KR100667629B1 - Variable pressure regulator of liquified petroleum gas injection system - Google Patents

Abstract

A variable pressure regulating apparatus for an LPI system is provided to prevent leakage of a fuel through an injector by returning the fuel to a bombe at a pressure lower than a set pressure of the system. A variable pressure regulating apparatus for an LPI system includes a valve housing(103), a diaphragm(107), a valve(111), an electromagnet(121), a spring(129), and a core pin(131). The valve housing is installed in the interior of a regulator housing. A fuel outlet pipe is formed at a central portion of the lower side of the valve housing and a plurality of fuel introduction openings are formed at the periphery of the fuel outlet pipe. The diaphragm divides the interior of the valve housing into a diaphragm chamber and a fuel introduction chamber. The valve includes a valve seat, an extending section, a spring recess, and a pin recess. The electromagnet is inserted into the extending portion of the valve and is supported by a support body to generate a magnetic force in a direction in which the valve is closed. The core pin is inserted into the pin recess through the spring recess of the valve.

Description

VARIABLE PRESSURE REGULATOR OF LIQUIFIED PETROLEUM GAS INJECTION SYSTEM}

1 is a schematic diagram of a general ELPIA system.

2 is a cross-sectional view of a regulator housing to which a pressure regulator for a general Elpia system is applied.

Figure 3 is a cross-sectional view of the pressure regulator for the ELPAI system according to the prior art.

Figure 4 is a cross-sectional view of the variable pressure regulating device for the ELPIA system according to an embodiment of the present invention.

5 is a cross-sectional view of a variable pressure regulating device for an ELPIIA system according to an embodiment of the present invention.

The present invention relates to a variable pressure regulator for an Elpia system, and more particularly, by varying the operating fuel pressure of the valve by using the spring force and the magnetic force of the electromagnet, the fuel in the fuel supply line is reduced. The present invention relates to a variable pressure regulator for an Elpia system that allows the return of fuel pressure to the cylinder, thus preventing fuel leakage through the injector.

In general, LPG Injection (LPG Injection), which is applied to LPG vehicles, is equipped with a fuel pump in a cylinder and presses fuel by driving the fuel pump to maintain an injector while maintaining a liquid phase. It means the LPG MPI (LIQUIFIED PETROLEUM GAS MULTI POINT INJECTION) system to inject the calculated amount to each cylinder through.

LPG fuel increases its volume by 250 times when liquid fuel phase changes into the gas phase due to temperature rise or pressure drop.

Therefore, if the phase change of the liquid fuel occurs during engine operation, the engine stop occurs because the amount of fuel actually introduced into the combustion chamber is only 1/250. Therefore, the phase change of the LPG fuel due to radiant heat of the engine during driving (including children) The fuel is injected by pressurizing the fuel in the cylinder so as not to occur.

As shown in FIG. 1, the Elpiai system is connected to the fuel supply line L1 connected to the injector 5 from the fuel pump 3 inside the cylinder 1 and to the cylinder 1 from the injector 5. A fuel return line L2 is provided, and a first shutoff valve 7 is provided at the outlet of the cylinder 1 of the fuel supply line L1, and a second shutoff valve is provided at one side on the fuel supply line L1. (9) is provided.

In addition, a pressure regulator 11 is configured at one side on the fuel return line L2 to maintain the pressure on the fuel supply line L1 about 5 bar higher than the pressure inside the cylinder 1.

Here, the pressure regulator 11, as shown in Figure 2, is connected to the fuel inlet end 13 and the cylinder 1 side connected to the injector 5 side on the fuel return line (L2). It is configured inside a regulator housing 17 having a fuel outlet end 15.

That is, in the specific configuration of the pressure regulator 11, as shown in Figure 3, the valve housing 21 is installed inside the regulator housing 17.

A fuel outlet tube 23 is formed at the center of the lower portion of the valve housing 21 to fit the fuel outlet end 15 of the regulator housing 17 in a hermetic state, and the lower portion of the valve housing 21. A plurality of fuel inlets 25 are formed around the fuel outlet pipe 23 to correspond to the fuel inlet end 13 of the regulator housing 17.

The diaphragm 27 is installed in the center of the valve housing 21 to divide the inside of the valve housing 21 into a diaphragm chamber C1 and a fuel inlet chamber C2, and the diaphragm 27 The valve 29 is installed at the fuel inlet chamber C2 side.

That is, the upper end of the fuel outlet pipe 23 is disposed in the fuel inlet chamber C2, and the valve 29 has the valve seat 31 mounted on the lower surface thereof. 31 is arranged to open and close the fuel outlet pipe 23.

In addition, a spring 33 is installed in the diaphragm seal C1 of the valve housing 21, and the spring 33 is supported by an upper spring seat 35 whose upper end is installed on the upper inner surface of the valve housing 21. The lower end is supported by the lower spring seat 37 installed at the upper end of the valve 29 to provide a constant elastic force to the valve 29.

In addition, a pin groove 39 is formed inward at the center of the upper end of the valve 29, and a core pin 41 is vertically installed at the center of the upper spring seat 35 to be inserted into the pin groove 39. It is configured to guide the up and down operation of the valve 29 in the state.

Therefore, the conventional pressure regulator 11 having the above-described configuration has a constant elastic modulus of the spring 33, and is returned from the injector 5 to return the fuel inlet 13 of the regulator housing 17. When the pressure of the fuel supplied to () overcomes the elastic force of the spring 33, the valve (29) opens the fuel outlet pipe 23 by pushing up the diaphragm (27), thereby fuel is a regulator housing ( It returns to the cylinder 1 via the fuel outlet stage 15 of 17).

On the other hand, if the pressure of the fuel supplied to the fuel inlet end 13 of the regulator housing 17 does not overcome the elastic force of the spring 33, the diaphragm 27 cannot be pushed up so that the valve 29 is the fuel outlet. Maintaining the closed state of the tube 23 to maintain a constant pressure of the fuel in the fuel supply line (L1).

For example, if the elastic modulus of the spring 33 is set so that the valve 29 can be pushed up when the fuel pressure in the fuel supply line L1 is 5 Bar or more (currently, the LPI mass production model is set to 5 Bar). When the fuel pressure difference (Pin-Pout) between the fuel inlet end 13 side and the fuel outlet end 15 side becomes 5 Bar or more, the valve 29 opens the fuel outlet pipe 23 to open the fuel cylinder 1. When the fuel pressure difference is less than 5 Bar, the valve 29 closes the fuel outlet pipe 23 so that fuel is not returned to the cylinder 1 so that the fuel inlet end 13 side and the fuel outlet end ( 15) Always keep the fuel pressure difference at 5Bar.

However, in the pressure regulator according to the related art, when the elastic modulus of the spring 33 therein is determined, the fuel pressure in the fuel supply line L1 is fixed. There is a disadvantage that the set pressure of 11) cannot be changed.

That is, in the above-mentioned Elpiai system, if the set pressure of the pressure regulating device 11 is fixed at 5 Bar, all systems are designed to be 5 Bar while the engine is running, but the fuel disposed in the engine room area A when the engine is stopped. In the process of increasing the temperature of the fuel on the supply line L1 by the internal heat of the engine compartment, the possibility of fuel leakage from the injector 5 or the connection between the injector 5 and the fuel supply line L1 increases. It is implicated.

Of course, even when the engine is stopped, if the fuel pressure in the fuel supply line (L1) is raised to the pressure set in the pressure regulator 11, the valve 29 of the pressure regulator 11 is the fuel outlet pipe 23 Although the fuel is returned to the cylinder 1 side by the opening, the pressure decreases slightly, but the problem of temporary fuel leakage through the injector 5 can be solved by the increase in the fuel pressure in the fuel supply line L1 until the set pressure. There is no downside.

Therefore, the present invention has been invented to solve the above problems and disadvantages, an object of the present invention is to supply fuel at engine stop by variably adjusting the operating fuel pressure of the valve by using the elastic force of the spring and the magnetic tension of the electromagnet Elpia offers a variable pressure regulator for the system, which allows fuel to be returned to the cylinder at low fuel pressure, preventing fuel leakage through the injector.

The variable pressure regulating device for an Elpia system of the present invention for realizing the above object is installed inside the regulator housing, a fuel outlet pipe is formed in the lower center, and a plurality of fuel inlets are formed around the fuel outlet pipe. A valve housing; A diaphragm installed at an inner center of the valve housing to divide the inside of the valve housing into a diaphragm chamber and a fuel inlet chamber; The diaphragm penetrates the center of the diaphragm and is fixedly installed to the diaphragm across the diaphragm chamber and the fuel inlet chamber, and a lower portion of the diaphragm includes a valve seat for opening and closing the fuel outlet tube in the fuel inlet chamber. A valve having an extension part disposed at the center of the seal, and having a spring groove at the center of the extension part and a fin groove extending into the spring groove; An electromagnet inserted into an extension part of the valve in the diaphragm chamber, the upper end of which is supported by a support formed on an upper inner surface of the valve housing to generate a magnetic tension in a direction of closing the valve; A spring inserted into a spring groove of the valve and having an upper end supported by the support and a lower end supported by an inner surface of the spring groove of the valve; The upper end is fixedly installed in the center of the support, the lower end includes a core pin inserted into the pin groove through the spring groove of the valve.

The extension portion of the valve is preferably made of a metal material, and the spring groove is preferably formed as a circular groove having a larger diameter than the pin groove.

In addition, it is preferable that one side of the valve housing is configured with a connector connecting a power supply terminal to supply power to the electromagnet, and the spring is preferably made of a coil spring.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, in the description of the present invention, the same reference numerals apply to the same components as those of the prior art.

4 and 5 are cross-sectional views of the state before and after the operation of the electromagnet of the variable pressure regulating device for the Elpia system in accordance with an embodiment of the present invention.

Looking at the configuration of the variable pressure regulating device 101 according to an embodiment of the present invention first through Figure 4 as follows.

That is, the configuration of the variable pressure regulating device 101 according to the embodiment of the present invention is seen inside the regulator housing 17 (see FIG. 2) on the fuel return line L2 (see FIG. 1) as mentioned in the prior art. The valve housing 103 of the invention variable pressure regulating device 101 is installed.

The valve housing 103 has a fuel outlet pipe 105 formed at a lower center thereof, and a plurality of fuel inlets 107 are formed around the fuel outlet pipe 105. The fuel outlet end 15 of the regulator housing 17 (see FIG. 2) is fitted in a state of being airtight, and the fuel inlet 107 corresponds to the fuel inlet end 13 of the regulator housing 17. Deployed

In addition, a diaphragm 109 is installed at an inner center of the valve housing 103 to divide the inside of the valve housing 103 into a diaphragm chamber C1 and a fuel inflow chamber C2.

In the center of the diaphragm 109, a valve 111 is installed through the diaphragm 109, and the valve 111 is disposed across the diaphragm chamber C1 and the fuel inlet chamber C2, so that the diaphragm 109 is located. It is fixed to).

That is, the valve 111 has a valve seat 113 for opening and closing the fuel outlet pipe 105 in the fuel inlet chamber C2 on the lower surface thereof, the upper portion of which is the center of the diaphragm chamber C1. The extension portion 115 of the metal material disposed in the integrally formed.

A spring groove 117 is formed at an inner center of the extension part 115, and a pin groove 119 is formed to extend inside the spring groove 117.

Here, the spring groove 117 is formed as a circular groove having a larger diameter than the pin groove 119.

In addition, an electromagnet 121 is inserted into the extension part 115 of the valve 111 in the diaphragm chamber C1, and an upper end of the electromagnet 121 is formed on the upper inner surface of the valve housing 103. Supported by the support 123 to generate a magnetic tension in the direction to close the valve 111 through the extension 115 when the power supply.

Here, it is preferable that a connector 127 connecting the power supply terminal 125 is configured at one side of the valve housing 103 to supply power to the electromagnet 121.

A spring 129 is inserted into the spring groove 117 of the valve 111, and an upper end of the spring 129 is supported by the support 123, and a lower end of the spring groove 117 of the valve 111. 117) To be supported on the inner surface.

In addition, a core pin 131 is fixedly installed at the center of the support 123 through the upper end thereof, and a lower end of the core pin 131 is fixed through the spring groove 117 of the valve 111. It is configured to guide the up and down operation of the valve 111 in the state inserted into 119).

At this time, the spring 129 is preferably made of a coil spring so that the core pin 131 can be fitted.

Therefore, in order to explain the operation of the variable pressure regulating device 101 having the configuration as described above, first, the configuration of the Elpia system mentioned through FIG. 1 will be briefly described.

That is, the Elpia system is equipped with a fuel pump (3) inside the cylinder (1), the fuel supply line (L1) connected to the injector (5) from the fuel pump (3), and the injector (5) A fuel return line (L2) connected to the cylinder (1) from the fuel supply line (L1) is provided with a first shut-off valve (7) at the outlet side of the cylinder (1), the fuel supply line (L1) One side of the phase is provided with a second shut-off valve (9).

In addition, the one side on the fuel return line (L2) is provided with a regulator housing 17 (see Fig. 2) is configured therein the variable pressure regulating device 101 of the present invention.

In the variable pressure regulating device 101 of the present invention having the configuration as described above, the spring 129 is lower than the fuel injection set pressure of the system in which fuel is injected through the injector 5 when the engine is driven by itself. The elastic modulus is set to open the valve 111 at the pressure and return the fuel to the cylinder 1 side.

In addition, the electromagnet 121 assists the elastic force of the spring 129 to open the valve 111 at a pressure lower than the fuel injection set pressure of the system when the engine is driven, and closes the valve 111 when the power is supplied. Magnetic force in the direction to act to suppress the opening of the valve 111 until the fuel pressure supplied to the fuel inlet 107 reaches the fuel injection set pressure of the system.

Here, when the power supply to the electromagnet 121 is connected to the fuel pump relay to turn on the IG key, the ECU turns on the main relay and the fuel pump relay. (ON) so that power is applied, and when the power is off, the IG KEY is turned off, and the ECU is preferably configured to cut off the power by turning off the main relay and the fuel pump relay.

That is, the basic concept of the variable pressure regulator 101 of the present invention is that after the engine is turned off, the magnetic tension of the electromagnet 121 is dissipated so that the fuel in the fuel supply line L1 is lower than the set pressure of the system. In order to be able to return to the cylinder 1 side through the fuel return line (L2) even at a low pressure, the injector (5) even if the fuel pressure in the fuel supply line (L1) increases due to the internal heat of the engine room after the engine start-off It is to prevent the fuel leakage phenomenon through.

Referring to the operation of the variable pressure regulating device 101 of the present invention in more detail, first, when the engine is started, as shown in FIG. 4, the electromagnet 121 is turned on (ON).

When the power is turned ON, the magnetic field is generated in the direction of closing the valve 111 according to Fleming's right-hand law, and the magnetic field is combined with the set elastic force of the spring 129 to form the final system pressure. .

That is, the set pressure P_system of the variable pressure regulator of the present invention is equal to P_system = P_spring when the power is not applied to the electromagnet 121 due to the engine stop (OFF), and the electromagnet 121 due to the engine starting. When power is applied (ON), P_system = P_spring + P_solenoid appears.

Here, P_spring is the pressure according to the elastic force of the spring 129, P_solenoid = the pressure determined by the electromagnet 121 P_solenoid is proportional to "μ * I * N / L".

That is, "μ * I * N / L" is a magnetic flux acting on the conductor inside the electromagnet 121 and is a constant value as μ = permeability, I = current flowing through the coil, and N is the number of turns of the coil (Turn number). Where L is the length of the electromagnet 121.

The variable pressure regulating device 101 of the present invention having the characteristics according to the above formula is applied on the Elpia system so that power is not applied to the electromagnet 121 due to the engine stop, in the fuel supply line L2. The fuel pressure P_eng becomes P_eng = P_spring + P_tank, and when power is applied to the electromagnet 121 due to engine starting, P_eng = P_system + P_tank.

Here, P_system = P_spring + P_solenoid, and P_tank is fuel pressure in the cylinder 1.

Therefore, as can be seen from the above equation, after the engine stops, the fuel pressure in the fuel supply line L1 disposed inside the engine area A increases in the fuel pressure due to the temperature rise. Since the fuel return set pressure of 101 decreases only to the set pressure according to the elastic force of the spring 129, the fuel pressure does not increase in the fuel supply line L1 disposed inside the engine room, and the spring 129 does not increase. When the fuel pressure rises to the set pressure level determined by), fuel is immediately returned to the cylinder 1 side through the variable pressure adjusting device 101 of the present invention.

Accordingly, it is possible to return the fuel in the fuel supply line L1 to the cylinder 1 at a lower fuel pressure than when the engine is started when the engine is stopped, thereby preventing fuel leakage through the injector 5 in advance. Therefore, the exhaust gas (EM) can be reduced when the engine is restarted.

As described above, according to the present invention, the variable pressure regulating device for an Elpia system can lower the fuel in the fuel supply line when the engine is stopped by variably adjusting the operating fuel pressure of the valve by using the spring force and the magnetic force of the electromagnet. By returning to the cylinder even at the fuel pressure, it is effective to prevent fuel leakage through the injector.

That is, when the temperature of the fuel on the fuel supply line disposed in the engine room area A when the engine stops increases by the internal heat of the engine room, the injector is returned to the cylinder at a pressure lower than the set pressure of the system when the engine starts. It prevents the leakage of fuel through, thereby minimizing the generation of exhaust gas upon restart.

Claims (5)

A valve housing installed inside the regulator housing, having a fuel outlet pipe formed at a lower center thereof, and a plurality of fuel inlets formed around the fuel outlet pipe; A diaphragm installed at an inner center of the valve housing to divide the inside of the valve housing into a diaphragm chamber and a fuel inlet chamber; The diaphragm penetrates the center of the diaphragm and is fixedly installed to the diaphragm across the diaphragm chamber and the fuel inlet chamber, and a lower portion of the diaphragm includes a valve seat for opening and closing the fuel outlet tube in the fuel inlet chamber. A valve having an extension part disposed at the center of the seal, and having a spring groove at the center of the extension part and a fin groove extending into the spring groove; An electromagnet inserted into an extension part of the valve in the diaphragm chamber, the upper end of which is supported by a support formed on an upper inner surface of the valve housing to generate a magnetic tension in a direction of closing the valve; A spring inserted into a spring groove of the valve and having an upper end supported by the support and a lower end supported by an inner surface of the spring groove of the valve; The upper end is fixedly installed in the center of the support, the lower end of the variable pressure regulating device for an Elpia system including a core pin is inserted into the pin groove through the spring groove of the valve. The method of claim 1, The extension portion of the valve is a variable pressure regulating device for an Elpia system, characterized in that the material is made of a metal material. The method of claim 1, The spring groove is a variable pressure regulating device for an Elpia system, characterized in that formed in a circular groove having a larger diameter than the pin groove. The method of claim 1, One side of the valve housing is a variable pressure regulating device for an Elpia system, characterized in that the connector is connected to the power supply terminal for supplying power to the electromagnet. The method of claim 1, The spring is a variable pressure regulating device for an Elpia system, characterized in that consisting of a coil spring.

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