JP2010216431A - Common rail - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a common rail achieving both securement of strength of the common rail enduring pressurization of high-pressure fuel to be accumulated and a structure having excellent productivity. <P>SOLUTION: This common rail 30 having a hollow portion 41 and accumulating the high-pressure fuel in the hollow portion 41 includes: a rail body 40 having the hollow portion 41 formed inside; a joint section 50 having a communication passage 51 formed inside, a cross hole 61 opened in the communication passage 51 and intersecting with the communication passage 51, and a pipe connection 60 with fuel pipes 16, 17 connected to an end on a side opposite to the communication passage 51; and a joint means 70 joining the rail body 40 to the joint section 50. The rail body 40 and joint section 50 are so configured that rail body 40 and joint section 50 are integrally jointed by the joint means 70 and also the hollow portion 41 communicates with the communication passage 51. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a common rail, and is suitable for application to, for example, a common rail used in an accumulator fuel injection device for an internal combustion engine.

  Conventionally, a common rail is provided in a cylindrical housing, and has a hollow portion that stores fuel therein, and a cross hole that opens to the hollow portion in a direction substantially perpendicular to the hollow portion extending in the longitudinal direction. It has been known. A pipe connection part to which a fuel pipe is connected is provided at the end opposite to the hollow part of the intersecting hole part so as to distribute fuel for each cylinder.

  In this type of common rail, an ultra-high pressure (for example, several hundred MPa) fuel is accumulated in the hollow portion. Therefore, among the inner walls forming the hollow portion and the intersecting hole portion, the intersecting hole portion where the hollow portion and the intersecting hole portion intersect. Stress concentrates on the inner wall portion around the opening on the hollow portion side.

  In the apparatus disclosed in Patent Document 1 as a kind of such a common rail, the peripheral inner wall portion of the opening portion on the hollow portion side of the cross hole portion is formed as a concave spherical surface so as to reduce stress caused by stress concentration. Yes.

  In this technique, a hollow part in which ultrahigh pressure fuel is accumulated is formed by an inner wall having a concave spherical surface.

JP 2002-89404 A

  In recent years, there has been a demand for increasing the fuel injection pressure accumulated in the common rail for the purpose of improving exhaust performance and the like.

  However, the inventor believes that there is a limit in ensuring the strength of the common rail that can withstand the increased fuel injection pressure in the technique of reducing the stress by improving the shape as in the prior art disclosed in Patent Document 1.

  For this reason, the inventor is considering using a high-strength material for the common rail or performing special processing. When this method is applied to the common rail of the prior art, there is a concern that the cost of manufacturing the common rail becomes high.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a common rail that achieves both a sufficient strength of the common rail that can withstand the high pressure of the high-pressure fuel that is accumulated and a configuration that has excellent productivity. It is to provide.

  In order to achieve the above object, the present invention comprises the following technical means.

  That is, in the invention according to claim 1, in the common rail having a hollow portion and accumulating high-pressure fuel in the hollow portion, a rail body having a hollow portion inside, and a joint portion having a communication passage portion inside. A joint portion having an opening in the connecting passage portion and intersecting the connecting passage portion, a pipe connecting portion to which the fuel pipe is connected to an end opposite to the connecting passage portion, a rail body and a joint portion The rail body and the joint portion are integrally joined to each other by the joining means, and the hollow portion and the communication passage portion are in communication with each other. To do.

  According to this, since the common rail is composed of a rail main body and a joint portion that are integrally joined by the joining means, the rail main body having a hollow portion, and the joint portion having a communication passage portion and a cross hole portion, Each can be formed of a separate member.

  Furthermore, the joint part is an intersecting hole part that intersects the connecting passage part, and a pipe connection in which the fuel pipe is connected to the intersecting hole part that opens to the connecting passage part and the end opposite to the connecting passage part. Since it has a part, it can be set as the structure which concentrates and arrange | positions an intersection hole part in a joint part. In other words, the rail body can be configured such that the opening portion of the cross hole portion is not formed on the inner wall forming the hollow portion.

  According to the above configuration, the inner wall of the rail main body is not formed with an opening of an intersecting hole portion where stress concentration is likely to occur, so for example, it is expensive for increasing the pressure of the high-pressure fuel accumulated in the common rail. High strength materials need not be used for the rail body.

  On the other hand, since the connecting passage portion communicates with the hollow portion on the inner wall forming the connecting passage portion of the joint portion, an opening portion of an intersecting hole portion where stress is easily concentrated is formed. Although the use of a high-strength material is required for increasing the pressure, the use of the material can be limited to the joint portion. Therefore, the expensive material and processing for the high pressure of the high-pressure fuel can be limited to the joint portion, so that the material cost and processing cost can be suppressed as compared with the common rail of the prior art.

  According to the first aspect of the present invention, ensuring the strength of the common rail that can withstand the high pressure of the high-pressure fuel that is accumulated can be compatible with the configuration having excellent productivity.

  In the invention according to claim 2, the pipe connecting portion protrudes radially outward with respect to the longitudinal direction of the connecting passage portion, is formed integrally with the joint portion, and is provided at a plurality of locations along the circumferential direction of the joint portion. It is characterized by being.

  Here, for example, in order to distribute fuel to a plurality of cylinders, in the case where a plurality of pipe connection portions are provided in the joint portion, a pipe for assembling the fuel pipe is arranged when the plurality of pipe connection portions are arranged in the longitudinal direction of the communication passage portion. It is necessary to place a longitudinal gap between the connecting portions. Therefore, there is a concern that the joint portion increases in size in the longitudinal direction, leading to an increase in the size of the joint portion.

  On the other hand, according to the second aspect of the present invention, the pipe connection portion projects radially outward with respect to the longitudinal direction of the communication passage portion, and is provided at a plurality of locations over the circumferential direction of the joint portion. These pipe connection portions can be arranged not in the longitudinal direction of the joint portion but in the circumferential direction. The space | interval between the piping connection parts for attaching fuel piping can be ensured with the space | interval of the circumferential direction of a joint part. Thereby, even if it is a case where a some piping connection part is provided in a joint part, the physique of a joint part can be suppressed and the physique can be reduced in size.

  Therefore, it is possible to achieve the effect of reducing the material cost and the processing cost for manufacturing the joint portion in order to cope with the high pressure of the high pressure fuel.

  According to a third aspect of the present invention, the passage diameter of the communication passage portion is smaller than the inner diameter of the hollow portion in which fuel is accumulated.

  In such an invention, it is possible to easily secure a pressure accumulation volume for stably accumulating high-pressure fuel in the hollow portion and the communication passage portion configured in the common rail. Therefore, according to the third aspect of the present invention, the passage diameter of the communication passage portion can be made smaller than the inner diameter of the hollow portion.

  By reducing the diameter of the connecting passage of the joint part, the stress generated on the inner wall part of the opening of the intersection hole part where stress tends to concentrate on the inner wall of the joint part can be reduced, so the strength of the joint part against high pressure fuel is increased. The margin can be increased. In other words, the reliability related to the strength of the joint can be improved with respect to the high pressure of the high pressure fuel.

  According to a fourth aspect of the present invention, the hollow portion extends in the longitudinal direction.

  Here, as a common rail product type, it is preferable to set a plurality of common rail types with different accumulator volumes according to the required characteristics of the internal combustion engine. However, in the conventional common rail, the hollow portion and the pipe connection portion are integrally formed in the housing. For this reason, there is a concern that the number of product types increases excessively due to the correspondence between the pressure accumulation volume and the cylinders of the internal combustion engine, which in turn leads to a decrease in productivity.

  On the other hand, according to the invention described in claim 4, since the hollow portion and the pipe connection portion are formed by separate members of the rail main body and the joint portion, respectively, an increase in the type of the rail main body extending in the longitudinal direction can be achieved. Therefore, productivity can be improved.

  In the invention according to claim 5, the joining means is a fastening element for fastening the rail body and the joint part, and either the rail body or the joint part has a male screw part, and the other is a female screw. It is comprised by the fastening element which has a part, It is characterized by the above-mentioned.

  According to this, as the joining means, the rail main body and the joint portion made of different members may be integrated in an airtight manner. For example, either the rail main body or the joint portion has a male screw portion and the other is Is constituted by a fastening element having a female threaded portion, whereby a simple and inexpensive joining means can be provided.

It is sectional drawing which shows the common rail by 1st Embodiment of this invention, Comprising: It is the II sectional view taken on the line in FIG. It is an external view which shows the common rail by 1st Embodiment. 3A and 3B are diagrams illustrating a joint portion in FIG. 1, in which FIG. 3A is a cross-sectional view, and FIG. 3B is a view as seen from the direction of an arrow IIIB in FIG. It is a schematic diagram which shows the structure of the pressure accumulation type fuel-injection apparatus carrying a common rail.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the component corresponding in each embodiment.

(First embodiment)
1 to 4 show a common rail 30 according to the present embodiment. 1-3 has shown the characteristic part by the common rail 30, and FIG. 4 shows typically the whole structure of the pressure accumulation type fuel-injection apparatus 10 to which the common rail 30 by this embodiment is applied.

  As shown in FIG. 4, the pressure accumulation fuel injection device 10 includes a common rail 30, a fuel injection pump 11, and a fuel injection valve 12. The fuel injection pump 11 sucks fuel from the fuel tank 13 via the suction passage 14. The fuel injection pump 11 pressurizes the sucked fuel to a predetermined pressure and supplies it to the common rail 30. The surplus fuel in the fuel injection pump 11 is discharged to the fuel tank 13 via the discharge passage 15. The fuel injection pump 11 supplies pressurized fuel to the common rail 30 via a supply pipe 16 as a “fuel pipe”. The common rail 30 stores the fuel pressurized by the fuel injection pump 11 in a so-called pressure accumulation state while maintaining the fuel at a predetermined pressure.

  The common rail 30 distributes the fuel accumulated through the fuel pipe 17 to the fuel injection valves 12 mounted on each cylinder of the engine (not shown).

  Further, as shown in FIGS. 1 and 4, the common rail 30 is provided with a pressure control valve 32. The pressure control valve 32 opens when the fuel pressure stored in the common rail 30 becomes greater than a predetermined value. The fuel discharged from the common rail 30 by opening the pressure control valve 32 is returned to the fuel tank 13 via the discharge passage 15.

  The pressure control valve 32 is attached to one end 48 of the common rail 30 by a joining means such as screw fastening. In the present embodiment, the pressure control valve 32 is provided with a male screw portion 32a, and the one end portion 48 of the common rail 30 is provided with a male screw portion 32a and a female screw portion 48a that can be screwed.

  Further, the common rail 30 or the fuel injection valve 12 is provided with pressure detection means such as a pressure sensor (not shown), and the pressure detection means detects the pressure of the fuel stored in the common rail 30. The pressure detection means is connected to an electronic control device (not shown). The electronic control device adjusts the flow rate of the fuel discharged from the fuel injection pump 11 based on the fuel pressure in the common rail 30 detected by the pressure detection means.

Heretofore, the overall configuration of the pressure accumulation type fuel injection device 10 having the common rail 30 as a main configuration has been described. Hereinafter, a characteristic configuration of the common rail 30 will be described.
(Characteristic configuration of common rail 30)
As shown in FIG. 1, the common rail 30 includes a rail body 40 having a hollow portion 41 and a joint portion 50 having a communication passage portion 51, and the rail body 40 and the communication passage portion 51 are integrated by a joining means 70. The hollow portion 41 and the communication passage portion 51 communicate with each other.

  The rail body 40 shown in FIGS. 1 and 2 is made of metal, and for example, carbon steel (high carbon steel (S48C) in this embodiment) is used. The rail body 40 is formed in a hollow cylindrical shape. The pressure control valve 32 and the joint portion 50 are airtightly attached to both end portions 47 and 48 of the rail body 40, and a hollow portion 41 is formed inside.

  The hollow portion 41 is formed by the inner wall 42 of the rail body 40 shown in FIG. The hollow portion 41 extends in the longitudinal direction L of the rail body 40 and can accumulate fuel inside. This is because the one end portion 48 side of the hollow portion 41 is closed by the tip portion 32 b of the pressure control valve 32, and the other end portion 47 side of the hollow portion 41 is closed by the joint portion 57 of the joint portion 50. .

  The rail body 40 is provided with a leak pipe 49 that penetrates the inner wall 42 and the outer wall 43. A leak passage 44 is formed between the leak pipe 49 and the hollow portion 41 by an outer peripheral wall of the tip portion 32 b that hermetically closes the hollow portion 41. The leak passage 44 discharges the fuel discharged from the pressure control valve 32 to the discharge passage 15 via the leak pipe 49.

  The joint portion 50 shown in FIGS. 1 to 3 is made of a metal made of a material different from that of the rail body 40, and for example, alloy steel for mechanical structure (in this embodiment, chromium molybdem steel (SCM435)) is used. Yes. The alloy steel for mechanical structure used for the material of the joint portion 50 according to the present embodiment is a material having excellent tensile strength, and has higher tensile strength than cheap carbon steel.

  The joint part 50 has a main body part 50a having a substantially cylindrical shape. The main body portion 50a is formed with a pipe connecting portion 60 and a joint portion 57 integrally with the main body portion 50a as a single member. The pipe connection part 60 and the joint part 57 protrude from the main body part 50a.

  As shown in FIGS. 1 and 3, the communication passage portion 51 is defined by an inner wall 52 inside the main body portion 50 a and extends in the longitudinal direction L so as to penetrate the joint portion 57.

  As shown in FIG. 1, a male screw portion 57 a is provided on the outer wall of the joint portion 57 and can be screwed to a female screw portion 47 a formed on the other end portion 47 side of the rail body 40. The male thread portion 57a of the joint portion 57 and the female thread portion 47a of the other end portion 47 of the rail body 40 are joining means for integrally joining the rail body 40 and the joint portion 50, and correspond to the joining means described in the claims. .

  The pipe connection portion 60 protrudes from the main body portion 50a of the joint portion 50 to the radially outer side (orthogonal direction R in the drawing) and to the side opposite to the joining portion 57 in the longitudinal direction L (left side in the longitudinal direction L in the drawing). Yes. In the present embodiment, five pipe connection portions 60 are provided along the periphery of the outer wall 53 of the main body portion 50a. A supply pipe 16 connected to the fuel injection pump 11 is connected to one of the five pipe connections 60. The remaining four pipe connection portions 60 are connected to the fuel pipe 17 connected to the fuel injection valve 12.

  On the outer wall of the pipe connection portion 60, a male screw portion 63 for connecting to any one of the fuel pipe 17 and the supply pipe 16 is formed. A connection nut (not shown) as a connection component on the pipe side is attached to the male screw portion 63. A male screw portion 63 and a female screw portion that can be screwed are formed on the inner wall of the connection nut. The connection nut is engaged with the main bodies of the pipes 16 and 17, and the main bodies of the pipes 16 and 17 are cylindrical pipes that form fuel passages therein. And the main body of the said piping 16 and 17 has a connection head pressed against the seat surface part 69 of a piping connection part.

  The pipe connection portion 60 has a seat surface portion 69 at the end opposite to the communication passage portion 51. In the seat surface portion 69, the inner wall 62 of the pipe connection portion 60 is formed in a truncated cone shape whose inner diameter decreases toward the connecting passage portion 51 side.

  The pipe connecting portion 60 includes an intersecting hole portion 61 penetrating the pipe connecting portion 60 on the inner peripheral side. The intersecting hole portion 61 has one opening 65 connected to the communication passage portion 51 and the other opening. Is open to the seat surface portion 69. In other words, the cross hole portion 61 is connected to the communication passage portion 51 through the pipe connection portion 50 and the main body portion 50a.

  In the present embodiment, the cross hole portions 61 of the four pipe connection portions 60 to which the fuel pipe 17 is connected are opened in the orthogonal direction R with respect to the communication passage portion 51 as shown in FIGS. As shown in FIG. 3 (b), these pipe connection portions 60 are arranged along the circumferential direction of the main body portion 50 a of the joint portion 50, and the adjacent pipe connection portions 60 are arranged at a predetermined mutual interval P. Has been.

Further, the cross hole portion 61 of the one pipe connection portion 60 to which the supply pipe 16 is connected opens in the longitudinal direction L with respect to the communication passage portion 51. As shown in FIG. 3A, the one pipe connection portion 60 is arranged at a predetermined mutual interval P with respect to the other four pipe connection portions 60.

Here, since the communication passage portion 51 communicates with the hollow portion 41, the inner walls 52 and 62 of the joint portion 50 are filled with the high pressure fuel accumulated in the hollow portion 41, the communication passage portion 51 and the cross hole portion 61, Tensile stress is generated. Of the inner walls 52, 62, stress concentration is likely to occur in the inner wall portion around the opening 65 on the side of the communication passage 51 of the intersecting hole portion 61, so that the maximum tensile stress is generated in the inner wall portion around the opening 65. Occurs.

  In other words, among the inner walls 42, 52, 62 that accumulate the fuel in the common rail 30 and receive the internal pressure due to the accumulated fuel, the tensile stress is generated in the inner walls 52, 52, 62 of the joint portion 50. It is limited to 62 and is limited to the area of the peripheral inner wall portion of the opening 65 of the cross hole 61.

  On the other hand, in the present embodiment, since the joint portion 50 uses alloy steel for mechanical structure having excellent tensile strength, the maximum tensile stress generated in the peripheral inner wall portion of the opening 65 of the cross hole portion 61 is effectively reduced. It becomes possible to do.

  In the present embodiment described above, the common rail 30 is composed of the rail body 40 and the joint portion 50 that are integrally joined by the joining means 70, and thus the rail body 40 having the hollow portion 41 and the communication passage portion 51. And the joint part 50 which has the cross hole part 61 can be formed with a different member, respectively.

  Further, since the intersecting hole portions 61 are concentratedly arranged in the joint portion 50, the region where the maximum tensile stress is generated by the action of the fuel pressure accumulated in the common rail 30 is limited to the joint portion 50, and the intersection portion 61 is crossed. This is limited to the region of the peripheral inner wall portion of the opening 65 of the hole 61.

  Such a rail body 40 does not need to use a high-strength material excellent in tensile strength for increasing the pressure of the high-pressure fuel accumulated in the common rail 30, and can use an inexpensive material such as carbon steel. .

  On the other hand, although the joint part 50 requires the use of a high-strength material for increasing the pressure of the high-pressure fuel, the use of the high-strength material can be limited to the joint part 50.

  Therefore, since the use of an expensive high-strength material for the high-pressure fuel can be limited to the joint portion 50, the material cost can be suppressed as compared with the common rail of the prior art.

  Therefore, the common rail 30 according to the present embodiment can achieve both the strength of the common rail that can withstand the high pressure of the high-pressure fuel that is accumulated and the configuration having excellent productivity.

  Moreover, in this embodiment demonstrated above, it is preferable to arrange | position the piping connection part 60 where the cross hole part 61 is concentratedly arranged by the joint part 50 as follows. That is, in the common rail 30 according to the present embodiment, the four pipe connection parts 60 are arranged along the circumferential direction of the main body part 50a of the joint part 50 as shown in FIGS.

  Here, for example, it is conceivable that the pipe connection portions are arranged in a line in the longitudinal direction of the common rail as in the conventional common rail, in other words, in a line in the longitudinal direction L of the joint portion 50. In this case, it is necessary to place an interval in the longitudinal direction L in which the fuel pipe can be assembled between the pipe connection portions 60 to which the fuel pipe is assembled. Therefore, there is a concern that the size of the joint portion 50 increases in the longitudinal direction L, and the size of the joint portion 50 increases.

  On the other hand, in the arrangement of the pipe connection portion 60 having the above-described configuration, the mutual interval P between the pipe connection portions 60 for assembling the fuel pipe can be ensured at the interval in the circumferential direction of the joint portion 50. Therefore, it can suppress that the joint part 50 becomes large in the longitudinal direction L, and by extension, size reduction is attained. As a result, it is possible to achieve the effect of reducing the material cost for manufacturing the joint portion 50 in order to cope with the high pressure of the high pressure fuel.

  Moreover, in this embodiment demonstrated above, it is preferable to set it as the structure formed so that the channel diameter D1 of the communication channel | path part 51 is smaller than the internal diameter D2 of the hollow part 41, as shown in FIG.

  Here, among the hollow portion 41 and the communication passage portion 51 configured in the common rail 30, a pressure accumulation volume for stably accumulating high-pressure fuel is secured by the hollow portion 41. Therefore, even when the diameter of the communication passage 51 is reduced, the fuel injection performance of the pressure accumulating fuel injection device 10 is not affected. Therefore, the passage diameter D1 of the communication passage 51 is set to the inner diameter of the hollow portion 41. It is possible to easily realize a smaller diameter than D2.

  By reducing the diameter of the connecting passage portion 51 of the joint portion 50 in this way, the thickness of the joint portion can be increased, and the stress can be reduced by the increase in the thickness. Therefore, the maximum tensile stress can be further reduced.

  Therefore, the strength margin of the joint part 50 can be increased with respect to the high pressure fuel. In other words, the reliability related to the strength of the joint portion 50 is improved with respect to the high pressure of the high pressure fuel.

  Here, as the product type of the common rail 30, it is preferable to set a plurality of types of common rails in which the pressure accumulation volume is changed according to the required characteristics of the engine. However, since the hollow portion and the pipe connection portion are integrally formed in the housing of the common rail of the prior art, the number of product types increases excessively due to the correspondence between the pressure accumulation volume and the engine cylinders, etc., resulting in a decrease in productivity. There was a concern to invite.

  On the other hand, in this embodiment described above, since the hollow part 41 and the pipe connection part 60 are formed by separate members of the rail body 40 and the joint part 50, respectively, the types of the rail body 40 extending in the longitudinal direction L are increased. For example, since it can suppress to the kind increase of the longitudinal direction L length according to a pressure accumulation volume, productivity improvement can be aimed at.

  In the above-described embodiment, the method for reducing the maximum tensile stress has been described by the method using the high-strength material. As a method for reducing the maximum tensile stress, in addition to the method using the above-described high-strength material, there can be considered a processing for imparting residual stress to the inner wall where stress is easily concentrated. Examples of such processing include shop peening, heat treatment, or autofrettage processing that generates residual stress by plastically deforming the inner wall by applying fluid pressure to the inner wall. Even in the case of adopting such processing, the processing can be limited to the joint portion 50 in the common rail 30 according to the present embodiment.

  Therefore, even in the case where the above expensive processing for the high pressure of the high pressure fuel is performed, since the processing can be limited to the joint portion 50, the processing cost is also the same as that of the conventional common rail. It can be suppressed in comparison.

  In addition, in this embodiment demonstrated above, it is preferable that the rail main body 40 and the joint part 50 have the following structures. That is, as shown in FIGS. 1 to 3, gripping portions 43 a and 53 a such as a two-sided width are formed on the outer wall 43 on the other end 47 side of the rail body 40 and the outer wall 53 of the joint portion 50, respectively. The configuration. Thereby, the assembly | attachment operation | work of the rail main body 40 and the joint part 50 becomes still easier.

(Other embodiments)
Although a plurality of embodiments of the present invention have been described above, the present invention is not construed as being limited to these embodiments, and can be applied to various embodiments without departing from the scope of the present invention. .

  (1) In this embodiment described above, the materials used for the rail main body 40 and the joint portion 50 have been described as material combinations of alloy steel for machine structure and high carbon steel, respectively. Not only this but the material of the joint part 50 which is one of the material combinations may be any high-strength material as long as the material is excellent in tensile strength.

  (2) Moreover, in this embodiment demonstrated above, arrangement | positioning of the piping connection part 60 provided in the joint part 50 was set as the arrangement | positioning provided in multiple places along the circumferential direction of the joint part 50. FIG. The pipe connection part 60 may be arranged in a line in the longitudinal direction L.

  (3) In the present embodiment described above, the cross hole 61 opens in the direction R perpendicular to the longitudinal direction L of the connecting passage 51. Not only this but the cross hole part 61 may open in the direction which inclines and cross | intersects with respect to the connection channel | path part 51. FIG. Further, for example, the cross hole portions 61 may be inclined in a V shape.

  (4) Moreover, in this embodiment described above, as the joining means 70 which joins the rail main body 40 and the joint part 50, the joint part 50 has the external thread part 57a, and the rail main body 40 has the internal thread part 47a. Consists of fastening elements. The fastening element is not limited to this, and the joint portion may have a female screw portion, and the rail body may have a male screw portion.

  (5) Moreover, in this embodiment demonstrated above, although it demonstrated by the said fastening element as the joining means 70, even if it joins the rail main body 40 and the joint part 50 with a welding material, not only this, The rail body 40 and the joint portion 50 may be joined together by a fitting structure.

DESCRIPTION OF SYMBOLS 10 Accumulated fuel injection device 12 Fuel injection valve 16 Supply piping (fuel piping)
17 Fuel Pipe 30 Common Rail 32 Pressure Control Valve 32b Tip 40 Rail Body 41 Hollow Part 42 Inner Wall 43 Outer Wall 43a Gripping Part 44 Leakage Path 47 Other End Part 47a Female Thread Part 48 One End Part 49 Leakage Pipe 50 Joint Part 50a Main Part 51 Connection Path Portion 52 Inner wall 53 Outer wall 53a Gripping portion 57 Joint portion 57a Male thread portion 60 Pipe connection portion 61 Cross hole portion 62 Inner wall 63 Male thread portion 65 Opening portion 69 Seat surface portion 70 Joining means

Claims (5)

In a common rail that has a hollow portion and accumulates high-pressure fuel in the hollow portion,
A rail body having the hollow portion therein;
A joint portion having a communication passage portion therein, the fuel pipe being connected to an intersection hole opening to the communication passage portion and intersecting the communication passage portion, and an end opposite to the communication passage portion A pipe connection part and a joint part having
A joining means for joining the rail body and the joint part;
The rail main body and the joint portion are configured so that the rail main body and the joint portion are integrally joined by the joining means, and the hollow portion and the communication passage portion are in communication with each other. .   The pipe connection portion projects radially outward with respect to the longitudinal direction of the communication passage portion, is formed integrally with the joint portion, and is provided at a plurality of locations along the circumferential direction of the joint portion. Item 2. The common rail according to item 1.   The common rail according to claim 1 or 2, wherein a passage diameter of the communication passage portion is smaller than an inner diameter of the hollow portion where the fuel is accumulated.   The common rail according to any one of claims 1 to 3, wherein the hollow portion extends in a longitudinal direction.   The joining means is a fastening element that fastens the rail body and the joint part, and one of the rail body and the joint part has a male screw part and the other has a female screw part. It is comprised, The common rail as described in any one of Claims 1-4 characterized by the above-mentioned.

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