JP2006064019A - Fastening structure of tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fastening structure of a tube and a pipe which reduces a parts number, achieves excellent mounting workability and prevents easy slip-off by an external force. <P>SOLUTION: A connector 3 comprises a first and second engaging cylindrical parts (31, 32) into which a tube 1 is inserted to be held and an intermediate flange 33 positioned in a midway between the engaging cylindrical parts. The first and second engaging cylindrical parts are provided with a first and second cutout windows (311, 321) extending in an axial direction, and with a first and second of engaging pieces (312, 322) which are protruded from an end opposite to the intermediate flange 33 between the first and second cutout windows and respectively engaged with a connector engaging part 11 of a tube and an engaging protrusion 21 formed on the outer periphery of the pipe. A gasket 4 is made up of the cylinder part 41 and a flange 42 which is provided to one end of the cylinder part and abutted to an end surface of a gasket holding part 12 of the tube. The first cutout window 311 extends to the vicinity of the intermediate flange 33 so that the flange 42 of the gasket can be viewed with the tube 1 and the pipe 2 fastened to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tube fastening structure in which a tube is connected to a pipe by a connector.

  As a conventional fastening structure of this type, the technique of Patent Document 1 is known. FIG. 4 is a sectional view showing a conventional connector. In FIG. 4, the first chamber P53 of the connector P5 is put on the housing h of the tube P4, the open end of the housing h is brought into contact with the flange portion P52, and the fixed piece P532 protruding into the first chamber P53 is attached to the housing. The connector P5 is fixed to the housing h by engaging with a mounting engaging portion (bulging portion) P36 provided on the outer peripheral surface. Then, the end portion of the pipe P51 is inserted into the housing h through the second chamber P54 and the inside of the flange portion P52, and each lock piece P543 is inserted into the lock engagement portion P42 provided on the outer peripheral surface of the pipe P51. The tube P4 and the pipe P51 are connected and fixed to each other by locking the other pipe P51 by engaging the tip of the tube.

However, since the O-ring P33 is disposed inside the bulging portion 36, the O-ring P33 is bitten between the pipe P51 and the tube P4 at the time of connection, or a torsional stress remains, so that the O-ring P33 is retained. There was a problem with durability. In addition, since the O-ring P33 cannot be confirmed from the outside in the assembled state, it is difficult to easily visually check for defective mounting due to a missing O-ring.
JP 2001-108176 A

  An object of the present invention is to solve the above-described problems of the prior art, and to provide a fastening structure with a simple configuration that does not easily come off due to an external force.

The present invention made to solve the above problems is a fastening structure comprising a tube and a connector assembled to the tube and connecting a pipe to the tube.
The connector has a substantially cylindrical shape, a first engagement cylinder part into which the tube is inserted and held, a second engagement cylinder part into which the pipe is inserted and held, and an intermediate flange located between the engagement cylinder parts Consists of parts
The first engagement tube portion is provided with a first notch window extending in the axial direction, and is provided on the tube while projecting from an end of the first notch window opposite to the intermediate flange portion. A first engagement piece that engages with the connector engagement portion is provided, a second notch window extending in the axial direction is provided in the second engagement cylinder portion, and the intermediate flange portion of the second notch window A second engagement piece is provided that protrudes from an end opposite to the pipe and engages with an engagement protrusion formed on the outer periphery of the pipe.
At the end of the tube, a gasket holding portion is formed into which a gasket for liquid-tight sealing the tube and the pipe is inserted,
The gasket comprises a cylindrical portion and a flange portion provided at one end of the cylindrical portion and abutting against an end surface of the gasket holding portion of the tube,
The first cutout window extends to the vicinity of the intermediate flange portion so that the flange portion of the gasket can be visually observed in a state where the tube and the pipe are fastened;
It is characterized by.

  According to the fastening structure of the present invention, since the first cutout window is opened to the vicinity of the intermediate flange portion of the connector, the flange portion of the gasket can be visually observed from the first cutout window in the fastened state, and defects due to missing parts are externally detected. Can be inspected from.

  In addition, since the flange of the gasket is placed in contact with the end face of the gasket holding part of the tube, the gasket does not shift to the back of the tube when the tube is mounted on the pipe, and the mounting workability is excellent. Can be prevented.

  In addition, since the first and second engaging pieces are formed so as to protrude from the end opposite to the intermediate flange portion of the first and second cutout windows, along the axial direction of the first and second engaging pieces. The force in the pulling direction can be received, and a high pulling strength can be secured.

  Further, as a preferred aspect, the flange portion of the gasket is configured to be held in an elastically compressed state between the end face of the gasket holding portion and the intermediate flange portion of the connector in a state where the tube and the pipe are fastened. be able to. With this configuration, the connector and the tube can be reliably engaged by absorbing the variation in the cutting dimension of the tube terminal portion, and the axial movement of the tube and the pipe can be regulated, thereby reducing the rattling of the connector. Can be prevented.

  Further, the second cutout window can be configured to extend to the vicinity of the intermediate flange portion so that the engagement protrusion of the pipe can be seen with the tube and the pipe fastened. With this configuration, when attaching the tube to the pipe, the operator can visually check the engagement protrusion of the pipe from the second cutout window at the attachment completion position, so that the attachment completion can be easily confirmed from the outside. be able to.

  Moreover, the 1st notch window and the said 2nd notch window can take the structure arrange | positioned along the same axis line. With this configuration, when the tube is attached to the pipe, the operator can simultaneously confirm the flange portion of the gasket and the engagement protrusion of the pipe from the first and second cutout windows at the same mounting completion position. Therefore, it is possible to more easily confirm the completion of mounting from the outside.

In order to further clarify the configuration and operation of the present invention described above, preferred embodiments of the present invention will be described below.
(1) Outline of Fastening Structure The fastening structure according to the present embodiment can be suitably used for, for example, a fuel path disposed in a fuel tank of an automobile. FIG. 1 is a side view for explaining a connection structure in which a tube 1 is connected to a fuel tank 5 by a fastening structure according to an embodiment of the present invention, and FIG. 2 is a sectional view thereof. 1 and 2, the connection structure includes a connector 3 and a gasket 4 that is inserted into the tube 1 and sealed against the pipe 2. The tube 1 is connected to the other end of the connector 3 via the engaging piece 312 and the connector engaging portion 11 of the tube 1. The pipe 2 is provided with a bead (engagement protrusion) 21 on its outer peripheral portion, and the pipe outer peripheral surface on the tip side of the bead 21 is a sealing surface, and is connected to the engagement piece 322 via the bead 21. Is done.
(2) Configuration of Each Part of Fastening Structure Hereinafter, the configuration of each part of the fastening structure will be described. (See Figures -1 and 2)
(2) -1 Tube 1
The tube 1 includes a bellows portion 13 that forms a fluid passage, a gasket holding portion 12 that holds the gasket 4 therein, and an engagement claw of the connector 3 at the boundary between the bellows portion 13 and the straight portion 121 of the gasket holding portion. A step portion 111 that engages with 312B is formed, and this step portion 111 functions as the connector engaging portion 11. The tube 1 can be manufactured by cutting a tube continuously formed by extrusion blow molding integrally with a corrugator, and is excellent in productivity. The cylindrical portion 41 of the gasket 4 is held on the inner peripheral surface 122 of the straight portion 121, and seals between the sealing surface of the pipe 2 shown in FIG.
(2) -2 Pipe 2
The pipe 2 protrudes from the fuel tank 5 and is connected by welding an injection-molded product to the tank surface if it is a resin tank, or by welding a metal pipe if it is an iron tank. An engagement protrusion (bead) 21 that engages with the second engagement piece 322 of the connector 3 is formed on the outer peripheral surface.
(2) -3 Connector 3
The connector 3 includes a first engagement cylinder part 31 for connecting the tube 1, a second engagement cylinder part 32 for connecting the pipe 2, and an intermediate flange part that divides the first and second engagement cylinder parts. 33, and these are cylindrical and integrally injection-molded with resin. The first engagement cylinder part 31 is formed with a larger diameter than the second engagement cylinder part 32. Four first cutout windows 311 are formed in the first engagement cylinder portion 31 at equal intervals in the circumferential direction and to the vicinity of the intermediate flange portion 32, and the intermediate flange portions 33 of the cutout windows are formed. The first engaging piece 312 is integrally projected inward in the radial direction at the end on the opposite side. The first engagement piece 312 includes an elastically deformable arm portion 312A protruding in a cantilevered manner in the notch window 311 and an engagement claw 312B formed in a mountain shape toward the tip of the arm portion 312A. The engaging claw 312B can be engaged with the step portion 111 on the tube side. Four second notch windows 321 are formed in the second engagement cylinder part 32 at equal intervals in the circumferential direction and to the vicinity of the intermediate flange part 32, and the intermediate flanges of the notch windows are formed. A second engaging piece 322 is integrally projected radially inward at an end portion on the side facing the portion 33. The second engagement piece 322 includes an arm portion 322A that can be elastically deformed and an engagement claw 322B that engages with the engagement protrusion 21 on the pipe side in the same manner as the first engagement piece.

Each of the first and second engaging cylinder portions is formed open to the vicinity of the intermediate flange portion 32, and the first and second cutout windows are arranged on the same axis.
(2) -4 Gasket 4
The gasket 4 has a cylindrical shape, and includes a cylindrical portion 41 that constitutes a seal portion, and a flange portion 42 that is integrally formed radially outward at one end portion of the cylindrical portion 41. The cylindrical portion 41 further includes a plurality of seal portions 411 and a connecting portion 412 that connects the seal portions 411. The seal portion 411 is interposed in a compressed state between the inner peripheral surface 122 of the gasket holding portion of the tube 1 and the pipe outer peripheral surface on the tip side of the bead 21 of the pipe 2. The gasket seal portion 411 can be easily manufactured by forming four ring-shaped bulge portions at equal intervals in the axial direction of the cylindrical portion 41. That is, since the seal portions 411 are connected by the connecting portion 412, they can be integrally vulcanized and molded from a rubber material such as NBR.
(3) Connection Work Next, the connection work will be described with reference to FIGS. FIG. 3 is an explanatory diagram for explaining a series of connection operations for connecting the tube 1 and the pipe 2. As shown in FIG. 3, first, the gasket 4 is inserted into the gasket holding portion 122 that is one end of the tube 1. At this time, the seal portion 411 of the gasket 4 can be positioned at a predetermined position by inserting until the flange portion 42 of the gasket 4 contacts the end surface 123 of the gasket holding portion 121. In this state, the seal portion 411 on the opposite side of the flange portion 42 of the gasket 4 is temporarily fixed to the step portion 111 of the tube 1 with a gap.

  Next, when the tube 1 assembled with the gasket 4 is inserted into the first engagement cylinder portion 31 of the connector 3, the first engagement piece 31 is elastically deformed and the outer periphery of the straight portion 121 of the tube 1. As shown in FIG. 2, the engaging claw 312 </ b> B engages with the connector engaging portion 11 (step portion 111) of the tube 1 and is fixed so as not to come off. At this time, the flange portion 42 of the gasket 4 is configured to be compressed and deformed between the end surface 123 of the tube 1 and the intermediate flange portion 33 of the connector 3, so that variations in the length of the straight portion 121 are absorbed. Thus, the connector 3 can be assembled to the tube 1 without causing backlash.

  In addition, since the first notch window 311 of the first engagement cylinder part 31 opens to the intermediate flange part 33, the operator can pass the flange part of the gasket 1 through the first notch window 311 from the outside even after the mounting is completed. 42 can be visually observed. Therefore, it is possible to effectively prevent defects due to a shortage.

  And the assembled tube 1 with the connector 3 is assembled | attached by extrapolating a 2nd engagement cylinder part to the pipe 2 of the fuel tank 5 in an assembly line. That is, the engagement claw 322B of the second engagement piece 322 gets over the bead 21 formed on the outer peripheral portion of the pipe 2 by bending the arm portion 322B of the second engagement piece 322 in the radial direction, and the bead portion The seal portion 411 of the gasket 4 is compressed in the radial direction so that the inner peripheral surface 122 of the tube 1 and the outer peripheral surface of the pipe 2 are liquid-tightly sealed. To do.

At this time, the gasket 4 tends to be pulled into the back of the tube 1 due to the frictional resistance of the pipe 2, but since the flange portion 42 is held by the end surface 123 of the tube 1, the gasket 4 moves to the back and the seal portion 411 is not bitten. Further, since the seal portion 411 is connected by the connecting portion 412, twisting of the seal portion 411 due to insertion can be prevented without using a spacer.
(4) Effect of fastening structure
In addition to the effects described above, the following effects are achieved by the configuration of the above embodiment.
(4) -1 The first and second engaging pieces (312 and 322) are inclined radially inward from the end of the first and second cutout windows (311 and 321) opposite to the intermediate flange portion 33, respectively. Since it is projectingly formed, it is possible to receive the force in the removal direction along the axial direction of the first and second engagement pieces (312, 322), and to ensure a high removal strength.
(4) -2 The second notch window 321 has a structure that extends to the vicinity of the intermediate flange portion 33 so that the engagement protrusion 21 of the pipe 2 can be visually observed in a state where the tube 1 and the pipe 2 are fastened. When the user attaches the tube 1 to the pipe 2, the pipe engaging protrusion 21 can be seen from the second notch window 321 at the attachment completion position, so that the attachment completion can be easily confirmed from the outside. Can do.
(4) -3 The first and second cutout windows (311, 321) are arranged along the same axis, so that when the operator attaches the tube to the pipe, the first, Since it is possible to simultaneously confirm the flange portion 33 of the gasket and the engagement protrusion 21 of the pipe from the two notched windows (311, 321) from the same line of sight, it is possible to more easily confirm the completion of the mounting from the outside. it can.
(4) -4 The configuration in which the first and second engagement pieces (31, 32) are provided in the first and second cutout windows (311, 321) can be easily formed by injection, thus reducing the cost. can do. Moreover, since it has taken the structure arrange | positioned along the position parallel to an axial direction, die-cutting is easy, and also a mold structure can be simplified.
(4) -7 Since the fastening structure of the present invention has two parts, the connector 3 and the gasket 4, the number of parts is small, and the assembly workability is excellent.

  The present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the scope of the invention.

  For example, the flange portion 43 of the gasket 4 need not be formed over the entire circumference, and may be formed partially. Thereby, the amount of elastic deformation in the axial direction can be increased, and it becomes easier to absorb the dimensional variation of the straight portion 121 of the tube 1.

  Further, at least two first and second cutout windows (311 and 321) may be provided. In particular, by providing a pair at opposite positions, the molding die of the connector 3 can have a simple structure.

It is a side view explaining the connection structure which connected the tube 1 to the fuel tank 5 with the fastening structure concerning one Example of this invention. It is sectional drawing of FIG. It is explanatory drawing explaining a series of connection work which connects the tube 1 and the pipe 2. FIG. It is sectional drawing explaining the fastening structure of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tube 11 ... Connector engaging part 111 ... Step 12 ... Gasket holding part 121 ... Straight part 122 ... Inner peripheral surface 123 ... End surface 13 ... Bellows part 2 ... pipe 21 ... engagement protrusion (bead)
DESCRIPTION OF SYMBOLS 3 ... Connector 31 ... 1st engagement cylinder part 311 ... 1st notch window 312 ... Engagement piece 312A ... Arm part 312B ... Engagement claw 32 ... 2nd Engagement cylinder part 321 ... second notch window 322 ... engagement piece 322A ... arm part 322B ... engagement claw 4 ... gasket 41 ... cylindrical part 411 ... seal part 412 ... Connecting part 42 ... Flange part 5 ... Fuel tank

Claims (4)

In a fastening structure comprising a tube (1) and a connector (3) for connecting a pipe (2) assembled to the tube (1) to the tube (1),
The connector (3) is substantially cylindrical and has a first engagement cylinder part (31) into which the tube (1) is inserted and held, and a second engagement cylinder part (in which the pipe (2) is inserted and held ( 32) and an intermediate flange portion (33) located in the middle of both engaging cylinder portions,
The first engagement tube portion (31) is provided with a first notch window (311) extending in the axial direction, and the end of the first notch window (311) opposite to the intermediate flange portion (33). The first engagement piece (312) is provided so as to protrude from the portion and engage with the connector engagement portion (11) provided on the tube, and the second engagement tube portion (32) is provided in the axial direction. An extended second notch window (321) is provided, protrudes from the end of the second notch window (321) opposite to the intermediate flange portion (33), and has an outer peripheral portion of the pipe (2). A second engagement piece (322) that engages with the engagement protrusion (21) formed on
At the end of the tube (1), there is formed a gasket holding part (12) into which a gasket (4) for liquid-tight sealing the tube (1) and the pipe (2) is inserted and held,
The gasket (4) comprises a cylindrical portion (41) and a flange portion (42) which is provided at one end of the cylindrical portion and abuts against the end surface (123) of the gasket holding portion (12) of the tube.
The first notch window (311) extends to the vicinity of the intermediate flange portion (33) so that the flange portion (42) of the gasket can be seen with the tube (1) and the pipe (2) being fastened. Growing,
A tube fastening structure characterized by The fastening structure according to claim 1,
The flange portion (42) of the gasket was elastically compressed between the end surface (123) of the gasket holding portion and the intermediate flange portion (33) of the connector in a state where the tube (1) and the pipe (2) were fastened. Fastening structure of tube held in a state. In the fastening structure according to claim 1 or 2,
The second notch window (321) extends to the vicinity of the intermediate flange portion (33) so that the engagement protrusion (21) of the pipe can be seen with the tube (1) and the pipe (2) being fastened. Fastening structure of the extending tube. The connector according to claim 3, wherein
The said 1st notch window (311) and the said 2nd notch window (321) are the fastening structures of the tube arrange | positioned along the same axis line.