KR19980036022A - Shock-absorbing shock absorber of pressure wave in high pressure fuel injection system - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection system of an engine, and more particularly to a common fuel storage device provided with a shock absorber for minimizing the occurrence of cavitation in a common fuel storage device which is one of the components constituting the fuel injection system. The common fuel storage device of the present invention includes a fuel inlet passage connected to the discharge side of the fuel compression pump, a fuel injection branch pipe connected to the fuel injection device and having a number corresponding to the number of cylinders of the engine, and an impulsive pressure in the common fuel storage device. And a shock absorber as a pressurizing means provided on at least one end side within the common fuel stockpile chamber to prevent transitions. The shock absorber is disposed between the sealing member which is movable in the longitudinal direction while maintaining airtightness between the inner wall of the common fuel stockpile, and between the inner end wall of the common fuel stockpile and the back of the sealing member, At least one convenience means for biasing the closure member and at least one formed on an inner wall of the common fuel stockpile spaced from an inner end wall of the common fuel stockpile to limit movement of the closure member toward the center of the common fuel stockpile. And a stop member.

Description

Shock-absorbing shock absorber of pressure wave in high pressure fuel injection system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection system of an engine, in particular a common fuel stockpile provided with a shock absorber as a pressurizing means for minimizing the occurrence of cavitation in a common fuel stockpile, which is one of the elements constituting the fuel injection system. Relates to a device.

The fuel injection system to which the present invention is applied includes a fuel compression pump for delivering fuel at high pressure from a fuel tank to an engine side, a fuel injection device such as an injector for injecting fuel into a combustion chamber of an engine cylinder, and a fuel discharged from a fuel compression pump. And a common fuel stockpiles having a compressed fluid stockpile that stocks and dispenses to the fuel injectors of each cylinder. At this time, the discharge side of the fuel compression pump and the common fuel storage device is connected by a fuel supply line, the common fuel storage device has a number of branch pipes corresponding to the number of cylinders of the engine has a fuel injection device such as an injector Connected.

In a conventional fuel injection system, at a moment when the amount of fuel introduced into the common fuel storage device from the discharge side of the fuel compression pump through the fuel supply line becomes smaller than the amount of fuel supplied to the engine cylinder through the branch pipes of the common fuel storage device, or the fuel When resonance occurs in the supply lines and branch pipes, cavitation occurs instantaneously in the common fuel stockpiles. Because of this cavitation, the fuel injection rate injected from the fuel injection device such as the injector into the cylinder causes abnormal pressure and fuel delivery wave, which causes unstable combustion, which greatly changes the engine performance and exhaust gas concentration.

The present invention solves the problems in the conventional common fuel storage device as described above, and minimizes the occurrence of cavitation caused by impulsive variations of pressure waves in the common fuel storage device, thereby reducing engine performance and exhaust gas concentration. It is to provide a common fuel storage device provided with a shock absorber as a pressurizing means for minimizing fluctuations of the fuel cell.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross sectional view showing a configuration of a fuel injection system of an engine to which a common fuel storage device according to the present invention is applied;

Fig. 2A is a schematic cross sectional view showing the structure of a common fuel storage device according to the present invention, with the sealing plate of the shock absorber in the retracted position;

Fig. 2B is a schematic cross sectional view showing the structure of a common fuel storage device according to the present invention, with the closure plate of the shock absorber in the forward position;

Explanation of symbols for the main parts of the drawings

10: common fuel storage device

13: compressed fluid storage room

20: fuel compression pump

30: fuel injector

42: sealing plate or sealing member

44: spring or convenience

46: stopper or stop member

According to the present invention, there is provided a common fuel storage device for use in a fuel injection system of an engine having a fuel compression pump, a fuel injection device and a fuel line, comprising: a fuel inlet passage connected to the discharge side of the fuel compression pump via a fuel supply line; A fuel injection branch pipe connected to the fuel injection device and having a number corresponding to the number of cylinders of the engine, and a shock absorber as a pressurizing means provided inside the common fuel storage room to prevent impulsive pressure variations in the common fuel storage device. A fuel stocking device is provided.

In one aspect of the common fuel storage device of the present invention, the shock absorber includes a sealing member that is movable in the longitudinal direction of the common fuel storage device while maintaining airtightness with the inner wall of the common fuel storage room, and the interior of the common fuel storage room. One or more convenient means disposed between the end wall and the back of the closure member and biasing the closure member in accordance with the pressure in the common fuel stockpile and the interior of the common fuel stockpile to limit movement of the closure member toward the center of the common fuel stockpile. At least one stop member spaced from the end wall and formed on the inner wall of the common fuel stockpile chamber.

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

Referring to FIG. 1, there is schematically shown a fuel injection system of an engine including a common fuel storage device 10, a fuel compression pump 20, and a fuel injection device 30 such as an injector. . The inlet side 22 of the fuel compression pump is connected to a fuel tank (not shown), and the discharge side 24 of the fuel compression pump 20 is connected to the fuel of the common fuel storage device 10 by the fuel supply line 2. The fuel injection branch pipe 15 of the common fuel storage device 10 is connected to a fuel injection device 30 such as an injector.

2A and 2B are schematic cross-sectional views showing the structure of a common fuel storage device provided with a shock absorber as a pressurizing means for preventing pressure wave impulse shifting according to the present invention, and FIG. 2A shows a sealed plate as a sealing member of the shock absorber ( 42 shows the state in the retracted position, and FIG. 2B shows the state in which the closure plate 42 of the shock absorber is in the forward position.

The common fuel storage device 10 of the present embodiment includes a hollow cylindrical body 11 that is long in length, as can be seen from FIGS. 1, 2A and 2B. However, the main body 11 of the common fuel stocking device 10 can be manufactured with any suitable cross section, such as cylindrical. The space in the main body 11 serves as the compressed fluid storage chamber 13.

One side of the common fuel storage device 10 is formed with a fuel inlet passage 12 connected to the discharge side 24 of the fuel compression pump 20 via the fuel supply line 2, and the opposite side of the common fuel storage device. The fuel injection branch pipe 15 is formed in the number corresponding to the number of cylinders of the engine and connected to the fuel injection device 30. In addition, a buffer device as a pressing means is formed in one or more of the longitudinal ends inside the common fuel storage chamber 13.

The shock absorber is movable in the longitudinal direction of the common fuel storage device 10 while maintaining the airtightness so that fuel does not leak between the inner wall of the common fuel storage room 13 and has a shape corresponding to the cross section of the main body 11. The sealing plate 42 and the inner end wall 16 or 18 of the common fuel stocking chamber 13 and the back surface of the sealing plate 42 and according to the pressure in the common fuel stocking chamber 13. Compression spring 44 as at least one convenient means of biasing 42 and an inner end of common fuel stockpile 13 to restrict the closure plate 42 from moving further toward the center of common fuel stockpile 13. And a stopper 46 as at least one stop member formed on the inner wall of the common fuel stockpile chamber 13 spaced apart from the subwall 16 or 18 by a predetermined distance.

The position of the stopper 46 and the spring constant of the compression spring 44 are the same as those of the common fuel storage device 10 when the closing plate 42 is in the retracted position (FIG. 2A) and the advanced position (FIG. 2B) as will be described later. It is designed so that a predetermined pressure can be maintained in the compressed fluid storage chamber 13.

On the other hand, as can be seen in FIGS. 2A and 2B, the stopper 46 should be disposed at a position such that at least the closure plate 42 does not move to block the fuel injection branch pipe 15.

In the present embodiment, the shock absorbers are provided at both ends of the common fuel storage chamber 13, but they may be formed only at one of both ends.

Now, operation of the common fuel storage device 10 and the fuel injection system including the same according to the present invention will be described.

Referring to Fig. 1, the fuel compression pump 20, which is electrically operated or driven by an engine driving force during engine operation, takes fuel from the fuel tank through the fuel intake side 22 in the direction indicated by arrow A, and compresses the fuel. The fuel pressurized by the pump 20 is discharged through the discharge side 24 of the fuel compression pump 20, and the discharged fuel is the fuel inflow passage 12 of the fuel supply line 2 and the common fuel storage device 10. It flows through the compressed fluid stockpile chamber 13 which is the space formed in the common fuel stockpile device 10 via. The fuel in the compressed fluid storage chamber 13 of the common fuel storage device 10 is each of the engines through the fuel injection branch pipes 15 formed in the common fuel storage device 10 by the number corresponding to the number of cylinders of the engine. To a fuel injection device 30 such as an injector mounted to an engine intake manifold so as to inject fuel into a cylinder of the fuel injection device 30, the fuel injection device 30 being provided at an end of the fuel injection device and positioned in the cylinder. Injects the optimum amount of fuel into the cylinder according to the instructions of the engine control device (not shown).

In a fuel injection system comprising a common fuel storage device 10 having a buffer device according to the present invention, fuel is normally supplied to the compressed fluid storage chamber 13 in the common fuel storage device 10 to provide a branch pipe 15. When flowing through the fuel injection device through, the compression spring 44 of the shock absorber having a biasing force less than the force of the fuel pressure flowing into the compressed fluid storage chamber 13 as shown in Figure 2A is compressed and sealed The plate 42 is retracted. This makes it possible to maintain a predetermined design pressure by maintaining the volume of the normal compressed fluid storage chamber 13 that is larger than the volume of the compressed fluid storage chamber 13 in the state of FIG. 2B described later.

However, due to any abnormal factors such as resonance phenomena in the fuel lines and passages, the amount of fuel in the compressed fluid storage chamber 13 of the common fuel storage device 10 is momentarily reduced, so that the compressed fluid of the common fuel storage device 10 is reduced. In the case where the cavity phenomenon occurs in the stockpile chamber 13 and an unstable flow phenomenon occurs and the pressure drops, the shock absorber takes a state as shown in Fig. 2B. That is, when the pressure in the compressed fluid storage chamber 13 decreases momentarily due to an abnormal condition, the shock absorber is sealed according to the difference between the biasing force for restoring the compression spring 44 and the pressure in the compressed fluid storage chamber 13. The plate 42 is moved from the retracted position shown in FIG. 2A to the advanced position shown in FIG. 2B. Therefore, by reducing the volume of the compressed fluid storage chamber 13, the lowered fuel pressure of the storage chamber 13 is raised and maintained to a predetermined design pressure. At this time, airtightness is maintained between the sealing plate 42 and the inner wall surface of the common fuel storage chamber 13 so that the fuel and the pressure in the storage chamber 13 are separated from the rear surface of the sealing plate 42 where the spring is disposed. It does not leak into the space between the sub walls 16 and 18. To this end, grooves are formed on the outer circumferential surface of the sealing plate 42 in the circumferential direction so that a sealing member such as an O-ring may be fitted.

If it is reduced from the abnormal condition back to the normal condition, it can be easily seen that the shock absorber is restored back to the state shown in Fig. 2A from the state shown in Fig. 2B.

As a result, the shock absorber of the present invention keeps the pressure in the compressed fluid stockpile 13 of the common fuel stockpile 10 at a constant design pressure at all times in response to instantaneous fluctuations in fuel pressure.

As mentioned above, although this invention was demonstrated to the preferred embodiment, this invention is not limited to this, In addition, it is possible to change or modify in various ways, without deviating from the range of this invention.

In a conventional fuel injection system, if the amount of fuel in the compressed fluid storage chamber of the common fuel storage device is momentarily reduced by any abnormality, for example, by resonance in the fuel lines and passages, the fuel fluid storage chamber in the common fuel storage device is compressed. Cavitation occurs, unstable flow occurs, pressure drops, and fuel output to the fuel injection branch is reduced. As a result, the optimum amount of fuel is not supplied to the engine, so that the performance of the engine is lowered and the exhaust gas concentration does not satisfy the regulation value.

On the contrary, the common fuel storage device provided with the shock absorber of the present invention varies the volume of the compressed fluid storage chamber in the common fuel storage device according to the variation of engine operating factors, thereby minimizing the occurrence of cavitation caused by the impulse variation of the pressure wave. Minimize fluctuations in engine performance and exhaust gas concentration.

Claims (2)

In the common fuel storage device 10 used in the fuel injection system of an engine having a fuel compression pump 20, a fuel injection device 30 and a fuel line, A fuel inlet passage 12 connected to the discharge side 24 of the fuel compression pump 20 via the fuel supply line 2, A fuel injection branch pipe 15 connected to the fuel injection device 30 and having a number corresponding to the number of cylinders of the engine, And a pressurizing means provided inside the common fuel stocking chamber (13) to prevent impulse pressure variations in the common fuel stocking apparatus (10). The method according to claim 1, wherein the pressurizing means includes a sealing member (42) movable in the longitudinal direction of the common fuel storage device (10) while maintaining airtightness with the inner wall of the common fuel storage room (13), and common fuel storage. At least one convenient means disposed between the inner end wall 16 or 18 of the seal 13 and the back of the closure member 42 and for biasing the closure member 42 according to the pressure in the common fuel stockpile chamber 13 ( 44 and the common fuel stock room 13, spaced apart from the inner end wall 16 or 18 of the common fuel stock room 13 to limit the movement of the closure member 42 toward the center of the common fuel stock room 13. And at least one stop member (46) formed on the inner wall of the fuel container.