JP2015102082A - Seal structure of fuel tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal structure of fuel tank showing a high level seal performance while its low cost and light weight being attained by a simple configuration.SOLUTION: This seal structure comprises a protrusion part 3 protruded from and arranged at a resin tank main body 2; a mouth member 7 fixed along the inner peripheral surface of the protrusion part 3 and having the first cylindrical part 7a; the second cylindrical part 10a inserted along the inner surface of the mouth member 7 and into the mouth member 7; a cover member 10 including a flange part 10b covering the upper end of the second cylindrical part 10a and extended and arranged at the outer peripheral side of the second cylindrical part 10a and a cylindrical suspended part 10d suspended down from the outer peripheral edge of the flange part 10b; and an annular seal member 9 installed between the protrusion part 3 and the cover member 10. The protrusion part 3 is provided with an annular shoulder surface 3a supporting the seal member 9 along inserting direction of the cover member 10, and the annular seal member 9 supported by the annular shoulder surface is held between the outer peripheral surface (the first seal surface 3b) of the protrusion part 3 and the inner peripheral surface (the second seal surface 10i) of the suspended part 10d.

Description

  The present invention relates to a fuel tank sealing structure for oil-tightly sealing a fuel tank.

  Conventionally, a fuel tank mounted on a passenger car or the like has been mainly composed of an iron plate, but in recent years, resinization has been promoted from the viewpoints of weight reduction, rust prevention, and ease of molding. For the production of resin fuel tanks, a blow molding method that makes it easy to mold hollow bodies is often used. A cylindrical parison melted with thermoplastic resin is extruded, and air is blown between the parisons sandwiched between molding dies. Thus, a molded product having a desired shape is obtained.

  In general, a fuel tank is formed with a protruding portion protruding outward in a blow molding process, and an opening is formed in the protruding portion in a subsequent secondary processing step. A lid member to which a functional component such as a fuel pump is fixed is attached to the protruding portion. And between a protrusion part and a cover member is sealed oil-tightly, when a cover member is mounted | worn with a protrusion part, a fuel and gas are prevented from leaking from opening.

  As an example of such a seal structure, the lid member includes a cylindrical portion housed in the opening, an outer flange portion that closes the upper end of the cylindrical portion, and further projects outward from the cylindrical portion, and an outer flange The flanged sleeve has a sleeve portion that is in close contact with the neck portion, and a lower end of the sleeve portion that protrudes to the outer peripheral side. The flanged sleeve is made of a resin having a heat resistant temperature higher than that of the resin constituting the tank body, and when the opening is closed by the lid member, the cylindrical portion is the sleeve portion. A seal structure is disclosed in which the outer flange portion is in contact with the upper ends of the neck portion and the sleeve portion, and the inner peripheral side of the seal member and the outer peripheral side of the neck portion are in close contact with each other (patent) Reference 1)In Patent Document 1, by adopting such a seal structure, a tightening structure such as a screw portion is not necessary, so that it is not necessary to manage tightening torque and axial force during tightening, and to attach and remove the lid member. It is said that a seal structure that can be easily managed is obtained.

International Publication No. 2012/018108

  However, in the seal structure disclosed in Patent Document 1, the lid member includes an extending portion that extends from the outer end of the outer flange portion to the lower portion, and a cross section that extends from the lower end of the extending portion in the inner diameter direction of the flange portion. And an L-shaped seal member mounting portion, and the structure of the lid member is very complicated. In particular, the structure of projecting from the lower end of the extending part in the inner diameter direction of the flange part is difficult to easily integrally mold the lid member by injection molding. For example, the number of molds used for manufacturing is increased and the shape is complicated. The manufacturing cost increases, for example, and the lid member is composed of a plurality of pieces and joined together. Further, in Patent Document 1, the seal member mounting portion includes a recess that is recessed in the outer peripheral direction on the inner peripheral surface of the lid member, and the seal member is mounted in the recess. Therefore, it is necessary to push the seal member into the recess when the seal member is mounted, which complicates the manufacturing process.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to reduce the cost with a simple configuration and to provide a fuel tank having high sealing performance. An object is to provide a seal structure.

  The present invention is formed integrally with a resin fuel tank main body (2), and protrudes from the fuel tank main body (3), and is fixed along the inner peripheral surface of the protrusion. A mouth member (7) having a shape portion (7a), a second tubular portion (10a) inserted into the mouth member along the inner peripheral surface of the first tubular portion, and the second tubular shape. A lid member (10d) that covers the upper end of the part and extends to the outer peripheral side of the second cylindrical part, and a cylindrical hanging part (10d) that hangs downward from the outer peripheral edge of the flange part ( 10) and an annular seal member (9) mounted between the protrusion and the lid member, and the seal member is inserted into the protrusion or the fuel tank body in the insertion direction of the lid member. A support surface (3a) to be supported is provided, and the lid member is attached to the mouth member The seal member supported by the support surface is sandwiched between the outer peripheral surface (first seal surface 3b) of the protrusion and the inner peripheral surface (second seal surface 10i) of the hanging portion. The fuel tank (1) has a sealed structure.

  Accordingly, the configuration of the lid member can be simplified and the cost can be reduced, and the fuel tank can be reliably sealed only by inserting the lid member into the mouth member.

  Further, according to the present invention, the support surface (3a) is formed on the protrusion between the protrusion (3) and the opening end (4) of the mouth member (7) and the fuel tank body (2). The annular shoulder surface (3a) is formed.

  Thereby, in the manufacturing process of the fuel tank 1, the operator can attach the seal member only by arranging the annular seal member on the annular shoulder surface formed in the protruding portion.

  Moreover, this invention is provided with the said support surface over the perimeter of the said protrusion part (3).

  Accordingly, when the lid member is mounted on the projecting portion, a part of the seal member is displaced downward, and deformation of the seal member is prevented, so that reliable sealing performance can be obtained.

  In the present invention, the second cylindrical portion (10a) is provided with a plurality of engaged portions (10c) each having a through hole in the circumferential direction, and the inner portion of the first cylindrical portion (7a) A plurality of engaging claws (7d) projecting in the inner diameter direction corresponding to the engaged portion are provided on the peripheral surface, and the engaging claw and the engaged portion are inserted into the second cylindrical portion. It is comprised so that it may engage about a direction.

  Accordingly, the lid member can be easily attached to the protruding portion by so-called snap fit.

  Further, according to the present invention, a gap is formed between the upper end of the protruding portion (3) and the flange portion (10b) in a state where the lid member (10) is mounted on the mouth member (7). Is.

  Thus, with the lid member mounted on the protruding portion, the lid member is given play in the vertical direction, and in the fuel tank manufacturing process, the vertical height of the opening end of the protruding portion is strictly controlled. Without this, the lid member can be reliably locked by the snap fit.

  In the present invention, the mouth member (7) is made of a resin material having a hardness higher than that of the resin material constituting the protruding portion (3).

  Thereby, the substantial strength of the projecting portion in the radial direction is ensured, and creep deformation in which the resin is constantly deformed by the reaction force of the seal member can be suppressed.

  According to the present invention, the structure of the lid member can be simplified to reduce the cost and weight, and the outer peripheral surface of the protrusion provided on the fuel tank and the flange of the lid member can be simply inserted into the mouth member. It is possible to reliably seal between the inner peripheral surface of the part.

The perspective view which shows the whole structure of the fuel tank which concerns on 1st Embodiment of this invention. Cross section of fuel tank (A) is an upper perspective view of the mouth member, (b) is a lower perspective view of the lid member, and (c) is a lower perspective view showing a state in which the lid member is engaged with the mouth member. The perspective view which shows the periphery structure of the protrusion part to which the opening member was fixed. (A) is sectional drawing which shows the seal structure at the time of attaching a cover member to the protrusion part of a fuel tank, (b) is a principal part enlarged view of (a). (A) is a principal part enlarged view which shows the 1st modification of a seal structure, (b) is a principal part enlarged view which shows the 2nd modification of a seal structure. (A), (b) is explanatory drawing explaining the manufacturing process of a fuel tank. (A)-(c) is explanatory drawing which shows the position which cut | disconnects a parison in the manufacturing process of a fuel tank. (A) is sectional drawing which shows the state which attached the cover member to the protrusion part, (b) is principal part sectional drawing which shows the engaging part of an engaging claw and to-be-engaged part. (A) is explanatory drawing which shows the engagement nail | claw provided in the internal peripheral surface of a mouth member, (b) is explanatory drawing which shows the state with which the mouth member and the cover member were engaged, (c), Explanatory drawing which shows the state by which engagement with the mouth member and the cover member was cancelled | released Sectional drawing which shows the modification of the structure which engages a cover member and a mouth member

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the direction is basically in accordance with the description of the direction in each figure. However, since the main component of the present invention has a cylindrical shape, the terms “circumferential direction”, “radial direction (inner diameter direction, outer diameter direction)”, and “axial direction” may be used. The “axial direction” may be expressed as “insertion direction”.

  FIG. 1 is a perspective view showing the overall configuration of the fuel tank 1 according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the fuel tank 1. FIG. 2 shows the II-II cross section shown in FIG. Hereinafter, the outline of the configuration of the fuel tank 1 will be described with reference to FIGS. 1 and 2. In the following description, “fuel tank 1” refers to a composite unit that includes the components described later, and “tank body 2” refers to the container itself.

  A fuel tank 1 mounted on a passenger car or the like and storing the fuel is mainly composed of a tank body 2 made of polyethylene, a protrusion 3 integrally formed with the tank body 2, a mouth member 7, and a seal member 9 ( 2), a lid member 10, various functional parts housed in the tank body 2, and a bracket 6 housed in the tank body 2 and supporting a part of the functional parts. Among these, the protrusion 3, the mouth member 7, the lid member 10, and the seal member 9 constitute a seal structure. The tank body 2 is connected to an oil supply pipe 8 for supplying fuel to the fuel tank 1 from the outside.

  As shown in FIG. 2, the mouth member 7 is fixed to the inner peripheral surface of the protruding portion 3. The mouth member 7 includes a cylindrical (sleeve) first cylindrical portion 7 a provided along the inner peripheral surface of the protruding portion 3, and the upper end of the first cylindrical portion 7 a is an open end together with the upper end of the protruding portion 3. 4 is configured. Here, if the opening end 4, the inner peripheral surface of the mouth member 7 (first cylindrical portion 7 a) connected to the opening end 4, and the outer peripheral surface of the projecting portion 3 are combined and defined as the opening portion 4 a, the first cylindrical portion 7 a. Is fixed to the inner peripheral surface of the protruding portion 3, the first cylindrical portion 7a constitutes the inner surface of the opening 4a, and the protruding portion 3 constitutes the outer surface of the opening 4a.

  The lid member 10 is a member that closes the opening 4a in an oil-tight manner. The lid member 10 includes a cylindrical second cylindrical portion 10a and a flange portion 10b, and the second cylindrical portion 10a is inserted into the first cylindrical portion 7a of the mouth member 7 and fixed as will be described later. Is done. That is, the mouth member 7 functions as a mounting (fixing) ring for the lid member 10.

  The seal member 9 is an O-ring in which an elastic body such as rubber is formed in an annular shape, and is attached to the outer surface of the protruding portion 3. When the second cylindrical portion 10a is inserted in the axial direction along the first cylindrical portion 7a, the seal member 9 is sandwiched between the inner peripheral surface of the flange portion 10b and the outer peripheral surface of the protruding portion 3, and the opening 4a. Is closed in an oil-tight manner to prevent leakage of liquid state or vaporized fuel. Details of the seal structure will be described later. The state in which the opening 4a of the fuel tank 1 is closed in this way is hereinafter simply referred to as “the state in which the cover member 10 is attached to the protrusion 3”, and the process leading to this state is referred to as “the cover member 10 being in the protrusion 3”. "When attaching to the projecting part 3", it may be referred to as "the process of attaching the lid member 10 to the protrusion 3".

  A fuel pump unit 15, which is one of functional parts, is fixed to the lower surface of the lid member 10. The fuel pump unit 15 includes a fuel pump, a filter, a pressure regulator (all not shown) and the like, and in the present embodiment, these are all so-called in-tank type modules mounted inside the tank body 2. Is adopted. The fuel pump unit 15 is connected to a fuel injector (not shown) through a pipe such as an external connection pipe 15 a protruding from the upper part of the lid member 10. The functional component fixed to the lower surface of the lid member 10 may include other members such as a full tank regulating valve (not shown).

  Further, on the lower surface of the lid member 10, there is provided an urging member 16 that is configured by, for example, a coil spring and urges the fuel pump unit 15 downward toward the bracket 6 or the bottom surface of the fuel tank 1. Since the urging member 16 urges the fuel pump unit 15 downward, as a result, the lid member 10 is urged upward.

  3A is an upper perspective view of the mouth member 7, FIG. 3B is a lower perspective view of the lid member 10, and FIG. 3C is a lower perspective view showing a state in which the lid member 10 is engaged with the mouth member 7. FIG. 3B and 3C, the description of the fuel pump unit 15 fixed to the lid member 10 is omitted (the same applies to FIGS. 4 to 6, 9, and 11).

  First, the mouth member 7 will be described. The mouth member 7 is made of a thermoplastic resin (here, polyacetal (POM)), and as shown in FIG. 3 (a), the outer surface of the cylindrical first sleeve 7a has left and right sides respectively. A pair of projecting arm-like stays 7b and 7b are provided integrally. Thus, cost reduction and weight reduction are achieved by making the mouth member 7 into resin.

  A groove portion 7c (see FIG. 5B) having a substantially trapezoidal cross section (see FIG. 5B) extends in the front-rear direction on the upper surfaces of the stays 7b and 7b. Further, on the outer peripheral surface between the two stays 7b, 7b, a convex portion 7h having a predetermined thickness is extended in the circumferential direction. The convex portion 7h is brought into close contact with the upper inner surface of the tank main body 2 when the tank main body 2 is formed (see FIG. 9B), and when the upper stress is applied to the mouth member 7 (for example, the cover member 10 is forcibly applied). The mouth member 7 is prevented from falling off together with the lid member and the pump unit in the case of trying to pull out. Moreover, the convex part 7h suppresses that the parison 20 (all refer FIG.7 (b) etc.) flows out from the area | region pinched | interposed by the metal mold | die 21 and the mouth member 7 when shape | molding the protrusion part 3. FIG. It also has an action to do.

  On the inner peripheral surface of the first tubular portion 7a, there are a plurality of engagement claws (six here, only three of the six appear in FIG. 3A) at a substantially central portion in the vertical direction. 7d protrudes in the circumferential direction. The engagement claw 7d restricts the upward displacement of the lid member 10 inserted into the mouth member 7 and prevents it from coming off.

  Further, on the side of the opening end 4 (see FIG. 2) where the protruding portion 3 opens, a sharpened portion 7f extends in the circumferential direction at the edge of the first cylindrical portion 7a, and the upper end of the first cylindrical portion 7a. An inclined surface 7e that is inclined from the sharpened portion 7f to the radial direction is formed in the lower predetermined range. Detailed configurations of the engaging claw 7d, the sharpened portion 7f, and the inclined surface 7e will be described later.

  Next, the lid member 10 will be described. The lid member 10 is made of a thermoplastic resin (here, polyacetal). As shown in FIG. 3B, the lid member 10 includes a second cylindrical portion 10a having a substantially cylindrical shape, and an upper surface portion 10e that covers (closes) the upper end of the second cylindrical portion 10a and has an outer diameter direction. And a flange portion 10b projecting over the surface. A plurality (six in this case) of through-holes penetrating through the second cylindrical portion 10a are provided at equal intervals in the circumferential direction at substantially the center in the vertical direction of the second cylindrical portion 10a. This through hole constitutes the engaged portion 10c.

  The flange portion 10b includes a cylindrical hanging portion 10d that hangs downward at an outer edge thereof. The inner diameter of the hanging portion 10d is slightly larger than the outer diameter of the base portion 3c (see FIG. 5B) of the protruding portion 3 (see FIG. 2), and when the lid member 10 is attached to the protruding portion 3, The flange portion 10b covers at least the upper half of the protruding portion 3 including the open end 4 (see FIG. 2). Since the lid member 10 has a simple shape including a through-hole (engaged portion 10c) in the second cylindrical portion 10a and a hanging portion 10d in the flange portion 10b, the lid member 10 is injection-molded with a mold having a simple configuration. The manufacturing cost can be reduced. In addition, you may give R chamfering and C chamfering to the lower edge of the internal peripheral surface of the hanging part 10d (refer FIG.5 (b)).

  As shown in FIG.3 (c), along the internal peripheral surface of the mouth member 7 (1st cylindrical part 7a) which fixed the 2nd cylindrical part 10a of the cover member 10 to the protrusion part 3 (refer FIG. 2). When inserted from above, the engaging claw 7d and the engaged portion 10c are engaged in the inserting direction of the second cylindrical portion 10a, and the lid member 10 is simply attached to the protruding portion 3. A detailed configuration related to this engagement will be described later.

  In addition, when attaching the cover member 10 to the protrusion part 3, the alignment in the circumferential direction is performed as follows. A mark is engraved on the mold for molding the lid member 10, and a positioning marker 10 h (see FIG. 1) is provided on the upper surface of the flange portion 10 b of the lid member 10. On the other hand, the mouth member 7 is supported by a bracket 6 (see FIGS. 1 and 2) accommodated in the tank body 2, and the mouth member 7, the bracket 6 and the tank body 2 (projecting portion 3) are blow-molded. Positioning is done when doing. Therefore, a reference marker 2a (see FIG. 1) is formed on the tank body 2 by marking the mark on the mold for molding the tank body 2. When attaching the lid member 10 to the protrusion 3, the positioning marker 10h is aligned with the reference marker 2a provided on the tank body 2, thereby aligning the positions of the engaged portion 10c and the engaging claw 7d in the circumferential direction. Can do.

  4 is a perspective view showing a peripheral configuration of the protruding portion 3 to which the mouth member 7 is fixed, and FIG. 5A is a cross-sectional view showing a seal structure when the lid member 10 is attached to the protruding portion 3 of the fuel tank 1. FIG. 2B is an enlarged view of the main part of FIG. 5A corresponds to an enlarged view of the periphery of the opening 4a in FIG.

  As shown in FIG. 4, an annular shoulder surface (hereinafter referred to as an annular shoulder surface 3 a) is provided at an intermediate position in the vertical direction of the protruding portion 3 over the entire circumference of the outer peripheral surface of the protruding portion 3. The protrusion 3 is formed thin in the radial direction above the annular shoulder surface 3a and relatively thick below. And the sealing member 9 is attached to the outer peripheral surface of the protrusion part 3 in the state supported from the downward direction by the annular shoulder surface 3a. Thus, the annular shoulder surface 3 a functions as a support surface for the seal member 9.

  Since the sealing member 9 made of an elastic body is easily deformed, in the manufacturing process of the fuel tank 1, the operator expands the annular sealing member 9 on the annular shoulder surface 3 a formed on the protruding portion 3. The mounting of the seal member 9 is completed only by arranging. Thus, the attachment of the seal member 9 is extremely simple, which shortens the production lead time. Further, since the annular shoulder surface 3a is provided over the entire circumference of the outer peripheral surface of the protruding portion 3, when the lid member 10 is attached to the protruding portion 3, a part of the seal member 9 is displaced downward. And the deformation | transformation of the sealing member 9 is prevented reliably, and reliable sealing performance can be exhibited.

  As shown in FIGS. 5A and 5B, the protruding portion 3 is provided in close contact with the outer peripheral surface of the mouth member 7 in the opening 4 a. The protruding portion 3 protrudes from the upper surface of the tank body 2 by about L1 = 12 mm, and the annular shoulder surface 3a is provided at a height of about L2 = 6 mm from the upper surface of the tank body 2. The radial thickness of the projecting portion 3 is about L3 = 4 mm below the annular shoulder surface 3a in the axial direction (that is, on the tank body 2 side) and above the annular shoulder surface 3a (that is, on the opening end 4 side). In this case, L4 is set to about 2 mm, and the annular shoulder surface 3a has a width of about 2 mm by subtraction (L3-L4).

  Since the downward movement of the seal member 9 is restricted by the annular shoulder surface 3 a, the seal member 9 is prevented from being detached from the protrusion 3 when the lid member 10 is attached to the protrusion 3. On the contrary, when the lid member 10 is removed from the protruding portion 3, the sealing member 9 is attached to the outer peripheral surface of the protruding portion 3 by its own elasticity, so that the sealing member 9 is prevented from being easily removed. Even if the seal member 9 is removed, it can be easily remounted.

  In a state where no external force is applied, the seal member 9 has a circular cross section (here, the diameter is about 3.5 mm), but in the state where the lid member 10 is mounted on the protruding portion 3, an annular shoulder surface The seal member 9 supported by 3a is suspended from the outer peripheral surface (hereinafter referred to as the first seal surface 3b) of the protruding portion 3 above the annular shoulder surface 3a as a support surface and the flange portion 10b of the lid member 10. It is sandwiched between the inner peripheral surface of the hanging portion 10d (hereinafter referred to as the second seal surface 10i) and deformed so as to be crushed from both sides in the radial direction (here, the left-right direction). In a state where the lid member 10 is mounted on the protruding portion 3, the first seal surface 3b, the second seal surface 10i, and the annular shoulder surface 3a form an annular groove as a whole, and the seal member 9 is accommodated therein. It will be.

  Thus, in this embodiment, the seal member 9 is brought into close contact with the first seal surface 3b of the projecting portion 3 and the second seal surface 10i of the lid member 10 (hanging portion 10d), whereby a shaft seal structure is realized and fuel is produced. The protruding portion 3 of the tank 1 is reliably sealed by the lid member 10. Further, with the shaft seal structure, the guarantee of the sealing performance is only required to manage the outer dimensions of the first seal surface 3b and the inner diameter of the second seal surface 10i, and the production process is simplified.

  Further, in a state where the cover member 10 is mounted on the protrusion 3, the second seal surface 10 i of the cover member 10 and the outer peripheral surface of the protrusion 3 (formed below the annular shoulder surface 3 a) in the vicinity of the base 3 c of the protrusion 3. In practice, a slight gap is formed in consideration of the dimensional tolerance. However, the gap is very small, so that the annular shoulder surface 3a and the seal member 9 are concealed from the outside by the hanging portion 10d, and the seal member 9 protrudes to the side of the base portion 3c and dust on the seal surface. Intrusion of foreign matter such as is prevented.

  Here, the first sealing surface 3b of the protruding portion 3 to which the seal member 9 is in close contact is supported by the first cylindrical portion 7a of the mouth member 7 from the inner diameter side. Since the polyacetal constituting the mouth member 7 has a relatively high hardness, this ensures a substantial strength of the protruding portion 3 on the first seal surface 3b, particularly in the thin portion above the annular shoulder surface 3a. Creep deformation (resin sag of the resin) in which the resin is constantly deformed by the reaction force 9 can be suppressed.

  On the other hand, the drooping portion 10d and the upper surface portion 10e of the lid member 10 with which the seal member 9 is in close contact with each other need to be strong enough not to be deformed by stress in the outer diameter direction received through the seal member 9. However, both the hanging portion 10d and the upper surface portion 10e are portions exposed to the outside of the fuel tank 1, and the thickness thereof is not particularly limited. Therefore, sufficient sealing performance is ensured by setting the thickness so as not to be deformed by the stress received through the seal member 9. Also, the strength of the lid member 10 may be ensured by providing a plurality of ribs (not shown) in the lid member 10 radially from the drooping portion 10d to the upper surface portion 10e. Providing such ribs makes it easier for an operator to grip the lid member 10 and improves workability.

  Further, as shown in the drawing, in a state where the lid member 10 is mounted on the protruding portion 3, a gap 13 is formed between the upper end of the protruding portion 3 and the flange portion 10b. Here, the interval of the gap 13 is about L5 = 1.0 mm. As described above, the functional member (here, the fuel pump unit 15) fixed to the lid member 10 is urged upward by the urging member 16 (both see FIG. 2), and the lid member 10 is interposed via this functional member. On the other hand, the lid member 10 is restricted from being displaced upward by an engaging claw 7d (see FIGS. 3A and 3C) formed on the mouth member 7. The size of the gap 13 can be adjusted by managing the vertical width of the engaging portion 10c (see FIGS. 3B and 3C).

  In this configuration, when the lid member 10 is further pushed down in a state where the lid member 10 is attached to the protruding portion 3 (that is, in the state shown in FIG. 5B), the lid member 10 has no gap 13 ( That is, it can be displaced downward (until it abuts the open end 4). Accordingly, the opening end 4 restricts the downward displacement of the lid member 10. That is, in the seal structure according to the present embodiment, the lid member 10 is provided with play of the length of the gap 13 in the vertical direction in a state in which the lid member 10 is mounted on the protruding portion 3, and as a result, the tank body 2. And when forming the protrusion part 3, it becomes unnecessary to strictly manage the dimension (height) of the opening end 4 in the vertical direction.

  Further, since no threaded portion or the like is formed on the protruding portion 3, the thickness of the protruding portion 3 can be reduced, and the weight of the fuel tank 1 can be reduced. In addition, the fitting length with the lid member 10 can be shortened, the protruding height of the protruding portion 3 can be minimized, the space can be effectively used and the capacity of the fuel tank 1 can be secured when the fuel tank 1 is mounted on the vehicle. Is planned.

  In the present embodiment, as described above, the tank body 2 and the protrusion 3 are made of high-density polyethylene, while the mouth member 7 and the lid member 10 are made of polyacetal. High density polyethylene refers to polyethylene having a density of 0.942 or more. It is known that high-density polyethylene has a larger swelling change due to fuel (gasoline) than polyacetal. For this reason, the opening 4a tends to increase in diameter as the tank body 2 swells. On the other hand, since the mouth member 7 and the lid member 10 are relatively difficult to swell, A force that creates a gap in the radial direction acts between them. However, at this time, since the diameter of the projecting portion 3 is restricted by the hanging portion 10d, the tightening allowance of the seal member 9 is tightened, and the projecting portion 3 is slightly deformed in the inner diameter direction by the reaction force. The expansion is offset. That is, in the present embodiment, the mouth member 7 and the lid member 10 are made of the same material having a small swelling rate due to fuel, and the protruding portion 3 made of a material having a large swelling rate is disposed between them in the radial direction. By doing so, the deterioration of seal performance over time is reduced.

Further, when the linear expansion coefficient of high-density polyethylene is αp and the linear expansion coefficient of polyacetal is αa,
αp = 12-14 × 10 ⁻⁵ / ° C.
αa = 8.1 to 8.5 × 10 ⁻⁵ / ° C.
And their linear expansion coefficients are close to each other. Therefore, even if the environmental temperature at which the fuel tank 1 is placed changes, the opening member 7 and the protruding portion 3 that are in close contact with each other in the radial direction in the opening 4a are not separated. Further, since the mouth member 7 and the lid member 10 are made of the same material, it is not necessary to consider the difference in linear expansion coefficient, and the protrusion supported by the mouth member 7 from the inside even when the environmental temperature changes. The distance between the first seal surface 3b of the portion 3 and the second seal surface 10i of the lid member 10 is not substantially changed, and good sealing performance is always ensured.

  FIG. 6A is an enlarged view of a main part showing a first modification of the seal structure, and FIG. 6B is an enlarged view of a main part showing a second modification of the seal structure. In the first modification, the outer surface of the tank body 2 is directly used as a support surface for supporting the seal member 9. In the first modification, the gap formed between the lower end of the drooping portion 10d and the tank body 2 is made small so that the sealing member 9 is securely sandwiched between the first sealing surface 3b and the second sealing surface 10i. It is desirable to do.

  In the second modification, a ring-shaped seal support member 9a is fitted into the protruding portion 3, and the upper surface of the seal support member 9a is used as a support surface. Also in the second modification, the upper surfaces of the first seal surface 3b, the second seal surface 10i, and the seal support member 9a form an annular groove as a whole, and the seal member 9 is accommodated therein.

  FIGS. 7A and 7B are explanatory diagrams for explaining the manufacturing process of the fuel tank 1, and FIGS. 8A to 8C are explanations showing positions where the parison 20 is cut in the manufacturing process of the fuel tank 1. FIG. Hereinafter, the manufacturing process of the fuel tank 1 in the present embodiment, particularly the process of forming the opening 4a (see FIG. 2) of the fuel tank 1 will be described in detail with reference to FIGS.

  The fuel tank 1 (the tank body 2 and the protruding portion 3) is molded using a known blow molding technique. That is, the fuel tank 1 is obtained by melting high-density polyethylene, which is a resin material constituting the tank body 2 and the projecting portion 3, sandwiching the pipe-shaped parison 20 with a molding die 21 and blowing air into the molding die 21. Is formed. Prior to blow molding, the bracket 6 (see FIG. 2) is arranged inside the pipe-shaped parison 20. Normally, the parison 20 is pushed downward from above to maintain the pipe shape, but FIG. 7 shows a state in which the parison 20 is rotated 90 degrees (in the description, it follows the direction shown in the drawing). Further, as described above, the mouth member 7 is supported from below by the bracket 6 or the jig, but the description thereof is omitted in FIG.

  In the manufacturing process of the fuel tank 1, first, as shown in FIG. 7A, the parison 20 is disposed between the mold 21 and the mouth member 7. Here, the mold 21 has a mold base surface 21a and a mold protrusion 21b protruding downward from the mold base surface 21a, and a mold inclined surface 21c is formed on the outer periphery of the mold protrusion 21b. ing. Further, the mold 21 has a mold shoulder surface 21d formed one step lower than the mold base surface 21a, and a tank facing surface 21e formed one step lower than the mold shoulder surface 21d.

  On the other hand, the sharpened portion 7f and the inclined surface 7e are extended in the circumferential direction at the upper end of the mouth member 7 disposed to face the mold 21 as described above. The inclined surface 7e has a tapered shape in which the inner diameter of the mouth member 7 (first tubular portion 7a) increases toward the opening end 4 (see FIG. 5B). With such a shape, when the mold 21 is pressed against the mouth member 7, the mold protrusion 21 b easily enters the mouth member 7 along the tapered shape and is centered. Here, the thickness of the mouth member 7 in the sharpened portion 7f is about L6 = 1 mm, and the thickness of the first cylindrical portion 7a excluding the sharpened portion 7f and the inclined surface 7e is about L8 = 4 mm. That is, the sharpened portion 7f is not a line but a surface having a certain width. Further, the inclination angle of the mold inclined surface 21c and the inclination angle of the inclined surface 7e of the mouth member 7 are substantially the same (θ) with respect to the vertical direction.

Although the inclination angle θ is not particularly limited, as will be described later, the width (L7) of the inclined surface 7e of the mouth member 7 affects workability during post-processing (resection of the parison 20). It is desirable to ensure about L7 = 5-10 mm from the inner edge. Here, the thickness of the first cylindrical portion 7a of the mouth member 7 (excluding the sharpened portion 7f and the inclined surface 7e) is about L8 = 4 mm, and the thickened portion 7f is L6 = 1 mm. When the width of the inclined surface 7e is L7 = 5 mm, the inclination angle θ is
θ = sin ⁻¹ ((L8−L6) / L7) (Equation 1)
= Sin ⁻¹ (3/5) = 36.9 (deg)
When L7 = 10 mm, the inclination angle θ is
= Sin ^-1 (3/10) = 17.5 (deg)
It becomes. In other words, the inclination angle θ may be set to about θ = 17.5-36.9 (deg).

Here, if the range occupied by the inclined surface 7e in the axial direction is L9, L9 is
L9 = L7 × cos (θ) (Formula 2)
It becomes. That is,
When the width of the inclined surface 7e is L7 = 5 mm and the inclination angle θ = 17.5 (deg),
When L9 = 5 × cos (17.5 (deg)) = 4.7 mm, when the width of the inclined surface 7e is L7 = 10 mm and the inclination angle θ = 17.5 (deg), L9 = 9. When 5 mm, the width of the inclined surface 7 e is L7 = 5 mm, and the inclination angle θ = 36.9 (deg), L9 = 4.0 mm, the width of the inclined surface 7 e is L7 = 10 mm, and the inclination angle θ = 36.9. When (deg) is set, L9 = 8.0 mm, and the inclined surface 7e occupies a range of 4 mm to 9.5 mm downward from the tip of the sharpened portion 7f.

  In the present embodiment, the mouth member 7 is used for relative positioning with the mold 21 when the fuel tank 1 is molded. When the mold 21 is pressed against the mouth member 7 in the direction D3 with the parison 20 interposed therebetween, as shown in FIG. 7B, the mold protrusion 21b is formed on the first tubular portion 7a of the mouth member 7, More strictly, it is guided by the inclined surface 7e, and as a result, the mold 21 and the mouth member 7 are centered (aligned). As described above, in the axial direction, the inclined surface 7e is provided over a predetermined range (4 mm to 9.5 mm), and by providing a guide length of this degree, the mouth member 7 and the mold protrusion 21b are formed. Smooth centering. Prior to molding, a release agent may be applied to the inner peripheral surface of the first cylindrical portion 7a excluding the sharpened portion 7f and the inclined surface 7e. This prevents the parison 20 from adhering to the inner peripheral surface of the mouth member 7.

  In the aligned region, the protruding portion 3 is formed by the parison 20 sandwiched (filled) between the mold 21 and the mouth member 7. Further, a part of the melted parison 20 enters the reverse tapered groove portion 7c of the stay 7b provided on the side surface of the mouth member 7, and the mouth member 7 fills the stay 7b by filling the groove portion 7c with the parison 20. Through the tank body 2. The thickness of the stay 7b may be about 4 to 5 mm, and if the depth of the groove 7c is about 2 to 3 mm from the upper surface of the stay 7b, the strength of the stay 7b itself and the attachment to the tank body 2 will be described. The strength can be sufficient.

  Here, by adjusting the stroke when pressing the mold 21 against the parison 20, the mold base surface 21a and the sharpened portion 7f of the mouth member 7 can be brought into contact with each other, and the parison 20 can be cut off by the sharpened portion 7f. . Further, by adjusting the stroke, it is between the mold base surface 21a and the sharpened portion 7f, and between the mold inclined surface 21c and the inclined surface 7e of the mouth member 7 which are substantially parallel (hereinafter, “molding gap 21f”). The thickness of the parison 20 sandwiched between the layers can be reduced to 1 mm or less (preferably 0.5 mm or less).

  The thickness of the resin remaining in the molding gap 21f immediately after molding, that is, the thickness of the protruding portion 3 on the sharpened portion 7f or the inclined surface 7e is thinner than other portions of the fuel tank 1 (specifically, The tank body 2 has a thickness of about 6 mm, and the protruding portion 3 has an L4 of about 2 mm above the annular shoulder surface 3a as described above (see FIG. 5B)). In the present embodiment, the sharpened portion 7f is configured as a surface having a certain width, but the sharpened portion 7f and the inclined surface 7e substantially constitute a knife edge extending in the circumferential direction and correspond to the forming gap 21f. The parison 20 is cut off in the molding process of the tank body 2 or thinned so that it can be easily cut off.

  Now, in blow molding, the mold 21 comes into contact with the outer surface of the molded product, so that the outer surface of the tank main body 2 and the protruding portion 3 can have significantly higher dimensional accuracy than the inner surface side. Moreover, since the mold 21 is centered by the mouth member 7 during molding, the outer shape of the protruding portion 3, that is, the thickness of the protruding portion 3 above the annular shoulder surface 3a (that is, the thickness of the first seal surface 3b). Thickness: L4 = 2 mm shown in FIG. 5B, the thickness of the protrusion 3 below the annular shoulder surface 3a (L3 = 4 mm shown in FIG. 5B), and the width of the annular shoulder surface 3a (L3) −L4 = 2 mm) can be managed with high accuracy. As a result, the coaxiality between the first seal surface 3b configured above the annular shoulder surface 3a and the mouth member 7 (first cylindrical portion 7a) is adjusted with high accuracy, and reliable sealing performance is expressed. Is possible.

  By separating the mold 21 from the state shown in FIG. 7B, the protruding portion 3 and the tank body 2 to which the mouth member 7 is fixed are obtained. However, immediately after the mold 21 is separated, since the parison 20 remains in the opening 4a of the protruding portion 3, a step of cutting the parison 20 covering the opening 4a (parison cutting step) is provided. As described above, the parison 20 is thinned to 1 mm or less in the molding gap 21f. By cutting the thinned portion, the resin remaining inside the opening 4a (opening end 4) can be easily cut out. Here, the Rockwell hardness of the high density polyethylene constituting the tank body 2 is D60 to 70, and is made of a material having a hardness smaller than that of the polyacetal (Rockwell hardness is R120) constituting the mouth member 7. In the above-described prior art, a large apparatus such as a cutting device is required to form the opening in the tank body 2, but in this embodiment, the operator uses an extra parison using a general-purpose tool such as a cutter knife. 20 can be excised easily.

  In the parison cutting process for the opening 4a, the parison 20 may be cut at the sharpened portion 7f as shown in FIG. 8A, and the sharpened portion 7f and the inclined surface 7e are cut as shown in FIG. 8B. You may cut | disconnect in a boundary and may cut | disconnect in the inclined surface 7e as shown in FIG.8 (c). Moreover, the aspect of Fig.8 (a)-(c) may be mixed in the circumferential direction of the opening part 4a. That is, in this embodiment, after the parison 20 is cut off in the opening 4a of the tank body 2 to which the mouth member 7 is attached, the protruding portion 3 is a part of the sharpened portion 7f or the sharpened portion 7f and the inclined surface 7e. A part of the protrusion 3 is covered, and the edge of the protrusion 3 is located on the sharpened portion 7f or the inclined surface 7e in the inner diameter direction.

  As a result, the surface of the mouth member 7 is protected on the side of the opening end 4, and a situation in which the mouth member 7 is damaged when the lid member 10 is attached to the protruding portion 3 or the like is prevented. In the parison excision step, as a result of excising the parison 20, some burrs may protrude upward. As described above, since the gap 13 of about L5 = 1 mm is provided between the opening end 4 and the lower surface of the lid member 10 (see FIG. 5B), the protruding burr is the gap 13. This is because the mounting of the lid member 10 is not affected at all.

  As described above, the method of manufacturing the fuel tank 1 according to the present embodiment includes the step of interposing the parison 20 between the mold 21 and the mouth member 7 used for molding the tank body 2 and the protruding portion 3, and the mouth member 7. The step of aligning the mold 21 and the mouth member 7 using the inclined surface 7e provided on the surface, forming the protruding portion 3 by sandwiching the parison 20 in the aligned region, and the step of performing blow molding And a step of cutting the parison 20 at the sharpened portion 7f or the inclined surface 7e of the mouth member 7 with respect to the molded fuel tank 1 (the tank body 2 and the protruding portion 3).

  9A is a cross-sectional view showing a state in which the lid member 10 is mounted on the protruding portion 3, and FIG. 9B is a main cross-sectional view showing an engaging portion between the engaging claw 7d and the engaged portion 10c. FIG. 10A is an explanatory view showing an engaging claw 7d provided on the inner peripheral surface of the mouth member 7, and FIG. 10B is an explanatory view showing a state in which the mouth member 7 and the lid member 10 are engaged. (C) is explanatory drawing which shows the state by which engagement with the mouth member 7 and the cover member 10 was cancelled | released. FIG. 9 shows an IX-IX cross section in FIG.

  Thereafter, FIGS. 9 and 10 are used in combination with FIGS. 2 and 3, the configuration of the engaging claw 7 d and the engaged portion 10 c, the process of attaching the lid member 10 to the protruding portion 3, and the lid member 10 as the protruding portion 3. The process of removing from will be described. In the process of attaching the lid member 10 to the projecting portion 3, as described above, the reference marker 2a formed on the tank body 2 and the positioning marker 10h formed on the lid member 10 (see FIG. 1). , The lid member 10 and the mouth member 7 are positioned in the circumferential direction.

  9A, 9B, and 10A, the inner peripheral surface 7i of the first tubular portion 7a of the mouth member 7 is directed toward the second tubular portion 10a of the lid member 10. A plurality of engaging claws 7d protruding in the circumferential direction are provided. The lower surface of the engaging claw 7d forms a parallel surface 7dd parallel to the inner diameter direction of the first cylindrical portion 7a, and the engaging claw 7d protrudes from the back surface of the parallel surface 7dd, that is, the upper surface of the engaging claw 7d. A second inclined surface 7dc is formed so that the thickness between the parallel surface 7dd and the parallel surface 7dd gradually decreases toward the inner diameter direction (here, the inner diameter decreases toward the lower side). That is, the engaging claw 7d has a wedge shape whose inner diameter direction is tapered in a sectional view.

  As shown in FIG. 10 (b) or FIG. 3 (b), the lid member 10 includes a first notch 10f extending from the lower edge (tip) of the second cylindrical portion 10a to the center in the axial direction in the circumferential direction. A second cutout portion 10g is extended, and a movable piece 10m is defined between the cutout portions. A plurality of first cutout portions 10f and second cutout portions 10g are provided in the circumferential direction. On the other hand, the notch does not extend above the center of the second cylindrical portion 10a in the axial direction, and this range constitutes a flat circumferential surface region 10n. By providing the circumferential surface region 10n, the shaft shake of both is prevented when the second tubular portion 10a is inserted into the first tubular portion 7a. Further, the open end of the movable piece 10m can be displaced in the radial direction (refer to the direction D1 in FIG. 3B) with respect to the circumferential surface region 10n by providing the notch portions on both sides. Yes. The engaged portion 10c is formed so as to penetrate the front and back of the movable piece 10m.

  Further, as shown in detail in FIG. 9B, a lower end inclined surface 10k is formed at the lower end of the second cylindrical portion 10a so that the outer diameter becomes smaller (that is, becomes thinner) toward the lower side. Is formed. The lower end inclined surface 10k is also formed at the lower end of the movable piece 10m.

  When the second cylindrical portion 10a of the lid member 10 is inserted into the first cylindrical portion 7a of the mouth member 7, first, the lower end of the movable piece 10m of the second cylindrical portion 10a is the inner peripheral surface of the first cylindrical portion 7a. Abuts against the engaging claw 7d projecting from. Then, the lower end inclined surface 10k of the movable piece 10m contacting the upper surface (second inclined surface 7dc) of the engaging claw 7d receives a force in the inner diameter direction along the second inclined surface 7dc, and the entire movable piece 10m has an inner diameter. Elastically deforms in the direction (see direction D1 in FIG. 3B). That is, the lid member 10 is pushed into the mouth member 7 while the movable piece 10m is pushed in the inner diameter direction by the engaging claw 7d.

  Further, when the lid member 10 is pushed in, the engaged portion 10c of the lid member 10 eventually reaches a position facing the engagement claw 7d, and at this point, the engagement claw 7d is a through-hole engaged portion 10c. (Hereinafter, a position where the engaged portion 10c faces the engaging claw 7d is referred to as an “engaging position”). At the same time when the engaging claw 7d enters the engaged portion 10c, the movable piece 10m is rapidly displaced in the outer diameter direction by its own elastic force and collides with the first cylindrical portion 7a of the mouth member 7. The operator can recognize that the lid member 10 and the mouth member 7 are engaged by the contact sound at this time. As described above, in this embodiment, the lid member 10 is engaged with the mouth member 7 by so-called “snap fit” that is fitted using the elasticity of the material.

  In addition, by making the opening width of the engaged portion 10c in the circumferential direction larger than the length of the engaging claw 7d, the positional accuracy of the lid member 10 and the mouth member 7 in the circumferential direction is relaxed, and the operator With reference to the above-described reference marker 2a and positioning marker 10h (both see FIG. 1), the lid member 10 is simply pushed into the mouth member 7 in the axial direction (that is, without rotating the lid member 10). The member 10 can be attached to the protruding portion 3.

  As described above, when the lid member 10 is mounted on the protruding portion 3, the lid member 10 to which the fuel pump unit 15 is fixed is urged upward by the urging member 16, so that the lid member 10 is engaged. The portion 10c is in contact with the parallel surface 7dd formed on the lower surface of the engaging claw 7d in the axial direction and is prevented from coming off, so that the lid member 10 is securely attached to the protruding portion 3 of the fuel tank 1 (that is, there is no play) ) Fixed.

  Now, as shown in FIG. 10 (a), the engaging claw 7d extends from the protruding end 7da projecting on the inner peripheral surface 7i of the first cylindrical portion 7a to the inner peripheral surface 7i of the first cylindrical portion 7a. The first inclined surface 7db is inclined with respect to the circumferential direction (the protruding height gradually decreases in the circumferential direction). Further, on the opposite side to the first inclined surface 7db across the protruding end 7da in the circumferential direction, it is formed substantially perpendicular to both the inner peripheral surface 7i and the parallel surface 7dd (see FIG. 9B). The vertical surface 7de is provided.

  In a state in which the lid member 10 is mounted on the protruding portion 3 (see FIG. 9A), as shown in FIG. 10B, the protruding end 7da, the first inclined surface 7db, and the vertical surface 7de are all of the lid member 10. It has entered the engaged portion 10c formed on the movable piece 10m.

  Here, among the edges of the engaged portion 10c configured as a through hole (opening), the first opening edge 10ca facing the parallel surface 7dd (see FIG. 9B) of the first tubular portion 7a, and The second opening edge 10cb facing the vertical surface 7de is a surface orthogonal to the main surface of the movable piece 10m in the thickness direction, the first opening edge 10ca is a parallel surface 7dd, and the second opening edge 10cb is Surface contact with the vertical surface 7de. Accordingly, when the lid member 10 is rotated in the direction D4, the second opening edge 10cb of the engaged portion 10c is locked to the vertical surface 7de of the engagement claw 7d, and the rotation of the lid member 10 is restricted. . Further, when the lid member 10 is to be pulled out in the axial direction, the first opening edge 10ca of the engaged portion 10c is locked to the parallel surface 7dd of the engaging claw 7d, and the removal of the lid member 10 is restricted. .

  The angles of inclination of the engaging claw 7d with respect to the main surface of the movable piece 10m of the third opening edge 10cc facing the first inclined surface 7db and the fourth opening edge 10cd facing the second inclined surface 7dc are not particularly limited. However, about the 3rd opening edge 10cc, you may comprise by the inclined surface that opening becomes large in the outer-diameter direction of the cover member 10. FIG. When the third opening edge 10cc is configured by an inclined surface, the first inclined surface 7db of the engaging claw 7d facing the third opening edge 10cc may be a vertical surface similar to the vertical surface 7de. In other words, the inclined surface with respect to the circumferential direction (here, the first inclined surface 7db) may be provided on either side of the engaging claw 7d and the engaged portion 10c. However, when the inclined surface is provided in the engaged portion 10c, the length that the engaging claw 7d protrudes in the inner diameter direction needs to be shorter than the thickness of the movable piece 10m.

  As shown in the drawing, the first notch 10f and the second notch 10g that define the movable piece 10m have different notch widths in the circumferential direction. That is, the first notch 10f formed close to the first inclined surface 7db has a larger notch width in the circumferential direction than the second notch 10g formed close to the vertical surface 7de. ing. Further, the notch width of the first notch portion 10f is larger than the circumferential width of the protruding end 7da, and the notch width of the second notch portion 10g is smaller than the circumferential width of the protruding end 7da. ing.

  Hereinafter, the process of removing the lid member 10 from the protrusion 3 will be described with reference to FIGS. When the operator rotates the lid member in the direction D2 from the state in which the lid member 10 is mounted on the protruding portion 3 (that is, the state shown in FIG. 10B), the movable piece 10m of the lid member 10 is engaged with the engaging claw 7d. The movable piece 10m gradually rides on the formed first inclined surface 7db and is displaced in the inner diameter direction (direction D1 (see FIG. 3B)). Thus, the engaged portion 10c is engaged with the engaging claw 7d. Further, when the lid member 10 is rotated in the direction D2, as shown in FIG.10 (c), the protruding end 7da of the engaging claw 7d reaches a position facing the first notch 10f. When the vertical surface 7de of the engaging claw 7d reaches the first notch 10f, the movable piece 10m is displaced in the outer diameter direction by its own elastic force, and at this time, a contact noise is generated and the operator protrudes. It can be recognized that the end 7da has entered the first notch 10f.

  In the state shown in FIG. 10 (c), the engaging claw 7d faces the first notch 10f, and the first notch 10f is notched downward, so that the lid member 10 is engaged. And the position where the first notch 10f faces the protruding end 7da of the engaging claw 7d is referred to as a “removal position”. Here, the first notch 10 f functions as a guide when the lid member 10 is removed. Even if the lid member 10 is not rotated to the removal position, the engagement itself is released when the engaged portion 10c is disengaged from the engagement claw 7d, so that the lid member 10 can be removed. is there. However, in this state, the amount of deformation of the movable piece 10m is large, and a load is applied to the movable piece 10m during removal. Therefore, it is desirable to provide a removal position as in this embodiment.

  Now, with the lid member 10 mounted on the protruding portion 3, the rotation of the lid member 10 in the direction D2 is not particularly restricted, but substantially the movable piece 10m rides on the first inclined surface 7db. The lid member 10 is pushed back to the engagement position (ie, in the direction D4) by the elasticity of the movable piece 10m, and the lid member 10 is prevented from easily rotating to the removal position. According to this configuration, for example, if the movable piece 10m is made thicker and the elastic coefficient is increased, the lid member 10 is difficult to be detached from the engagement position. Of course, when it is assumed that the fuel tank 1 is placed in a very vibrant environment, for example, an anti-rotation restricting piece is formed on the outer peripheral surface of the flange portion 10b (see FIG. 3B, etc.). In addition, this may be prevented by rotating the outer surface of the tank body 2 with screws or the like.

  Now, the first notch portion 10f is formed to have such a width as to allow entry of “a part of the engaging claw 7d (the side protruding in the inner diameter direction of the engaging claw 7d)” including the protruding end 7da in the circumferential direction. However, “the whole engaging claw 7d” does not enter the first notch 10f. Therefore, when in the removal position, the fixed piece 10r sandwiched between the two movable pieces 10m in the circumferential direction of the second cylindrical portion 10a rides on the first inclined surface 7db of the engaging claw 7d and is urged in the inner diameter direction. (As shown in FIG. 10 (c), a part of the fixed piece 10r is slightly deformed), and as a result, the lid member 10 cannot be easily removed from the mouth member 7 (relatively loose binding force is generated). State). On the other hand, since the cover member 10 is urged upward by the urging member 16 as described above, the urging force and the restraining force by the urging member 16 (see FIG. 9A) balance and are moderate. The lid member 10 can be removed with a sufficient force.

  Of course, you may comprise so that the width | variety of the 1st notch part 10f and the width | variety of the engaging claw 7d may correspond substantially in the circumferential direction. In this case, the force required for removing the lid member 10 is adjusted by slightly reducing the biasing force by the biasing member 16.

  Thus, according to the present embodiment, the lid member 10 is configured to be detachable from the protruding portion 3 via the mouth member 7, and a simple operation such as inserting the lid member 10 in the axial direction with respect to the protruding portion 3. Thus, the lid member 10 can be attached to the protruding portion 3, and when the lid member 10 is attached, the lid member 10 is removed from the protruding portion 3 by a simple operation such as rotating the lid member 10 in the circumferential direction. be able to. This makes it possible to easily replace functional components such as the fuel pump unit 15 (see FIG. 2) fixed to the lid member 10.

  As described above, the engaged portion 10c is formed with a through-hole penetrating the front and back of the movable piece 10m, but instead of the through-hole, from the outer peripheral surface of the movable piece 10m (see FIG. 3B). A non-penetrating recess that is recessed may be provided, and this may be used as the engaged portion 10c.

  FIG. 11 is a cross-sectional view showing a modification of the configuration in which the lid member 10 and the mouth member 7 are engaged. In the example described above, the engaging claw 7d is provided in the mouth member 7, while the engaged portion 10c is formed in the lid member 10. In the modified example, as shown in the drawing, a through-hole constituting the engaged portion 7j is formed in the first cylindrical portion 7a of the mouth member 7, while the lid member 10 has the second cylindrical portion 10a. An engaging claw 10p that protrudes from the outer peripheral surface is provided. That is, in the configuration shown in the modified example, a through hole is formed in a portion where the engaging claw 7d is provided in FIG. 10A to form an engaged portion 7j, and the engaged portion 10c in FIG. 10B. The engaging claw 10p which protrudes in an outer diameter direction is provided in the part in which is formed.

  The configuration of the engaging claw 10p and the specific configuration of the engaged portion 7j are basically the same as those described with reference to FIGS. 10 (a) and 10 (b). However, the modification is different in that the second inclined surface 10pa is formed in the lower part of the engaging claw 10p and the parallel surface 10pb is formed in the upper part. Also in the modified example, the lid member 10 can be easily attached to and detached from the protruding portion 3. By inserting the lid member 10 into the protruding portion 3 in the axial direction, it is easily attached by snap fit, and in the attached state, the lid member 10 can be removed by rotating the lid member 10 in the circumferential direction. Is possible. In the modification, a recessed portion that is recessed from the inner peripheral surface of the first tubular portion 7a of the mouth member 7 may be provided instead of the through hole, and this may be used as the engaged portion 7j.

  As mentioned above, although this invention was demonstrated based on specific embodiment, this embodiment is an illustration to the last and this invention is not limited by this embodiment. For example, the tank main body 2 and the protruding portion 3 have been described as being made of a single-layer high-density polyethylene, but this may be a multilayer structure. The mouth member 7 may be made of nylon instead of polyacetal.

  Further, in the present embodiment, the functional component such as the fuel pump unit 15 is attached to the lid member 10, but the presence or absence of the functional component does not affect the effect of the present invention. That is, the lid member 10 may not be provided with a functional component. However, in this embodiment, the functional component has an action of urging the lid member 10 upward and fixing it in the axial direction. Therefore, in the configuration in which the functional component is not provided on the lid member 10, an alternative attachment is provided. It is desirable to provide a biasing means. However, even if the biasing means is not provided, the shaft seal structure exhibits sufficient sealing performance even when the lid member 10 is displaced in the vertical direction, as is apparent from the configuration shown in FIG.

  Also, the configuration of the fuel tank 1 according to the present invention, the sealing structure in the protruding portion 3 of the fuel tank 1, the configuration in which the resin is cut off at the edge of the mouth member 7 provided in the protruding portion 3, and the lid member The configuration in which 10 can be easily attached and detached is not limited to the fuel tank 1 mounted on a passenger car, and can be applied to any tank that stores liquid in a liquid-tight manner or gas in an air-tight manner.

  Further, the seal structure is not based on a configuration in which the lid member 10 is attached to the mouth member 7 by snap fitting. The mouth member 7 and the lid member 10 are formed on the outer peripheral surface of the protruding portion 3, for example. The fitting may be achieved by a screw portion.

  It should be noted that all of the constituent elements shown in the above embodiments are not necessarily essential, and can be appropriately selected as long as they do not depart from the scope of the present invention.

  The fuel tank seal structure according to the present invention is capable of oil-tightly closing the fuel tank while reducing the cost with a simple configuration. It can be suitably used.

1 Fuel tank 2 Tank body (fuel tank body)
3 Protruding part 3a Annular shoulder surface (support surface)
3b First seal surface (outer peripheral surface)
4 Open end 4a Opening portion 7 Opening member 7a First tubular portion 7d Engaging claw 7da Protruding end 7db First inclined surface 7dc Second inclined surface 7dd Parallel surface 7de Vertical surface 7e Inclined surface 7f Sharp portion 9 Seal member 10 Lid member 10a 2nd cylindrical part 10b Flange part 10c Engagement part 10d Hanging part 10f 1st notch part 10g 2nd notch part 10i 2nd sealing surface (inner peripheral surface)
10m Movable piece 20 Parison 20a Hollow part 21 Mold 21f Molding gap

Claims (6)

A protrusion formed integrally with the resin fuel tank body and projecting from the fuel tank body;
A mouth member fixed along the inner peripheral surface of the protruding portion and having a first tubular portion;
A second cylindrical part inserted into the mouth member along the inner peripheral surface of the first cylindrical part, covers the upper end of the second cylindrical part, and extends to the outer peripheral side of the second cylindrical part. A lid member comprising a flange portion provided and a cylindrical hanging portion that hangs downward from an outer peripheral edge of the flange portion;
An annular seal member mounted between the protrusion and the lid member;
The projecting portion or the fuel tank body is provided with a support surface that supports the seal member in the insertion direction of the lid member,
In a state where the lid member is attached to the mouth member, the seal member supported by the support surface is sandwiched between an outer peripheral surface of the projecting portion and an inner peripheral surface of the hanging portion. A fuel tank seal structure.   2. The fuel tank according to claim 1, wherein the support surface is an annular shoulder surface formed on the protrusion between the protrusion and the opening end of the mouth member and the fuel tank main body. Seal structure.   The fuel tank seal structure according to claim 1, wherein the support surface is provided over the entire circumference of the protrusion.   The second cylindrical portion is provided with a plurality of engaged portions formed by through holes or concave portions recessed from the outer peripheral surface in the circumferential direction, and the inner peripheral surface of the first cylindrical portion is provided with the engaged portion. A plurality of engaging claws projecting in the inner diameter direction corresponding to the portion are provided, and the engaging claws and the engaged portion are configured to engage in the insertion direction of the second tubular portion. The fuel tank seal structure according to any one of claims 1 to 3, wherein the fuel tank seal structure is provided.   5. The fuel tank seal structure according to claim 4, wherein a gap is formed between an upper end of the protruding portion and the flange portion in a state in which the lid member is attached to the mouth member.   6. The fuel tank seal structure according to claim 1, wherein the mouth member is made of a resin material having a hardness higher than that of the resin material constituting the protruding portion. .

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