KR20150089159A - High presure fuel pump for direct injection type liquid petroleum injection system - Google Patents

Abstract

The present invention relates to a high pressure fuel pump for a direct injection type LPI system comprising: a body including an inlet, an outlet, and a collector in a lateral surface; a seal carrier combined with the lower part of the body, and wherein a suction means for generating a suction force and a press force is combined with a lower part; and a flow control valve combined with one side of the body to control discharge pressure and supply flow of fuel supplied to an engine. Moreover, the body includes: a high pressure forming chamber to form preset high pressure by pressing some of the fuel inhaled through the inlet by operation of the suction means; and a low pressure part to temporarily store remaining fuel to be collected in a bomb in a low pressure state before the remaining fuel is pressed at high pressure. The present invention has an effect of preventing restart failure due to air bubbles contained in fuel by quickly collecting some containing air bubbles among fuel inhaled inside a high pressure fuel pump to a bomb.

Description

HIGH PRESURE FUEL PUMP FOR DIRECT INJECTION TYPE LIQUID PETROLEUM INJECTION SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a high-pressure fuel pump for a direct injection type air-fuel ratio system, and more particularly, to a high-pressure fuel pump for direct injection type air- To a high-pressure fuel pump for a direct-injection type Elf-i system.

In general, a liquid fuel injection system for a gas vehicle is provided with a fuel pump in a cylinder, unlike a mechanical type LPG fuel system which depends on the pressure of a fuel tank, and a high pressure (5 to 15 bar ) Is injected by an injector to drive the engine.

In such an ELFi system for gas vehicles according to the related art, there is a problem that cavitation occurs in the inside of the cylinder due to a change in the gas state of the LPG stored in the cylinder in response to a change in the atmospheric temperature.

In order to solve such a problem, the applicant of the present invention has already filed and filed a direct injection type ELFI system in the following Patent Documents 1 and 2.

Patent Literature 1 and Patent Literature 2 disclose a technique in which part of the LPG supplied to the high-pressure pump is recovered from the low-pressure portion of the high-pressure pump to the bomb by the continuous pumping operation of the high-pressure fuel pump to maintain the thermal balance inside the bomb, And a configuration for preventing the generation of the temperature of the liquefied fuel is described.

Korean Patent Publication No. 10-2012-0064815 (published on June 20, 2012) Korea Patent Registration No. 10-1199321 (issued on November 9, 2012)

However, in the high pressure fuel pump for the direct injection type ELFi system according to the related art including the Patent Documents 1 and 2, when the flow control valve provided inside the high-pressure fuel pump generates heat and the heat generated from the engine, And bubbles are generated.

Accordingly, the high-pressure fuel pump for the direct injection type ELPHIS system according to the prior art can not sufficiently pressurize to a predetermined high pressure in the process of pressurizing the LPG due to the bubbles contained in the LPG fuel, or the time for generating the high pressure is delayed There was a problem.

Therefore, in the direct injection type ELFI system according to the related art, there is a problem that the high starting pressure can not be formed at the time of restart after the constant speed operation due to the bubbles of the LPF filled in the high pressure fuel pump.

The high-pressure fuel pump for the direct injection type Elpiai system according to the related art has a function of reducing the bubbling speed and cooling inside the high-pressure fuel pump as the damper part, which reduces the pulsation of the fuel sucked into the inside, There is a problem that the speed is lowered.

The object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a direct injection type ELISA system capable of recovering gas containing bubbles into a cylinder by heat generated in a flow control valve and an engine provided in a high- Pressure fuel pump.

It is another object of the present invention to provide a high pressure fuel pump for a direct injection type Elfia system capable of improving the bubble removal rate and the cooling rate of the LPG by removing the damper part.

It is still another object of the present invention to provide a high-pressure fuel pump for a direct injection type ELPHI system capable of removing a space where bubbles of an LPG fuel are generated and improving the flow path structure to quickly remove bubbles of the LPG fuel.

In order to achieve the above object, a high-pressure fuel pump for a direct injection type ELPHI system according to the present invention includes a body having a suction port, a discharge port, and a recovery port formed on a side thereof, a body coupled to a lower portion of the body, And a flow rate control valve coupled to one side of the body and controlling a supply flow rate and a discharge pressure of fuel supplied to the engine, Pressure forming chamber for pressurizing a part of the fuel sucked through the suction port to form a predetermined high pressure and a low-pressure portion for temporarily storing the remaining fuel to be recovered from the low-pressure state to the cylinder before pressurizing the remaining fuel to high pressure .

A supply passage for supplying a part of the fuel sucked to the storage portion is formed between the suction port and the low-pressure portion, and a transfer passage for transferring low-pressure fuel to the collection port is formed between the low- .

And an inlet side check valve connected to the discharge side check valve coupled to the discharge port and an inlet side check valve connected to the flow rate control valve and supplying the fuel to the discharge side check valve while preventing the backward flow of fuel sucked into the body is provided in the body. do.

The present invention further includes a roller tappet portion provided between the body and the cam of the engine cam shaft for converting the rotational motion of the cam into a linear reciprocating motion and transferring the rotational motion to the suction means, And a return spring coupled to the piston to provide a restoring force. The piston may include a piston that is connected to the piston and generates a suction force and a pressing force of the fuel within the body.

The seal carrier includes a cylindrical portion to which a piston of the suction means is coupled and a ring portion which is formed in a ring shape and is coupled to an upper end of the cylindrical portion, at a center portion of the seal carrier, .

As described above, according to the high-pressure fuel pump for the direct injection type ELFI system according to the present invention, a part of the low-pressure LPF supplied into the body is supplied to the high-pressure forming chamber to form a predetermined high pressure, The pressure can be quickly recovered from the low-pressure state to the bomb via the low-pressure portion and the recovery means.

 Accordingly, according to the present invention, in the prior art, the damper portion provided on the upper portion of the body and the cover forming the damper portion are removed to eliminate a space in which bubbles of the LPG fuel can be generated, The effect of preventing the filling of the bubbles of the LPG can be obtained.

According to the present invention, it is possible to remove the damper which acts as a resistor for preventing movement in the process of collecting the LPG fuel, thereby improving the bubble removal speed and the cooling rate inside the high-pressure fuel pump.

In addition, according to the present invention, by removing the damper and the cover, the overall size, volume and weight of the high-pressure fuel pump can be minimized, and space utilization inside the vehicle can be improved when the damper and the cover are mounted on the vehicle.

FIG. 1 is a configuration diagram of a direct injection type ELFI system to which a high-pressure fuel pump for a direct injection type ELFY system according to a preferred embodiment of the present invention is applied;
FIG. 2 is a perspective view of a high-pressure fuel pump for a direct injection type ELPIP system according to a preferred embodiment of the present invention,
3 is a cross-sectional view taken along line A-A 'of the high-pressure fuel pump shown in FIG. 2,
4 is a cross-sectional view of the high-pressure fuel pump shown in FIG. 2 taken along line B-B '
5 is a cross-sectional view taken along the line C-C 'of the high-pressure fuel pump shown in FIG. 2;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a high-pressure fuel pump for a direct injection type ELFi system according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Before describing a high-pressure fuel pump for a direct injection type ELFi system according to a preferred embodiment of the present invention, a configuration of a direct injection type ELFi system to which a high-pressure fuel pump is applied will be schematically described with reference to FIG.

FIG. 1 is a configuration diagram of a direct injection type ELFI system to which a high-pressure fuel pump for a direct injection type ELFY system according to a preferred embodiment of the present invention is applied.

In the present embodiment, the fuel supplied through the fuel supply line S by the pumping operation of the fuel pump 12 at the time of starting the engine is initially delivered to the high-pressure fuel pump 14 at a predetermined pressure, for example, a pressure of about 5 bar, The fuel pressure supplied at the beginning of the start-up is referred to as a low-pressure state.

The transfer path for transferring the low-pressure LPG fuel from the intake port 21 of the high-pressure fuel pump 14 to the fuel recovery line R is referred to as a low pressure section 30 (see FIG. 3).

1, the direct injection type ELF system 10 includes a cylinder 11 in which fuel is stored, a fuel pump 12 which is installed in the cylinder 11 to pump the fuel, a fuel pump 12 which is pumped in the fuel pump 12, A high-pressure fuel pump 14 for pressurizing the fuel pumped by the fuel pump 12 to a high pressure, and a high-pressure fuel pump 14 for supplying fuel to the high- A fuel recovery line R for collecting a part of the fuel from the low pressure section 30 of the high pressure fuel pump 14 to the cylinder 11, a delivery pipe 15 for filling the pressurized fuel from the high pressure fuel pump 14 at high pressure, An injector I for directly injecting the fuel filled in the delivery pipe 15 into the combustion chamber of the engine E, a motor in the fuel pump 12 and the injector I based on the target RPM of the engine E, (I) according to the control signals of the ECU (17) and the ECU (17) which generate control signals for controlling the driving of the motor and the injector And a motor controller 18 for controlling the motor.

The fuel supply line S is opened and closed in response to the drive signal of the motor controller 18 based on the control signal from the ECU 17 to the front end of the high pressure fuel pump 14 to shut off the fuel supplied from the cylinder 11 A valve SV is provided at a downstream end of the high pressure fuel pump 14 of the fuel recovery line R and a fuel for reducing the pressure of the fuel recovered from the low pressure portion 30 of the high pressure fuel pump 14 to the cylinder 11 A pressure regulator 16 may be installed.

The fuel pump 12 pumps the LPG stored in the cylinder 11 and supplies it to the fuel supply line S. [ Here, the fuel supplied through the fuel supply line S is initially delivered to the high-pressure fuel pump 14 at a low-pressure state, for example, a pressure of about 5 bar.

The high pressure fuel pump 14 for the direct injection type ELFi system according to the preferred embodiment of the present invention is configured to inject a portion of the fuel pumped by the fuel pump 12 and supplied through the fuel supply line S at a low pressure, The fuel is supplied to the delivery pipe 15 and the remaining fuel is recovered to the cylinder 11 through the fuel return line R from the low pressure section 30 inside.

The configuration of the high-pressure fuel pump 14 will be described in detail with reference to Figs. 2 to 4. Fig.

FIG. 2 is a perspective view of a high-pressure fuel pump for a direct-injection type LPI system according to a preferred embodiment of the present invention, FIG. 3 is a cross-sectional view taken along line A-A ' 2 is a cross-sectional view taken along the line B-B 'of the high-pressure fuel pump shown in FIG. 2, and FIG. 5 is a cross-sectional view taken along line C-C' of the high-pressure fuel pump shown in FIG.

2 and 3, the high-pressure fuel pump 14 for the direct injection type ELFi system according to the preferred embodiment of the present invention has a suction port 21, a discharge port 22, a recovery port 23, A seal carrier 24 coupled to a lower portion of the body 20 and coupled to a suction means 26 for generating a suction force and a pressing force of the fuel and a seal carrier 24 coupled to one side of the body 20, And a flow control valve (spill valve) 27 for controlling the flow rate and the discharge pressure.

In addition, the high-pressure fuel pump 14 for the direct injection type ELFi system according to the preferred embodiment of the present invention is installed between the body 20 and the cam of the engine camshaft (not shown) to rotate the cam in a linear reciprocating motion (Not shown) for transferring the toner to the suction unit 26. The suction unit 26 is provided with a roller cap (not shown).

The suction means 26 functions to generate a suction force and a pressing force of the fuel inside the body 20. [

To this end, the suction means 26 may include a piston 261 connected to the camshaft of the engine through the roller tappet and moving up and down, and a return spring 262 coupled to the piston 261 to provide restoring force.

3 to 5, the body 20 is connected to a discharge check valve 28 connected to the discharge port 22 and a flow control valve 27 and connected to the fuel 20 sucked into the body 20, Side check valve 29 for preventing the backflow of the refrigerant gas to the discharge side check valve 28. [

A discharge port 211, a suction port 221 and a recovery port 231 may be provided in the suction port 21, the discharge port 22 and the recovery port 23, respectively.

3 and 4, a high-pressure forming chamber 201 may be formed at the center of the body 20 to pressurize the LPG fuel to a preset high pressure state by the lifting operation of the piston.

A supply passage 202 for supplying the fuel sucked through the suction port 21 to the high pressure forming chamber 201 and a fuel pressurized at a high pressure in the high pressure forming chamber 201 are provided in the discharge port 22 in the body 20, A discharge passage 203 for discharging the refrigerant to the outside can be formed.

Further, a low-pressure portion 30 for temporarily storing the low-pressure fuel in the lower portion of the body 20 so as to recover the low-pressure fuel to the cylinder 11 through the fuel recovery line R is provided.

The supply passage 204 for supplying the fuel sucked through the intake port 21 to the low pressure section 30 and the fuel supplied to the low pressure section 30 are provided in the body 20 to the recovery port 23 A transfer passage 205 for transferring the fluid can be formed.

A lower portion of the body 20 is formed into a cylindrical shape with a lower surface opened and a seal carrier 24 forming a lower pressure portion 30 may be coupled to a lower inner peripheral surface of the body 20.

Suction means 26 for generating a suction force and a pressing force of the fuel may be coupled to the lower portion of the seal carrier 24.

The seal carrier 24 may include a cylindrical portion 241 to which the piston 261 is coupled at the center and a ring portion 242 that is formed in a ring shape and is coupled to the upper end of the cylindrical portion 241.

The lower end of the cylindrical portion 241 may be bent toward the piston 261 coupled to the center portion and the outer end of the ring portion 242 may be bent downward to seal the lower portion of the body 20.

A piston seal 243 and a seal stopper 244 may be provided between the cylindrical portion 241 and the piston 261 to prevent leakage of the fuel filled in the low-pressure portion 30 to the outside.

The high-pressure fuel pump according to the present invention configured as described above supplies a part of the low-pressure LPG supplied to the inside of the body to the high-pressure forming chamber to form a preset high pressure, and before the remaining LPG is pressurized to the high pressure, And is quickly recovered to the cylinder through the low-pressure section and the recovery section.

 Accordingly, in the prior art, the damper portion provided on the upper portion of the body and the cover forming the damper portion are removed to eliminate a space in which bubbles of the LPG fuel can be generated. As a result, It is possible to prevent the air bubbles from being filled.

In addition, the present invention can improve the bubble removal speed and the cooling rate inside the high-pressure fuel pump by removing the damper which acts as a resistor which obstructs movement during the recovery process of the LPG fuel.

In addition, the present invention minimizes the overall size, volume, and weight of the high-pressure fuel pump, thereby improving space utilization inside the vehicle when the damper and the cover are removed.

Next, the coupling relationship and operation of the high-pressure fuel pump for the direct injection type ELFi system according to the preferred embodiment of the present invention will be described in detail.

First, after the piston 261 and the return spring 262 are coupled, a piston 261 is installed in the body 20.

The discharge check valve 28 is installed through the discharge port 22 formed at one side of the body 20 and then the discharge port 221 is coupled to the discharge port 22.

Likewise, the inlet-side check valve 29 is provided through the coupling port formed at one side of the body 20, and then the flow control valve 27 is engaged.

The fuel recovery line R is connected to the recovery port 231 in a state where the recovery port 231 is coupled to the recovery port 23 formed at one side of the body 20.

When the engine is driven, the assembled high-pressure fuel pump 14 performs suction, discharge, and recovery operations of the fuel as the piston 261 moves up and down in conjunction with the camshaft.

That is, when the piston 261 moves downward, a suction force is generated in the space inside the body 20, so that fuel is sucked into the space inside the body 20 through the suction port 21 formed in the body 20, Pressure generating chamber 201 through the suction flow passage 202 formed in the inner casing 20.

At this time, the flow control valve 27 opens and closes the inlet-side check valve 29 to control the fuel supply flow rate and the discharge pressure.

Bubbles may be generated as the fuel filled in the body 20 is vaporized by the heat generated in the process of the flow control valve 27 and the heat generated in the engine.

Thus, the high-pressure fuel pump 14 according to the present embodiment recovers fuel containing bubbles through the recovery port 23 to the cylinder 11 at a low pressure.

The remaining fuel other than the fuel supplied to the high pressure forming chamber 201 from among the fuel sucked through the intake port 21 is supplied to the low pressure section 30 through the supply flow passage 204, The fuel is recovered to the cylinder 11 through the recovery valve 205 and the recovery port 23 and the fuel recovery line R. [

As described above, according to the present invention, since a part of the fuel sucked into the inside of the body through the inlet-side check valve of the high-pressure fuel pump is quickly recovered to the bomb, As shown in Fig.

Accordingly, the present invention can prevent the restart failure due to the bubbles contained in the fuel at the time of restarting the vehicle after the constant-speed running of the vehicle, thereby improving the restartability.

Although the invention made by the present inventors has been described concretely with reference to the above embodiments, the present invention is not limited to the above embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

The present invention is applied to a high-pressure fuel pump technique for a direct injection type Elfia system for quickly recovering a part of the fuel sucked into the high-pressure fuel pump into a bomb to prevent a restart failure due to bubbles contained in the fuel.

10: Direct injection type ELISA system 11: Bombardment
12: fuel pump 13: multi-valve
14: High-pressure pump 15: Delivery pipe
16: Fuel pressure regulator 17: ECU
18: motor controller 20: body
201: high-pressure forming chamber 202:
203: Discharge channel 204:
205: transfer passage 21: inlet
211: suction port 22: discharge port
221: Discharge port 23:
231: Recovery port 24: Seal carrier
241: cylindrical portion 241:
243: Piston seal 244: Seal stopper
25: Bracket 26: Suction means
261: piston 262: return spring
27: Flow control valve 28: Discharge side check valve
29: inlet side check valve 30: low pressure portion
SV: Shutoff valve S: Fuel supply line
R: fuel recovery line

Claims (5)

A body having a suction port, a discharge port and a recovery port formed on a side surface thereof,
A seal carrier coupled to a lower portion of the body and coupled to suction means for generating a suction force and a pressing force of fuel,
And a flow control valve coupled to one side of the body and controlling a supply flow rate and a discharge pressure of fuel supplied to the engine,
A high pressure forming chamber in which a part of the fuel sucked through the suction port is pressurized by the action of the suction unit to form a predetermined high pressure,
Pressure portion for temporarily storing the remaining fuel so as to be recovered from the low-pressure state to the high-pressure state before the high-pressure fuel is pressurized to the high-pressure fuel. The method according to claim 1,
A supply passage for supplying a part of the sucked fuel to the storage portion is formed between the suction port and the low-pressure portion,
Pressure fuel pump for a direct-injection type Elf-i system, wherein a transfer passage for transferring low-pressure fuel to a recovery port is formed between the low-pressure portion and the recovery port. 3. The method of claim 2,
A discharge-side check valve coupled to the discharge port,
And an inlet side check valve connected to the flow control valve and supplying the fuel to the discharge side check valve while preventing backward flow of the fuel sucked into the body is provided. 4. The method according to any one of claims 1 to 3,
And a roller tappet provided between the body and the cam of the engine cam shaft for converting the rotational motion of the cam into a linear reciprocating motion and transmitting the rotational motion to the suction unit,
The suction means being connected to the camshaft of the engine through the roller tappet portion and moving up and down to generate a suction force and a pressing force of the fuel in the body,
And a return spring coupled to the piston to provide a restoring force. 5. The method of claim 4,
A seal carrier forming the low-pressure portion is coupled to a lower portion of the body,
Wherein the seal carrier includes a cylindrical portion to which a piston of the suction means is coupled at a central portion thereof,
And a ring portion formed in a ring shape and coupled to an upper end of the cylindrical portion.

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