JP2005188344A - Gas fuel regulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability of a balance mechanism for compensating a variation of valve opening force caused by a change of a cylinder pressure. <P>SOLUTION: In a regulator for reducing the pressure of gas fuel in a cylinder to a predetermined positive pressure by a pressure control valve 12 and for introducing it into a pressure regulating chamber 10, the balance mechanism 21 is constructed so that it has a pressing member 36 movable by a balance diaphragm 24 receiving the cylinder pressure introduced into a pressure chamber 25 and causes the member to act on an opposite side of a valve lever 17 across a center of rotation from a valve body of the pressure control valve for compensating the variation of the valve body opening force caused by the cylinder pressure change, the pressing member 36 opens a feed port 29 for introducing the cylinder pressure into the pressure chamber 25 at the time of opening the pressure control valve, a shut-off valve 26 is provided for closing at the time of closing the pressure control valve and gas fuel in a large quantity at the cylinder pressure is prevented from flowing through a broken portion into the pressure regulating chamber 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a gas used to adjust LPG or CNG to a pressure of about atmospheric pressure in order to send it to a mixer installed in the intake pipe of the engine, or to adjust to a predetermined positive pressure to send it to a fuel injection valve. The present invention relates to a fuel regulator.

  LPG or CNG filled in the cylinder is introduced into the primary chamber through a primary valve that opens and closes following the displacement of the diaphragm according to the pressure change in the primary chamber, and then the diaphragm according to the pressure change in the secondary chamber A regulator (vaporizer) that is introduced into a secondary chamber through a secondary valve that opens and closes following the displacement of the engine and that is sent to a mixer installed in the intake pipe of the engine is well known. Primary and secondary valves Thus, the pressure is reduced twice so that the LPG and CNG in the secondary chamber are at atmospheric pressure. In addition, LPG or CNG filled in the cylinder is introduced into the pressure regulating chamber through a pressure regulating valve that opens and closes following the displacement of the diaphragm according to the pressure change in the pressure regulating chamber, and then into the engine intake pipe. A regulator that sends the fuel to the installed fuel injection valve is also widely known, and the pressure is reduced once by the pressure regulating valve so that LPG and CNG in the pressure regulating chamber are set to a predetermined positive pressure.

  The valve bodies of the primary valve, the secondary valve and the pressure regulating valve are attached to a valve lever that rotates following the displacement of the diaphragm, and the gas fuel inlet from the cylinder to the primary chamber or the pressure regulating chamber, the secondary from the primary chamber The fuel passage to the chamber is opened and closed. For this reason, the cylinder pressure acts on the valve body of the primary valve or the pressure regulating valve to apply a force in the valve opening direction.

  On the other hand, the cylinder pressure varies depending on the temperature, and particularly in LPG, it varies greatly depending on the blending ratio of butane and propane (changes to about 0.1 MPa to 1.8 MPa). Therefore, the valve body of the primary valve or the pressure regulating valve. The force in the valve opening direction applied to the valve changes significantly. As a result, when the cylinder pressure increases, the valve body easily opens and the pressure in the primary chamber and the pressure regulating chamber increases, and when the cylinder pressure decreases, the valve body becomes difficult to open and the pressure in the primary chamber and the pressure regulating chamber decreases. The amount delivered to the mixer and the fuel injection valve fluctuates, which causes an adverse effect on engine operability and exhaust conditions.

  As a countermeasure, in the LPG regulator (vaporizer), a pressure chamber communicated with the fuel introduction path from the cylinder to the gas fuel inlet on the opposite side of the valve body of the primary valve across the fulcrum that is the rotation center of the valve lever. In addition to providing a balance diaphragm that blocks the pressure chamber and the primary chamber from each other, a balance mechanism is provided in which a bar-shaped pressing member fixed to the balance diaphragm projects into the primary chamber and engages the valve lever, with the fulcrum sandwiched between them. Cylinder pressure acts on the valve disc and the balance diaphragm to give the valve lever moments in opposite directions, offsetting fluctuations in the valve opening force caused by changes in the cylinder pressure, and performing a predetermined opening / closing operation on the primary valve. What has been made to perform stably is described in Japanese Utility Model Publication No. 55-4536.

When the balance diaphragm that directly receives the cylinder pressure is damaged, the gas fuel of the cylinder pressure flows directly into the primary chamber and abnormally increases the primary chamber pressure, and the amount of gas fuel supplied to the engine is excessive. As a safety measure, there is no need to worry about stopping the engine or causing gas leakage from equipment or piping. That is, this safety means secures the auxiliary diaphragm to the pressing member, and when the balance diaphragm is broken, the auxiliary diaphragm is deformed by receiving cylinder pressure, so that the pressing member penetrating portion of the lid member holding the peripheral portion of the balance diaphragm is deformed. The gap is closed so that high-pressure gas fuel does not flow directly into the primary chamber.
Japanese Utility Model Publication No. 55-4536

  The auxiliary diaphragm, which is a safety means in the balance mechanism, has a peripheral portion in contact with the inner wall surface of the lid member inside the lid member, and is uniformly deformed when cylinder pressure is applied to close the gap on the outer periphery of the pressing member. However, depending on the contact area and contact pressure of the peripheral edge of the auxiliary diaphragm on the inner wall surface of the lid member, a large resistance to the movement of the pressing member is generated, and the movement corresponding to the change in the cylinder pressure is obstructed and the primary valve performs a predetermined opening / closing operation. There is a concern that there may be cases where it cannot be performed stably. Alternatively, if the pressing member moves in the axial direction due to a change in the cylinder pressure while the peripheral edge of the auxiliary diaphragm is in contact with the inner wall surface of the lid member, deformation or pulling of the peripheral edge occurs, and if this is repeated, the auxiliary diaphragm deteriorates early. When the cylinder pressure is applied, there is a concern that it may be easily broken and the gap cannot be closed.

  The present invention has the above-mentioned safety means that prevents the gas fuel of the cylinder pressure from directly flowing into the primary chamber when the balance diaphragm that directly receives the cylinder pressure is damaged. It was made to eliminate the concern that the rise could not be prevented, and has a reliable safety means that can reliably prevent an abnormal rise in the primary chamber pressure when the balance diaphragm is damaged. It aims at making it the regulator which provided the balance mechanism.

  The present invention is applicable to both a regulator that performs two times of decompression and a regulator that performs one time of decompression. The primary chamber and the primary valve in the regulator that performs two times of decompression are subject to one decompression. Corresponds to the pressure regulating chamber and pressure regulating valve in the regulator. Therefore, in the present invention, the terms pressure regulating chamber and pressure regulating valve are used, and these include the primary chamber and the primary valve.

  The present invention attaches a valve body of a pressure regulating valve that opens and closes the gas fuel inlet to the pressure regulating chamber and sandwiches a fulcrum of a valve lever that rotates about a fulcrum according to a pressure change in the pressure regulating chamber on the opposite side of the valve body. The gas fuel regulator provided with a balance mechanism that cancels the variation of the valve opening force caused by the change in the cylinder pressure and causes the pressure regulating valve to perform a predetermined opening / closing operation is as follows. It was supposed to be solved by doing so.

  That is, the balance mechanism according to the present invention includes a pressure chamber, an inlet for sending cylinder pressure into the pressure chamber, an on-off valve for opening and closing the inlet, and a balance diaphragm that blocks the pressure chamber and the pressure regulating chamber from each other. And a pressing member which is superimposed on the balance diaphragm and linearly moves in accordance with the displacement thereof and applies resistance to the valve opening direction to the valve lever corresponding to the change in the cylinder pressure. The on-off valve closes the inlet when the pressing member moves toward the pressure regulating chamber and opens the inlet when moved toward the pressure chamber.

  The on-off valve has a valve body in which a valve opening spring is actuated, and an operation member that moves the valve body in the opening direction, and when the pressing member moves toward the pressure chamber, the valve body is pressed by pressing the operation member. Or the pressing member and the operating member in the above-mentioned one have a gap that does not allow the valve body of the on-off valve to open in the minute opening range of the pressure regulating valve. This is suitable for carrying out the present invention.

  When the pressure regulating valve opens, the valve lever rotated around the fulcrum moves the pressing member toward the pressure chamber, and the cylinder pressure is introduced into the pressure chamber by opening the on-off valve. The fluctuation of the valve opening force that acts on the valve body of the pressure regulating valve due to the decrease is offset. When the pressure regulating valve is closed, the valve lever is rotated in the opposite direction, the pressing member is moved toward the pressure regulating chamber following the valve lever by the cylinder pressure of the pressure chamber, and the on-off valve is closed. At the time of the next pressure regulating valve opening, the valve opening determined by the balance between the cylinder pressure acting as the valve opening force on the valve body and the cylinder pressure sealed in the pressure chamber is performed.

  When the balance diaphragm is damaged, if the on / off valve is closed and the damage occurs, the high-pressure gas fuel sealed in the pressure chamber is released to the pressure adjusting chamber through the damaged portion, and the pressing member Pushes the operating member, but the valve body of the on-off valve is held in the closed position by the valve closing spring and the cylinder pressure and is not opened. When a failure occurs when the on-off valve is open, the pressure regulator chamber can be set in a short time by allowing gas fuel of cylinder pressure to flow into the pressure regulator chamber through the on-off valve, pressure chamber, and damaged part. Pressure is reached and the pressure regulator is closed. Further, the opening / closing valve is closed by the pressing member moving toward the pressure adjusting chamber by the cylinder pressure entering the pressure chamber. When the pressure regulating valve opens and closes after it is damaged, gas fuel enters the pressure regulating chamber from the damaged part in addition to the pressure regulating valve when the valve is opened. it can. Further, when the pressure regulating valve is closed, the on-off valve is also closed, so that an abnormal increase in the pressure regulating chamber pressure is prevented, and the concern about engine stop and gas leakage can be eliminated.

  According to the present invention, the balance mechanism that cancels the fluctuation of the valve opening force of the pressure regulating valve that introduces the gas fuel LPG or CNG from the cylinder pressure to a predetermined positive pressure and introduces it into the pressure regulating chamber due to the change in the cylinder pressure. Because the safety means consists of the on-off valve as described above, when the balance diaphragm is damaged, gas fuel of cylinder pressure flows in a large amount from the damaged part to the pressure adjusting chamber, causing the pressure adjusting chamber pressure to rise abnormally. This makes it possible to reliably prevent the engine from running, and can continue the engine operation without any particular trouble even after damage, resulting in a gas fuel regulator having a balance mechanism having a reliable safety means. It is done.

  Referring to the drawings, an embodiment of the present invention will be described. A supply conduit 3 having a shut-off valve 2 extends from a cylinder 1 filled with LPG or CNG, and a filter is provided directly or in an inlet chamber 6 provided in a main body 5 of the regulator. Connected through. A depression is provided on the opposite side of the main body 5 from the inlet chamber 6, and this depression is covered with a diaphragm 8 having a peripheral edge sandwiched between the main body 5 and the cover body 7 to form a pressure regulating chamber 10. Yes. A pressure adjusting spring 9 with adjustable spring force is applied to the diaphragm 8 to urge a load in the direction of the pressure adjusting chamber 10.

  A valve seat 13 of a pressure regulating valve 12 is provided protruding from the pressure regulating chamber 10 at the tip of a fuel introduction path 11 extending from the inlet chamber 6 toward the pressure regulating chamber 10. The proximal end of the valve lever 17 is engaged with a hook 16 attached to the center of the diaphragm 8, and the valve body 15 of the pressure regulating valve 12 is attached to the distal end of the valve lever 17. When the pressure regulating chamber 10 becomes lower than the set pressure, the diaphragm 8 is displaced toward the pressure regulating chamber 10 to rotate the valve lever 17 around the pin 18 and separate the valve body 15 from the valve seat 13. The gas fuel of the cylinder pressure filled in the inlet passage 6, the fuel introduction passage 11, and the valve passage 14 of the valve seat 13 is depressurized through a gap between the seat surface of the valve seat 13 and the contact surface of the valve body 15 to adjust the pressure. It is sent to the room 10. When the pressure regulating chamber 10 becomes higher than the set pressure, the diaphragm 8 is displaced in the opposite direction, and the valve body 15 is seated on the valve seat 13. With the above operation, a constant positive pressure gas fuel is held in the pressure regulating chamber 10, which is exactly the same as the conventional regulator.

  A recess is provided in the main body 5 so as to be positioned on the opposite side of the valve seat 13 with the pin 18 on the surface facing the diaphragm 8 of the pressure adjusting chamber 10 interposed therebetween, and a peripheral portion between the surface of the recess and the pressing member 22. A space sandwiched between the balance diaphragm 24 sandwiching the valve and a valve seat body 27 of the on-off valve 26 described later forms a pressure chamber 25. The valve seat body 27 is fixed by being screwed into the recess, has a valve chamber 28 on the opposite side of the pressure chamber 25, and has an inlet 29 for communicating the valve chamber 28 and the pressure chamber 25. A seat surface 30 is formed at the open end of the 29 valve chamber 28. The valve chamber 28 is loaded with a valve body 31 made of a ball and a valve closing spring 32 that acts to press the valve body 31 against the seat surface 30. The valve chamber 28 opens to the inlet chamber 33 at the back end of the recess. The inlet chamber 33 communicates with the fuel introduction path 11 through a communication path 35, and gas fuel with a cylinder pressure is introduced. Further, a rod-like operation member 34 is loosely inserted into the feeding port 29, and its proximal end protrudes into the pressure chamber 25.

  The valve seat body 27, the valve chamber 28, the inlet 29, the valve body 31, the valve closing spring 32, and the operation member 34 constitute an on-off valve 26. On the other hand, a cylindrical pressing member 36 is disposed on the surface of the balance diaphragm 24 opposite to the pressure chamber 25 so as to overlap the base end surface. The pressing member 36 loosely penetrates the insertion opening 23 at the center of the pressing member 22. Thus, the tip of the pressure regulating chamber 10 is projected. A small-diameter shaft-like protrusion 37 a is provided at the tip of the pressing member 36 and is loosely fitted into a through hole 37 b provided in the valve lever 17. As a result, the valve lever 17 and the pressing member 36 are always engaged with each other to ensure their interlocking.

  The on-off valve 26 provided with the above-described balance diaphragm 24, pressure chamber 25, pressing member 36, and inlet 29 in the valve seat body 27 constitutes a balance mechanism 21, and the on-off valve 26 is a cylinder when the balance diaphragm 24 is damaged. It functions as a safety means for preventing a pressure gas fuel from flowing in a large amount into the pressure adjusting chamber 10 and causing an abnormal increase in pressure.

  The operation of the present embodiment configured as described above will be described below. In a normal state, the cylinder pressure in the pressure chamber 25 and the positive pressure in the pressure regulating chamber 10 act on both surfaces of the balance diaphragm 24. When the pressure in the pressure regulating chamber 10 falls below the set pressure, the diaphragm 8 is displaced toward the pressure regulating chamber 10 to rotate the valve lever 17 in the clockwise direction in the drawing, and the valve body 15 of the pressure regulating valve 12 is moved. The gas fuel at the cylinder pressure is separated from the valve seat 13 and is fed into the pressure adjusting chamber 10 while being reduced. At this time, the pressing member 36 is pushed by the valve lever 17 and moved toward the pressure chamber 25, and the operating member 34 is pushed to separate the valve body 31 of the on-off valve 26 from the seat surface 30, and gas gas at cylinder pressure is discharged. It introduces into the pressure chamber 25. The state at this time is shown in FIG. 2, and a moment in the valve closing direction according to the pressure in the pressure chamber 25 is applied to the valve lever 17 via the pressing member 36. Therefore, when the cylinder pressure changes, the fluctuation of the valve opening force acting on the valve body 15 of the pressure regulating valve 12 is canceled according to the change, and the pressure regulating chamber 10 is opened by causing the pressure regulating valve 12 to perform a predetermined opening / closing operation. A constant predetermined positive pressure can be maintained.

  When the pressure in the pressure regulating chamber 10 reaches the set pressure, the diaphragm 8 is displaced in the opposite direction to rotate the valve lever 17 in the counterclockwise direction in the figure, and the valve body 15 of the pressure regulating valve 12 is seated on the valve seat 13. Let At this time, the pressing member 36 is moved toward the pressure regulating chamber 10 following the valve lever 17 by the pressure in the pressure chamber 25, and the operating member 34 is moved toward the pressure chamber 25 by the spring force of the valve closing spring 32. At the same time, the valve body 31 of the on-off valve 26 sits on the seat surface 30 and closes the inlet 29. The state at this time is shown in FIG. 3, in which gas fuel with a cylinder pressure is sealed in the pressure chamber 25, and a narrow gap A is formed between the balance diaphragm 24 and the operation member 34. When the next pressure regulating valve 12 is opened, the valve opening determined by the balance between the cylinder pressure acting as the valve opening force on the valve body 15 and the cylinder pressure sealed in the pressure chamber 25 is performed, and then the on-off valve 26 is opened. The valve is brought into a state shown in FIG.

  The gap A eliminates the inconvenience that when the pressure regulating valve 12 opens with a small opening, the pressing member 36 pushes the operating member 34 and receives the resistance of the valve closing spring 32 to hinder the valve opening operation. Thus, a slight pressure drop from the set pressure of the pressure regulating chamber 10 can be recovered properly and a constant predetermined positive pressure can be stably maintained.

  If the balance diaphragm 24 is damaged in the state shown in FIG. 3 in which the on-off valve 12 is closed, the gas fuel of the cylinder pressure sealed in the pressure chamber 25 passes through the damaged portion and enters the pressure adjusting chamber 10. Released. For this reason, the pressing member 36 moves toward the pressure chamber 25 by its own weight and pushes the operating member 34, but the valve body 31 of the on-off valve 26 is compressed by the spring force of the valve closing spring 32 and the cylinder pressure introduced into the valve chamber 28. The gas fuel of cylinder pressure is prevented from flowing into the pressure regulating chamber 10 from the on-off valve 26 through the pressure chamber 25 and the damaged part. In addition, since the gas fuel enclosed in the pressure chamber 25 is a small amount, the increase in pressure caused by the gas fuel flowing into the pressure regulating chamber 10 can be ignored.

  When the balance diaphragm 24 is damaged in the state shown in FIG. 2 in which the on-off valve 26 is open, the gas fuel of the cylinder pressure passes through the on-off valve 26, the pressure chamber 25, and the damaged portion to the pressure regulating chamber 10. The pressure adjusting chamber 10 becomes a set pressure in a very short time and closes the pressure adjusting valve 12. Further, the pressing member 36 is moved toward the pressure regulating chamber 10 following the valve lever 17 by the cylinder pressure entering the pressure chamber 25, and thus the on-off valve 26 is closed.

  When the pressure regulating valve 12 is opened / closed after the balance diaphragm 24 is broken, the gas fuel of the cylinder pressure flows into the pressure regulating chamber 10 from the damaged portion in addition to the pressure regulating valve 12 when the valve is opened, so that the pressure regulating chamber 10 is short-time. At the set pressure. When the on-off valve 26 is closed when the valve is closed, the pressure control accuracy of the pressure regulating chamber 10 is reduced as compared with the normal state, but the gas fuel of the cylinder pressure does not flow into the pressure regulating chamber 10 in large quantities, so And can eliminate the risk of gas leaks from downstream equipment and piping.

The longitudinal cross-section partial figure which shows embodiment of this invention. FIG. 2 is an enlarged longitudinal sectional partial view showing a state when the valve of FIG. 1 is opened. The expanded longitudinal cross-section fragmentary figure which shows the state at the time of valve closing of the form of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pressure regulation chamber, 12 Pressure regulation valve, 15 Valve body, 17 Valve lever, 18 Pin, 21 Balance mechanism, 24 Balance diaphragm, 25 Pressure chamber, 26 On-off valve, 29 Inlet, 31 Valve body, 32 Valve closing spring, 34 Operation member, 36 Pressing member

Claims (3)

A valve body of a pressure regulating valve that opens and closes the gas fuel inlet to the pressure regulating chamber is attached, and on the opposite side of the valve body with the fulcrum of the valve lever that rotates about the fulcrum according to the pressure change of the pressure regulating chamber In the gas fuel regulator provided with a balance mechanism that cancels the variation of the valve opening force caused by the change in the cylinder pressure and causes the pressure regulating valve to perform a predetermined opening / closing operation,
The balance mechanism includes a pressure chamber, an inlet for sending cylinder pressure into the pressure chamber, an on-off valve for opening and closing the inlet, a balance diaphragm that blocks the pressure chamber and the pressure regulating chamber from each other, and the balance A pressing member that is superimposed on the diaphragm and linearly moves according to the displacement thereof and applies resistance to the valve opening direction to the valve lever in response to a change in cylinder pressure, and the opening / closing valve includes the pressing member When moving toward the pressure regulating chamber, the inlet is closed, and when moving toward the pressure chamber, the inlet is opened.
A regulator for gas fuel.   The on-off valve has a valve element that operates a valve closing spring and an operation member that moves the valve element in an opening direction, and the operation member is moved when the pressing member moves toward the pressure chamber. The regulator for gas fuel according to claim 1, wherein the valve body is opened by pressing. 3. The gas fuel regulator according to claim 2, wherein the pressing member and the operation member have a gap between them to prevent the valve body of the on-off valve from being opened in a minute opening range of the pressure regulating valve.

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