JP3376307B2 - Fuel inlet and its manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel inlet for injecting fuel into a fuel tank of an automobile or the like and a method for manufacturing the fuel inlet.

[0002]

2. Description of the Related Art Generally, when injecting fuel such as gasoline into a fuel tank of an automobile or the like, a fuel inlet 101 as shown in FIG. 10 is used. A connection pipe J is attached to an end portion of the fuel inlet 101 on the fuel tank side, and a breather tube 103 communicating with the fuel tank T is provided near the fuel inlet 101a of the fuel inlet 101. When refueling, the fuel inlet 10 of the fuel inlet 101
A fuel supply nozzle (not shown) is inserted from 1a, and the fuel tank T is inserted through the fuel inlet 101 and the connecting pipe J.
Is supplied with fuel. When the fuel starts to be supplied to the fuel tank T, the air in the fuel tank T flows into the breather tube 103.
It is pushed out to the fuel inlet side of the fuel inlet 101 via. When the fuel continues to be supplied, when the fuel stored in the fuel tank T reaches a certain amount, the fuel supply nozzle is automatically stopped due to the increase in the tank internal pressure, and thereafter, the fuel cannot be injected automatically. After confirming this, the refueling person switches the refueling to the manual mode, injects a small amount of gasoline 2-3 times, and then finishes the work.

By the way, since the air pushed out toward the fuel inlet side during refueling contains a high concentration of fuel vapor,
If it is unprotected and released into the atmosphere as it is, the concentration of fuel in the surroundings becomes high, which is not preferable in terms of environment. As a solution to this problem, it has been proposed to use the fuel inlet 201 shown in FIG. This fuel inlet 201 is provided with a breather tube 20.
3 is connected to a mouthpiece portion 202 and a general portion 204 that serves as a fuel passage. The general portion 204 is provided with a small diameter portion 206 having a smaller pipe diameter than the mouthpiece portion 202. By providing this small diameter portion 206,
The void portion 207 in the passage cross section when the fuel supplied at a constant flow rate passes through the general portion 204 becomes smaller than in the conventional case. With this configuration, a Venturi negative pressure is generated to increase the degree of negative pressure in the void portion 207, whereby the air returning from the fuel tank side to the fuel inlet side via the breather tube 203 is released to the atmosphere. It is effectively prevented. This idea is called a liquid seal, and is one means of ORVRS (on-road refueling vapor recovery system).

[0004]

As described above, as a method of forming the fuel inlet 201 in which the pipe diameter of the mouthpiece portion 202 and the pipe diameter of the general portion 204 (small diameter portion 206) are different from each other, A method of manufacturing by preparing one base pipe of the same diameter and expanding a part of the base pipe to form the base 202, and forming the base 202 and the general part 204 from separate base pipes. A method of joining these to each other and manufacturing them is considered.

However, in the former case, for example, φ
For the fuel inlet 201 having the small diameter portion 206 having a diameter of 25.4 mm, if one element pipe is processed to be manufactured as an integral type, a φ25.4 mm element tube is prepared and the fuel of the tip portion, that is, the base portion 202 is prepared. Entrance side is φ50 ~
It must be expanded to 60 mm. If the pipe expansion ratio is large and it is attempted to expand the pipe in one step, the material structure change of the raw pipe cannot withstand the internal tensile stress and may cause cracks in the fuel inlet. . Therefore, in order to prevent this cracking, it is necessary to increase the number of pipe expanding processes and gradually expand the pipes. This complicates the process.

[0006] Generally, the mouthpiece portion and the general portion of the fuel inlet differ in the required thickness of the raw pipe. That is, since the fuel supply nozzle is inserted into and removed from the mouthpiece portion, wear resistance between the fuel supply nozzle and the fuel supply nozzle and predetermined strength are required. Therefore, the required tube thickness is generally large. On the other hand, since the general portion usually has a long overall length, the required pipe thickness is generally thin from the viewpoint of weight reduction. However, in the former case, since the mouthpiece portion side is formed by pipe expanding, the mouthpiece portion side becomes thinner than the general portion side, which causes a phenomenon contrary to the above request.

Therefore, in order to satisfy the contradictory requirements, it is necessary to use the base tubes used in the mouthpiece portion and the general portion having different thicknesses. For that purpose, the base portion and the general portion are different from each other. It is considered that the latter method is more suitable, in which the respective tubes are formed from individual tubes having different thicknesses, and then these are joined.

However, in the latter case, since the mouthpiece part and the general part are manufactured separately, the process becomes more complicated than the former and the manufacturing cost increases.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel inlet that has a small number of parts during manufacturing and can be easily manufactured in a small number of steps.

[0009]

Means for Solving the Problems and Effects of the Invention In order to solve the above problems, the fuel inlet according to claim 1 of the present application is provided with a cap portion for receiving a fuel supply nozzle and a cap portion connected to the cap portion. A fuel inlet having a general portion for guiding fuel to a fuel tank, wherein the mouthpiece portion has a large thickness of a raw pipe formed by joining circular pipes having different thicknesses at respective ends thereof. The general portion is formed by molding a circular pipe portion, and the general portion is formed by molding a circular pipe portion having the small thickness of the raw pipe.

In order to simplify the manufacturing process, the fuel inlet of the present invention is prepared by forming a base pipe in which two circular pipes having different thicknesses are joined as described above, and processing this base pipe. To be done. Therefore, in the processing step of the fuel inlet, it is possible to manufacture with a smaller number of processing steps than those formed by processing the base portion and the general portion separately and joining them. As a result, the manufacturing efficiency can be increased and the unit price can be reduced. In addition, a circular pipe part with a large thickness is applied to the mouthpiece that requires a large thickness, while a circular pipe part with a small thickness is applied to a general part that requires a small thickness. To be done. Therefore, the raw pipe can be effectively used without waste.

Specifically, as described in claim 2 of the present application, by expanding a part of the circular pipe portion having a large thickness, a cap attachment portion of the base portion is formed, and the circular pipe having a small thickness is formed. It is conceivable that the small diameter portion of the general portion is formed by contracting a part of the pipe portion.

In this case, as a raw pipe used for forming the fuel inlet, the pipe diameter is smaller than the cap mounting portion of the mouthpiece portion having the largest diameter in the fuel inlet, and the general portion having the smallest diameter. The larger diameter part is used.

Therefore, at the manufacturing stage, the pipe expansion ratio is smaller than that of the conventional integral fuel inlet made of the same body as described above, which causes a problem that the product strength becomes uneven due to thinning or uneven thickness. Hateful. In addition, for example, as described in claim 3 of the present application, a part of the small-diameter circular tube portion is crushed from the outside to form a plurality of ridges in the small-diameter portion, so that the part is contracted. It may be formed by being piped.

In the above-mentioned structure, the extra wall portion, which is inevitably generated when the circular pipe is contracted, is formed as a ridge protruding from the outer peripheral surface of the small diameter portion. Since these ridges are formed as a pattern on the appearance of the product, it is not necessary to remove them. Further, as described in claim 4 of the present application, it is preferable that the thick circular tube portion has a three-layer structure of a stainless layer, an aluminum layer, and a stainless layer from the outside.

The stainless layer is provided from the viewpoint of rust prevention and abrasion resistance, and the aluminum layer is provided from the viewpoint of weight reduction. In particular, by providing a stainless layer, the coating process for rust prevention can be omitted,
It leads to reduction of manufacturing cost.

The fuel inlet of the present invention is manufactured by the following method. That is, the manufacturing method is, as described in claim 5 of the present application, a step of forming circular pipes by joining circular pipes having different thicknesses at respective end portions thereof, and a circular pipe portion having the large thickness of the raw pipes. Forming the base portion by molding, and forming the general portion by molding the circular pipe portion having the small thickness of the raw pipe.

According to the above-described method for manufacturing a fuel inlet, a pipe in which two circular pipes having different thicknesses are joined at the stage of the raw pipe is prepared in advance. Therefore, in the processing step of the fuel inlet, the base portion and the general portion can be processed at the same time, and the manufacturing cost can be reduced due to the reduction of the processing steps.

Specifically, as described in claim 6 of the present application, a step of forming a cap attachment portion of the base portion by expanding a part of the thick circular tube portion,
Forming a small diameter portion of the general portion by contracting a portion of the circular pipe portion having a small thickness.

That is, in the manufacturing method of the fuel inlet, the diameter of the raw pipe is smaller than that of the cap mounting portion of the mouthpiece portion having the largest diameter in the fuel inlet, and the small diameter of the general portion having the smallest diameter. It is formed larger than the part. Then, the circular tube that constitutes the element tube is expanded to have a larger thickness and the thin tube is contracted to have a smaller thickness. Therefore, the expansion rate of the raw tube is smaller than that of the conventional configuration. As a result, there is no problem that cracks or the like occur at the manufacturing stage of the fuel inlet. Further, by appropriately selecting the expansion pipe mold and the contraction pipe mold, the expansion pipe and the contraction pipe can be performed in the same process.

More specifically, as described in claim 7, the circular pipe portion having a small thickness is pressed to crush the circular pipe portion from the outside, and at the same time, the circular pipe produced at this time. By forming the surplus portion of the portion into a plurality of protrusions, the circular pipe portion having the small thickness may be contracted.

That is, in this method, the extra wall portion produced when the circular pipe is contracted is formed as a ridge protruding from the outer peripheral surface of the small diameter portion. There are various conceivable processing methods for contracting a circular pipe, but if the form of contracting is performed by crushing as described above, a pressing force is gradually applied from the outer circumference of the circular pipe, such as swaging. Processing time will be shorter than when shrinking.

When circular pipes having different thicknesses are used, the outer diameters of the circular pipes are equal to each other, as described in claim 8, the appearance of the fuel inlet is not deteriorated. Further, in the step of forming the blank pipe, as described in claim 9 of the present application, a step of forming a circular pipe by rounding and butt-joining a plurality of plate materials having different thicknesses, and What has a step of abutting each end surface of the circular pipe while arranging the abutting portions to form a straight line, and a step of welding the abutting portions and the abutting portions in the same step Conceivable.

Generally, the circular pipe constituting the above-mentioned raw pipe is formed by extrusion molding, or is formed by rolling a plate material and then welding the abutting portions thereof. When a plurality of circular pipes are welded at the bare pipe stage as in the present application, it is conceivable to manufacture the circular pipes by the latter method and then weld these end faces to each other.

However, unlike such a method, as described above, at the stage of rounding each circular pipe, the butted portions are arranged in a straight line, and welding is continuously performed along this straight line. By adopting a mode in which the joints of the circular pipes are welded in the same step, the circular pipes are formed at the same time when the circular pipes are formed. Therefore, the processing efficiency is extremely improved.

Further, when it is necessary to process a flat portion on the mouthpiece portion in order to join one end of the breather tube to the fuel inlet, as described in claim 10 of the present application, the thick circular pipe portion is formed. The step of forming a flat portion by pressing a part of the above and the step of forming the plurality of ridges may be performed in the same pressing step.

For example, when the flat portion is formed on the upper surface and two ridges extending horizontally are formed, an outer die having a flat portion forming portion and a ridge pressing portion is used. By press-molding the blank tube, the flat portion and the ridge can be formed at the same time. As a result, manufacturing efficiency can be further improved.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view of the fuel inlet of the present embodiment, FIG. 2 is a sectional view of the fuel inlet, and FIG. 2A is a sectional view taken along the line AA of FIG.
FIG. 2B is a sectional view taken along line BB of FIG. In the following description, the fuel inlet side (left side in FIG. 2A) of the fuel inlet will be referred to as “upstream side” and the tank side (right side in FIG. 2A) will be referred to as “downstream side” for convenience.

The fuel inlet 1 is manufactured by pressing a pipe (hereinafter referred to as "element pipe") in which two circular pipes having the same outer diameter but different thicknesses are butted against each other at their end faces and welded. That is, the fuel inlet 1
Is a base portion 10 formed by molding a circular pipe portion having an outer diameter of 42.7 mm and a thickness of 1.2 mm in the raw pipe, and an outer diameter of 42.7 mm,
The general portion 20 is formed by molding a circular pipe portion having a thickness of 0.5 mm.

The base portion 10 is composed of a cap mounting portion 11 and a large diameter portion 12. The cap mounting portion 11 is formed by expanding one end of a raw tube by bulging to a diameter of 50 mm, and is provided with a spiral groove 11a for mounting a screw-in cap. The spiral groove 11a is formed directly on the cap mounting portion 11 by using the method described in paragraphs 0013 to 0018 of JP-A-9-249036, but the description thereof is omitted here.

The large-diameter portion 12 is a portion where the raw pipe is used as it is, and a flat portion 13 for joining one end of the breather tube 30 is provided on the upper surface thereof. The flat portion 13 is provided for joining the breather tube 30 by a ring projection described later. The other end of the breather tube 30 communicates with the fuel tank T. In addition, an interferance 17 may be attached to the large diameter portion 12 if necessary. here,
The interferance 17 is a member that prevents leaded gasoline from being mistakenly supplied when fuel is supplied to an automobile dedicated to unleaded gasoline, and allows insertion of a fuel supply nozzle for unleaded gasoline, but does not allow leaded gasoline. It is a member that prohibits the insertion of a fuel supply nozzle for gasoline. If the diameter of the cap mounting portion 11 is made the same as that of the large diameter portion 12 when the interferance 17 needs to be mounted, the spiral groove 11a appears inside the cap mounting portion 11 as a raised shape. Therefore, the interference 17 cannot pass through this portion and cannot be mounted. In order to avoid such a state, the cap mounting portion 11 has a larger diameter than the large diameter portion 12.

As shown in FIG. 3, it is preferable that the pipe forming the base portion 10 has a three-layer structure of a stainless layer (SUS), an aluminum layer (Al) and a stainless layer (SUS) from the outside. The stainless layer is provided
It is from the viewpoint of rust prevention and wear resistance, and the aluminum layer is provided from the viewpoint of weight reduction.

The general portion 20 includes a first taper portion 21, a small diameter portion 22 (outer diameter 25.4 mm), a second taper portion 23,
It is composed of a connecting portion 24 (outer diameter 42.7 mm). As shown in FIG. 2 (b), the small-diameter portion 22 is formed by reducing the diameter of the raw pipe by crushing it up and down, and when the diameter is reduced, the remaining portion (excess portion) of the raw pipe overlaps. A pair of ridges 25 that protrude horizontally are formed. The ridge 25 is formed along the axial direction.

The first taper portion 21 is a portion forming a boundary between the large diameter portion 12 and the small diameter portion 22, and the height of the protrusion 25 gradually increases in the process from the large diameter portion 12 to the small diameter portion 22. Therefore, the inner diameter is formed in the opposite manner, that is, the inner diameter is gradually reduced.

The second taper portion 23 is a portion which forms a boundary between the small diameter portion 22 and the connecting portion 24, and the height of the projection 25 is gradually lowered in the process from the small diameter portion 22 to the connecting portion 24. Is formed, and thus the inner diameter is formed in the opposite, that is, gradually increasing.

The connecting portion 24 is a portion where the raw pipe is used as it is, and here, the connecting pipe J connected to the fuel tank T is provided.
The ends of (for example, a flexible tube) are connected. The connecting portion 24 may be provided with a circumferential protrusion (not shown). The circumferential protrusion plays a role of preventing the connecting tube such as a flexible tube from falling out when the connecting tube is fitted.

Next, an example of use of the fuel inlet 1 of this embodiment will be described. A screw-in type cap (not shown) is screwed into the cap mounting portion 11 of the fuel inlet 1. When it becomes necessary to supply fuel, the cap is removed, a fuel supply nozzle (not shown) is inserted from the cap mounting portion 11, and fuel is supplied at a constant flow rate. Then, the supplied fuel flows through the inside of the fuel inlet 1, and then is sent to the fuel tank T through the connection pipe J. At this time, the air in the fuel tank T passes through the breather tube 30 and escapes to the inlet side of the fuel inlet 1.

Here, the fuel inlet 1 of this embodiment has a first taper portion 21, a small diameter portion 22, and a second taper portion 2.
3 has a large Venturi negative pressure in the void portion in the passage cross section when the fuel supplied at a constant flow rate passes therethrough. As a result, it is possible to effectively prevent the air that has escaped from the fuel tank T to the inlet via the breather tube 30 to be released into the atmosphere. That is, a liquid seal is realized.

Next, a method for manufacturing the fuel inlet 1 of this embodiment will be described with reference to FIGS. FIG. 4 is an explanatory view showing a manufacturing method of a raw pipe for forming the fuel inlet 1, and FIG. 5 is an explanatory view showing a manufacturing process of the fuel inlet 1 using the raw pipe.

As shown in FIG. 4, the shell 1'in this embodiment is formed as follows. First, the base 10
A plate material 10 'having a plate thickness of 1.2 mm for forming the plate and a plate material 20' having a plate thickness of 0.5 mm for forming the general portion 20 are prepared (FIG. 4A). And these plate materials 1
0'and 20 'are each rounded and each end face 1
0'a and 10'b, the end faces 20'a and 20'b,
Circular tubes 10 "and 20" are formed in a butted state, respectively (Fig. 4 (b)). Thereafter, the circular tubes 10 "and 20" are aligned such that the abutting portions form a straight line, and the respective axial end surfaces 10'c,
And 20'c are abutted. Then, welding W1 is applied to each abutting portion along the straight line in one step, and welding W2 in the circumferential direction is applied to the abutting portion to complete the raw pipe (FIG. 4 (c)).

According to the manufacturing method of the above-mentioned blank tube 1 ', two circular tubes 10 "and 20" having different thicknesses at the stage of the blank tube 1'.
What is joined is obtained. Therefore, in the processing steps of the fuel inlet 1 described below, the mouthpiece portion and the general portion, which are required to have different thicknesses, can be processed at the same time, and the manufacturing cost can be reduced by reducing the processing steps.

In the method of manufacturing the above-mentioned raw tube 1 ',
Welding W1 and W2 are preferably set in a welding control program so that they are performed in the same process. By doing so, the time required for the process in the manufacturing stage of the raw tube 1'can be shortened, and the manufacturing efficiency can be further improved. Various forms of welding can be considered such as laser welding and seam welding.

Next, a manufacturing process of the fuel inlet 1 using the raw pipe 1'will be described. The raw tube 1'produced as described above is prepared (Fig. 5 (a)), and this raw tube 1'is placed in the press machine (Fig. 5 (b)). The pressing apparatus includes an outer mold 50 for molding the outer shape of the fuel inlet 1, and an inner mold 60 for press-molding the raw pipe 1 ′ between the outer mold 50 and the outer mold 50.

The outer mold 50 is composed of two molds which are divided into an upper mold and a lower mold, and each of the upper mold and the lower mold is provided with a base portion forming portion 51 and a general portion forming portion 52. Meanwhile, the inner mold 60
As shown in FIGS. 5 and 6, a cap mounting portion holding portion 61 and a cap mounting portion forming portion 62 for forming the cap mounting portion 11 of the fuel inlet 1, and a flat portion forming for forming the flat portion 13 are formed. The part 63 and the small diameter part forming part 64 for forming the small diameter part 22 are integrally configured.

The cap attachment portion forming portion 62 has an outer diameter larger than the inner diameter of the raw pipe 1'for expanding one end of the raw pipe 1'by bulging. Further, the downstream end portion of the cap attachment portion forming portion 62 has a tapered shape, so that the cap attachment portion forming portion 62 can be smoothly pushed into the raw pipe 1 ′. The cap attachment portion holding portion 61 is formed in a disk shape having an outer diameter larger than that of the cap attachment portion forming portion 62, and the downstream end surface 61a presses the end portion of the raw pipe 1 ′, thereby The fuel inlet is formed by bending back a predetermined amount. The flat portion forming portion 63 has a rectangular parallelepiped shape, and its upper surface is a flat surface for forming the flat portion 13. The small diameter portion forming portion 64 has a cylindrical shape, and the outer diameter thereof matches the inner diameter of the small diameter portion 22.

In the manufacturing process, first, in a state in which the raw tube 1'is supported in the pressing apparatus by a supporting mechanism (not shown), the inner die 60 is driven by a driving means (not shown) in the G direction (pressing direction) in FIG. 5B. ), And the small diameter portion forming portion 6
4 is inserted into the inside of the tube 1 '(FIG. 5 (b)). Eventually, the cap mounting portion forming portion 62 of the inner mold 60 becomes the base tube 1 ′.
When it reaches the upstream side end portion of, the tapered portion 62a is further pushed into the inside of the raw tube 1'while expanding the end portion. In the meantime, the upstream end of the raw pipe 1'is expanded to form the cap attachment portion 11. Eventually, the end surface 61a of the cap attaching portion holding portion 61 presses the end portion of the raw tube 1 ',
The insertion of the inner mold 60 is stopped while the end portion is warped by a predetermined amount.

Then, from this state, the outer die 50 is moved in the E direction (pressing direction) in FIG. 5B by a driving means (not shown) to press-mold the blank tube 1'with the inner die 60 (see FIG. 5 (c)). The details at this time are shown in FIGS. 7 and 8 as the state of the DD cross section in FIGS. 5B and 5C.
Are shown respectively.

As shown in FIG. 7, the general portion forming portions 52, 52 of the outer die 50 are arranged in the direction E (press) in the drawing with respect to the raw pipe 1'coaxially arranged with the small diameter portion forming portion 64 of the inner die 60. Direction). The general portion forming portions 52, 52 press the raw pipe 1 ′ in the vertical direction and press the extra portion of the raw pipe 1 ′ formed in the process while enclosing the raw pipe 1 ′ in the ridge forming portion 52 a. Then, as shown in FIG. 8, when the general portion forming portions 52, 52 of the outer die 50 come into contact with each other, the formation of the small diameter portion 22 having the protrusion 25 is completed.

At the same time, the mouthpiece portion forming portions 51, 51 of the outer die 50 and the flat portion forming portion 63 of the inner die press the raw tube 1'up and down to join one end of the breather tube. The flat part 13 for forming is formed. In this way, after the semi-finished product 1 ″ of the fuel inlet 1 is formed, the outer dies 50, 50 of the press machine are moved in the direction of withdrawal (see FIG. 5).
While moving in the direction of arrow F in (b), the inner mold 60 is moved in the direction of retreat (direction of arrow H in FIG. 5) to retreat (FIG. 5 (d)).

Although the process of forming the first taper portion 21 and the second taper portion 23 is omitted in FIGS. 3 to 8, the taper of the outer molds 50, 50 is actually omitted. Since the portion corresponding to is formed in a taper shape, the taper shape is formed at the same time when the ridge 25 and the like are formed during the press forming.

The breather tube 3 is added to the semi-finished product 1 ".
0 is installed and the fuel inlet 1 is completed. The breather tube 30 is attached to the semi-finished product 1 ″ by a ring projection method (Japanese Unexamined Patent Publication No. Hei 9 (1999) -96).
The method described in paragraphs 0014 to 0016 of Japanese Unexamined Patent Publication No. 150637) is used, but the description thereof is omitted here.

It is needless to say that the embodiment of the present invention is not limited to the above embodiment, and various forms can be adopted as long as they are within the technical scope of the present invention. For example, the axes of the first taper portion 21, the small diameter portion 22, and the second taper portion 23 may deviate from the axes of the cap attachment portion 11 and the large diameter portion 12. Further, in the above embodiment, the ridge 2
Although two 5 are provided, for example, four protrusions 25 may be provided at a predetermined interval, and the number may be appropriately set. Further, although the two protrusions 25 are arranged in symmetrical positions in FIG. 2B, they may be arranged randomly. Further, in the above-described embodiment, the crushing process using the press device is adopted in the shrinking process for forming the small diameter portion,
A mode in which the tube is contracted by upsetting such as swaging may be adopted. The shapes, dimensions, etc. described in the above embodiment are not limited to the above, and it goes without saying that they can be appropriately selected.

[Brief description of drawings]

FIG. 1 is a perspective view of a fuel inlet of this embodiment.

2 is a cross-sectional view of the fuel inlet of the present embodiment, (a) is a cross-sectional view taken along the line AA of FIG. 1, and (b) is a cross-sectional view taken along the line BB of FIG.

FIG. 3 is a detailed explanatory view of a cross section of the mouthpiece portion of the fuel inlet of the present embodiment.

FIG. 4 is a schematic explanatory diagram of a method for manufacturing a shell used in manufacturing the fuel inlet of the present embodiment.

FIG. 5 is an explanatory diagram showing a manufacturing process of the fuel inlet of the present embodiment.

FIG. 6 is a perspective view of an inner mold used for manufacturing the fuel inlet of the present embodiment.

FIG. 7 is an explanatory diagram showing the manufacturing process of the fuel inlet of the present embodiment.

FIG. 8 is an explanatory diagram showing the manufacturing process of the fuel inlet of this embodiment.

FIG. 9 is an explanatory diagram of a conventional fuel inlet.

FIG. 10 is an explanatory view showing a mounting structure of a fuel inlet.

[Explanation of symbols]

1 ... Fuel inlet, 1 '... Element pipe, 1
0 ... Clasp part, 11 ... Cap mounting part, 12 ...
..Large diameter portion, 13 ... Flat portion, 14 ... Small diameter portion, 17 ... Interference, 20 ... General portion, 21 ... First taper portion, 22 ... Small diameter portion ,
23 ... second taper portion, 24 ... connecting portion, 25.
..Ridges, 30 ... Breather tubes, 50 ...
Outer mold, 51 ... Clasp part forming part, 52 ... General part forming part, 52a ... Ridge forming part, 60 ... Inner mold,
61 ... Cap mounting portion holding portion, 62 ... Cap mounting portion forming portion, 63 ... Flat portion forming portion, 64 ...
Small diameter part forming part, J ... Connection pipe, T ... Fuel tank, W1, W2 ... Welding

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 9-39591 (JP, A) JP-A 58-194627 (JP, A) JP-A 2000-159296 (JP, A) JP-A 64-22625 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60K 15/00-15/077

Claims (10)

(57) [Claims] 1. A fuel inlet comprising: a mouthpiece portion for receiving a fuel supply nozzle; and a general portion connected to the mouthpiece portion for guiding the supplied fuel to a fuel tank, wherein the mouthpiece portion has a thickness. Is formed by molding a circular pipe portion having a large thickness of a raw pipe formed by joining different circular pipes at respective ends thereof, and the general portion is a circle having a small thickness of the raw pipe. A fuel inlet formed by molding a pipe portion. 2. A cap attachment portion of the cap portion is formed by expanding a part of the thick circular tube part, and a part of the thin circular tube part is contracted to form the cap mounting part. The fuel inlet according to claim 1, wherein a small diameter portion of the general portion is formed. 3. The small-diameter portion is formed by crushing a part of the small-diameter circular tube portion from the outside to form a plurality of ridges, and contracting the part. The fuel inlet according to claim 2, which is characterized in that. 4. The fuel inlet according to claim 1, wherein the thick circular pipe portion has a three-layer structure of a stainless layer, an aluminum layer, and a stainless layer from the outside. 5. A method of manufacturing a fuel inlet, comprising: a mouthpiece portion for receiving a fuel supply nozzle; and a general portion connected to the mouthpiece portion for guiding the supplied fuel to a fuel tank, wherein the fuel inlet has a different thickness. A step of joining circular pipes at each end thereof to form a raw pipe; a step of forming the mouthpiece part by molding the thick circular pipe portion of the raw pipe; And a step of forming the general portion by forming a circular pipe portion having a small thickness, and a method for producing a fuel inlet. 6. A step of forming a cap attachment portion of the cap portion by expanding a part of the thick circular tube portion, and a step of contracting a part of the thin circular tube portion. And a step of forming a small-diameter portion of the general portion, the manufacturing method of the fuel inlet according to claim 5. 7. By pressing the circular pipe portion having a small thickness to crush the circular pipe portion from the outside, at the same time, forming a surplus portion of the circular pipe portion at this time into a plurality of ridges. The method for producing a fuel inlet according to claim 5 or 6, wherein the circular pipe portion having a small thickness is contracted. 8. The method for manufacturing a fuel inlet according to claim 5, wherein the circular pipes having different thicknesses have the same outer diameter. 9. A step of forming a circular pipe by rounding and butt-joining a plurality of plate materials having different thicknesses in the step of forming the raw pipe, and the step of forming the circular pipe so that the abutting portions of the respective plate materials form a straight line. The step of abutting each end face of the circular pipe while arranging the step, and the step of welding the abutting part and the abutting part in the same step are included. The method for manufacturing the fuel inlet according to 1. 10. A step of pressing a part of the thick circular tube portion to form a flat portion for joining one end of a breather tube, the flat portion being formed and the plurality of protrusions. The method for producing a fuel inlet according to any one of claims 7 to 9, wherein the forming of the strip is performed in the same pressing step.