KR20110062122A - High pressure fuel pump - Google Patents

Abstract

PURPOSE: A high pressure fuel pump is provided to improve noise by using fluid as a damper which prevents a collision between metals. CONSTITUTION: A high pressure fuel pump comprises a fuel supply path(130), a suction valve(300), a stopper(320), and a fuel discharge path(150). The fuel supply path supplies fuel to a pressing chamber(160). The suction valve controls the amount of the fuel supplied to the pressing chamber. The stopper supports one end of the suction valve and has a stopper hole(321). The fuel discharge path discharges the fuel from the pressing chamber to the outside.

Description

High pressure fuel pump {HIGH PRESSURE FUEL PUMP}

The present invention relates to a high pressure fuel pump, and more particularly to a high pressure fuel pump having the effect of interruption and noise improvement.

In general, gasoline direct injection (GDI) technology is being developed to improve fuel economy and performance in gasoline engines. Compared to the combustion process of a conventional gasoline engine that generates power by intake / compression / ignition / explosion / exhaust of an air / fuel mixture, the GDI engine inhales and compresses only air and injects fuel. Done. This method is similar to the compression ignition method of a diesel engine.

Therefore, in the GDI engine, it is possible to realize a high compression ratio that exceeds the limit of the compression ratio of a conventional gasoline engine, thereby maximizing fuel economy. In such a GDI engine, high pressure fuel pressure is a very important factor, and a high performance fuel pump is required for this purpose.

However, such a fuel pump typically uses a mechanical driving method of driving a tappet by a cam, and since the fuel must be compressed at a high pressure, friction is largely operated in the fuel pump.

In particular, the valves mounted inside the fuel pump repeatedly open and close to continuously control and open the flow of fuel, thereby causing a problem of noise generated due to permanent contact and collision inside the pump housing.

Therefore, the study of the lubricator of the fuel pump for compressing fuel in the GDI engine plays a very important role in improving the durability and performance of the GDI engine.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a high pressure fuel pump having the effect of interruption and noise improvement.

In the high pressure fuel pump according to the embodiment of the present invention for achieving this object, a plunger for reciprocating the cylinder is driven by a driving member, and the volume of the pressure chamber is changed by the reciprocating movement of the plunger. A high pressure fuel pump for pressurizing fuel and adjusting the pressure by a solenoid valve, comprising: a fuel supply passage for supplying fuel to the pressurizing chamber, an intake valve for controlling an amount of fuel supplied to the fuel supply passage, And a fuel discharge passage through which a fuel is discharged from the pressurizing chamber and a stopper having one end of the intake valve and having a stopper hole.

In addition, the intake valve and the housing contact portion is characterized by reducing the resistance to the flow of the fuel in the suction direction by having a conical inclined surface shape.

In addition, the solenoid valve is characterized in that for controlling the fuel pressure in the pressure chamber is increased by using the solenoid.

In addition, the stopper hole is cut along the edge of the stopper is characterized in that formed in a plurality.

In addition, the intake valve is elastically supported in the direction to block the fuel supplied from the fuel supply passage by the elastic member provided therein.

In addition, between the intake valve and the fuel supply passage is formed a valve seat which is in surface contact with each other, the valve seat is characterized in that the conical inclined surface shape.

As described above, according to the high-pressure fuel pump according to the present invention, when the intake valve is closed, since the contact surface of the intake valve and the valve seat has an inclined surface shape in the circumferential direction, the intermittence is excellent and a very small amount up to the moment of contact of the contact surface. Since the fluid exists between the contact surfaces and acts as a damper to prevent sudden metal collisions, noise improvement can be obtained.

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

1 is a cross-sectional view showing a high pressure fuel pump according to an embodiment of the present invention.

2 is a cross-sectional view illustrating main parts of a high pressure fuel pump according to an exemplary embodiment of the present invention.

3 is a perspective view of FIG. 2.

Since the engine used herein is a configuration generally understood by those skilled in the art as a technical configuration to be applied, such a basic configuration is not shown in the drawings for the purpose of the present invention, but a schematic description thereof will be provided.

The engine typically includes a crankcase with a crank seal, a cylinder block with a cylinder bore, a combustion chamber and an intake / exhaust port opening in the combustion chamber.

Here, the fuel tank may be disposed on the bottom of the engine.

The cylinder head is provided to be integrally coupled to the upper side of the cylinder block to form a combustion chamber, and the crankcase is fastened to a lower end of the cylinder block by a coupling member such as a bolt.

The crankcase is divided into two halves on both sides with respect to the central part, and are joined by bolts.

The crankshaft received in the crank seal is rotated via a ball bearing interposed therebetween and the crankshaft is connected via a connecting rod to a piston received in the cylinder bore.

An oil seal may be further installed in the periphery of the bearing in order to secure the close contact with the outer circumferential surface of the crankshaft, and a gasket is interposed between the cylinder block and the connection portion of the crankcase.

On the other hand, an exhaust manifold is formed which extends outside of the cylinder head.

This exhaust manifold serves to exhaust the exhaust gas.

In addition, the partition wall is formed to be evenly divided back and forth across the engine.

The front part of the compartment then comprises an exhaust system and the rear part of the engine comprises an intake system such as an intake manifold.

The combustion chamber formed in the cylinder head includes a spark plug, at least two intake valves and at least two exhaust valves.

The intake valve and the exhaust valve are installed in the cylinder head so as to be parallel to the axial direction of the cylinder bore to open and close the intake port and the exhaust port, respectively.

At this time, the intake valve and the exhaust valve are driven by a valve drive device described later.

Here, the cylinder head forms a wall partitioned on the rear side by having a cam shaft having a plurality of cams and a fuel pump driving cam disposed vertically on an outer circumferential surface thereof.

The camshaft has journal portions located at the top and bottom thereof and the journal portion is supported by a bearing device.

In addition, the upper end of the cam shaft is fixed to the cam shaft pulley.

In addition, a rocker arm shaft supporting a valve rocker arm for driving intake and exhaust valves is disposed in proximity to the cam shaft.

The rocker arm shaft extends vertically parallel to the cam shaft and is spaced apart from the cam shaft to form a space.

The valve rocker arm is arranged to control the intake and exhaust valves and is pivotally supported by the rocker arm shaft.

That is, as described above, the camshaft, the cam, the valve rocker ram, and the intake / exhaust valve operate as a valve driving device.

Therefore, the tappet roller and the tappet mounted in the fuel pump are driven by the fuel pump driving cam on the same axis of the cam shaft so as to vertically reciprocate.

A high pressure fuel pump according to an embodiment of the present invention having the above configuration will be described in detail with reference to FIGS. 1 to 3.

1 to 3, the high pressure fuel pump according to an embodiment of the present invention includes a pump housing 100, a cylinder 110, a plunger 120, an electromagnetic valve 200, and a fuel supply passage 130. ), A suction valve 300 and a fuel discharge passage 150.

Here, the fuel pump is for delivering the fuel discharged from the fuel tank (not shown) by a low pressure lift pump (not shown), for example, to the injector of the GDI engine at high pressure.

The cylinder 110 forming a cylindrical inner space is formed in the pump housing 100.

The plunger 120 is vertically reciprocated along the inner wall of the cylinder 110 is provided.

As described above, the plunger 120 is elastically supported by the plunger spring 121 and vertically reciprocates by the fuel pump driving cam.

The pressurizing chamber 160, which is a space pressurized by the plunger 120, is formed.

The fuel is sucked into the pressure chamber 160, and a fuel supply passage 130 communicating with the pressure chamber 160 is formed.

At this time, the solenoid valve 200 for controlling the amount of fuel supplied from the fuel supply passage 130 is provided.

The solenoid valve 220 may be applied to the solenoid valve 200.

The solenoid valve 220 controls the amount of fuel by reciprocating the rod 210 is elastically supported by an elastic member (not shown) therein.

In addition, an intake valve 300 elastically supported by the valve spring 310 is installed at one end of the rod 210.

The intake valve 300 controls the opening and closing of the fuel supply passage 130, and a valve seat 170 is formed in the pump housing 100 in a direction in which the intake valve 300 is closed.

When the intake valve 300 is closed, it is formed to be in close contact with the valve seat 170, the contact surface is formed to have a conical inclined surface.

In addition, the stopper 320 is tightly fixed to the other end of the suction valve 300.

That is, by using the suction valve 300 having the inclined surface contact shape, when the plunger 120 descends, the valve spring 310 is contracted and fuel is introduced into the pressure chamber 160 through the stopper hole 321. In order to generate the required pressure, the operation of the solenoid valve 220 is interrupted by the operation of the solenoid valve 220 at a predetermined time when the rise of the plunger 120 is performed to increase the fuel pressure in the pressure chamber 160. To be possible.

In addition, by making the contact portion of the suction valve 300 and the pump housing 100 have a conical inclined surface shape, the flow resistance in the suction direction of the fuel is reduced.

Therefore, due to the action of fuel being pushed out between the contact surfaces in the process of closing the intake valve 300, it is possible to reduce noise generated at the same time as the intermittent without leakage.

Referring to the operation of the high-pressure fuel pump according to an embodiment of the present invention configured as described above in detail as follows.

First, when the plunger 120 is lowered, the suction valve 300 moves to the right in the drawing and moves to the stopper 320 position due to the pressure difference.

The stopper hole 321 is positioned at the edge of the stopper 320 to allow the fuel to be sucked into the pressurizing chamber 160 even when the stopper hole 321 is in contact with the valve seat 170.

In this case, the valve spring 310 is contracted and fuel is continuously sucked into the pressure chamber 160 while the plunger 120 moves downward.

On the other hand, when the plunger 120 rises, the pressure in the pressure chamber 160 rises, so that the current is applied to the solenoid valve 220 forcibly by applying a current to the solenoid valve 220 when the suction valve 300 is not interrupted. Keep) open.

At this time, the fuel flows back to the fuel supply passage 130 again.

As described above, when the interruption time (time to be pressed) of the suction valve 300 is released, the suction valve 300 is released due to the force of the pressure of the pressure chamber 160 and the restoring force of the valve spring 310. Returning to the original position quickly, the pressure of the fuel begins to rise by continuously decreasing the volume of the pressure chamber 160 due to the rise of the plunger 120.

When the intake valve 300 is closed, since the valve seat 170 which is the contact surface of the intake valve 300 and the pump housing 100 has an inclined surface shape in the circumferential direction, the intermittence of the fuel is excellent, A very small amount of fuel is present between the contact surfaces until the moment of contact between the intake valve 300 and the pump housing 100 and serves as a damper to prevent a sudden metal collision.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and easily changed and equalized by those skilled in the art from the embodiments of the present invention. It includes all changes to the extent deemed acceptable.

1 is a cross-sectional view showing a high pressure fuel pump according to an embodiment of the present invention.

2 is a cross-sectional view illustrating main parts of a high pressure fuel pump according to an exemplary embodiment of the present invention.

3 is a perspective view of FIG. 2.

* Explanation of Major Parts Used in Drawings *

100: pump housing 110: cylinder

120: plunger 121: plunger spring

130: fuel supply passage 150: fuel discharge passage

160: pressurizing chamber 170; Valve seat

200: solenoid valve 210: rod

220: solenoid valve 300: suction valve

310: valve spring 320: stopper

321: stopper hole

Claims (6)

The plunger which enables the reciprocating motion to the cylinder is driven by the driving member, and the high pressure fuel is pressurized at the same time as the volume of the pressure chamber is changed by the reciprocating motion of the plunger, and the degree of pressurization is controlled by the solenoid valve. In the pump, A fuel supply passage for supplying fuel to the pressure chamber; An intake valve controlling an amount of fuel supplied to the fuel supply passage; A stopper supporting one end of the suction valve and having a stopper hole; And A fuel discharge passage through which fuel is discharged from the pressure chamber; High pressure fuel pump comprising a. The method of claim 1, And the resistance of the flow of the fuel in the suction direction is reduced by having the intake valve and the housing contact portion have a conical inclined surface shape. The method of claim 1, The solenoid valve is controlled to increase the fuel pressure in the pressure chamber by using the solenoid. The method of claim 1, The stopper hole is cut along the edge of the stopper is formed of a plurality of high-pressure fuel pump. The method of claim 1, The intake valve is elastically supported in the direction to block the fuel supplied from the fuel supply passage by the elastic member provided therein. The method of claim 1, A high pressure fuel pump, characterized in that the valve seat is in contact with each other between the intake valve and the fuel supply passage is formed in a conical inclined surface shape.

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