KR20170074661A

KR20170074661A - Fuel rail for high pressure system

Info

Publication number: KR20170074661A
Application number: KR1020150184208A
Authority: KR
Inventors: 김형준; 윤성현
Original assignee: 주식회사 현대케피코
Priority date: 2015-12-22
Filing date: 2015-12-22
Publication date: 2017-06-30

Abstract

The fuel rail for a high-pressure system according to the present invention comprises a pipe including a hollow fuel transfer portion, at least one fixing portion formed integrally with the fuel rail at a predetermined interval outside the pipe for fixing the fuel rail to the engine, At least one inlet portion for supplying fuel from the outside to the fuel rail and at least one outlet portion protruding in the Z axis direction of the pipe at a predetermined interval outside the pipe to supply fuel from the fuel rail to the injector, And the withdrawing intersection hole is characterized in that the length of the planar pipe in the X-axis direction is shorter than the length of the pipe in the Y-axis direction, Fuel injection and the droplet injection distribution ratio are improved, It is possible to improve the energy output while satisfying the regulation of the international exhaust gas emission by decreasing the emission of harmful exhaust gas by improving the fuel efficiency and increasing the weight and weight due to the increase in thickness and size Can be solved through optimization of the fuel rail intersection hole.

Description

[0001] FUEL RAIL FOR HIGH PRESSURE SYSTEM [0002]

The present invention relates to a fuel rail for a high-pressure system that can ultimately reduce weight and production cost by optimally designing a fuel rail intersection hole to solve such a problem.

As sustainable development and low-carbon green growth have become a global social issue in recent years, social interest in carbon dioxide emissions has been highlighted in Korea. In the case of Korea, since 2000, the rate of increase in the use of energy has been reported to exceed that of major advanced countries such as the United States, Japan, and Germany due to the rapid expansion of industrial production facilities and infrastructures. Since the amount of energy consumption accounts for about 20% of the total energy consumption in Korea, much attention is paid to the development and dissemination of transportation means with relatively low carbon dioxide emissions.

In particular, the diesel engine has a relatively high thermal efficiency as compared with a gasoline engine, and is attracting attention as a future engine in addition to a hybrid vehicle. Fuel economy and combustion performance have been improved mainly by developing a fuel injection system. The fuel injection system which was applied to the existing diesel engine was applied from the fuel pump driven by the cam drive device of the engine by injecting the fuel into the cylinder by the mechanically driven injector, Mixing and combustion environment with air for combustion is relatively poor and precise control of injector such as fuel injection amount and fuel injection timing is not possible and combustion efficiency is low and harmful exhaust gas generation due to incomplete combustion is large .

However, the common rail fuel injection system applied to the diesel engines currently adopted adopts a high-pressure fuel pump to compensate for the disadvantages of the conventional mechanical-driven fuel injection system. The injection pressure and the injection amount of the fuel are independent (Injection control system), which controls the injection pressure and injection timing that best suits the engine operating conditions by means of an engine control unit (ECU), thereby improving fuel economy and reducing harmful emissions This system is capable of improving the output by about 30% compared to the conventional diesel engine and satisfies the emission regulation Euro-4.

The injection pressure of the common rail fuel injection system is the key technology that enables the complete combustion in the combustion chamber by properly atomizing the injected fuel droplet and appropriately distributing it in the cylinder. However, the first-generation common rail system operating at the present injection pressure of 1,350 bar is compatible with the Euro-4 exhaust standards, but the next-generation common rail system to meet the more stringent Euro-5 and Euro-6 regulations It is required to increase the injection pressure of the fuel to 2,000 bar or more to improve the combustion efficiency by reducing the fuel atomization and the distribution of the atomized fuel droplet and ultimately to increase the injection pressure of the fuel to 2,400 bar or more And the development of technology to increase it.

Therefore, in order to realize the atomization of the fuel and the distribution of the droplet, in order to realize the high-pressure system, the thickness and the size of the engine are increased and the fuel cost and the production cost are increased due to the increase of the weight. And the optimal design such as the design of the component parts is urgent.

The present invention relates to a high pressure fuel rail apparatus for a direct injection type gasoline engine and a method for manufacturing the same, and Japanese Patent Laid-Open Publication No. 2010-169099 (published on May 12, 2010), which is disclosed in Korean Patent Laid-Open Publication No. 2013-0138610 ) 'Accumulator for common rail system' has been proposed.

An object of the present invention is to develop a high-pressure fuel system for a next-generation automobile engine. The present invention relates to a high-pressure fuel system for a next-generation automobile engine, which is capable of reducing the harmful exhaust gas through complete combustion in the engine, And an increase in size.

In order to accomplish the above object, the fuel rail for a high-pressure system according to the present invention includes a pipe including a hollow fuel transfer portion in the X-axis direction, At least one inlet portion extending in the X-axis direction of the pipe and supplying fuel from the outside to the fuel rail, and at least one inlet portion projecting in the Z-axis direction at a predetermined distance from the outside of the pipe, And the draw-out intersection hole is formed such that the length of the plane-shaped pipe in the X-axis direction is smaller than the length of the pipe in the X-axis direction of the pipe. Axis direction is shorter than the length in the Y-axis direction.

Further, the withdrawal intersection hole is characterized by being elliptical.

Further, the shape of the drawing intersection hole may be such that the central axes of two or more circles overlap.

Further, the shape of the withdrawal intersection hole may be characterized in that one ellipse and one or more circles are overlapped.

The inlet portion may further include an inlet cross hole formed in the X-axis direction of the pipe and connected to the fuel transfer portion, wherein the Y-axis direction length of the inlet cross hole is shorter than the Z-axis direction length of the pipe .

In addition, the incoming intersection hole is characterized by being elliptical.

Further, the shape of the incoming intersection hole may be characterized in that the center axes of two or more circles are overlapped.

Further, the shape of the incoming intersection hole may be characterized in that one ellipse and one or more circles are overlapped.

According to the present invention, the high-pressure injection of automobile engine fuel improves fuel atomization and droplet injection distribution ratio to induce complete combustion in the engine and improve fuel efficiency, thereby satisfying international exhaust emission regulations through reduction of harmful exhaust gas emissions The energy output can be improved.

In order to realize a high-pressure system, problems such as an increase in weight and an increase in production cost due to an increase in thickness and size can be solved through optimization of fuel rail intersection holes.

1 is a perspective view showing an embodiment in which the fuel rail and the injector of the present invention are combined.
2 is a view showing an embodiment of the fuel rail according to the present invention, wherein (a) is a perspective view of the fuel rail, and (b) is a plan view of the fuel rail.
Fig. 3 is a drawing showing a drawing cross hole shape. Fig. 3 (a) is a drawing draw intersection hole, Fig. 3 (b) Out drawing intersection hole.
Fig. 4 is a sectional view of the fuel rail according to the present invention. Fig. 4 (a) is a cross-sectional view in the X-axis direction aa 'of the pipe, and Fig.
Fig. 5 is a view showing the shape of a leading intersection hole. Fig. 5 (a) shows a conventional leading intersection hole, Fig. 5 (b) Inlet Crosshole A plan view showing the third embodiment.
Fig. 6 is a view simulating the stress applied to the fuel rail in the conventional drawing crosshole. Fig.
Fig. 7 is a view simulating the stress when the drawing cross hole of the present invention is applied to the fuel rail. Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to facilitate a person skilled in the art to easily carry out the technical idea of the present invention. . In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

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

1 is a view showing an embodiment in which a fuel rail 100 for a high-pressure system and an injector 200 are combined. Fig. 2 (a) is a perspective view of the fuel rail 100 for a high-pressure system in Fig. 1, and Fig. 2 (b) is a plan view of the fuel rail 100 for a high-

The fuel rail 100 shown in FIG. 1 refers to a fuel line extending from the fuel manifold of the fuel injecting apparatus to each cylinder. The engine includes a plurality of injectors 200 for injecting fuel from the fuel tank, do.

The fuel rail 100 includes a pipe 110 including a hollow fuel transfer portion 130 and at least one fixing portion 130 integrally formed at a predetermined interval outside the pipe 110 for fixing the fuel rail 100 to the engine. At least one inlet 120 formed to extend in the X axis direction of the pipe 110 and to supply fuel from the outside to the fuel rail 100 and a pipe 110 Axis direction of the fuel rail 100 to supply the fuel from the fuel rail 100 to the injector 200. [

The lead-in portion 120 is formed at one end of the pipe 110 in the X-axis direction and further includes a finishing portion 150 at the other end. The inlet 120 is configured to receive fuel from a fuel tank (not shown) through a hollow fuel transferring unit 130 in the X-axis direction of the pipe 110. The finishing portion 150 is coupled to the other end in the X-axis direction of the pipe 110. This functions to seal the fuel injected into the fuel rail 100 to move along the inner passage of the fuel rail 100 without being exposed to the outside Or may be a control part such as a high pressure sensor or a pressure regulating valve.

Here, the X-axis direction refers to the direction of the long axis of the pipe 110 in the plan view, the Y-axis direction refers to the direction with respect to the short axis of the pipe 110 in plan view, When the axis is shown, it means a three-dimensional height direction.

A sealing member (not shown) may be further included between the pipe 110 and the finishing portion 150 formed to be coupled to the pipe 110. This is to prevent the occurrence of defects due to the loss of the fuel and the drop in the injection pressure due to the filling of the microscopic gaps generated inevitably in the physical structure.

The lead-out portion 300 is protruded in the Z-axis direction of the pipe at a predetermined interval outside the pipe 110.

The injector 200 injecting the high pressure fuel is communicated by the injector fixing part 210 such as a connecting hose directly or separately from the drawing part 300 formed on the fuel rail 100 pipe 110.

Further, the pipe 110 further includes a fixing portion 140 for mounting the fuel rail 100 to the cylinder head of the engine.

2 (a) is a perspective view showing an embodiment of the fuel rail 100 of the present invention. The fuel rail 100 is protruded in the Z axis direction of the pipe 110 at regular intervals outside the pipe 110 and is provided with at least one outlet 300 for supplying fuel from the fuel rail 100 to the injector 200 ).

2 (b) is a plan view showing an embodiment of the fuel rail 100 of the present invention. The drawer 300 formed at a predetermined interval in the pipe 110 has a draw-out cross hole 400 formed in the Z-axis direction of the pipe 110 and connected to the fuel feeder 130. Here, a-a 'in the pipe X-axis direction and b-b' in the Y-axis direction of the pipe will be described in more detail in FIG. 4 for explaining the configuration of the drawing cross hole 400 in detail.

3 is a view showing a draw-out intersection hole 400 formed in the draw-out portion 300, wherein (a) is a view showing a conventional draw-out intersection hole 400a. The conventional drawing cross hole 400a is formed in a circular shape and passes through the center of the drawing portion 300 in the Z axis direction of the pipe 110. [ Accordingly, in order to realize an engine having a small amount of noxious gas emission and a high efficiency due to a limited size that can be formed in a circle, a larger fuel rail and a space and weight for accommodating the fuel rail must be secured.

3 (b) to 3 (d) are views showing an embodiment of the draw-out intersection hole 400 of the present invention in order to solve the problem of the conventional draw-out intersection hole 400a, Axis direction of the pipe 110 and a draw-out intersection hole 400 connected to the hollow fuel transfer section 130 in the pipe 110. The draw-out intersection hole 400 is formed in the X axis of the pipe 110, Direction is shorter than the length of the pipe 110 in the Y-axis direction.

3 (b) is a drawing crosshole 400 according to the first embodiment of the present invention, which is characterized in that the sum of distances between two vertices on a plane is a constant ellipse. Drawing Crosshole 400 The long axis of Embodiment 1 is formed perpendicular to the direction in which the fuel is injected. The length of the drawing-out intersection hole 400 in the X-axis direction of the pipe 110 in which the maximum stress is generated is shortened in consideration of the fact that the maximum stress is generated in the direction in which the fuel is injected, It will reduce it. This is because the pressure received by the withdrawal crosshole 400 is greater than the pressure received in the direction perpendicular to the direction in which the fuel is injected, and the stress decreases as the radius of the hole decreases with respect to the fuel injection direction.

As the area of the draw-out crosshole 400 is larger than a certain size, the stress applied to the crosshole increases as the hole size is smaller, so that the area of the draw-out crosshole 400 of the present invention is the same as that of the conventional drawhole crosshole 400a . 3 (b), the width of the drawing cross hole 400 in the direction in which the fuel is injected is smaller than the width of the drawing cross hole 400 When the length of the withdrawing intersection hole 400 is shorter than the length of the withdrawing intersection hole 400a, the width of the withdrawing intersection hole 400 perpendicular to the fuel injecting direction is smaller than the area of the withdrawing intersection hole 400 finally formed, Should be formed so as to be equal to or larger than the thickness.

Fig. 3 (c) is a diagram showing a second embodiment of the drawing cross hole 400 according to the present invention, in which two or more circles are overlapped.

FIG. 3 (d) is a view showing the shape of the drawing crosshole 400 according to the third embodiment of the present invention, in which one ellipse and one or more circles are overlapped. This is because the amount of fuel flowing into the injector 200 is increased to increase the efficiency of the engine and the area of the injector 200 is regulated so that the size of the engine is not increased You can optimize fuel economy.

4 is a cross-sectional view of the fuel rail 100 of the present invention. The fuel rail 100 includes a hollow fuel transfer unit 130 at the center of the pipe 110 and a draw- Axis direction of the pipe 110 and connected to the fuel transfer unit 130 in the Z-axis direction.

FIG. 4A is a view showing a-a 'in the X-axis direction in FIG. 2B and FIG. 4B is a view showing b-b' in the Y-axis direction.

The width W 'of the drawing cross hole 400 shown in FIG. 4 (a) is formed to be narrower than the width W of the drawing intersection hole 400 shown in FIG. 4 (b). This indicates that the outer wall of the drawing portion 300 of FIG. 4 (a) is formed thicker than the outer wall of the drawing portion 300 of FIG. 4 (b).

FIG. 5 is a view showing the shape of the incoming intersection hole 500, and FIG. 5 (a) is a view showing a conventional incoming intersection hole 500a. The conventional inlet intersection hole 500a is circular and formed in the center of the inlet 120 in the X axis direction of the pipe 110. [ Accordingly, in order to realize an engine having a limited size that can be formed in a circle and having a low emission of noxious gases and an excellent efficiency, a larger fuel rail and a space and weight for accommodating the fuel rail must be secured.

5 (b) to 5 (d) are views showing an embodiment of the inlet intersection hole 500 of the present invention in order to solve the problem of the conventional inlet intersection hole 500a, Axis direction of the pipe 110 and the inlet cross hole 500 connected to the hollow fuel transfer unit 130 in the pipe 110. The inlet cross hole 500 is connected to the Y axis of the pipe 110, Direction is shorter than the length of the pipe 110 in the Z-axis direction.

FIG. 5 (b) is a perspective view of an inlet intersection hole 500 according to an embodiment of the present invention. In FIG. 5 (b), the sum of distances between two vertices on a plane is an ellipse.

FIG. 5C is a diagram showing a second embodiment of the inlet intersection hole 500 according to the present invention in which two or more circles are overlapped.

FIG. 5 (d) is a view showing the shape of the third embodiment of the lead-in intersection hole 500 according to the present invention, wherein one ellipse is overlapped with one or more circles.

FIG. 6 is a graph simulating the stress generated when the conventional draw-out intersection hole 400a is formed in the fuel rail 100. FIG. The stress applied to the conventional drawing intersection hole 400a by the simulation is displayed in color. The portion where the maximum stress is generated in the conventional drawing intersection hole 400a is red, and the portion where the minimum stress occurs is blue Is displayed.

The maximum stress applied to the conventional intersecting hole 400a is 487.19 MPa and the portion indicated by red is the X-axis direction outer portion of the pipe 110 on the conventional intersecting hole 400a. The stress applied to the Y-axis direction of the pipe 110 is 6.8188 MPa and is displayed in blue, and relatively low stress acts on the pipe 110 in the X-axis direction.

7 is a view simulating the stress generated when the drawing cross hole 400 of the present invention is formed on the fuel rail 100. FIG. The distribution of the stress applied to the drawing crosshole 400 is also displayed in a color as shown in FIG. 6, which is relative to each of the experimental maximum values in red and the minimum value in blue.

The maximum stress applied to the drawing cross hole 400 is not concentrated in the X axis direction portion of the pipe 110 as the length is shorter than the conventional cross hole 400a, .

As described above, an optimal embodiment has been disclosed in the drawings and specification. Although specific terms have been employed herein, they are used for purposes of illustration only and are not intended to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: fuel rail 110: pipe
120: inlet part 130: fuel transfer part
140: Fixing portion 150: Finishing portion
200: Injector 210: Injector fixing part
300: Draw-out part 400: Draw-out intersection hole
400a: Conventional drawing intersection hole 500: Incoming intersection hole
500a: Conventional inlet intersection hole

Claims

The fuel rail,
A pipe including a hollow fuel transfer portion;
At least one fixing part formed integrally with the fuel rail at a predetermined interval outside the pipe to fix the fuel rail to the engine;
At least one inlet portion extending in the X-axis direction of the pipe and supplying fuel from the outside to the fuel rail;
And at least one outflow portion protruding in the Z axis direction of the pipe at a predetermined interval outside the pipe to supply fuel from the fuel rail to the injector,
Wherein the lead-out portion includes a lead-out cross hole formed in the Z-axis direction of the pipe and connected to the fuel feed portion,
Wherein the drawing intersection hole is formed such that the length of the pipe in the X-axis direction is shorter than the length of the pipe in the Y-axis direction in plan view.

The method according to claim 1,
And the withdrawing intersection hole is elliptical.

The method according to claim 1,
Wherein the shape of the drawing out intersection hole may be such that the center axes of two or more circles overlap each other.

The method according to claim 1,
Wherein the shape of the withdrawal intersection hole may be such that one ellipse and one or more circles overlap.

The method according to claim 1,
The inlet portion further includes an inlet cross hole formed in the X-axis direction of the pipe and connected to the fuel transfer portion,
Wherein the length of the pipe in the Y-axis direction is shorter than the length of the pipe in the Z-axis direction on the plane of the inlet intersection hole.

The method of claim 5,
Wherein the inlet cross hole is elliptical.

The method of claim 5,
Wherein the shape of the inlet cross hole may be such that the center axes of two or more circles overlap.

The method of claim 5,
Wherein the shape of the inlet cross hole may be such that one ellipse and one or more circles overlap.