JP2001329929A - High-pressure fuel pipe supporting structure for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise due to resonance of a high-pressure fuel pipe in a common rail type fuel injector. SOLUTION: In each cylinder, an injector 2 and a common rail 1 are connected together by means of the high-pressure fuel pipe 4 extended from the common rail 1. By means of the high-pressure fuel pipe 5 extended axially from one end part of the common rail 1, the common rail 1 and a supply pump 3 are connected together. A supporting member 7 is formed into an approximately L-shaped form having a long side part 7a and a short side part 7b extended from it at right angles, and in the long side part 7a, the high-pressure fuel pipes 4 are fixed respectively, while the high-pressure fuel pipe 5 is fixed in the short side part 7b. In each pipe supporting part, an elastic member 18 is arranged. The high-pressure fuel pipe 4 is different from the high-pressure fuel pipe 5 in vibrating direction by 90 degrees, so that vibration can be effectively reduced by mutual connection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure fuel pipe support structure for an internal combustion engine such as a direct injection diesel engine, and more particularly to a high pressure fuel pipe support structure suitable for a common rail type fuel injection device.

[0002]

2. Description of the Related Art As a conventional common rail type fuel injection device, the one shown in FIG. 1 is known (or FIG. 3 of JP-A-9-87661). In FIG. 1, 1
Denotes a common rail, 2 denotes an injector provided for each cylinder, and 3 denotes a supply pump that pressurizes fuel and supplies it to the common rail 1. Each injector 2
Is attached to a cylinder head (not shown).
The injector 2 and the common rail 1 are connected by a high-pressure fuel pipe 4 extending from the common rail 1 for each cylinder. A high-pressure fuel pipe 5 extends from one end of the common rail 1, and connects the common rail 1 and the supply pump 3 with the high-pressure fuel pipe 5.
The common rail 1 has an elongated tubular shape along the cylinder row direction of the internal combustion engine.
It is attached to a cylinder head (not shown).

[0003]

However, in such a conventional common rail type fuel injection device, the high pressure fuel pipe 4 is connected to the high pressure fuel pipe 4 by the combustion exciting force of the internal combustion engine or the like.
1 and the high-pressure fuel pipe 5 corresponds to the arrow B in FIG.
In this case, there is a problem that the noises are increased in the directions shown in FIG. In particular, the end of the common rail 1 protrudes from the mounting tab 6 serving as the mounting point of the common rail 1 as a free end, and the cantilevered portion easily vibrates as shown in FIG. Fuel pipe 5
Will amplify the vibrations. In addition, since the rigidity of the high-pressure fuel pipe 5 leading to the supply pump 3 is lower than the rigidity of the common rail 1 itself, the amplitude of the high-pressure fuel pipe 5 increases, and there is a problem that noise is further deteriorated.

[0004]

According to a first aspect of the present invention, there is provided a support structure for a high-pressure fuel pipe of an internal combustion engine, wherein a plurality of first high-pressure fuel pipes are arranged substantially in parallel. At least one of the high-pressure fuel pipes;
And a second high-pressure fuel pipe disposed substantially at right angles to the high-pressure fuel pipe.

According to a second aspect of the present invention, the first high-pressure fuel pipe is a pipe between a common rail for storing high-pressure fuel and each injector, and the second high-pressure fuel pipe is a second high-pressure fuel pipe. The high-pressure fuel pipe is a pipe between the common rail and the supply pump, and the support member
It is substantially L-shaped, one or more first high-pressure fuel pipes are fixed to one side thereof, and the second high-pressure fuel pipe is fixed to the other side. I have.

The invention according to claim 3 is characterized in that all of the plurality of first high-pressure fuel pipes are supported by the support member.

That is, according to the present invention, the first high-pressure fuel pipe and the second high-pressure fuel pipe have vibration directions that differ from each other by approximately 90 °. , Each vibration is effectively suppressed. Therefore, vibration of a plurality of high-pressure fuel pipes can be reduced by one support member. In particular, in claim 3, all the high-pressure fuel pipes are interconnected by one support member, and the respective vibrations are suppressed.

The invention according to claim 4 is characterized in that the first or second high-pressure fuel pipe is supported by the support member via an elastic member.

By interposing the elastic member in this manner, a slight positional error between the high-pressure fuel pipes is absorbed.

According to a fifth aspect of the present invention, wherein the second high-pressure fuel pipe extends from one end of the common rail, the second high-pressure fuel pipe is connected to one end of the support member. The pipe is fixed, and the other end of the support member is connected to the other end of the common rail.

That is, since the second high-pressure fuel pipe extending from one end of the common rail is fixed to the support member,
The vibration of the end of the common rail having the second high-pressure fuel pipe is also suppressed. And in the invention of claim 5,
Since the support member and the common rail are connected at the end opposite to the second high-pressure fuel pipe, vibration of the end of the common rail itself is suppressed.

The invention according to claim 6 is characterized in that the other end of the support member is connected to the other end of the common rail via an elastic member.

By interposing the elastic member in this manner, a slight positional error between the high-pressure fuel pipes is absorbed.

Further, according to the present invention, the support member partially has rigidity between the first high-pressure fuel pipe closest to the second high-pressure fuel pipe and the second high-pressure fuel pipe. It is characterized by being raised. For example, by providing a reinforcing rib or making it partially thicker,
Rigidity is high.

In the invention according to claim 8, the common rail has attachment points for the internal combustion engine main body at a plurality of locations in the longitudinal direction, and each end of the common rail is attached to an attachment point adjacent thereto. The distance between the ends having the second high-pressure fuel pipe is longer than that of the other end.

The end of the common rail, which is a free end protruding from the mounting point, becomes longer as its protruding length becomes longer.
Easy to vibrate. Here, in the invention of claim 8, vibration of the end of the common rail having the second high-pressure fuel pipe is suppressed by fixing the second high-pressure fuel pipe to the support member. Therefore, even if the protruding length of this end (the distance from the attachment point to the end) is long, no large vibration occurs. Conversely, if the protruding length of the opposite end is reduced, the vibration is reduced. In other words, the position of the attachment point
By setting as described above, high rigidity of the entire common rail can be ensured, and vibration of the common rail itself is suppressed. In addition, as a result of suppressing the vibration of the common rail itself, the vibration of each high-pressure fuel pipe related thereto is also suppressed.

[0017]

According to the present invention, for example, the first high-pressure fuel pipe connecting between the injector and the common rail, and the second high-pressure fuel pipe extending substantially perpendicularly thereto, for example, between the supply pump and the common rail. The vibration of both the fuel pipe and the fuel pipe can be effectively suppressed by one support member, and the noise caused by the pipe vibration can be reduced. In particular, the number of parts and the number of assembling steps can be reduced as compared with the case where each high-pressure fuel pipe is individually fixed by, for example, a bracket.

According to the fourth and sixth aspects of the present invention, the elastic member can be attached even when the position of the pipe is shifted.

According to the fifth aspect of the present invention, since both ends of the common rail are substantially supported by the support member and the vibration of each end is suppressed, the noise caused by the vibration of the common rail itself can be reduced.

According to the seventh aspect of the invention, the vibration of the second high-pressure fuel pipe can be sufficiently reduced while reducing the weight of the entire support member.

Further, according to the invention of claim 8, the common rail can be held with high rigidity as a whole without changing the number of attachment points or the span between the attachment points, and the effect of suppressing vibration of the high-pressure fuel pipe is improved. .

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 4 shows a first embodiment of the present invention. As in FIG. 1, 1 is a common rail, 2 is an injector provided for each cylinder, and 3 is a supply pump that pressurizes fuel and supplies it to the common rail 1. Each injector 2 is attached to a cylinder head (not shown), and the injector 2 and the common rail 1 are connected as a first high-pressure fuel pipe by a high-pressure fuel pipe 4 extending from the common rail 1 for each cylinder. The illustrated example is an in-line four-cylinder engine, in which four high-pressure fuel pipes 4 exist.
In a plan view seen from above, they extend parallel to each other.
A high-pressure fuel pipe 5 serving as a second high-pressure fuel pipe extends from one end of the common rail 1, and connects the common rail 1 and the supply pump 3 by the high-pressure fuel pipe 5. The high-pressure fuel pipe 5 extends from the end of the common rail 1 along the axial direction of the common rail 1 and bends into a crank shape on the way to supply pump 3
Has been reached. That is, the portion of the high-pressure fuel pipe 5 near the common rail 1 extends along a direction orthogonal to the high-pressure fuel pipe 4.

The common rail 1 has an elongated tubular shape along the direction of the cylinders of the internal combustion engine, and is attached to a main body of the internal combustion engine, for example, a cylinder head (not shown) at a pair of attachment tabs 6. At the end of the common rail 1 opposite to the high-pressure fuel pipe 5, a short cylindrical high-pressure regulator 9 is attached. Since the pressure regulator 9 is rigidly connected in series to the common rail 1, the vibration of the common rail 1 can be regarded as a part of the common rail 1.

Here, the mounting tabs 6 serving as mounting points for the common rail 1 are respectively disposed at positions slightly offset to the pressure regulator 9 side. That is, as shown in the drawing, the distance L1 from the end of the common rail 1 on the high-pressure fuel pipe 5 side to one mounting point and the distance from the end on the pressure regulator 9 side, that is, the end face of the pressure regulator 9 to the other mounting point. L1> L between L2
2, the positions of the respective mounting tabs 6 are set.

In this embodiment, the support member 7 for regulating the vibration of each of the high-pressure fuel pipes 4 and 5 is formed of an elongated strip-shaped metal plate. Specifically, it is formed in a substantially L-shape having a long side portion 7a having substantially the same length as the common rail 1 and a short side portion 7b extending at a right angle from one end thereof.
Four high-pressure fuel pipes 4 are fixed to the long side 7a, and high-pressure fuel pipes 5 are fixed to the short side 7b. In addition, in order to ensure high bending rigidity in the bent portion 7c, the front and back planes of the band-shaped metal plate are configured so that the long side portion 7a and the short side portion 7b have the same plane.

The high-pressure fuel pipe 4 in the support member 7
An elastic member 8 made of rubber or synthetic resin is interposed in the pipe support portion 5. FIG. 5 shows a specific configuration of the pipe support portion. As shown in the drawing, a flat, substantially U-shaped bracket 10 is attached to the support member 7 by a pair of bolts 11.
The elastic member 8 divided into two is held, and the high-pressure fuel pipes 4 and 5 are sandwiched between the elastic members 8 divided into two.

According to the above configuration, the high-pressure fuel pipe 4 that vibrates along the longitudinal direction of the common rail 1 and the high-pressure fuel pipe 5 that vibrates in a direction perpendicular to the same.
And are connected to each other, so that the respective vibrations are mutually suppressed. Further, the vibration of the end of the common rail 1 on the high-pressure fuel pipe 5 side is also suppressed by the support member 7. By reducing the length L2 of the cantilever portion of the common rail 1 on the pressure regulator 9 side, the vibration of this portion is also suppressed. Therefore, the vibration of the common rail itself is reduced, and the generated noise can be reduced in conjunction with the vibration of each of the high-pressure fuel pipes 4 and 5 being regulated by the support member 7.

FIG. 3 shows an example of the noise reduction effect of the present embodiment.
Noise has been reduced.

FIGS. 6 and 7 show a main part of a second embodiment of the present invention. This is because the bent portion 7c of the support member 7
The reinforcing ribs 13 are formed on the bent portion 7c so as to partially increase the rigidity of the device. This reinforcing rib 13
For example, it is integrated with the support member 7 by welding or the like. By providing the reinforcing ribs 13 in this manner, the bending rigidity of the L-shaped support member 7, particularly the long side portion 7a and the short side portion 7
The bending rigidity at the bent portion 7c between the high-pressure fuel pipe 4b and the high-pressure fuel pipe 5 is increased, and the vibration reduction effect due to the connection of the high-pressure fuel pipe 4 and the high-pressure fuel pipe 5 is reliably obtained. In particular, the required rigidity can be secured without excessively increasing the thickness of the long side portion 7a and the short side portion 7b of the linear shape, so that both weight reduction and vibration reduction can be achieved. Note that, instead of the reinforcing ribs 13, the plate thickness or width of the bent portion 7c may be partially enlarged to increase rigidity.

FIG. 8 shows a third embodiment of the present invention. In this embodiment, the end of the support member 7 is fixed to a pressure regulator 9 which is the end of the common rail 1 on the side opposite to the high-pressure fuel pipe 5. Specifically, the end of the long side portion 7a is bent in an annular shape and the ring portion 7
d is formed, and the ring portion 7 d is fitted to the outer periphery of the pressure regulator 9 via the cylindrical elastic member 12. The elastic member 12 is also made of rubber or synthetic resin.

As a result, the vibration of the common rail 1 on the side where there is no pipe is also suppressed, and the noise can be further reduced. In particular, the end of the common rail 1 is similar to the high-pressure fuel pipe 5,
Vibration in directions different from the vibration direction of the plurality of high-pressure fuel pipes 4 by 90 ° is attempted, so that the vibration is effectively suppressed by being connected to the support member 7.

FIG. 9 is a diagram showing a fourth embodiment of the present invention. This embodiment shows an example in which the present invention is applied to a V-type six-cylinder internal combustion engine provided with a pair of common rails 1. Both common rails 1 are arranged near the center of the V bank.
The high-pressure fuel pipes 4 extend toward the injectors 2 arranged on the outside. A high-pressure fuel pipe 5 extends from the same side end of each common rail 1 and is connected to a common supply pump 3. In this embodiment, the support member 7 is integrated in both banks and is formed in a rectangular frame shape. That is, three high-pressure fuel pipes 4 are supported on each of the pair of long sides 7a, and a pair of high-pressure fuel pipes 5 are supported on one short side 7b. In this case as well, it is desirable to fix and support via an elastic member.

If the support members 7 of the left and right banks of the V-type internal combustion engine are integrated in a rectangular shape as described above, the rigidity is further improved, and the vibration of the high-pressure fuel pipes 4 and 5 can be reduced more reliably. At the same time, the number of parts can be reduced. Of course, the fourth embodiment can be applied to a multi-cylinder V-type internal combustion engine other than the six cylinders.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a conventional common rail fuel injection device.

FIG. 2 is an explanatory view showing a vibration mode of the common rail.

FIG. 3 is a characteristic diagram showing generated noise in a conventional example and an example in comparison.

FIG. 4 is a perspective view of a common rail type fuel injection device showing a first embodiment of the present invention.

FIG. 5 is an enlarged view of a pipe support portion of the support member.

FIG. 6 is a plan view showing a bent portion of a support member according to a second embodiment.

FIG. 7 is a sectional view taken along the line CC of FIG. 6;

FIG. 8 is a perspective view of a common rail type fuel injection device showing a third embodiment of the present invention.

FIG. 9 is a plan view of a main part of a fuel injection device showing a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Common rail 2 ... Injector 3 ... Supply pump 4 ... High-pressure fuel pipe 5 ... High-pressure fuel pipe 7 ... Support member 8, 12 ... Elastic member

Claims (8)

[Claims] A structure for supporting a high-pressure fuel pipe of an internal combustion engine, wherein at least one of a plurality of first high-pressure fuel pipes arranged substantially in parallel and at least one of the first high-pressure fuel pipes is provided. A high-pressure fuel pipe support structure for an internal combustion engine, wherein a second high-pressure fuel pipe disposed at a right angle is connected to each other by a support member. 2. The first high-pressure fuel pipe is a pipe between a common rail for storing high-pressure fuel and each injector, and the second high-pressure fuel pipe is a pipe between the common rail and a supply pump. The support member is formed in a substantially L-shape, and one or more first high-pressure fuel pipes are fixed to one side thereof, and the second high-pressure fuel pipe is fixed to the other side. The high-pressure fuel pipe support structure for an internal combustion engine according to claim 1, wherein: 3. The high-pressure fuel pipe support structure for an internal combustion engine according to claim 1, wherein all of the plurality of first high-pressure fuel pipes are supported by the support member. 4. The high-pressure internal combustion engine according to claim 1, wherein the first or second high-pressure fuel pipe is supported by the support member via an elastic member. Fuel pipe support structure. 5. The second high-pressure fuel pipe extends from one end of the common rail, the second high-pressure fuel pipe is fixed to one end of the support member, and the other end of the support member is connected to the second high-pressure fuel pipe. 3. The high pressure fuel pipe support structure for an internal combustion engine according to claim 2, wherein the high pressure fuel pipe support structure is connected to the other end of the common rail. 6. The high pressure fuel pipe support structure for an internal combustion engine according to claim 5, wherein the other end of said support member is connected to the other end of said common rail via an elastic member. 7. The first high pressure fuel pipe closest to the second high pressure fuel pipe.
3. The high-pressure fuel pipe support structure for an internal combustion engine according to claim 2, wherein the support member has a partially high rigidity between the high-pressure fuel pipe and the second high-pressure fuel pipe. 8. The common rail has attachment points for the internal combustion engine main body at a plurality of positions in the longitudinal direction thereof,
The distance between each end of the common rail and the mounting point adjacent thereto is longer at the end provided with the second high-pressure fuel pipe than at the other end. Item 2
2. A high-pressure fuel pipe support structure for an internal combustion engine according to claim 1.