JP2010164089A - Pipe connection structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe connection structure capable of improving sealing performance and assemblability in a pipe connection portion by suppressing corrosion of a pipe arrangement. <P>SOLUTION: The pipe connection structure includes the pipe arrangement 10 having a head 12 with an outer diameter larger than a cylindrical part in an end of the cylindrical part, a nut member 40 pierced by the pipe arrangement 10 and pressing the head 12 to a tip side of the head 12, a pipe arrangement member 30 screwed together with the nut member 40, and a seat member 20 interposed between the head 12 and the pipe arrangement member 30, having a through hole 22 communicated from a flow path of the pipe arrangement 10 to a flow path of the pipe arrangement member 30, pressed and positioned in an inner circumference of the pipe arrangement member 30, and softer than at least a material of the pipe arrangement member 30. An area (an area of a face of a pressure contact part 32) fit with the seat member 20 in an inner circumference face of the pipe arrangement member 30 is a fuel non-contact part not contacting fuel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pipe connection structure in which fuel pipes for an internal combustion engine are connected to each other.

  2. Description of the Related Art Conventionally, in a pipe connection structure in which fuel pipes for an internal combustion engine are connected to each other, one fuel pipe is brought into pressure contact with the other fuel pipe to ensure a sealing property at a pipe connection portion. For example, in Patent Document 1, an external thread is formed on the outer peripheral surface of the end portion of the counterpart part, and a pressure receiving seat surface that opens outwardly is formed. On the other hand, a spherical surface is formed on the end portion of the fuel pipe made of a steel pipe or a stainless steel pipe Forming a pressing head having a pressure-like or curved pressing seat surface and pressing the pressure-receiving surface on the back of the head with a cap nut screwed to the external screw, and only elastic deformation of the pressing seat surface A pipe connection structure for sealing with is disclosed.

  Moreover, in patent document 2, a flare part is shape | molded in the edge part of one metal piping among two metal piping, and the union part which has an external thread part is provided in the edge part of the other metal piping, The said flare part Is brought into contact with the sealing surface of the tip of the union part, a nut is fastened to the male screw part, and the flare part is directly crimped to the sealing surface by fastening the nut to form a metal seal between the metal faces. A pipe connection structure is disclosed in which an elastic member that elastically compresses and deforms to generate an elastic force by tightening the nut is interposed between the nut and the flare portion.

JP 2007-77807 A JP 2003-214570 A

  In the pipe connection structure described in Patent Document 1, since the fuel pipe is made of a steel pipe or a stainless steel pipe, when aluminum is used for the mating part, the mating part is plastically deformed. The mating part is formed with a surface treatment portion for preventing corrosion of the alcohol-mixed fuel. When the head of the fuel pipe is pressed against the seating surface of the mating part, the plastic treatment of the mating part causes cracking and peeling in the surface treatment part of the mating part, exposing the aluminum, and corrosion of the exposed aluminum part by the alcohol-mixed fuel. It may occur and the sealing performance between the counterpart part and the fuel pipe may be impaired.

  In the pipe connection structure described in Patent Document 2, since the elastic member interposed between the flare portion and the nut is not positioned in a fixed state, the elastic member may be displaced at the time of attachment / detachment, and the sealing performance may be impaired. There is. Further, if the elastic member is not positioned in a fixed state, the assembly process becomes complicated, and there is a possibility that a poor sealing performance may occur due to the assembly failure.

  The main subject of this invention is providing the piping connection structure which can suppress the corrosion of piping and can improve the sealing performance in a piping connection part, and an assembly | attachment property.

  In one aspect of the present invention, in a pipe connection structure in which fuel pipes for an internal combustion engine are connected to each other, a pipe having a head having an outer diameter larger than that of the cylindrical part at an end of the cylindrical part, and the pipe are inserted And a nut member that presses the head portion toward the distal end side of the head portion, a piping member that is screwed to the nut member, and interposed between the head portion and the piping member, and the circulation of the piping A through-hole that leads from the passage to the flow path of the piping member, is press-fitted into the inner periphery of the piping member, is positioned and fixed, and includes a sheet member that is at least softer than the material of the piping member, A region where the sheet member is press-fitted on the inner peripheral surface is a fuel non-contact portion that does not contact the fuel.

  According to the present invention, since the sheet member softer than the material of the piping member (for example, aluminum) is interposed between the piping member and the piping, the surface of the piping member that does not plastically deform and the fuel in the piping member contacts. Sealing can be performed without cracking or peeling off at the processing section. In addition, since the seat member can be positioned and fixed by press-fitting the inner periphery of the piping member, assembly, sealing, and detachability can be established. Furthermore, even if the surface treatment portion of the piping member is cracked or peeled off due to the press-fitting of the sheet member, it is a fuel non-contact portion, so that corrosion due to fuel does not occur.

  In one embodiment of the present invention, a pipe (10 in FIG. 1) having a head (12 in FIG. 1) having an outer diameter larger than that of the cylindrical part at the end of the cylindrical part, and the pipe (in FIG. 1). 10) and a nut member (40 in FIG. 1) for pressing the head (12 in FIG. 1) against the tip side of the head (12 in FIG. 1), and the nut member (40 in FIG. 1). ) And the piping member (30 in FIG. 1), and between the head (12 in FIG. 1) and the piping member (30 in FIG. 1), and in the piping (10 in FIG. 1) A through hole (22 in FIG. 1) communicating from the flow passage to the flow passage of the piping member (30 in FIG. 1), press-fitted into the inner periphery of the piping member (30 in FIG. 1), and positioned and fixed, A sheet member (20 in FIG. 1) softer than the material of the piping member (30 in FIG. 1), and the piping part The region where the sheet member (20 in FIG. 1) is press-fitted on the inner peripheral surface of (30 in FIG. 1) (the region of the surface of the press contact portion 32 in FIG. 1) is a fuel non-contact portion that does not come into contact with the fuel ( Form 1).

Furthermore, the following forms are also possible.
The piping member has a first pressure contact portion on an inner peripheral surface, and a first pressure receiving seat portion that is inclined on the back side with respect to the first pressure contact portion on the inner peripheral surface, and the seat member includes the head member And an inclined second pressure receiving seat portion that is in pressure contact with the portion, and a second pressure contacting portion that is in pressure contact with the first pressure contacting portion of the piping member on the outer peripheral surface, and presses the first pressure receiving seat portion at the end portion. It is preferable that the second pressure seat portion is the fuel non-contact portion (mode 2).
It is preferable that the sheet member has concave portions that are chamfered or notched over the entire circumference on both sides in the axial direction of the second pressure contact portion (mode 3).
It is preferable that the sheet member has a groove portion that communicates between the concave portions at a predetermined position of the second pressure contact portion (mode 4).
It is preferable that the head is formed in a spherical or curved surface having an outer diameter larger than that of the cylindrical portion at the end of the cylindrical portion of the pipe (form 5).
It is preferable that the nut member has a third pressing seat portion that presses the head portion toward the sheet member (form 6).
It is preferable that the piping member has an inner thread portion on an inner peripheral surface, and the nut member has an outer thread portion that is screwed with the inner thread portion on the outer peripheral surface (form 7).
It is preferable that the piping member has an outer thread portion on an outer peripheral surface, and the nut member has an inner thread portion that is screwed with the outer thread portion on an inner peripheral surface (mode 8).
The piping member is preferably made of surface-treated aluminum, and the sheet member is preferably made of brass or copper (form 9).
The sheet member is preferably softer than the material of the pipe (form 10).
The piping is preferably made of steel or stainless steel (form 11).

  A pipe connection structure according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a configuration of a pipe connection structure according to Embodiment 1 of the present invention. FIG. 2 is a perspective view schematically showing the configuration of the sheet member used in the pipe connection structure according to the first embodiment of the present invention.

  Referring to FIG. 1, in the pipe connection structure, a pipe 10 and a pipe member 30 are connected via a sheet member 20, and the pipe 10 is pressed against the sheet member 20 by a nut member 40 that is screwed with the pipe member 30. The pipe connection structure includes the pipe 10, the sheet member 20, the pipe member 30, and the nut member 40.

  The pipe 10 is a cylindrical member. The pipe 10 is made of a material that can ensure fuel corrosion resistance and is harder than the material of the sheet member 20 (metal, alloy). For example, steel or stainless steel can be used. The pipe 10 has a flow passage 11 inside the cylindrical portion. The flow passage 11 communicates with the through hole 22 of the sheet member 20. The pipe 10 is inserted into the through hole 41 of the nut member 40 at a cylindrical portion with a predetermined clearance. The pipe 10 has a head portion 12 that is plastically processed at the tip portion of the cylindrical portion on the sheet member 20 side.

  The head 12 is processed to have an outer diameter larger than that of the cylindrical portion, and the surface shape is formed into a spherical shape, a curved surface shape, a conical shape, or the like. The head portion 12 includes a nut pressure receiving seat portion 12b whose outer diameter gradually increases from the cylindrical portion to the tip end, and a pressure seat portion 12a whose outer diameter gradually increases on the tip side from the nut pressure receiving seat portion 12b. . The nut pressure receiving seat portion 12 b is a portion that receives the pressing of the pressing seat portion 43 of the nut member 40 when the nut member 40 is fastened to the piping member 30. The pressing seat portion 12 a is a portion that presses the pressure receiving seat portion 21 of the seat member 20 when the nut pressure receiving seat portion 12 b is pressed by the pressing seat portion 43 of the nut member 40. The pressing seat portion 12 a is in annular contact with the pressure receiving seat portion 21 of the seat member 20 to seal between the pipe 10 and the seat member 20.

  The sheet member 20 is an annular member interposed between the pipe 10 and the pipe member 30. The sheet member 20 is a material that can ensure fuel corrosion resistance, and is made of a material (metal, alloy) that is softer than the material of the pipe 10 (for example, steel) and the material of the pipe member 30 (aluminum). Copper and brass can be used.

  The sheet member 20 has a pressure receiving seat portion 21 that is inclined so that the inner diameter becomes smaller toward the through hole 22 on the surface in the vicinity of the pipe 10 on the inner peripheral surface. The pressure receiving seat portion 21 is a portion that receives the pressure of the pressing seat portion 12 a of the head portion 12 of the pipe 10. The pressure receiving seat portion 21 is in annular contact with the pressing seat portion 12 a of the pipe 10 to seal between the pipe 10 and the sheet member 20. The surface shape of the pressure receiving seat portion 21 is the shape of a rotating surface (for example, a conical surface) with the through hole 22 as an axis. The sheet member 20 has a through hole 22 on the back side of the pressure receiving seat portion 21. The through hole 22 communicates with the flow passage 34 of the piping member 30.

  The sheet member 20 has a pressure contact portion 23 that is in pressure contact with the pressure contact portion 32 of the piping member 30 on the outer peripheral surface. The sheet member 20 is positioned and fixed by being press-fitted into the inner periphery of the pressure contact portion 32 of the piping member 30. The pressure contact portion 23 is disposed in a fuel non-contact portion that does not contact the fuel.

  The seat member 20 has a pressing seat portion 27 inclined on the surface near the flow passage 34 of the piping member 30 on the outer peripheral surface so that the inner diameter decreases toward the flow passage 34. The pressing seat portion 27 is a portion that presses the pressure receiving seat portion 33 of the piping member 30. The pressing seat portion 27 is in annular contact with the pressure receiving seat portion 33 of the piping member 30 to seal between the seat member 20 and the piping member 30. The surface shape of the pressing seat portion 27 is the shape of a rotating surface (for example, a conical surface) with the through hole 22 as an axis.

  The sheet member 20 has concave portions 25 and 26 that are chamfered or cut out over the entire circumference on both sides in the axial direction (vertical direction in FIG. 1) of the press contact portion 23. The recesses 25 and 26 are spaces for storing burrs when the sheet member 20 is press-fitted into the inner periphery of the pressure contact portion 32 of the piping member 30, and are for preventing the surface treatment portion of the piping member 30 from peeling and cracking. .

  The sheet member 20 has a groove portion 24 communicating with the recesses 25 and 26 at a predetermined position of the press contact portion 23. The groove portion 24 is for inspecting the airtightness of the pressing seat portion 27 and the pressure receiving seat portion 33 after the sheet member 20 is assembled to the piping member 30. When the pressure contact portion 23 and the pressure contact portion 32 are in pressure contact over the entire circumference, the airtight leak between the pressing seat portion 27 and the pressure receiving seat portion 33 cannot be detected, so that the groove portion 24 is provided.

  The piping member 30 is a thick cylindrical member. The piping member 30 is made of a material harder than the material of the sheet member 20 (for example, copper or brass). For example, aluminum having a surface treatment portion (for example, nickel phosphorus) can be used. The piping member 30 has an internal thread portion 31 in which an internal thread is formed on the internal peripheral surface of the distal end portion on the opening side where the piping 10 is inserted. The inner screw portion 31 is screwed with the outer screw portion 42 of the nut member 40.

  The piping member 30 has a pressure contact portion 32 that is smaller than the inner diameter of the inner screw portion 31 on the back side of the inner screw portion 31. The sheet member 20 is press-fitted into the press contact portion 32, and the sheet member 20 is positioned and fixed by press contact with the press contact portion 23 of the sheet member 20. The pressure contact portion 32 is disposed in a non-fuel contact portion that does not contact the fuel.

  The piping member 30 has a pressure receiving seat portion 33 which is inclined so that the inner diameter becomes smaller toward the flow passage 34 on the back side than the pressure contact portion 32. The pressure receiving seat portion 33 is a portion that receives the pressing of the pressing seat portion 27 of the sheet member 20. Regardless of whether or not the pipe 10 is pressing the sheet member 20, the pressure receiving seat portion 33 is in annular contact with the pressing seat portion 27 of the sheet member 20 in a state where the sheet member 20 is press-fitted into the pressure contact portion 32. Thus, the space between the sheet member 20 and the piping member 30 is sealed. The surface shape of the pressure receiving seat portion 33 is the shape of a rotating surface (for example, a conical surface) with the flow passage 34 as an axis. The piping member 30 has a flow passage 34 on the back side of the pressure receiving seat portion 33.

  The nut member 40 is a member for pressing the head portion 12 of the pipe 10 and pressing the head portion 12 of the pipe 10 against the pressure receiving seat portion 21 of the seat member 20 by being fastened to the pipe member 30. The nut member 40 has a through hole 41 for inserting the cylindrical portion of the pipe 10. The through hole 41 has a predetermined clearance from the outer peripheral surface of the cylindrical portion of the pipe 10. The nut member 40 has an external thread portion 42 having an external thread formed on the outer peripheral surface. The external thread portion 42 is screwed with the internal thread portion 31 of the piping member 30.

  The nut member 40 has a pressing seat portion 43 that is inclined on the surface near the head 12 of the through hole 41 so that the inner diameter increases toward the seat member 20 side. The pressing seat portion 43 is a portion that presses the nut pressure receiving seat portion 12 b of the head portion 12 of the pipe 10. The pressing seat portion 43 is in annular contact with the nut pressure receiving seat portion 12 b of the head portion 12 of the pipe 10 to seal between the pipe 10 and the nut member 40. The surface shape of the press seat portion 43 is a shape of a rotating surface (for example, a conical surface) with the through hole 41 as an axis.

  Next, a method for assembling the pipe connection structure according to the first embodiment of the present invention will be described.

  First, the sheet member 20 is press-fitted into the pressure contact portion 32 of the piping member 30. At this time, the press seat portion 27 of the sheet member 20 is press-fitted until it presses against the pressure receiving seat portion 33 of the piping member 30. Thereby, the space between the sheet member 20 and the piping member 30 is sealed. In addition, although the surface treatment part may be cracked or peeled off at the pressure contact part 32 of the piping member 30 due to the press-fitting of the sheet member 20, the basic material (for example, aluminum) of the piping member 30 may be exposed. Since it is a non-fuel contact part, corrosion by fuel does not occur.

  Next, the nut member 40 inserted in advance through the pipe 10 is screwed into the pipe member 30 and tightened. At this time, tightening is performed until the pressing seat portion 12 a of the head portion 12 of the pipe 10 is pressed by the pressure receiving seat portion 21 of the sheet member 20. Thereby, the space between the pipe 10 and the sheet member 20 is sealed.

  According to the first embodiment, since the sheet member 20 softer than the material (for example, aluminum) of the piping member 30 is interposed between the piping member 30 and the piping 10, the piping member 30 is not plastically deformed and the piping member. 30 can be sealed without cracking or peeling off at the surface treatment portion where the fuel contacts. In addition, since the seat member 20 can be positioned and fixed by press-fitting the inner periphery of the pressure contact portion 32 of the piping member 30, assembly performance, sealing performance, and detachability can be established. Furthermore, even if the surface treatment portion of the piping member 30 is cracked or peeled off due to the press-fitting of the sheet member 20, since it is a fuel non-contact portion, corrosion due to fuel does not occur.

  A pipe connection structure according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a cross-sectional view schematically showing the configuration of the pipe connection structure according to the second embodiment of the present invention.

  In the first embodiment, the nut member (40 in FIG. 1) is screwed on the inner peripheral side of the piping member (30 in FIG. 1). In the second embodiment, the nut is disposed on the outer peripheral side of the piping member 50. The member 60 is configured to be screwed together. Other configurations are the same as those of the first embodiment.

  The piping member 50 is a thick cylindrical member. For the piping member 50, a material harder than the material of the sheet member 20 (for example, copper or brass) is used, and for example, aluminum having a surface treatment portion (for example, nickel phosphorus) can be used. The piping member 50 has an external thread portion 51 in which an external thread is formed on the outer peripheral surface of the distal end portion on the piping 10 side. The outer screw portion 51 is screwed with the inner screw portion 62 of the nut member 60.

  The piping member 50 has a pressure contact portion 52 on the inner peripheral surface of the distal end portion on the piping 10 side. The sheet member 20 is press-fitted into the press contact portion 52, and the sheet member 20 is positioned and fixed by press contact with the press contact portion 23 of the sheet member 20. The pressure contact portion 52 is disposed in a non-fuel contact portion that does not contact the fuel.

  The piping member 50 has a pressure receiving seat portion 53 that is inclined so that the inner diameter becomes smaller toward the flow passage 54 on the back side than the pressure contact portion 52. The pressure receiving seat portion 53 is a portion that receives the pressure of the pressing seat portion 27 of the sheet member 20. Regardless of whether the pipe 10 is pressing the sheet member 20 or not, the pressure receiving seat portion 53 is annularly pressed against the pressing seat portion 27 of the sheet member 20 in a state where the sheet member 20 is press-fitted into the pressure contact portion 52. Thus, the space between the sheet member 20 and the piping member 50 is sealed. The surface shape of the pressure receiving seat 53 is a shape of a rotating surface (for example, a conical surface) with the flow passage 54 as an axis. The piping member 50 has a flow passage 54 on the back side of the pressure receiving seat portion 33.

  The nut member 60 is a cap-like member that is fastened to the piping member 50 to press the head portion 12 of the piping 10 and press the head portion 12 of the piping 10 against the pressure receiving seat portion 21 of the seat member 20. is there. The nut member 60 has a through hole 61 for inserting the cylindrical portion of the pipe 10. The through hole 61 has a predetermined clearance from the outer peripheral surface of the cylindrical portion of the pipe 10. The nut member 60 has an inner thread portion 62 having an inner thread formed on the inner peripheral surface. The inner thread portion 62 is screwed with the outer thread portion 51 of the piping member 50.

  The nut member 60 has a pressing seat portion 63 inclined on the surface near the head 12 of the through hole 61 so that the inner diameter increases toward the sheet member 20 side. The pressing seat portion 63 is a portion that presses the nut pressure receiving seat portion 12 b of the head portion 12 of the pipe 10. The pressing seat 63 is in annular contact with the nut pressure receiving seat 12 b of the head 12 of the pipe 10 and seals between the pipe 10 and the nut member 60. The surface shape of the pressing seat portion 63 is a shape of a rotating surface (for example, a conical surface) with the through hole 61 as an axis.

  According to the second embodiment, the same effect as the first embodiment is obtained.

It is sectional drawing which showed typically the structure of the pipe connection structure which concerns on Example 1 of this invention. It is the perspective view which showed typically the structure of the sheet | seat member used in the piping connection structure which concerns on Example 1 of this invention. It is sectional drawing which showed typically the structure of the pipe connection structure which concerns on Example 2 of this invention.

DESCRIPTION OF SYMBOLS 10 Piping 11 Flow path 12 Head 12a Press seat part (1st press seat part)
12b Nut pressure seat 20 Seat member 21 Pressure seat (second pressure seat)
22 through hole 23 pressure contact part (second pressure contact part)
24 Groove parts 25, 26 Recessed part 27 Pressing seat part (second pressing seat part)
30 Piping member 31 Internal thread part 32 Pressure contact part (1st pressure contact part)
33 Pressure-receiving seat (first pressure-receiving seat)
34 Flow path 40 Nut member 41 Through hole 42 External thread portion 43 Press seat (third press seat)
50 Piping member 51 External thread portion 52 Pressure contact portion (first pressure contact portion)
53 Pressure-receiving seat (first pressure-receiving seat)
54 Flow path 60 Nut member 61 Insertion hole 62 Internal thread part 63 Press seat part (3rd press seat part)

Claims (11)

A pipe having a head having an outer diameter larger than that of the cylindrical portion at the end of the cylindrical portion;
The pipe is inserted, and a nut member that presses the head against the tip side of the head;
A piping member screwed with the nut member;
It is interposed between the head and the piping member, and has a through-hole that communicates from the flow path of the piping to the flow path of the piping member, and is press-fitted into the inner periphery of the piping member to be positioned and fixed. A sheet member softer than the material of the piping member;
With
An area where the sheet member is press-fitted on the inner peripheral surface of the pipe member is a fuel non-contact portion that does not come into contact with fuel. The pipe member has a first pressure contact portion on the inner peripheral surface, and a first pressure receiving seat portion that is inclined on the back side of the first pressure contact portion on the inner peripheral surface,
The seat member has an inclined second pressure receiving seat portion that is in pressure contact with the head portion, and has a second pressure contact portion that is in pressure contact with the first pressure contact portion of the piping member on an outer peripheral surface, A second pressure seat that presses the first pressure receiving seat;
The pipe connection structure according to claim 1, wherein the second pressure contact portion is the fuel non-contact portion.   3. The pipe connection structure according to claim 1, wherein the sheet member has concave portions that are chamfered or notched over the entire circumference on both sides in the axial direction of the second pressure contact portion.   The pipe connection structure according to claim 3, wherein the sheet member has a groove portion that communicates between the concave portions at a predetermined position of the second pressure contact portion.   The pipe connection structure according to any one of claims 1 to 4, wherein the head is formed in a spherical shape or a curved surface shape.   The pipe connection structure according to any one of claims 1 to 5, wherein the nut member has a third pressing seat portion that presses the head portion toward the seat member. The piping member has an inner thread portion on an inner peripheral surface,
The pipe connection structure according to any one of claims 1 to 6, wherein the nut member has an outer thread portion that is screwed to the inner thread portion on an outer peripheral surface. The piping member has an external thread portion on the outer peripheral surface,
The pipe connection structure according to any one of claims 1 to 6, wherein the nut member has an inner screw portion that is screwed to the outer screw portion on an inner peripheral surface. The piping member is made of surface-treated aluminum,
The pipe connection structure according to claim 1, wherein the sheet member is made of brass or copper.   The pipe connection structure according to any one of claims 1 to 9, wherein the sheet member is softer than a material of the pipe.   The pipe connection structure according to claim 10, wherein the pipe is made of steel or stainless steel.

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