JPS634073B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a servo-type gas control valve that can proportionally control gas pressure using an electric signal.

[Conventional technology]

In a servo-type gas control valve in which the main valve is driven by a main diaphragm that is displaced according to the pressure in the main diaphragm chamber, and the pressure in the outlet passage is adjusted, the working gas passage that leads gas to the main diaphragm chamber is By changing the opening area, it is possible to freely change the set pressure of the outlet passage.

As described above, as means for changing the opening area of the working gas passage, there is a known electromagnetic actuator in which a main valve is attached to the tip of a plunger that moves within a coil.

[Problem that the invention seeks to solve]

Conventional servo-type gas control valves that use electromagnetic actuators have the problem of large sliding resistance when the plunger moves, which tends to cause errors in valve body position control and makes precise pressure control difficult. It was hot.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a servo-type gas control valve that can perform pressure control that accurately corresponds to input control signals.

[Means for solving problems]

The servo type gas control valve according to the present invention includes a coil that generates an electromagnetic force according to a control signal supplied from the outside, and a magnet attached to a feedback diaphragm so as to be displaced in response to the electromagnetic force. It is equipped with an electromagnetic device.

[Effect]

In the servo type gas control valve according to the present invention, when a control signal is supplied to the coil, the feedback diaphragm is controlled by an electromagnetic force according to the magnitude of the control signal.

〔Example〕

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

In the figure, 1 indicates a valve body, and the inside thereof is formed with an inlet passage 2 connected to the combustion gas supply side and an outlet passage 3 connected to the burner side. Both passages 2 and 3 are connected to the main valve 4. They communicate with each other via a port 5 that is opened and closed.

The main valve 4 is supported by a guide 6,
The main valve 4 is urged in the direction of closing the port 5 by the spring 7 and is in contact with a main diaphragm 9 that defines a main diaphragm chamber 8 with respect to the outlet passage 3 .

A servo valve body 10 having a built-in working gas switching valve mechanism is fixed to the valve body 1.
The working gas switching valve mechanism includes a small valve seat 13 that closes off the working gas introduced from the inlet passage 2 through the passage 11 and the orifice 12, a bypass valve seat 14, a switching valve 15, and a servo valve that controls the working gas. The switching valve 15 is configured by a passage 16 leading to the side and a passage 17 communicating with the main diaphragm chamber 8.
and a set of passages leading from the inlet passage 2 to the outlet passage 3 via the servo valve 20 and a passage leading from the main diaphragm chamber 8 to the outlet passage 3.

Note that a drive unit that drives the switching valve 15 is not shown in the figure.

Furthermore, an electromagnetic device 21 for driving the servo valve 20 via a feedback diaphragm 19 is attached to the servo valve body 10. This electromagnetic device 21 includes an electromagnetic coil 22 to which a control signal is supplied from the outside, a pole piece 23 provided at the center of this electromagnetic coil 22, and a feed so as to be displaced in response to magnetic flux from this pole piece 23. It consists of a magnet 24 supported by a back diaphragm 19.

Note that 25 indicates a passage, and 28 indicates a seat plate in which a hole 29 is formed.

In the servo type gas control valve configured in this manner, the small valve seat 13 is closed by the switching valve 15 when there is no demand for heat from the gas combustion device.

Therefore, the working gas guided through the inlet passage 2 is blocked by the small valve seat 13, and the bypass valve seat 14 is opened.

On the other hand, the main diaphragm chamber 8 has a bypass valve seat 14
The remaining working gas in the main diaphragm chamber 8 is communicated with the outlet passage 3 through the outlet passage 3.
The main valve 4 is urged to close the port 5 by the force of the spring 7.

Next, when a heat request occurs, the switching valve 15 opens the small valve seat 13 and closes the bypass valve seat 14 instead.

Therefore, since the working gas is led into the main diaphragm chamber 8 through the passage 17, the pressure in the main diaphragm chamber 8 is increased by the working gas and becomes higher than the pressure in the outlet passage 3, so that the main diaphragm 9 A force is generated in the direction of opening the main valve 4 against the force of. When the force developed on the main diaphragm 9 becomes greater than the force of the spring 7, the main valve 4 begins to open and the combustion gases begin to flow through the port 5 into the outlet passage 3. At the same time, the pressure in the outlet passage 3 begins to rise and is fed back through the passage 26 to the feedback diaphragm 19.

On the other hand, the electromagnetic coil 22 is supplied with an output current from a controller (not shown), and a force acting on the magnet 24 is applied to the feedback diaphragm 19 due to the magnetic force generated by this current.

Therefore, the feedback diaphragm 19
Feedback pressure is applied from below and force is applied from above by the magnet 24, but ultimately the force of the magnet 24 generated by the set current calculated by the controller and the feedback pressure generated via the feedback diaphragm 19 are combined. Works to balance. Therefore, when the opening degree of the port 5 is large compared to the degree of heat demand, the pressure in the outlet passage 3 is high, that is, the gas flow rate is large;
The feedback pressure is also high, the feedback diaphragm 19 moves upward, and the servo 20 fixed to the feedback diaphragm 19 moves in the direction of increasing the opening area of the servo valve seat 18.

The working gas in the main diaphragm chamber 8 therefore bleeds through the servo valve seat 18 into the outlet passage 3. Due to this bleed, the pressure in the main diaphragm chamber 8 decreases and the main valve 4 moves in the closing direction, so the degree of opening of the port 5 decreases and balances at a position that matches the heat demand.

Also, as the magnitude of the heat demand changes, the level of the control signal supplied to the electromagnetic coil 22 of the electromagnetic device 21 changes, and the pressing force exerted by the magnet 24 on the feedback diaphragm 19 also changes. As a result, the servo valve 20 is displaced, and the pressure in the main diaphragm chamber 8 is changed according to the amount of displacement, whereby the main valve 4 is displaced and the pressure in the outlet passage 3 can be adjusted.

〔Effect of the invention〕

As described above, according to the present invention, as an electromagnetic device for changing the pressure in the main diaphragm chamber according to the magnitude of heat demand, the electromagnetic coil is operated with a pressing force corresponding to the level of the control signal supplied to the electromagnetic coil. Since a device with a magnet that presses the feedback diaphragm is used, the magnet does not come into contact with other members during movement, so it is possible to apply a pressing force to the feedback diaphragm that accurately corresponds to the control signal. This has the excellent effect of greatly improving the control accuracy of the gas control valve.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view showing a servo-type gas control valve according to an embodiment of the present invention. In the figure, 1 is the valve body, 2 is the inlet passage,
3 is an outlet passage, 4 is a main valve, 5 is a port, 6 is a guide, 7 is a spring, 8 is a main diaphragm chamber, 9
is the main diaphragm, 10 is the servo valve body, 11,
16, 17, 25, 26 are passages, 12 is an orifice, 13 is a small valve seat, 14 is a bypass valve seat, 15 is a switching valve, 18 is a servo valve seat, 19 is a feedback diaphragm, 20 is a servo valve, 21 is an electromagnetic device, 22 is an electromagnetic coil, 23 is a pole piece,
24 is a magnet, 28 is a seat plate, and 29 is a hole.

Claims (1)

[Claims] 1. A valve body having an artificial passage and an outlet passage that communicate with each other via a port, a main valve that adjusts the pressure of the outlet passage by controlling the opening area of the port, and a main valve that controls the position of the main valve. a main diaphragm that regulates, a spring that biases the main valve in the closing direction, a feedback diaphragm that detects the pressure in the outlet passage, and a main diaphragm that moves from the inlet passage to the main diaphragm according to the displacement of the feedback diaphragm. and an electromagnetic device that applies a pressing force to the feedback diaphragm in a direction opposite to the direction of displacement due to the pressure in the working gas passage. , the electromagnetic device comprises a coil that generates an electromagnetic force in response to a control signal supplied from the outside, and a magnet attached to the feedback diaphragm so as to be displaced in response to the electromagnetic force. A servo-type gas control valve featuring: