 8 extending from the gas inlet 10 to the gas outlet 11;
An electromagnetic device 13 that externally controls the movement of the diaphragm 1 by magnetic force, a magnet body 2 fixed to the diaphragm side, and a corresponding magnet body 2 fixed at a fixed position at a predetermined close distance from the magnet body. The valve body 9 is formed into a cup shape exhibiting a spherical or conical surface, and a coating film 3 of fluororesin or the like is provided on the surface thereof. The valve port 8 has an edge portion 6 in line contact with the valve body.
A rubber valve seat 6 is provided.

[Operation] In the non-energized state where the electromagnetic coil 5 is not energized, the magnet body 2 fixed to the diaphragm 1 is attracted to the fixed iron core 4, and therefore the valve body 9 moves upward together with the diaphragm 1 to close the valve opening. It is in a closed state because it is pressed against the rubber valve seat 6 of No. 8 by magnetic force.

Now, when current is passed through the electromagnetic coil 5, the fixed iron core 4 is induced, and the magnetic force becomes repulsive to the corresponding magnet body 2. Therefore, the diaphragm 1 is pushed downward, and the valve body 9 is separated from the rubber valve seat 6, so that the valve port 8 is opened wide. As a result, gas flows from the inlet 10 through the valve port 8 to the outlet 11. At this time, when the gas flow rate increases and the gas pressure on the primary side increases, the diaphragm 1 is pushed upward, so the valve body 9 operates to close the valve port 8 and restrict the flow rate. When the gas pressure decreases due to this restriction, the diaphragm 1 descends again, the valve opening widens, and the gas flow rate is controlled within a predetermined range.

When the movable core 14 is moved upward or downward relative to the fixed core 4, the magnetic force acting on the lower end surface 4b of the fixed core 4 changes, so that the control characteristics by the magnetic force are adjusted.

When the gas passes through the valve port 8, the narrower the gap between the valve body 9 and the rubber valve seat 6, the faster the flow rate of the gas passing through the gap. Therefore, since the gas comes into strong contact with the surface of the valve body 9, tar, dirt, dust, etc. contained in the gas adhere to it, leading to an increase in adhesive strength. membrane 3
is applied, and since the contact area is small due to line contact with the rubber valve seat 6, it is naturally moved downstream by a slight contact force and gas flow velocity, and is removed by a so-called cleaning action, so that the surface is always clean. kept clean.

[Effects] Since the present invention has the above-described configuration, it produces the following effects.

(a) By fixedly fixing the mounting position of the fixed core 4 relative to the magnet 2, the cap between the fixed core and the magnet is kept constant, and the fluctuation of the magnet attraction force when the magnet is not energized, that is, the closing load of the valve body 9, is reduced. By eliminating fluctuations, it is possible to prevent variations in the valve closing function.

(b) Even if the distance between the fixed core 4 and the magnet body 2 is constant, by moving and adjusting the movable core 14, the magnetic force during energization can be changed, so the maximum and minimum gas flow rates can be set. Afterwards, it can be controlled arbitrarily.

(c) It is possible to reduce the sliding resistance of the valve body 9 against the valve seat and reduce the hysteresis characteristic.

[Embodiment] The magnet body 2 is made of an iron piece of a permanent magnet, and is fixed to the back surface of the diaphragm 1 to form an integral body. A non-magnetic partition plate 12 is provided between the fixed iron core 4 and the magnet body 2, and the fixed iron core 4 is fixed in a fixed position so as to be abutted and supported by the partition plate 12.

The magnet body 2 is attracted to the fixed iron core 4 when the electromagnetic coil 5 is not energized, but since there is a partition plate 12 in the middle, the magnet body 2 is attracted to the partition plate 12.

The movable core 14 is moved up and down by the screw 14b, and the fixed position is adjusted.

The facing surfaces of the fixed iron core 4 and the movable iron core 14 are formed so that one taper surface 4a of a conical concave portion and the other taper surface 14a of a conical convex portion are formed for tapered fitting.

The movable core 14 is fixed immovably by a lock nut 15.

The valve body 9 is formed into a cup shape with a spherical or conical surface from metal or hard synthetic resin, etc.
A surface treatment film 3 such as fluororesin or Techron processing is provided on the surface.

The rubber valve seat 6 is removably fitted into the circumferential hole of the valve port 8.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view of the device of the present invention, Fig. 2 is a governor characteristic diagram showing changes in outlet pressure with respect to primary pressure, Fig. 3 is a characteristic diagram showing changes in outlet pressure with respect to applied current, and Fig. 4 is a conventional FIG. 1...Diaphragm, 2...Magnetic body, 3
...Surface treatment membrane, 4...Fixed iron core, 5...Electromagnetic coil, 6...Rubber valve seat, 8...Valve port, 9...Valve body, 10...Gas inlet, 11...Gas outlet ,
13...Electromagnetic device, 14...Movable iron core.

Claims (1)

[Claims for Utility Model Registration] (1) A diaphragm 1 that is displaced by gas pressure, and a valve port 8 that is directly connected to the diaphragm and runs from the gas inlet 10 to the gas outlet 11.
In a gas proportional control valve equipped with a valve body 9 that opens and closes, and an electromagnetic device 13 that externally controls the movement of the diaphragm using magnetic force, a magnet body 2 is provided on the diaphragm 1 side, and a corresponding electromagnetic device is provided. On the 13 side, a fixed core 4 is immovably fixed at a fixed position at a predetermined close distance from the magnet body 2, and a movable core 4 is fixed to the fixed core 4 so as to be movable forward and backward relative to its upper end. 14. A proportional control valve with a closing function. (2) A coating film 3 made of fluororesin is provided on the surface of the valve body 9, and a rubber valve seat 6 having an edge portion 6a is provided opposite to the coating film 3 so as to be closed by line contact. A proportional control valve with a closing function according to claim 1 of the utility model registration claim.