DE102011055667A1 - Liquefied petroleum injection device for vehicle, has tank for storing fuel and fuel pump, which delivers fuel from tank to engine through suction line, where fuel stop valve is mounted on tank - Google Patents

Abstract

The liquefied petroleum injection device has a tank for storing fuel and a fuel pump, which delivers the fuel from the tank to an engine through a suction line. A fuel stop valve is mounted on the tank and controls the opening and closing of the suction line. A path, where the fuel flows, is formed in the tank.

Description

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the priority of Korean application no. 10-2010-123370 , filed on Dec. 6, 2010, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to a liquefied petroleum injection (LPI) injector for a vehicle, particularly to an LPI apparatus for a vehicle, which improves the structure of a fuel cutoff valve, a fuel rail, and a fuel pump as referred to Technology to suppress heat generation and provide fuel more efficiently.

2. Description of related art

LPG (abbreviated to "liquefied petroleum gas") is stored in a liquid state. Since the LPG is produced in a petrochemical ethylene process, and is relatively inexpensive, the LPG is used as fuel for vehicles, in addition to home or industrial fuel.

A vehicle using LPG as fuel has a fuel tank to store the LPG.

A known LPG vehicle has an internal combustion engine having a structure similar to that of a gasoline engine, but the main distinguishing feature against the internal combustion engine of a gasoline-powered vehicle is that the fuel injection device is removed. Since LPG is easy to vaporize, a fuel injector which mixes the ambient air and the fuel and vaporizes the mixture is not necessary.

In recent years, however, the LPG vehicle has been equipped with the fuel injection apparatus which stably provides the fuel and increases the combustion efficiency to prevent startup errors in winter, increase the output power, and improve fuel efficiency , This Applicant has devised and put into service an LPI (liquefied petroleum injection) device which operates according to a process in which LPG fuel is injected directly into an engine cylinder.

At this time, the LPG is transmitted to the engine in a state in which a high pressure state is maintained to guide the LPG to the engine. The original LPI device has a structure in which the fuel pump is in the tank. However, since the fuel pump is inside the tank, LPG left in the tank should be taken out before repair. That's why a repair takes a lot of time and money. In addition, since the built-in fuel pump causes vibration and noise, it is necessary to additionally incorporate a damper for damping vibrations and noise. Moreover, the tank is made by welding a container made of metal, but foreign matter generated in a welding operation may cause failure of the fuel pump. Therefore, to solve the problem in the latest LPI device, the fuel pump is mounted separately outside the tank.

1A shows a structure in which a fuel pump is mounted outside of a fuel tank. In the drawing, a multi-valve device is attached to the lower portion of the tank. A fuel shut-off valve which opens for fuel (liquid LPG) and closes in response to a start signal, an overflow prevention valve, which prevents fuel in the tank from quickly draining when a pipe is damaged, and a manual feed valve In manual mode, the release of fuel stops when a vehicle is stationary for a long time, are designed in modular design and mounted in the multi-valve device.

The known fuel shut-off valve as a solenoid valve is mounted on the tank to shut off a path where fuel flows as in 1B That means that a liquid chamber is formed at a location where the path is formed, and an inlet and an outlet are formed at (on) one and the other side of the liquid chamber, respectively. In this case, a piston is mounted to shut off the outlet by utilizing the spring force of a spring. In addition, the piston is raised by electromotive force, which is generated when electric current is applied to a coil to open the outlet.

Moreover, the fuel pump of the LPI device has a fuel chamber suitable for a number of cylinders (the number of engine cylinders) and which provides fuel for each individual engine cylinder. The fuel chamber has a structure in which an annular fuel distribution passage, which has a plurality of nipples protruding to be connected to the fuel chamber, and which is connected to a suction line, is connected to a lower portion of the fuel pump to receive fuel. In addition, fuel that is introduced through the nipples into the fuel chamber is forwarded to the engine through a fuel supply line in response to the volumetric change, by a reciprocating operation of a pump piston, as in FIG 1C shown. The pump piston is supported by a diaphragm and reciprocates when an eccentric cam rotates, which is mounted on a rotating shaft of an engine, and in which the diameter of one side is greater than the diameter of the other side. Therefore, the diaphragm vibrates as the piston reciprocates, and as a result, the volume of the fuel chamber is repeatedly increased and decreased. The internal pressure changes repeatedly depending on the volumetric change, and fuel is released to the outside of the fuel pump (toward the fuel passage). The fuel pump points to a lubricant sealed area where lubricant is applied for smooth rotation of the engine. Since the lubricant is a volatile component, the motor housing has a vent hole, and a housing, which is mounted outside the motor housing, is mounted so that it may not be sealed therein, so that gas from the lubricant, which exits through the vent hole, can escape outside.

In addition, fuel exiting the fuel pump is provided to the fuel supply line, and an injector of the engine is provided by a main filter and a regulator, and excess fuel that is not consumed in the engine is returned to the tank through a return passage.

BRIEF EXPLANATION OF THE INVENTION

In the known LPI device as described above, in cases where individual components are heavily loaded, such as in the FTP driving mode (a mode used in an exhaust test) and wide-open throttle driving (WOT for Wide open throttle), the fuel flow rate deteriorates, and as a result, heat is generated when fuel passes through a check valve, or the fuel delivery performance is often problematic. In addition, the heat generation causes LPG to be evaporated, which reduces the life of a valve, and the deterioration of the fuel output results in the degradation of the performance of a vehicle.

Moreover, if the vehicle has an accident, and as a result a diaphragm is damaged, fuel that is released through a ventilation hole to the atmosphere can catch fire.

Accordingly, the present invention has been made with the intention of providing a fluid gas injector (LPI) for a vehicle which avoids heat generation from the fuel shut-off valve, and prevents fuel from being easily transmitted, and prevents fuel from leaking itself if the membrane is damaged.

An exemplary embodiment of the present invention includes an LPI device for a vehicle, comprising: a tank storing fuel, a fuel pump that delivers the fuel provided in the tank to the engine through a suction line, and a fuel shut-off valve attached to the tank and controlling the opening and closing of a suction pipe, wherein a path where the fuel flows is formed in the tank, and a liquid chamber having a predetermined size and having an entrance opening through which the fuel is introduced and an exit opening; by which the fuel is discharged, in which path is formed, wherein the fuel shut-off valve comprises: a coil to which electric current is applied, a first piston which moves upward in the longitudinal direction when electric current is applied to the coil , and a second piston, which a Rohrf and has been inserted into the liquid chamber and is located at the end of the first piston and has a relatively reduced small diameter portion on one side and a relatively enlarged large diameter portion on the other side, the first piston pressurizing the second piston and closing the outlet, with the end of the small diameter portion located at the end face of the end of the first piston, and the large diameter end positioned so as to face the outlet.

Further, the electric current is applied to the coil in the form that the first piston is moved up by a relatively high voltage and that the first piston is held in the upper position by a relatively low voltage. That is, for the electric current applied to the coil, a holding voltage that maintains the upward movement of the first piston is lower than the original voltage that has moved the first piston upward.

A flange with an expanded diameter is formed at the end of the small diameter portion of the second piston, and an elastic member which is in contact with the Flange is attached to the end of the first piston.

Moreover, a plurality of fuel chambers are arranged circularly in the fuel pump to distribute fuel to each cylinder of an engine, and a fuel distributor device which distributes fuel to each of the fuel chambers and communicates with the suction line comprises: a lower cup; wherein an annular groove is formed on the inner lower surface thereof, and wherein one side of the annular groove is connected to the suction pipe, a distributor plate which is connected to an upper part of the annular groove on (in) the lower surface of the lower cup and which Path grooves (through holes) to communicate with the fuel chambers.

Furthermore, the fuel pump provides fuel in response to volumetric fluctuations that depend on the vibration of a diaphragm, which diaphragm vibrates when a motor is operated with an eccentric cam formed on a rotating shaft, with an exhaust port in one Housing is formed, which is connected to the outside of the motor, and, when the internal pressure reaches a predetermined pressure, a check valve is placed in position, which closes the outlet opening to seal the inner part of the housing.

The check valve comprises: a spring which is mounted at the entrance of the discharge port formed in the housing, and a shut-off member which is connected to the end of the spring, and when the housing internal pressure reaches a predetermined value, the shut-off member overcomes the spring force the spring to lock the entrance of the outlet opening.

An exemplary embodiment of the present invention includes a first piston which operates in response to an electrical signal and a second piston which operates in response to a pressure differential between an inner portion and an outer portion, thereby reducing power consumption. Accordingly, the fuel supply performance can be improved because the diameter of a path which a coil and a piston of the same size can open and close can be increased (although the path is larger, the heat generation is suppressed, and the path can be opened and getting closed).

Furthermore, a relatively high electromotive force is needed when an inlet is initially opened, and the application of electric current is controlled by utilizing an electrical characteristic of a solenoid valve which can be held in the open position by a relatively small electromotive force the heat generated by the coil is further reduced.

Further, a fuel distribution device according to an exemplary embodiment of the present invention has a simple structure to achieve cost saving, and replaces (can replace) a distribution pipe, which increases the manufacturing cost by a complicated shape. In addition, a fuel pump according to an exemplary embodiment of the present invention is attached to an inner portion of the housing, and a check valve which is installed to prevent fuel from leaking to the outside even if a diaphragm is damaged. is.

BRIEF DESCRIPTION OF THE DRAWINGS

1A is a diagram showing an arrangement of an LPI system for a vehicle in which a fuel pump is installed outside.

1B is a sectional view of a known shut-off valve.

1C Fig. 12 is a drawing showing the shape of a known fuel pump and a fuel distribution pipe mounted in a lower part of the fuel pump.

2 FIG. 10 is a sectional view of a fuel cutoff valve according to an exemplary embodiment of the present invention; FIG.

3 FIG. 10 is a sectional view showing an operation of the fuel shut-off valve according to an exemplary embodiment of the present invention at the time of opening an outlet. FIG.

4 shows a fuel distribution device according to an exemplary embodiment of the present invention, and

5 shows a sectional view of a fuel pump with a check valve attached thereto according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION

An LPI device for a vehicle according to an exemplary embodiment of the present invention includes a tank for storing the fuel, a fuel pump, from the tank is separated and fuel, which is provided from the tank through a suction line, transported to a motor, and a fuel shut-off valve, which is attached to the tank and controls the opening and closing of the suction line. Hereinafter, the LPI device for a vehicle according to an exemplary embodiment of the present invention will be described in detail.

2 shows a path where fuel flows, with an inlet (at the back of a first piston in the figure and not shown), in which fuel is admitted, and an outlet port, through which fuel is discharged into the fuel pump, in connection with the suction line in a liquid chamber having a predetermined size.

In addition, the fuel shut-off valve points to a spool 23 , which generates an electromotive force when it is supplied with electric power, a first piston 20 which is of a spring 22 is biased toward a downward movement and which moves upward by the spring force of the spring 22 through from the coil 23 generated electromotive force overcomes, and a second piston 10 which is inserted into the liquid chamber and has a tube shape (or tube shape) and at one end of the first piston 20 is arranged and a relatively reduced section 10b with a small diameter on one side and a relatively enlarged section 10c with large diameter on the other side. The second piston 10 is mounted so that it from the first piston 20 is pressurized, which of the spring 22 is moved down to close the outlet. In addition, this is the end of the small diameter section 10b of the second piston 10 arranged so that it reaches the end of the first piston 20 shows, and the end of the section with the large diameter 10c is arranged so that it points to the outlet.

An elastic component 21 which is made of a rubber material is at the end of the first piston 20 attached, and a flange 10a which has an enlarged diameter is at the end of the small diameter portion 10b of the second piston 10 educated. (Although not shown in the picture, the second piston is guided by a holder (eg, holding arm), etc. to move in the longitudinal direction when the first piston moves up and down, neither of which are separated.)

The fuel shut-off valve as above works as in 3 shown when the outlet is open. As in 3 shown, the first piston sets 20 the second piston 10 under pressure and closes the outlet connected to the suction line so that the delivery of fuel is stopped before the vehicle starts. In this case, as a condition in which the flange 10a in (touch) contact with the elastic member 21 is fuel is introduced (introduced from the tank through the inlet) in the liquid chamber. When electrical current to the coil 23 is applied (when the vehicle starts), moves the first piston 20 by the electromotive force upward. Because the flange 10a and the elastic member 21 be separated from each other, fuel is in the second piston 10 filled. When fuel is filled, the inner and the outer pressure of the second piston 10 identical. In this case (the cross-sectional area A of the small diameter portion 10b is smaller than the cross section B of the large diameter portion 10c , and the section with the big diameter 10c is longer than the small diameter section 10b ) has the section with the big diameter 10c a larger area than the small diameter section 10b , and thus the lift is greater than gravity. That's why the second piston moves 10 upwards and comes into contact with the elastic member 21 , As a result, the end of the large diameter section becomes 10c , which closes the outlet, separated from the outlet, so that the fuel delivery begins.

If in addition to the coil 23 no electric current is applied, moves the first piston 20 down, and the second piston 10 is determined by the spring force of the spring 22 pressurized, and the second piston 10 closes the outlet. In this case, the fuel that enters the second piston 10 filled (was), delivered to (through the) outlet.

Further, in an LPI device according to the exemplary embodiment of the present invention, with respect to the electric current applied to the coil 23 applied, an initial voltage (13V to 14V) applied to the first piston 20 moved up and which is higher than a holding voltage (4 V to 6 V), which is the first piston 20 keeps moving upwards. This means that the vehicle voltage is only supplied directly when the first piston 20 initially moved up, so that the heat generated by the coil 23 is suppressed to the maximum extent, and when the voltage has stabilized after the lapse of a predetermined period of time, the voltage which is the first piston 20 moved up, down and applied.

Since according to the exemplary embodiment of the present invention, which is as stated above, the generation of bubbles due to a rise in temperature is suppressed, and (Pipe resistance is reduced) A path having a further increased diameter can be opened and closed, the path can be made larger than in the related art.

In addition, the exemplary embodiment of the present invention provides a fuel distributor device which is from a lower cup 30 and a distributor plate 32 is formed, instead of the known fuel distribution line (in 1C shown). As described above, in the fuel pump of the LPI device, fuel chambers are provided for each individual engine cylinder to supply fuel to each individual engine cylinder, and the fuel chambers are arranged in a ring shape. Therefore, the fuel distribution device has the shape of a cup, wherein an annular groove 31 formed on its (the cup) inner lower surface, and wherein one side of the annular groove 31 in the lower cup 30 is formed so that it is connected to the suction line, and a distributor plate, which at the upper part of the annular groove 31 on an inner lower surface of the lower cup 30 coupled, and the path grooves (through holes) 33 to communicate with the respective fuel chambers, as in 4 shown. For reference shows 4 a state in which an inner shape of the cup 30 is cut through to make the details clearer. The fuel distributor device having such a structure has a structure in which a path length is minimized (since a known nipple has been removed) and the fuel is annularly moved, whereby the generation of bubbles is suppressed and the fuel distributor device has a simpler shape ( as a known fuel rail), thereby saving manufacturing costs.

Moreover, in an LPI device for a vehicle according to the exemplary embodiment of the present invention, a check valve is formed in a housing of the fuel pump to prevent fuel from leaking even if a diaphragm is damaged.

That is, as in the conventional structure, a vent hole is formed in the motor housing to discharge a gaseous component of the lubricant, which is a volatile component, outside, and as in FIG 5 shown, a discharge hole 42 is formed through and a check valve is mounted on one side of the housing. That is, the housing coupled to the outside of the motor is mounted so that its interior is sealed, and the discharge hole 42 is formed on one side, and when the internal pressure reaches a predetermined pressure, the check valve closes the discharge hole to seal the inner portion of the housing, the check valve points to a spring 41 , which at the inlet of the discharge hole 42 , which is formed in the housing, is mounted, and a shut-off 40 , which coincides with the end of the spring 41 connected is.

The shut-off element 40 So stands in waiting position while the discharge hole 42 is opened by the spring force of the spring, and when fuel enters the housing and the housing internal pressure increases due to the damaged membrane, the shut-off element overcomes 40 the spring force of the spring 41 to the entrance of the outlet opening 42 shut off.

As described above, the exemplary embodiments explained in this specification and the drawings are merely given as predetermined examples facilitating the understanding of the present invention and are not intended to limit the invention to the embodiments in any way. It will be obvious to those skilled in the art that various modifications and changes may be made which are nevertheless within the scope of the claims.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• KR 10-2010-123370 [0001]

Claims (6)

An LPI device for a vehicle, comprising: a tank for storing fuel, a fuel pump that supplies the fuel that is introduced from the tank through a suction line to the engine, and a fuel shut-off valve, which is mounted on the tank and the Opening and closing the suction pipe controls, wherein a path where the fuel flows, is formed in the tank, and a liquid chamber, which has a predetermined size and which has an inlet opening through which the fuel is introduced, and an outlet opening through which the Fuel is discharged, is formed in the path, wherein the fuel shut-off valve comprises: a coil ( 23 ), to which an electric current is drivable, a first piston ( 20 ) which moves upward in the longitudinal direction when electrical current is applied to the coil, and a second piston (FIG. 10 ), which is shaped like a tube, is inserted into the liquid chamber and at the end of the first piston ( 20 ) and a relatively reduced section ( 10b ) with a small diameter on one side and a relatively enlarged section ( 10C ) has a large diameter on the other side, wherein the first piston ( 20 ) the second piston ( 10 ) and closes the outlet, with the end of the small diameter portion ( 10b ) the end of the first piston ( 20 ) and the end of the large diameter portion (FIG. 10c ) is arranged so that it points in the direction of the outlet. The LPI device according to claim 1, wherein the electric current applied to the coil ( 23 ), is provided such that a holding voltage, which maintains the upward movement of the first piston, is smaller than the initial tension, which moves the first piston upwards. The LPI device according to claim 1, wherein a flange ( 10a ) is formed with an enlarged diameter at the end of the small diameter portion of the second piston, and an elastic member ( 21 ), which is in contact with the flange, at the end of the first piston ( 20 ) is attached. The LPI device according to any one of claims 1-3, wherein a plurality of fuel chambers are arranged circularly in the fuel pump to distribute fuel to each cylinder of an engine, and wherein a fuel distributor device distributing fuel to each of the fuel chambers and in Connection to the suction line, comprising: a lower cup ( 30 ) in which on the inner lower surface thereof an annular groove (FIG. 31 ) is formed and one side of the annular groove is connected to the suction line, and a distributor plate ( 32 ) which is connected to an upper part of the annular groove on the lower surface of the lower cup and which has path grooves to communicate with the fuel chambers. The LPI device according to any one of claims 1-3, wherein the fuel pump delivers fuel depending on the volumetric fluctuations which depend on the vibration of a diaphragm, the diaphragm vibrates when a motor is operated with an eccentric cam which is on a is formed rotating shaft, and wherein a discharge opening ( 42 ) is formed in a housing which is connected to the outside of the engine, and a check valve is mounted, which, when the internal pressure reaches a predetermined pressure, the outlet opening closes to seal the inner part of the housing. The LPI device according to claim 5, wherein the check valve comprises: a spring ( 41 ) which is mounted at the inlet of the Äbführöffnung which is formed in the housing, and a shut-off element ( 40 ), which is connected to the end of the spring, and when the housing internal pressure reaches a predetermined value, the shut-off element overcomes ( 40 ) the spring force of the spring to the inlet of the discharge opening ( 42 ) shut off.

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