JP2004232766A - Pipe body sealing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe body sealing structure for securing high sealing performance even if attachment/detachment is repeated again. <P>SOLUTION: A pipe body 10 forms a flange part 12, an energizing part 13 and a seal part 14 in an end part of a pipe body part 11. The pipe body 10 is installed on an engine side flange EF by a flange plate 20, a flange bolt 24 and a flange nut 25. At this time, pressing force is transmitted to the flange part 12 from a bottom surface 22a of the plate 20. Thus, the energizing part 13 is elastically deformed, and the energizing part 13 and the seal part 14 are housed inside a housing step part 22. Thus, the pipe body 10 can be attached-detached again without plastically deforming the flange EF by elastically deforming the energizing part 13. The high sealing performance can be secured by excellently keeping bearing pressure of the seal part 14. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a seal structure for ensuring a sealing property between connected members, and more particularly to a seal structure formed integrally with a pipe.
[0002]
[Prior art]
DESCRIPTION OF RELATED ART Conventionally, as shown in the following patent documents 1, the sealing structure of a pipe body is known. In this conventional sealing structure for a tubular body, a sealing surface having a shape matching the sealing surface of a mating member (for example, a valve body) is formed at a terminal portion of the tubular body. Further, an annular convex portion having a hardness higher than the hardness of the mating member is formed on the sealing surface to further enhance the sealing performance. When the tube is fastened to the mating member, the annular convex portion plastically deforms the sealing surface of the mating member, and the annular convex portion and the plastically deformed surface mesh with each other to enhance the sealing property.
[0003]
[Patent Document 1]
Japanese Patent No. 2815235
[Problems to be solved by the invention]
By the way, in the conventional sealing structure of a tubular body, for example, when the tubular body is detached from the mating member due to inspection, failure, or the like, an indentation due to the previous plastic deformation remains in the mating member. If the annular projections do not coincide with each other and mesh with each other, there is a possibility that necessary sealing properties cannot be secured.
[0005]
Summary of the Invention
SUMMARY OF THE INVENTION The present invention has been made to address the above-described problem, and an object of the present invention is to provide a tubular body sealing structure capable of securing a sealing property even when re-attachment / removal is repeated.
[0006]
A feature of the present invention is that a pipe body and a mating member to which the tube body is attached are connected by using fastening means, so that a seal portion formed at an end of the tube body is in close contact with a sealing surface of the mating member, and a seal is formed. In the seal structure, the urging portion that elastically deforms in accordance with the amount of fastening by the fastening means and resiliently urges the sealing portion of the tube to the sealing surface of the mating member is provided in the sealing member. In that it is formed integrally.
[0007]
According to this, the sealing portion of the tubular body is pressed by the urging portion against the sealing surface of the mating member with a predetermined pressing force. For this reason, by setting the pressing force to an appropriate value, it is possible to secure the necessary sealing performance without plastically deforming the sealing surface of the mating member. do not need. Therefore, the replacement cost can be reduced, and the time required for the replacement operation can be reduced.
[0008]
Further, another feature of the present invention is that a defining means for defining a fastening amount by the fastening means is formed.
[0009]
According to this, when the pipe body and the mating member are connected by the fastening means, the elastically deformed urging portion is housed inside the step formed in the fastening means. For this reason, an assembly error hardly occurs, and the elastic deformation amount of the urging portion is set to a predetermined value. Thereby, the assembling work can be easily performed, and the assembling property is improved. Further, the urging portion is not permanently deformed (plastically deformed) by the fastening operation of the fastening means. Therefore, for example, in the inspection of the pipe body, even when the fastened pipe body is once removed from the mating member and reassembled, the urging portion may resiliently press the seal portion against the sealing surface of the mating member. As a result, necessary sealing properties can be ensured. Further, since there is no need to replace the tube, the cost required for replacing the tube can be reduced.
[0010]
Further, the fastening means can adjust an amount of fastening between the tube and the mating member.
[0011]
According to this, it is possible to adjust the amount of elastic deformation according to the amount of fastening between the tube and the mating member, and to adjust the seal portion of the tube against the sealing surface of the mating member with a pressing force according to the elastic deformation. It is possible to adjust the pressing force (surface pressure) per unit area. Therefore, the sealing portion of the tubular body can be brought into close contact with the entire surface of the sealing surface of the mating member without excessively pressing, and the sealing performance can be improved. Further, since it is possible to prevent the sealing surface of the mating member from being plastically deformed, it is not necessary to replace the mating member, and the necessary cost can be reduced.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows a cross section of a seal structure of the present invention comprising a pipe 10, a flange plate 20, a flange bolt 24 and a flange nut 25 as fastening means, and an engine side flange EF as a mating member. Is shown.
[0013]
The tube 10 has a tube main body 11 that is bent into various bent shapes and conducts a fluid (for example, EGR (recirculation) gas) to an engine mounted on a vehicle. As shown in detail in FIG. 2, a flange portion 12, a biasing portion 13, and a seal portion 14 are formed at an end of the tube main body 11.
[0014]
The flange portion 12 stands upright from the outer peripheral surface of the pipe main body 11 and extends radially outward, and is formed coaxially with the pipe main body 11 with a predetermined radius. The biasing portion 13 projects a predetermined amount axially forward of the pipe main body 11, that is, leftward in FIG. 2 with the outer peripheral end of the flange 12 as a base end, and is formed coaxially with the pipe main body 11. I have. The urging portion 13 is formed to have a predetermined elastic coefficient by appropriately setting a plate thickness and a radius so as to elastically deform within a predetermined range of deformation stress.
[0015]
The seal portion 14 stands substantially perpendicularly to the axis of the tube body 11 with the outer peripheral end of the urging portion 13 as a base end, and is formed coaxially with the tube body 11. Accordingly, as shown in FIG. 2, the formed flange portion 12, biasing portion 13 and seal portion 14 are integrally connected to each other so that their cross-sections are substantially S-shaped. ing.
[0016]
The flange plate 20 is attached to the outer peripheral portion of the pipe main body 11, as shown in FIGS. For this reason, the flange plate 20 is formed with a through hole 21 having an inner diameter slightly larger than the outer peripheral radius of the pipe main body 11. Thus, it can be displaced in the axial direction. The flange plate 20 is provided with a housing step 22 that can house the flange 12, the urging unit 13, and the seal 14 formed at the end of the tube main body 11.
[0017]
The housing step 22 is in contact with the flange portion 12 at its bottom surface 22a, and the urging portion 13 and the seal portion 14 which move with the elastic deformation of the urging portion 13 when the pipe body 10 is assembled to the engine. At a predetermined depth and a predetermined radius. Further, a through hole 23 is formed in the flange plate 20 to penetrate a flange bolt 24 for fixing the pipe body 10 to the engine side flange EF. Thereby, the pipe body 10 and the flange plate 20 are connected to the engine side flange EF by the flange bolt 24 and the flange nut 25 penetrated through the through hole 23.
[0018]
The operation of the sealing mechanism when the tube 10 configured as described above is assembled to the engine will be described in detail below. In the operation of assembling the tube 10, the operator first holds the tube 10 and the flange plate 20 at a predetermined position facing the engine-side flange EF, as shown in FIG. And the through hole formed in the engine side flange EF. Then, as shown in FIG. 5, the flange nut 25 is temporarily fixed to the inserted flange bolt 24. At this time, the surface of the flange portion 12 of the tube body 10 facing the flange plate 20 (hereinafter referred to as the back surface) is in contact with the bottom surface 22a of the housing step portion 22 of the flange plate 20. Further, a surface (hereinafter, referred to as a front surface) of the seal portion 14 of the pipe body 10 facing the engine-side flange EF and the engine-side flange EF are entirely in contact with each other.
[0019]
From this state, the operator tightens the flange bolt 24 or the flange nut 25 using a tool (for example, a wrench or the like). With the tightening operation of the operator, the flange plate 20 starts to be displaced relative to the pipe body 10 in the direction of the engine-side flange EF. Then, due to the relative displacement of the flange plate 20, the bottom surface 22a of the housing step portion 22 starts transmitting the pressing force in the direction of the engine side flange EF to the back surface of the flange portion 12, and the entire pipe 10 is moved to the engine side flange EF. Begins to displace. In this state, immediately after the displacement of the pipe body 10 is started, the front surface of the seal portion 14 and the engine-side flange EF are still in surface contact.
[0020]
Further, when the operator tightens the flange bolt 24 or the flange nut 25, the flange plate 20 finally comes into contact with the engine-side flange EF, as shown in FIG. 1, and the pipe body 10 is assembled to the engine-side flange EF. . In this state, the urging portion 13 is elastically deformed between the front surface of the seal portion 14 and the engine side flange EF, and comes into contact with the connecting portion of the urging portion 13 and the seal portion 14, that is, the ring E1. This will be described in detail below.
[0021]
When the flange plate 20 and the engine-side flange EF are brought into contact with each other, a predetermined fastening amount is given, and the entire pipe body 10 is displaced to a predetermined position. At this time, the flange portion 12 transmits the pressing force applied from the bottom surface 22 a of the flange plate 20 to the seal portion 14 via the urging portion 13 based on the fastening amount. However, the surface on which the bottom surface 22 a of the flange plate 20 exerts the pressing force, that is, the back surface of the flange portion 12, and the surface that supports the transmitted pressing force, that is, the front surface of the seal portion 14, have a radius via the urging portion 13. The direction is shifted outward. For this reason, when the urging portion 13 is elastically deformed, the urging portion 13 and the seal portion 14 rotate in the clockwise direction in FIG. Although the point P has been described as a point in the description, the point P is an arbitrary point existing on the circumference where the flange portion 12 and the urging portion 13 are connected.
[0022]
Further, in the rotation operation of the urging portion 13 and the seal portion 14, since no external force acts on the back surface (the surface facing the flange plate 20) of the seal portion 14, the gap between the urging portion 13 and the seal portion 14 is generated. , There is no relative deformation. For this reason, the urging portion 13 and the seal portion 14 are rotated while keeping their shapes at the time of molding, and are accommodated in the accommodation step portion 22. Therefore, the contact between the seal portion 14 and the engine-side flange EF is changed from the entire surface contact to the contact at the portion E1 by the rotation of the urging portion 13 and the seal portion 14.
[0023]
As described above, the contact between the seal portion 14 and the engine-side flange EF becomes the contact at the portion E1, so that the sealability can be more easily ensured. Explaining this, the contact area between the seal portion 14 and the engine side flange EF can be further reduced by changing the contact from the entire surface to the contact of the portion E1. By the way, for the same pressing force, when the contact area changes, the pressing force (surface pressure) per unit area also changes. That is, the surface pressure increases as the contact area decreases, and decreases as the contact area increases. By increasing the surface pressure, the gap between the seal portion 14 and the engine-side flange EF can be made smaller. Therefore, as the surface pressure increases, the sealing performance can be better ensured. become.
[0024]
As can be understood from the above description, since the seal portion 14 is formed via the urging portion 13, the urging portion 13 is elastically deformed in accordance with the fastening amount of the flange plate 20, and the point P Around the center. Therefore, by appropriately setting the elastic coefficient of the urging portion 13, it is possible to prevent the engine-side flange EF from being plastically deformed. That is, if the transmitted pressing force is large, the amount of elastic deformation of the urging portion 13 is large and the amount of rotation is large, and if the transmitted pressing force is small, the amount of elastic deformation of the urging portion 13 is small. As a result, the amount of rotation is reduced. Thus, by appropriately setting the elastic coefficient of the urging portion 13, the pressing force with which the seal portion 14 is pressed against the engine-side flange EF can be set arbitrarily within a range where the engine-side flange EF does not undergo plastic deformation. . Therefore, it is possible to prevent the engine-side flange EF from being plastically deformed.
[0025]
Thus, for example, when the tube 10 is replaced, it is not necessary to replace the engine-side flange EF at the same time, so that it is possible to reduce the cost of replacing the component and shorten the work time required for the replacement of the component. it can. In addition, even if the attachment and detachment of the tube 10 are repeated, the urging portion 13 functions to ensure the necessary sealing performance. Furthermore, since the plastic deformation of the engine-side flange EF can be prevented, the necessary sealing performance can be reliably exhibited even when a new pipe body 10 is assembled by replacing parts.
[0026]
In the above embodiment, the contact between the seal portion 14 and the engine-side flange EF is performed at the portion E1. However, depending on the required sealing performance, the seal portion 14 and the engine-side flange EF may be used. It is needless to say that it is possible to carry out the contact with the entire surface.
[0027]
That is, the seal portion 14 is required to have a proper surface pressure based on the elastic deformation of the urging portion 13 and to have a required sealing property in a state where the entire surface is in contact with the engine-side flange EF, that is, a predetermined member. It is possible to demonstrate. Also in this case, similarly to the above-described embodiment, the sealing surface of the engine-side flange EF to which the pipe 10 is assembled is not plastically deformed by the seal portion 14. Therefore, the same effect as the above embodiment can be obtained.
[0028]
In the above embodiment, the urging portion 13 is formed at the outer peripheral end of the flange portion 12 as a seal structure, and the seal portion 14 is formed at the outer peripheral end of the urging portion 13. However, as shown in FIG. 6, the seal structure of the above-described embodiment may be modified so as to form an annular convex portion 15 having an elastic deformation portion and a seal portion function on the flange portion 12. Hereinafter, this modified example will be described in detail, but the same portions as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0029]
As shown in FIG. 7, the convex portion 15 is formed in a substantially arc-shaped cross section, the distal end portion 15a functions in the same manner as the seal portion 14 of the above embodiment, and the proximal end portion 15b has the same shape as that of the above embodiment. It functions similarly to the force part 13. Further, the flange plate 20 is formed by omitting the accommodation step 22 of the above embodiment. And also in this modification, the pipe body 10 is temporarily fixed to the engine side flange EF via the flange plate 20, the flange bolt 24 and the flange nut 25 in the same manner as in the above embodiment. In this state, the distal end portion 15a of the protrusion 15 is in contact with the engine side flange EF.
[0030]
When the flange bolt 24 or the flange nut 25 is adjusted and tightened to have a specified tightening force, the flange plate 20 applies a pressing force based on the tightening force of the flange bolt 24 and the flange nut 25 to the flange portion. 12 to the back. Due to the transmitted pressing force, the convex portion 15 is firmly adhered to the engine side flange EF. As shown in FIG. 6, when the convex portion 15 is firmly adhered, the base end portion 15b is elastically deformed, and the opening side of the convex portion 15 (the side facing the flange plate 20) becomes the flange portion. Twelve radially outwards. As described above, the base end portion 15b is elastically deformed, so that the surface pressure of the front end portion 15a can be adjusted and the engine side flange EF is prevented from being plastically deformed.
[0031]
Therefore, for example, when the tube 10 is replaced, the engine-side flange EF does not need to be replaced at the same time, so that the cost of replacing the component can be reduced, and the work time required for the replacement of the component can be reduced. In addition, even if the attachment and detachment of the tube 10 are repeated, the base end portion 15b functions, and the necessary sealing performance can be reliably ensured. Furthermore, since the plastic deformation of the engine-side flange EF can be prevented, the necessary sealing performance can be reliably exhibited even when a new pipe body 10 is assembled by replacing parts.
[0032]
Further, in the above-described embodiment and modified examples, the urging portion 13 as the urging means and the base end portion 15b are implemented to be elastically deformed. However, these portions 13, 15b are permanently deformed (plastically deformed). May be implemented. In this case, the detachability of the tube body 10 is inferior to the above-described embodiment and modified examples, but the pressing force for pressing the seal portion 14 or the tip portion 15a against the engine-side flange EF can be constant. For this reason, for example, when exchanging parts of the tube 10, it is not necessary to exchange the engine side flange EF at the same time, so that it is possible to reduce the cost of exchanging parts and to shorten the work time required for exchanging parts. it can. In addition, since plastic deformation of the engine side flange EF can be prevented, even when a new pipe body 10 is assembled by exchanging parts or the like, necessary sealing properties can be reliably exhibited.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a seal structure according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view schematically showing a state where fastening of the seal structure of FIG. 1 is released.
FIG. 3 is a perspective view showing a state in which a tube and a flange plate constituting the seal structure of FIG. 1 are assembled.
FIG. 4 is a cross-sectional view for explaining the operation of the seal structure of the present invention, and is a cross-sectional view showing a state where the seal structure is held at an assembly position.
FIG. 5 is a cross-sectional view for explaining the operation of the seal structure of the present invention, and is a cross-sectional view showing a temporarily fixed state.
FIG. 6 is a sectional view schematically showing a seal structure according to a modification of the present invention.
FIG. 7 is a cross-sectional view schematically showing a state where the fastening of the seal structure of FIG. 6 is released.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... pipe body, 11 ... pipe main body part, 12 ... flange part, 13 ... urging | biasing part, 14 ... sealing part, 15 ... convex part, 15a ... tip part, 15b ... base end part, 20 ... flange plate, 21 ... Through hole, 22 ... accommodation step, 22a ... bottom surface, 23 ... through hole, 24 ... flange bolt, 25 ... flange nut, EF ... engine side flange

Claims (3)

By connecting the tubular body and a mating member to which the tubular body is assembled by using fastening means, a seal formed at an end of the tubular body comes into close contact with the sealing surface of the mating member, and a seal that ensures sealing properties is secured. In the structure, an urging portion that elastically deforms in accordance with the amount of fastening by the fastening means and elastically urges the sealing portion of the tube toward the sealing surface of the mating member is formed integrally with the tube. A seal structure for a tubular body, characterized in that: 2. A sealing structure for a tubular body according to claim 1, wherein a defining means for defining an amount of fastening by said fastening means is formed. 2. The sealing structure for a tubular body according to claim 1, wherein an amount of fastening between the tubular body and the counterpart member is adjustable by the fastening means.

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