JP2005041298A - Connecting structure of resin pipe and connecting method for resin pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To connect a resin pipe to a pipe connector 50 with high sealing performance and reduce the number of component parts using a simple constitution. <P>SOLUTION: A fuel supply device 10 is structured so that an inlet pipe 30 is connected with the pipe connector 50 of a fuel tank FT. The inlet pipe 30 is connected with the pipe connector 50. The pipe connector 50 is equipped with a pipe body 51 in cylindrical shape to form a passage 52a and a ring projection 52b protruded from the peripheral surface of the pipe body 51. The inlet pipe 30 is fitted by pressure on the pipe connector 50 to be in tight attachment to the ring projection 52b and is connected with the passage 52a. The inlet pipe 30 is formed from a resin material to be put in fusion attachment to the pipe connector 50 and is put in hot fusion attachment by a laser beam to a place in tight attachment to the ring projection 52b. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin pipe connection structure in which a resin pipe is connected to a pipe connection body and a connection method thereof.
[0002]
[Prior art and problems]
2. Description of the Related Art Conventionally, a configuration in which a rubber inlet hose is fastened to a metal pipe by a clamp is known as a fuel supply device for supplying fuel to an automobile fuel tank. Such a rubber inlet hose has a problem that fuel vapor is easily transmitted and the number of parts increases. As a technique for solving such a problem, a technique of welding a resin inlet pipe to an opening of a fuel tank is known (for example, Patent Document 1). However, this technique has a problem that it is difficult to maintain a high sealing performance because a large force is applied between the resin inlet pipe and the welded portion of the fuel tank.
[0003]
As another conventional technique, there is known a technique in which a connector having a double structure is attached to a fuel tank, and a resin pipe is connected to the connector via an O-ring (for example, Patent Document 2). As another conventional technique, a configuration in which an O-ring is disposed between a connector and a resin pipe is also known (for example, Patent Document 3).
[0004]
In such conventional technology, in order to increase the fuel permeation resistance to the O-ring, expensive fluororubber must be used, which not only increases the cost, but also requires a resin pipe to be pressed into the O-ring. Therefore, there was a problem that the O-ring was easily damaged. Moreover, the double-structured connector has a problem that the configuration is complicated.
[0005]
[Patent Document 1]
JP 2000-71763 A [Patent Document 2]
JP 2003-2074 A [Patent Document 3]
JP-A-2000-81183 [0006]
An object of the present invention is to solve the above-described problems of the prior art, and to provide a resin pipe connection structure excellent in sealing performance and a manufacturing method thereof while reducing the number of parts and simplifying the configuration. And
[0007]
[Means for solving the problems and their functions and effects]
The present invention made to solve the above problems
A pipe connection body having a passage, and a resin pipe that is press-fitted into the outer periphery of the pipe connection body to be in close contact with the outer periphery and connected to the passage, and the pipe body absorbs laser light. The resin pipe is formed of a resin material that is welded to the outer peripheral portion of the pipe connecting body, and is thermally welded by a laser beam at a location where the outer peripheral portion is in close contact. It is characterized by this.
[0008]
According to the connection structure of the resin pipe according to the present invention, since the portion where the connection end of the resin pipe and the outer periphery of the pipe connection body are in close contact is sealed by laser welding, high sealing performance is obtained without using a seal member. Can be secured.
[0009]
Since the resin pipe is press-fitted into the outer peripheral portion of the pipe connector and is in close contact with the outer peripheral portion, it can be reliably welded. That is, if a gap is formed between the resin members during laser welding, energy does not concentrate and it is difficult to reach the melting temperature of the resin member. Therefore, it is possible to reliably weld with low energy.
[0010]
It is not necessary to use a fastening member such as a clamp to connect the resin pipe to the pipe connection body, and the number of parts can be reduced.
[0011]
Here, there is no particular limitation on the light source of the laser light, but various wavelengths such as a far-infrared region and a visible light region using a semiconductor laser or a YAG laser as a light source can be used. In addition, a plurality of light sources can be used for the laser light, or the laser light from a single light source can be branched into a plurality of optical fibers.
[0012]
The resin constituting the resin pipe is preferably a resin material having a lower laser light absorptance in the wavelength region of the laser light to be used, and is preferably a resin material having excellent fuel permeability. In addition, fiber reinforced resins in which various kinds of resins do not absorb laser light or are difficult to absorb, for example, reinforcing materials such as glass fiber and nylon fiber, can be preferably used. On the other hand, as the resin material of the tube body, it is possible to use a resin having a functional group having a high laser light absorptance in the wavelength region of the laser light. It is preferable to employ a resin having the same composition as the resin pipe to be used or a highly compatible resin even if the composition is different. Therefore, as the resin material of the tube main body, each of the above-mentioned resins contains an additive having a high laser light absorption rate in the laser light wavelength region, for example, 0.1 to 2.0 parts by weight of carbon black, It is preferable to use a mixture of various colored pigments.
[0013]
Moreover, as a suitable aspect of the pipe connecting body for press-fitting the resin pipe, it is constituted by a pipe main body that forms a passage and an annular protrusion that protrudes from the outer peripheral surface of the pipe main body and expands the diameter of the resin pipe. Can do.
[0014]
Furthermore, as a preferable aspect of the pipe connection body, the pipe support part includes the pipe support part that is formed integrally with the pipe main body and expands the diameter of the resin pipe, and the pipe support part is a resin material having a mechanical strength larger than that of the pipe main body. The structure formed from can be taken. In this configuration, the tube main body and the resin pipe can be made of polyethylene having a polar functional group, and the tube support portion can be made of polyamide.
[0015]
Another aspect of the present invention is a method of manufacturing a resin pipe connection structure,
A step of preparing a pipe connector formed of a resin material that melts by absorbing laser light;
Preparing a resin pipe formed of a resin material that transmits laser light;
Press-fitting the resin pipe into the outer periphery of the pipe connector;
In the state where the resin pipe is press-fitted into the pipe connection body, the resin pipe is in close contact by irradiating a focused laser beam at a position where the resin pipe is in close contact with the outer periphery of the pipe connection body. A process of thermally welding the locations;
It is provided with.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
(1) Schematic Configuration of Fuel Refueling Device 10 FIG. 1 is a schematic diagram showing a fueling device according to this embodiment. As shown in FIG. 1, the fuel refueling device 10 is disposed between the inlet box IB and the fuel tank FT, and sends fuel supplied from a fuel gun (not shown) to the fuel tank FT. A filler neck 20 having an inlet 21a that is opened and closed by a cap CP, and an inlet pipe 30 (resin pipe) that connects the filler neck 20 and the pipe connector 50 of the fuel tank FT are provided. That is, the vehicle body panel VP of the automobile is provided with an inlet box IB, and a filler neck 20 is attached to the bottom of the inlet box IB. The inlet pipe 30 is bent along the oil supply path and connected to the fuel tank FT. Further, a breather pipe (not shown) is connected to the filler neck 20 to the fuel tank FT. At the time of refueling, when the fuel cap CP is removed and fuel is injected from the fuel gun into the filler neck 20, the fuel is supplied into the fuel tank FT through the fuel supply passage 10P. Hereinafter, the configuration of each unit will be described in detail.
[0017]
(2) Configuration of each part (2) -1 Filler neck 20
The filler neck 20 includes a neck body 21 that connects the injection port 21a and the outflow port 21b and forms an injection passage 20P that is a part of the fuel supply passage 10P. At the lower end of the neck body 21, a neck connection portion 22 having an outlet 21b for connecting the inlet pipe 30 is formed. On the outer periphery of the neck connection portion 22, an annular protrusion 22 a that extends and prevents the pipe connection end 31 a of the inlet pipe 30 is formed. A fitting 24 for attaching the fuel cap CP so as to be freely opened and closed is attached to the inside of the neck body 21. A seal member made of an O-ring is interposed between the mounting bracket 24 and the inner wall of the neck body 21.
[0018]
(2) -2 Inlet pipe 30
The inlet pipe 30 includes straight pipe portions 32, 33, 34 and bellows portions 35, 36 that are bent along an oil supply path formed between the straight pipe portions 32, 33, 34. The inlet pipe 30 has a pipe connection end 31a connected to the neck connection portion 22 of the filler neck 20 at one end, and a pipe connection end 31b connected to the pipe connection body 50 of the fuel tank FT at the other end. I have.
[0019]
FIG. 2 is an enlarged cross-sectional view of the inlet pipe 30. The inlet pipe 30 is formed of three layers in which an inner layer 30a, a barrier layer 30b, and an outer layer 30c are stacked. The inner layer 30a and the outer layer 30c are formed from a polyethylene (modified PE) resin material modified with maleic acid (polar functional group). The barrier layer 30b is made of an ethylene vinyl alcohol copolymer (EVOH) having excellent fuel permeation resistance. Since the modified PE has a property of being thermally welded to EVOH by maleic acid modification, the barrier layer 30b is thermally welded to the inner layer 30a and the outer layer 30c. The inner layer 30a of the inlet pipe 30 contains 0.1 to 2.0 parts by weight of carbon black for laser welding described later.
[0020]
(2) -3 Connection Structure of Inlet Pipe 30 and Pipe Connection Body 50 FIG. 3 is an enlarged cross-sectional view of the vicinity of the pipe connection body 50 of the fuel tank FT. The fuel tank FT is formed of a plurality of resin layers in which polyethylene is disposed as an outer layer. A tank opening FTa is formed on the outer wall of the fuel tank FT, and a pipe connector 50 is welded so as to surround the tank opening FTa. ing. The pipe connector 50 includes a pipe main body 51 and a pipe support portion 55 integrated with the pipe main body 51 and two-color molding.
The tube body 51 is integrally formed with a cylindrical portion 52 that forms a passage 52 a and a flange portion 53 that is formed on the outer periphery of one end of the cylindrical portion 52. An annular protrusion 52b having a triangular cross section for welding is formed on the outer peripheral end of the cylindrical portion 52, and a weld portion 53a welded to the fuel tank FT is formed in the flange portion 53 in an annular shape.
The tube support portion 55 includes a cylindrical support portion 56 and a flange portion 57, which are integrally formed. The tube support portion 55 is welded to the tube main body 51 from a part of the outer surface of the cylindrical support portion 56 to the upper surface of the flange portion 57. On the outer surface of the cylindrical support portion 56, three rows of annular projections 56a having a triangular cross section for preventing the inlet pipe 30 from protruding are provided.
[0021]
The tube main body 51 is formed of a modified PE that is the same kind of resin material as the inner layer 30a of the inlet pipe 30 and further contains 0.1 to 2.0 parts by weight of carbon black in order to absorb laser light. It is formed from a resin material. On the other hand, the tube support portion 55 is made of polyamide (PA) having high mechanical strength. The polyamide is reactively bonded to the modified PE to which a polar functional group is added by maleic acid modification. By such a resin combination of the tube main body 51 and the tube support portion 55, the tube connection body 50 is integrated by two-color molding.
[0022]
(3) -1 Connection Process of Inlet Pipe 30 and Pipe Connection Body 50 Next, a process of welding the inlet pipe 30 to the pipe connection body 50 will be described. FIG. 4 is an explanatory view for explaining a welding process by the laser welding apparatus 90. The laser welding apparatus 90 rotates the first chuck 91 that supports one end of the inlet pipe 30, the second chuck 92 that supports one end of the pipe connector 50, and the first and second chucks 91 and 92 in synchronization with each other. A rotation driving mechanism 93 for driving and a laser irradiation device 94 disposed outside the axis are provided.
[0023]
In order to thermally weld the inlet pipe 30 to the pipe connection body 50 by the laser welding apparatus 90, first, both ends of the joining object including the pipe connection body 50 and the inlet pipe 30 press-fitted into the connection end of the pipe connection body 50 are used. Are supported by the first chuck 91 and the second chuck 92, respectively. In this state, the laser beam is emitted from the laser irradiation device 94 toward the contact portion of the object to be joined while being rotated by the drive of the rotation driving mechanism 93. FIG. 5 is an enlarged view of FIG. The laser light passes through the inlet pipe 30 and strikes the slope of the annular protrusion 52b of the tube body 51. Since the tube main body 51 contains 0.1 to 2.0 parts by weight of carbon black, it absorbs the laser beam, melts the slope of the annular protrusion 52b, and melts the inner surface of the inlet pipe 30. Since the melted resin material is the same type of resin material, it is compatible and welded by cooling and solidifying.
[0024]
(3) -2 Assembly to Fuel Tank FT As shown in FIG. 3, in order to fix the pipe connector 50 to the fuel tank FT, the welded portion 53a of the flange portion 53 of the pipe body 51 and the tank opening of the fuel tank FT The peripheral part of FTa is melted by a hot plate or the like, and then the welded part 53a is pressed against the peripheral part of the tank opening FTa. Since the outer layer of the fuel tank FT is formed of polyethylene, it is thermally welded to the welded portion 53a formed of modified PE.
[0025]
(4) Operation and effect of the embodiment The configuration of the above embodiment provides the following effect in addition to the above-described effect.
[0026]
(4) -1 Since the gap between the pipe connection end 31b of the inlet pipe 30 and the outer peripheral surface of the pipe connection body 50 is sealed over the entire circumference by laser welding, high sealing performance is ensured without using a seal member. Can do. In addition, it is not necessary to use an expensive seal member made of fluororubber or the like, and the cost can be reduced.
[0027]
(4) -2 The inlet pipe 30 is expanded in diameter by the annular protrusion 52b and is in close contact with each other, so that it can be reliably welded. That is, if there is a gap between the resin members during laser welding, energy is not concentrated and it is difficult to reach the melting temperature of the resin member. In this embodiment, however, the inlet pipe 30 is annularly projected by elastic force. Since it is pressed against and closely adhered to the portion 52b, it can be surely welded with low energy.
[0028]
(4) -3 It is not necessary to use a fastening member such as a clamp to connect the inlet pipe 30 to the pipe connector 50, and the number of parts can be reduced.
[0029]
(4) -4 Since the inlet pipe 30 is press-fitted into the annular projection 52b having a triangular cross section, it has a sealing function as well as a sealing function. Therefore, the welding part does not require high strength, and the laser welding process is shortened. Miniaturization of the apparatus can be realized.
[0030]
The present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.
[0031]
(1) FIG. 6 is an explanatory view illustrating a state in which a resin pipe 30B according to another embodiment is connected to a pipe connector 50B. The pipe connector 50B includes a pipe main body 51B made of polyethylene and a reinforcing metal pipe 58B integrally formed facing the passage of the pipe main body 51B. The metal tube 58B is integrally formed with the tube body 51B and an insert, and mechanically reinforces the tube body 51B. By reinforcing the pipe body 51B with such a metal pipe 58B, even if the pipe body 51B is formed of a single resin material, there is little deformation when the resin pipe 30B is press-fitted, and the clearance can be eliminated. Laser welding can be performed reliably.
[0032]
(2) FIG. 7 is an explanatory diagram for explaining a state in which a resin pipe 30C according to another embodiment is connected to the pipe connector 50C. On the outer peripheral portion of the pipe connector 50C, a retaining convex portion 51Ca formed in a gentle mountain shape is formed. Such a retaining protrusion 51Ca also increases the surface pressure with the resin pipe 30C and eliminates the clearance, so that laser welding can be reliably performed.
[0033]
(3) In the above embodiment, the laser welding is performed over the entire circumference of the pipe connecting body to further improve the sealing performance, and may be at one or a plurality of locations in the circumferential direction. It is possible to prevent deterioration of the sealing performance due to the rotation of the pipe.
[0034]
(4) In the above-described embodiment, the fuel tank refueling device has been described as the connector connection structure. However, the present invention is not limited to this, and when the fuel in the fuel tank exceeds a predetermined level, the fuel flows out to the outside. It can be applied to a fuel shut-off valve that prevents the above, a joint that connects the inside of the fuel tank to the outside, and the like.
[0035]
(5) The inlet pipe 30 may be formed as a single layer using a resin material (for example, PE) that is excellent in fuel resistance and easily transmits laser light, as well as being formed in multiple layers as in the above embodiment. .
[Brief description of the drawings]
FIG. 1 is a schematic view showing an oil supply apparatus according to the present embodiment.
FIG. 2 is an enlarged cross-sectional view of the inlet pipe 30. FIG.
FIG. 3 is an enlarged cross-sectional view of the vicinity of a pipe connection body 50 of a fuel tank FT.
FIG. 4 is an explanatory view for explaining a welding process by a laser welding apparatus 90;
FIG. 5 is an enlarged view of FIG. 4;
FIG. 6 is an explanatory diagram for explaining a state in which a resin pipe 30B according to another embodiment is connected to a pipe connector 50B.
FIG. 7 is an explanatory diagram illustrating a state in which a resin pipe 30C according to still another embodiment is connected to a pipe connector 50C.
[Explanation of symbols]
10. . . Fuel supply device 10P. . . Fuel supply passage 20. . . Filler neck 20P. . . Injection passage 21. . . Neck body 21a. . . Inlet 21b. . . Outlet 22. . . Neck connection 22a. . . Annular projection 24. . . Mounting bracket 30. . . Inlet pipe 30a. . . Inner layer 30b. . . Barrier layer 30c. . . Outer layer 30B. . . Resin pipe 30C. . . Resin pipe 31a. . . Pipe connection end 31b. . . Pipe connection ends 32, 33, 34. . . Straight pipe part 35,36. . . Bellows 50. . . Pipe connector 50B. . . Pipe connector 50C. . . Pipe connector 51. . . Tube body 51B. . . Tube body 51Ca. . . Stop projection 52. . . Cylindrical portion 52a. . . Passage 52b. . . Annular protrusion 53. . . Flange portion 53a. . . Welding section 55. . . Tube support 56. . . Cylindrical support 56a. . . Annular protrusion 57. . . Flange portion 58B. . . Metal tube 90. . . Laser welding apparatus 91. . . First chuck 92. . . Second chuck 93. . . Rotation drive mechanism 94. . . Laser irradiation device CP. . . Fuel cap FT. . . Fuel tank FTa. . . Tank opening IB. . . Inlet box VP. . . Body panel

Claims (6)

A pipe connector (50) having a passage (52a);
A resin pipe that is in close contact with the outer periphery by being press-fitted into the outer periphery of the pipe connector (50) and connected to the passage (52a);
With
The outer periphery of the pipe connector (50) is formed of a resin material that absorbs and melts laser light,
The resin pipe is formed of a resin material that is welded to the outer peripheral portion of the pipe connector (50), and is thermally welded by a laser beam at a location where the outer peripheral portion is in close contact. Resin pipe connection structure. In the connection structure of the resin pipe according to claim 1,
The outer periphery of the pipe connector is a resin pipe connection structure formed of a resin material containing 0.1 to 2.0 parts by weight of carbon black. In the connection structure of the resin pipe according to claim 1 or 2,
The pipe connector (50) includes a pipe body (51) that forms the passage (52a), and an annular protrusion (52b) that protrudes from the outer peripheral surface of the pipe body (51) and expands the diameter of the resin pipe. And a resin pipe connection structure. In the connection structure of the resin pipe according to claim 3,
The pipe connector (50) includes the pipe support (55) that is formed integrally with the pipe main body (51) and expands the diameter of the resin pipe. The pipe support (55) 51) A resin pipe connection structure formed of a resin material having higher mechanical strength. In the connection structure of the resin pipe according to claim 4,
The pipe body (51) and the resin pipe are formed of polyethylene having a polar functional group, and the pipe support (55) is a resin pipe connection structure formed of polyamide. A method for producing a resin pipe connection structure according to any one of claims 1 to 5,
Preparing a pipe connector (50) formed of a resin material that melts by absorbing laser light;
Preparing a resin pipe formed of a resin material that transmits laser light;
Press-fitting the resin pipe into the outer periphery of the pipe connector (50);
By irradiating a laser beam focused on the portion where the resin pipe is in close contact with the outer peripheral portion of the pipe connector (50) in a state where the resin pipe is press-fitted into the pipe connector (50). , The step of heat-welding the above-mentioned close contact points,
A method for manufacturing a resin pipe connection structure, comprising:

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