JP2017089520A - Fuel injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and weight of a common rail, and to achieve common use of the common rail.SOLUTION: After attaching a common rail 2 to a holding member 7 fixed by a cylinder head 6, a supply pump 1 and the common rail 2 are connected with each other through first fuel piping 91, and a fuel injection valve 3 and the common rail 2 are connected with each other through second fuel piping 92. The common rail 2 is positioned and fixed by the first fuel piping 91, the second fuel piping 92, and the holding member 7, and thereby, a flange of the common rail 2 can be dispensed with, and the reduction of the size and weight of the common rail 2 and common use of the common rail 2 can be achieved.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fuel injection device that injects fuel into an internal combustion engine.

  A conventional fuel injection device includes a common rail that stores high-pressure fuel discharged from a pump (see, for example, Patent Document 1). The common rail has a flange portion in which a bolt through hole is formed, and the common rail is directly fixed to the internal combustion engine by inserting the bolt into the bolt through hole and screwing it into the cylinder block of the internal combustion engine. .

JP 2010-159725 A

  However, in the conventional fuel injection device, in order to directly fix the common rail to the internal combustion engine, it is necessary to provide a flange portion on the common rail, and this flange portion contributes to an increase in the size of the common rail.

  Moreover, since the position which provides a flange part differs for every internal combustion engine mounted, there existed a problem that the kind of common rail increased.

  In view of the above points, the first object of the present invention is to reduce the size and weight of the common rail. A second object is to make common rails common.

  In order to achieve the above object, according to the first aspect of the present invention, a supply pump (1) that pressurizes and discharges fuel and a pressure accumulation chamber (21) that stores high-pressure fuel discharged from the supply pump are formed inside. A cylindrical common rail (2), a fuel injection valve (3) for injecting fuel supplied from the common rail to the internal combustion engine, and a first fuel pipe (91) for guiding high-pressure fuel discharged from the supply pump to the common rail; A second fuel pipe (92) for guiding the fuel in the common rail to the fuel injection valve, and a holding member (7) which is fitted in the recesses (61, 64) formed in the internal combustion engine and holds the common rail. Prepare.

  According to this, the common rail can be positioned and fixed by the fuel pipe and the holding member. Therefore, the common rail flange portion can be eliminated, and the common rail can be reduced in size and weight and the common rail can be shared.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a perspective view showing typically the composition of the fuel injection device concerning a 1st embodiment of the present invention. It is a front view of the fuel injection device concerning a 1st embodiment. It is a top view of the fuel injection device concerning a 1st embodiment. It is IV-IV sectional drawing of FIG. It is a perspective view which shows typically the structure of the fuel-injection apparatus which concerns on 2nd Embodiment of this invention. It is a front view of the fuel injection device concerning a 2nd embodiment. It is a top view of the fuel injection device concerning a 2nd embodiment. It is VIII-VIII sectional drawing of FIG.

  Embodiments of the present invention will be described below with reference to the drawings. Note that, in each of the following embodiments, parts that are the same as or equivalent to the matters described in the preceding embodiment are denoted by the same reference numerals, and the description thereof may be omitted. Moreover, in each embodiment, when only a part of the component is described, the component described in the preceding embodiment can be applied to the other part of the component.

(First embodiment)
A first embodiment of the present invention will be described.

  As shown in FIGS. 1 to 4, the fuel injection device injects fuel into a supply pump 1 that pressurizes and discharges fuel, a common rail 2 that stores high-pressure fuel, and an internal combustion engine (more specifically, a diesel engine) (not shown). The fuel injection valve 3 is provided as a main component.

  The supply pump 1 is integrally assembled with the internal combustion engine and driven by the internal combustion engine. The high-pressure fuel discharged from the supply pump 1 is guided to the common rail 2 through the first fuel pipe 91 and stored in the pressure accumulating chamber 21.

  The high-pressure fuel stored in the pressure accumulating chamber 21 is guided to the fuel injection valve 3 through the second fuel pipe 92 and is injected from the fuel injection valve 3 into the combustion chamber of the internal combustion engine.

  The common rail 2 is made of metal. The common rail 2 includes a substantially cylindrical rail main body 22 in which a pressure accumulating chamber 21 is formed, a single inflow port 23 protruding from the outer peripheral surface of the rail main body 22 and connected to the first fuel pipe 91, a rail main body. A plurality of outflow ports 24 projecting from the outer peripheral surface of the portion 22 and connected to the second fuel pipe 92; and one drain port 25 formed on the outer peripheral surface of the rail body portion 22 and connected to a drain pipe (not shown). Yes. The longitudinal direction of the rail body 22 (namely, the left and right direction in FIG. 2 and FIG. 3) is hereinafter referred to as the rail axial direction.

  The pressure accumulating chamber 21 extends along the axial direction of the rail body 22 and is a through hole. The inflow port 23 and the outflow port 24 communicate with the pressure accumulation chamber 21. The drain port 25 is connected to a fuel tank (not shown) via a drain pipe. Further, the pressure accumulation chamber 21 and the drain port 25 are opened and closed by the pressure reducing valve 4.

  A pressure sensor 5 that detects the fuel pressure in the pressure accumulating chamber 21 and outputs an electrical signal to an ECU (not shown) is attached to one end of the rail body 22 in the axial direction. A pressure reducing valve 4 is mounted on the other axial end side of the rail body 22. The pressure reducing valve 4 operates based on a drive signal from the ECU. When the fuel pressure in the pressure accumulating chamber 21 becomes a predetermined value or more, the pressure accumulating chamber 21 and the drain port 25 are communicated with each other, and the fuel in the pressure accumulating chamber 21 is supplied to the fuel tank. To escape. The pressure sensor 5 and the pressure reducing valve 4 also have a function as a plug that closes both end openings of the pressure accumulating chamber 21.

  A plurality (two in this example) of holding members 7 are arranged between the common rail 2 and the cylinder head 6 of the internal combustion engine. The holding member 7 is made of an elastic body such as rubber. Specifically, nitrile rubber is used in consideration of heat resistance and oil resistance.

  The holding member 7 includes a holding portion 71 that is fitted with the rail main body portion 22 and holds the common rail 2. The holding portion 71 has a U-shaped or arcuate cross-sectional shape perpendicular to the rail axis direction. The inner peripheral part of the holding part 71 has an arc shape. Further, the inner diameter of the inner peripheral part of the holding part 71 is substantially equal to the outer diameter of the rail body part 22.

The holding member 7 includes a columnar convex portion 72 protruding from the outer peripheral surface of the holding portion 71. An annular collar 73 is formed on the outer peripheral surface of the convex portion 72. The convex portion 72 is fitted into a hole 61 that is a cylindrical space formed in the cylinder head 6. Further, the flange 73 is engaged with an annular groove 62 formed on the outer peripheral side of the hole 61 in the cylinder head 6. In addition, the hole 61 is corresponded to the recessed part of this invention. Next, the assembly procedure of the common rail 2 grade | etc., Is demonstrated. First, the convex portion 72 of the holding member 7 is fitted into the hole 61 of the cylinder head 6 to fix the holding member 7 to the cylinder head 6. Further, the hook portion 73 is engaged with the groove portion 62 to prevent the holding member 7 from coming off the cylinder head 6.

  Subsequently, the common rail 2 to which the pressure sensor 5 and the pressure reducing valve 4 are assembled is assembled to the holding member 7. Specifically, the rail main body portion 22 is fitted to the holding portion 71.

  Subsequently, the cap nut provided at the end of the first fuel pipe 91 is screwed into the supply pump 1 and the common rail 2, and the supply pump 1 and the common rail 2 are connected by the first fuel pipe 91.

  Subsequently, a cap nut provided at an end of the second fuel pipe 92 is screwed into the fuel injection valve 3 and the common rail 2, and the fuel injection valve 3 and the common rail 2 are connected by the second fuel pipe 92.

  Here, when the supply pump 1 and the common rail 2 are connected to each other through the first fuel pipe 91, the force of the first fuel pipe 91 is generated so as to generate a force that presses the common rail 2 and the holding member 7 against the cylinder head 6. Bending shape and dimensions are set. Further, when the fuel injection valve 3 and the common rail 2 are connected in the second fuel pipe 92, the second fuel pipe 92 is configured so that a force that presses the common rail 2 and the holding member 7 against the cylinder head 6 is generated. Bending shape and dimensions are set.

  In this way, the common rail 2 is positioned and fixed by the first fuel pipe 91 and the second fuel pipe 92 and the holding member 7. Note that misalignment due to variations in shapes and dimensions of the first fuel pipe 91 and the second fuel pipe 92 is absorbed by the holding member 7 made of an elastic body.

  According to the present embodiment, since the common rail 2 can be positioned and fixed by the first fuel pipe 91 and the second fuel pipe 92 and the holding member 7, the flange portion of the common rail 2 is eliminated, and the common rail 2 is reduced in size and weight. In addition, the common rail 2 can be shared.

  Moreover, since the holding member 7 consists of an elastic body, while being able to suppress the vibration of the common rail 2, it can absorb the shift | offset | difference of the alignment at the time of an assembly | attachment.

  Further, since the convex portion 72 of the holding member 7 is fitted into the hole 61 of the cylinder head 6, the holding member 7 can be easily and accurately positioned with respect to the internal combustion engine.

  Further, since the flange 73 is engaged with the groove 62, it is possible to prevent the holding member 7 from coming off the cylinder head 6.

(Second Embodiment)
A second embodiment will be described with reference to FIGS. In this embodiment, the joining structure of the holding member 7 and the cylinder head 6 is different from that of the first embodiment. In the present embodiment, description of the same or equivalent parts as in the first embodiment will be omitted or simplified.

  As shown in FIGS. 5 to 8, the holding member 7 is configured by only the holding portion 71 without the convex portion 72 and the flange portion 73 in the first embodiment.

  The cylinder head 6 is formed with a plurality (two in this example) of rail holding portions 63 protruding from the outer surface of the cylinder head 6. The rail holding portion 63 has a U-shaped or arcuate cross-sectional shape orthogonal to the rail axial direction.

An arcuate groove portion 64 into which the holding member 7 is fitted is formed on the inner peripheral portion of the rail holding portion 63. Further, the inner diameter of the inner peripheral portion of the groove portion 64 is substantially equal to the outer diameter of the rail body portion 22. In addition, the groove part 64 is equivalent to the recessed part of this invention. Next, the assembly procedure of the common rail 2 grade | etc., Is demonstrated. First, the holding member 7 is fitted into the rail holding portion 63 of the cylinder head 6, and the holding member 7 is fixed to the cylinder head 6.

  Subsequently, the common rail 2 to which the pressure sensor 5 and the pressure reducing valve 4 are assembled is assembled to the holding member 7. Specifically, the rail body 22 is fitted to the holding member 7.

  Subsequently, the cap nut provided at the end of the first fuel pipe 91 is screwed into the supply pump 1 and the common rail 2, and the supply pump 1 and the common rail 2 are connected by the first fuel pipe 91.

  Subsequently, a cap nut provided at an end of the second fuel pipe 92 is screwed into the fuel injection valve 3 and the common rail 2, and the fuel injection valve 3 and the common rail 2 are connected by the second fuel pipe 92.

  According to the present embodiment, since the common rail 2 can be positioned and fixed by the first fuel pipe 91 and the second fuel pipe 92 and the holding member 7, the flange portion of the common rail 2 is eliminated, and the common rail 2 is reduced in size and weight. In addition, the common rail 2 can be shared.

  Moreover, since the holding member 7 consists of an elastic body, while being able to suppress the vibration of the common rail 2, it can absorb the shift | offset | difference of the alignment at the time of an assembly | attachment.

(Other embodiments)
In each of the above embodiments, the holding member 7 is fixed to the cylinder head 6, but the holding member 7 may be fixed to a cylinder block or a head cover of the internal combustion engine.

  In addition, this invention is not limited to above-described embodiment, In the range described in the claim, it can change suitably.

  Further, the above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible.

  In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Yes.

  Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case.

  Further, in each of the above embodiments, when referring to the shape, positional relationship, etc. of the component, etc., the shape, unless otherwise specified and in principle limited to a specific shape, positional relationship, etc. It is not limited to the positional relationship or the like.

DESCRIPTION OF SYMBOLS 1 Supply pump 2 Common rail 3 Fuel injection valve 7 Holding member 21 Accumulation chamber 61 Hole 64 Groove part 91 1st fuel piping 92 2nd fuel piping

Claims (3)

A supply pump (1) for pressurizing and discharging fuel;
A cylindrical common rail (2) in which a pressure accumulating chamber (21) for storing high-pressure fuel discharged from the supply pump is formed;
A fuel injection valve (3) for injecting fuel supplied from the common rail into the internal combustion engine;
A first fuel pipe (91) for guiding high-pressure fuel discharged from the supply pump to the common rail;
A second fuel pipe (92) for guiding fuel in the common rail to the fuel injection valve;
A fuel injection device comprising: a holding member (7) for holding the common rail while being fitted in a recess (61, 64) formed in the internal combustion engine.   The fuel injection device according to claim 1, wherein the holding member is made of an elastic body. The recess (61) is a hole,
3. The fuel injection device according to claim 1, wherein the holding member has a holding portion (71) that holds the common rail by fitting the common rail, and a convex portion (72) that fits the concave portion.

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