JP5457910B2 - Resin fuel tank - Google Patents

Description

  The present invention relates to a resin fuel tank formed by free blow molding or blow molding and having a hollow shape in which an upper collar part and a lower collar part are combined.

  In recent years, the weight of vehicles has been reduced for the purpose of reducing fuel consumption. As one of such weight reduction methods, the fuel tank has been changed from a metal one to a resin one. As an example of such a resin fuel tank, there is one described in Patent Document 1 whose source is shown below.

  The blow molded resin container described in Patent Document 1 is used as a gasoline tank for automobiles, and is formed in a rectangular box shape by blow molding using a resin.

Japanese Utility Model Publication No. 57-159614

  In general, in a container that stores this type of fuel, stress due to internal pressure tends to concentrate on the corner portion between the tank formation surfaces (hereinafter referred to as “corner portion”). The same applies to the blow molded resin container described in Patent Document 1. For this reason, in order to ensure the intensity | strength of the site | part which a stress tends to concentrate (in the blow molding resin container of patent document 1, it is a box-shaped corner | angular part), it is necessary to make the plate | board thickness of the said part thick. is there. However, if blow molding is performed so that the plate thickness of the corner portion is increased, the plate thickness of other portions (portions other than the corner portion) becomes thicker than necessary, and the amount of resin used increases. For this reason, the weight as a fuel tank becomes heavy and it becomes a factor of the cost increase as a product.

  In view of the above problems, an object of the present invention is to provide a resin fuel tank that can be reduced in weight without increasing costs.

Features of the resin fuel tank according to a first invention for achieving the above Symbol purpose, the predetermined parison tubular axially partitioned by length and sealed, the air into the parison of the tubular by free blowing A mounting portion that is molded by blow molding in which air is blown into a tubular parison disposed in the molding die using a molding die having a shape that is blown and inflated , and can be attached to a vehicle. The mounting portion is formed in a virtual quadrangle surrounding the resin fuel tank in a top view of the molded resin fuel tank, and the mounting portion includes a part of the parison as a first mold. It exists in the point formed by pinching with a 2nd shaping | molding die .

According to the characteristics of the first aspect of the invention, the resin fuel tank having a shape in which the tubular parison is inflated using free blow molding can be formed using the molding die (mold). Since the resin fuel tank having such a shape can achieve a uniform thickness over the entire surface of the resin fuel tank, the fuel stored in the formed resin fuel tank volatilizes and the pressure is increased. Even when the pressure increases, the increased pressure can be evenly applied to the inner wall of the resin fuel tank. For this reason, there is little concentration of stress partially. Accordingly, the overall plate thickness can be reduced by that amount and the amount of resin used can be reduced, so that the cost and weight of the resin fuel tank can be reduced. Further, according to this configuration, it is possible to mold the mounting portion while maintaining the resin fuel tank in a bulging state with a uniform thickness. For this reason, since uneven thickness due to the mounting portion does not occur in the resin fuel tank, it is not necessary to increase the thickness of the resin fuel tank in order to form the mounting portion. Therefore, it is possible to form the attachment portion while realizing a reduction in cost and weight of the resin fuel tank.

A feature of the resin fuel tank according to the second invention for achieving the above object is a hollow shape formed by blow molding, in which an upper collar part and a lower collar part are combined. The inner surface of the cross section in the second direction orthogonal to the first direction at the center of the lower collar part and the upper collar part in the first direction along the cylindrical central part of the lower collar part is the upper collar part and A pair of first arc portions connected to the connecting portion of the lower collar portion and extending to the center side of the upper collar portion and the lower collar portion and having a predetermined radius, and having a radius larger than the predetermined radius And a second arc portion connected across the pair of first arc portions, and in the first direction at the center of the upper collar portion and the lower collar portion in the second direction. The inner surface of the cross-section is connected to the connection part of the upper collar part and the lower collar part, and the upper collar part and A third arc portion of the pair to be extended toward the center of the serial lower bowl portion lies in that is formed with a, a connecting portion connected the pair of third over the arcuate portion.

According to the configuration of the second invention, when the fuel stored in the resin fuel tank volatilizes and the pressure increases, the increased pressure can be uniformly applied to the inner wall of the resin fuel tank. Stress is less concentrated. For this reason, it is possible to reduce the overall plate thickness accordingly. Therefore, since the amount of resin used can be reduced, the cost and weight of the resin fuel tank can be reduced.

A feature of the resin fuel tank according to the third invention resides in that an opening having a depression around it is formed at the center of the upper collar.

According to the configuration of the third aspect of the invention, the recess functions as a reinforcing rib for the upper collar, and the rigidity of the resin fuel tank can be further improved.

It is an upper perspective view of the resin fuel tank concerning a first embodiment. It is a top view of the resin fuel tank which concerns on 1st embodiment. It is a bottom view of the resin fuel tank concerning a first embodiment. It is a figure which shows the IV-IV sectional view of FIG. It is a figure which shows the VV line cross section of FIG. It is a figure which shows the VI-VI line cross section of FIG. It is a top view of a pyramid part. It is an upper perspective view of a pyramid part. It is a figure shown about the tubular parison which concerns on 2nd embodiment. It is a figure shown about the resin fuel tank which concerns on 2nd embodiment. It is a figure shown about the shaping | molding die used for shaping | molding of the resin fuel tank which concerns on 3rd embodiment. It is a figure shown about the resin fuel tank which concerns on 3rd embodiment. It is a figure which shows the pyramid part which concerns on other embodiment.

[First embodiment]
Hereinafter, embodiments of the present invention will be described. The resin fuel tank 100 according to the present invention is a container for storing fuel (for example, gasoline or light oil) supplied to an internal combustion engine of a vehicle. The resin fuel tank 100 is generally provided at a position that is not visible to the passengers of the vehicle (for example, under the rear seat). Such a resin fuel tank 100 is shown in FIGS.

  FIG. 1 is an upper perspective view of the resin fuel tank 100. 2 is a top view of the resin fuel tank 100, and FIG. 3 is a bottom view of the resin fuel tank 100. As shown in FIG. 4 is shown in FIG. 4, and the VV line cross section in FIG. 2 is shown in FIG. 5. As shown in FIGS. 1 to 5, the resin fuel tank 100 has a hollow shape in which an upper flange portion 51 and a lower flange portion 52 are combined. The upper collar portion 51 is a collar member on the side shown in FIG. 2, and the lower collar portion 52 is the collar member on the side shown in FIG. In the resin fuel tank 100, the upper flange portion 51 and the lower flange portion 52 are formed in a hollow shape having a space inside with the respective hook-shaped edge portions as connection portions Z (see FIGS. 4 and 5). In addition, the resin fuel tank 100 is formed in a horizontally long rectangular shape with a corner in plan view (see FIGS. 2 and 3). Of course, it is also possible to form it in the shape of a square with a rounded corner.

  The resin fuel tank 100 including the upper collar portion 51 and the lower collar portion 52 is molded by blow molding using resin. It is preferable that the resin used for the resin fuel tank 100 has a high mechanical strength and does not react with the fuel stored in the resin fuel tank 100. Blow molding is one of thermoplastic resin molding methods, and air pressure is used in the processing.

  In blow molding, a material called a parison is melted into a pipe and extruded into divided molds. After the mold is closed, air is blown into the parison through an injection nozzle. The parison is inflated by air pressure, pressed against the outer mold, cooled, and solidified into a hollow shape, so that the mold can be opened and the resin fuel tank 100 can be taken out. In the resin fuel tank 100, the upper collar portion 51 and the lower collar portion 52 described above are integrally formed so as not to be separated. Therefore, the above-described connection portion Z is a name for convenience of explanation, and does not indicate a portion in which the upper collar portion 51 and the lower collar portion 52 are separately formed and connected.

  Here, let the direction along the cylindrical center part 79 of the upper collar part 51 and the lower collar part 52 be a 1st direction. The central portion 79 is a central portion having a predetermined width as shown in FIG. 1 when the upper collar portion 51 and the lower collar portion 52 are viewed as a long cylindrical shape. The direction along the central portion 79 corresponds to the direction A shown in FIG. Therefore, in the following description, the first direction will be described with reference A. Further, a second direction to be described later will be described with reference B.

  The inner surface of the cross section in the second direction B perpendicular to the first direction A at the center of the upper collar portion 51 and the lower collar portion 52 in the first direction A is connected to the connection portion Z of the upper collar portion 51 and the lower collar portion 52. The pair of first arc portions 71 extending to the center side of the upper collar portion 51 and the lower collar portion 52 and having a predetermined radius r1, and the pair of first arcs having a radius R1 larger than the predetermined radius r1. And a second arc portion 72 connected across the arc portion 71. The second direction B is a direction orthogonal to the first direction A as shown in FIG. The cross section in the second direction B is a cross section in the central portion 79 of the upper collar portion 51 and the lower collar portion 52. A cross section in the second direction B of the upper collar portion 51 and the lower collar portion 52 is shown in FIG. The cross section shown in FIG. 4 corresponds to the cross section taken along the line IV-IV in FIG.

  The inner surface of the cross section is a surface along the inner wall in the cross sectional view of the resin fuel tank 100. As shown in FIG. 4, a supply port 31, a pump attachment port 32, and a bottom portion 33 are formed in the upper collar portion 51 and the lower collar portion 52. Moreover, the cross section of the position which remove | deviated from the pump attachment port 32 along the 1st direction A from the IV-IV line in FIG. 2 becomes like the dashed-dotted line as shown in FIG. If the radius of the first arc portion 71 is r1, the radius of the second arc portion 72 is formed with a radius R1 larger than r1. Thus, the resin fuel tank 100 is formed in a hot water tampo type (rugby ball type) cross-sectional shape in a cross-sectional view as shown in FIG.

  Here, when the length along the inner surface of the first arc portion 71 is β and the length along the inner surface of the second arc portion 72 is α, the first arc portion 71 and the second arc portion 72 have α> β It is formed to become. In particular, it is preferable to form β so that it is about ½ (about half) of α. Of course, it is naturally possible to form the first arc portion 71 and the second arc portion 72 so that α <β. Further, the portion denoted by the symbol γ corresponding to the inner surface of the connecting portion Z (the portion connecting the first arc portion 71 of the upper collar portion 51 and the first arc portion 72 of the lower collar portion 52) is the first arc portion. It is preferable to form with a radius smaller than the radius r1 of 71. In addition, it is preferable that the length of the portion indicated by γ is formed such that β> γ in the relationship with β described above. In particular, it is preferable to form so that γ is about ½ (about half) of β. Of course, it is of course possible to directly connect the two first arc portions 71 having the length β without forming the portion γ.

  The inner surface of the cross section in the first direction A at the center of the upper collar part 51 and the lower collar part 52 in the second direction B is connected to the connection portion Z of the upper collar part 51 and the lower collar part 52 to connect the upper collar part 51 and A pair of third arc portions 82 extending toward the center side of the lower collar portion 52 and a connection portion 81 connected across the pair of third arc portions 82 are formed. A cross section in the first direction A is shown in FIG. The cross section shown in FIG. 5 corresponds to the cross section taken along line VV in FIG.

  As shown in FIG. 5, the inner surface of the cross section of the upper collar portion 51 and the lower collar portion 52 in the first direction A has a pair extending from the connecting portion Z of the upper collar portion 51 and the lower collar portion 52 to the center side. The third arc portion 82 is formed. The third arc portion 82 is preferably formed with the same radius r1 as the first arc portion 71. In addition, a connection portion 81 is formed between the pair of third arc portions 82. The inner surface of the cross section is a shape along the inner wall in the cross sectional view of the resin fuel tank 100 as described above. As described above, the supply port 31, the pump mounting port 32, and the bottom 33 formed in the upper collar portion 51 and the lower collar portion 52 are shown in FIG. Moreover, the cross section of the position removed from the pump attachment port 32 along the 2nd direction B from the VV line in FIG. 2 becomes like the dashed-dotted line as shown in FIG. Thus, the resin fuel tank 100 is formed in a flat and thin shape in a side view as shown in FIG.

  The resin fuel tank 100 has an inner surface with a central cross section as described above. Therefore, even when the fuel in the resin fuel tank 100 is volatilized and the pressure becomes high, the pressure can be uniformly received, so that deformation and breakage of the resin fuel tank 100 can be prevented.

  Here, as described above, it is preferable that the first arc portion 71 and the third arc portion 82 are both formed with a radius r1. If it is set as such a structure, each applicable site | part of the upper collar part 51 and the lower collar part 52 will be formed similarly to a part of spherical body surface which makes a radius r1. Thereby, even when the fuel is volatilized in the resin fuel tank 100 and the pressure is increased, the pressure is uniformly applied, so that the effect of preventing deformation and breakage can be enhanced. Thus, this resin fuel tank 100 is formed in the hot water tampo shape as a whole.

  A fuel supply port 31 stored in the resin fuel tank 100 is formed on the upper surface of the resin fuel tank 100. In the present embodiment, the supply port 31 is illustrated as being formed at a position deviated from the center of the upper collar 51, but is not limited to this position. Naturally, the supply port 31 can be formed at another position by routing an oil supply pipe (not shown) connected to an oil supply port (not shown) of the vehicle. The supply port 31 is formed with a round hole, and an oil supply pipe is connected thereto.

  An opening 32 having a recess 41 around is formed in the central portion 79 of the upper collar portion 51. The opening 32 corresponds to a pump attachment port to which a pump (not shown) for sucking out fuel stored in the resin fuel tank 100 is attached. Therefore, in the following description, the opening 32 will be described as the pump attachment port 32. By providing the depression 41 around the pump attachment port 32, the strength of the portion where the pump attachment port 32 is formed can be increased. Note that, similarly to the supply port 31 described above, the pump mounting port 32 is not limited to the illustrated position. The pump attachment port 32 is formed by a round hole.

  A bottom portion 33 having a flat surface is formed on the lower surface of the resin fuel tank 100, that is, the connecting portion 81 of the lower collar portion 52 so that the arrangement posture can be maintained when the resin fuel tank 100 is arranged in a vehicle. The It is possible to maintain the resin fuel tank 100 in an intended posture by contacting the bottom portion 33 with a flat surface of the vehicle.

  The resin fuel tank 100 is provided with a plurality of mounting portions 21. FIG. 6 is an enlarged view (sectional view) of the mounting portion 21. As shown in FIG. 6, a through hole 22 is formed in the approximate center of the attachment portion 21. The resin fuel tank 100 can be fixed by fixing the through hole 22 and a vehicle holding unit (not shown) with a bolt. In addition, when this attachment part 21 is formed, the position of the knob part 23 is a predetermined jig (not shown) so that the plate thickness in the vicinity of the attachment part 21 of the upper collar part 51 and the lower collar part 52 is not thinned. In this way, the upper hook part 51 and the lower hook part 52 are formed so that the vicinity of the attachment part 21 is not pulled outward together with the attachment part 21. Thereby, the plate | board thickness of the vicinity part of the attaching part 21 of the upper collar part 51 and the lower collar part 52 is ensured.

  At least a part of the inner and outer surfaces of the upper collar portion 51 and the lower collar portion 52 of the resin fuel tank 100 are formed by connecting a plurality of pyramidal portions 77 each having a plurality of pyramidal surfaces 78. The pyramid portion 77 corresponds to a pyramid, and the pyramid surface 78 corresponds to a surface composed of a plurality of triangles included in the pyramid. Therefore, the pyramid portion 77 is formed in a diamond shape or a pyramid shape. In the present embodiment, the pyramid portion 77 is formed so as to protrude inward with respect to the resin fuel tank 100. A top view of such a pyramid portion 77 is shown in FIG. 7, and an upper perspective view of the pyramid portion 77 is shown in FIG. Note that the pyramid portion 77 shown in FIG. 8 is exaggerated in the height direction (vertical direction) for easy understanding of the description, and is not limited to that shown in FIG.

  As shown in FIGS. 7 and 8, at least one of the plurality of pyramid surfaces 78 made of a triangle is formed of an isosceles triangle. In particular, in the present embodiment, the pyramid portion 77 is described as a quadrangular pyramid having four isosceles triangles and a pyramid surface 78. Therefore, the plurality of pyramid surfaces 78 correspond to the four pyramid surfaces 78 constituting the quadrangular pyramid. The upper collar part 51 and the lower collar part 52 are at least partially formed with the pyramid surface 78 as an inner surface and an outer surface thereof.

  One of the lines connecting each vertex 76 of the bottom surface of the pyramid portion 77 and the top 80 of the pyramid portion 77 is the first direction A along the cylindrical central portion 79 of the upper collar portion 51 and the lower collar portion 52 or It is formed along a second direction B orthogonal to the first direction A. The cylindrical central portion 79 is formed with a predetermined width along the first direction A as shown in FIG. 1 when the upper collar portion 51 and the lower collar portion 52 are cylindrical. The part corresponds.

  The bottom surface of the pyramid portion 77 corresponds to a quadrangular surface formed by connecting four vertices 76. The top 80 of the pyramidal portion 77 corresponds to the tip of a square pyramid. One line (for example, a line 77A) connecting each vertex 76 of the bottom surface of the pyramid portion 77 and the top portion 80 of the pyramid portion 77 is formed along the first direction A. Here, as described above, in the present embodiment, the pyramid portion 77 is configured to include the pyramid surface 78 including four isosceles triangles. Therefore, when the line 77A is formed along the first direction A, the line 78B is formed along the second direction B. By configuring the pyramid portion 77 in this manner, when the resin fuel tank 100 receives a load from the outside, the pyramid portion 77 absorbs the load and prevents the resin fuel tank 100 from being damaged and leaking fuel. It becomes possible.

  As shown in FIG. 1 to FIG. 3, the pyramid portion 77 is formed over substantially the entire circumference in the second direction B of the upper collar portion 51 and the lower collar portion 52, and the upper collar portion 51 and the lower collar portion 52. It is preferable to form the central portion 79 in the first direction A. In particular, the pyramid portion 77 is not formed in the pump attachment port 32, its periphery, or the bottom 33, but can be formed as necessary. The substantially entire circumference is substantially the entire circumference because the pyramid portion 77 is not formed in the connection portion Z connecting the upper collar portion 51 and the lower collar portion 52. However, it is naturally possible to form the pyramid portion 77 also in the connection portion Z between the upper collar portion 51 and the lower collar portion 52, and is within the scope of the present invention.

  As described above, at least a part of the inner surface and the outer surface of the upper collar portion 51 and the lower collar portion 52 are formed by connecting a plurality of pyramidal portions 77 each having a plurality of pyramidal surfaces 78. That is, as shown in FIGS. 4 and 5, at least a part of the inner surface and the outer surface of the upper collar part 51 and the lower collar part 52 are formed to have irregularities.

  For example, when the environmental temperature in which the resin fuel tank 100 is provided increases, the fuel evaporates in the resin fuel tank 100 and the internal pressure increases. On the other hand, when the environmental temperature becomes low, the internal pressure becomes lower than when the environmental temperature is high. As described above, the pressure in the resin fuel tank 100 also varies due to the variation in the environmental temperature.

  The pyramid portion 77 has a function of absorbing such fluctuations in internal pressure. That is, when the internal pressure of the resin fuel tank 100 is increased, the irregularities of the pyramid portion 77 are widened to increase the volume. Therefore, the internal pressure of the resin fuel tank 100 is prevented from becoming too high. On the other hand, when the internal pressure of the resin fuel tank 100 becomes low, the unevenness of the pyramid portion 77 narrows and returns to the original volume. Therefore, the internal pressure of the resin fuel tank 100 is prevented from becoming too low. As described above, the pyramid portion 77 repeats elongation and restoration as appropriate, so that the resin fuel tank 100 can be hardly cracked.

  Thus, the pyramid portion 77 also has a function of maintaining the pressure in the resin fuel tank 100 substantially constant. The pyramidal portion 77 is preferably formed on the basis of the case where the internal pressure of the resin fuel tank 100 becomes high.

[Second Embodiment]
The resin fuel tank 100 according to the above-described first embodiment has been described as being molded by blow molding. The resin fuel tank 100 according to the present embodiment is different from the resin fuel tank 100 according to the first embodiment described above in that it is formed by free blow molding. Below, the resin fuel tank 100 shape | molded by such free blow molding is demonstrated.

  The resin fuel tank 100 according to the present embodiment is molded using free blow molding. In the free blow molding, a tubular parison made of a raw material resin is used. The tubular parison corresponds to the pipe-shaped parison used in the first embodiment. FIG. 9 shows a perspective view of such a tubular parison.

  The tubular parison is in a molten state, and is sealed by being partitioned by a predetermined length in the axial direction. The molten state does not indicate a state where the resin is completely melted, but can be partitioned as described later, and melted to such an extent that a part that becomes a sealed state can be formed by partitioning. Indicates the state. The axial direction is the axial direction of a tubular parison. Partitioning with a predetermined length in the axial direction means that the tubular parison is partitioned at two locations separated by a predetermined interval so as to have a predetermined length in the axial direction. In the present embodiment, as shown in FIG. 9, the tubular parison is picked and partitioned by the picking jig T at the picking positions T1 and T2 (two places) that are separated by a predetermined distance in the axial direction. Such an interval between the picking position T1 and the picking position T2 corresponds to the “predetermined length” in the present invention. The tubular parison is partitioned in two places as described above, so that the partitioned portion is sealed.

  An injection nozzle is inserted into the tubular parison thus sealed, and air is blown into the tubular parison through the injection nozzle. The tubular parison swells uniformly by the air pressure corresponding to the air. The expanded tubular parison is then cut at the picking positions T1 and T2. What was cut | disconnected in this way is equivalent to the resin fuel tank 100 in this embodiment, and is shown by FIG. The resin fuel tank 100 according to the present embodiment is formed with an outer shape formed by blowing air into a tubular parison.

  Although not shown in the figure, the resin fuel tank 100 formed by free blow molding is formed by combining the upper flange portion 51 and the lower flange portion 52 in the same manner as the resin fuel tank 100 according to the first embodiment described above. The inner surface of the cross section in the second direction B perpendicular to the first direction A at the center of the upper collar part 51 and the lower collar part 52 in the first direction A is the upper collar part 51 and the lower collar part 52. And a pair of first arc portions 71 having a predetermined radius r1 and extending to the center side of the upper flange portion 51 and the lower flange portion 52, and a radius R1 larger than the predetermined radius r1. And a second arc portion 72 connected across the pair of first arc portions 71. In addition, the inner surface of the cross section in the first direction A at the center of the upper collar part 51 and the lower collar part 52 in the second direction B is connected to the connection portion Z of the upper collar part 51 and the lower collar part 52 and the upper collar part 51 and a pair of third arc portions 82 extending to the center side of the lower collar portion 52, and a connection portion 81 connected across the pair of third arc portions 82.

  As described above, the resin fuel tank 100 according to the present embodiment can be formed by a simple method of inflating a tubular parison without using a mold. Further, since the shape is not corrected by the mold in the process of forming the resin fuel tank 100, the tubular parison can be uniformly inflated by the air pressure supplied into the tubular parison. For this reason, since a uniform thickness can be realized over the entire surface of the resin fuel tank 100, even when the fuel stored in the resin fuel tank 100 after molding evaporates and the pressure becomes high, The increased pressure can be evenly applied to the inner wall of the resin fuel tank 100, and the stress is less likely to partially concentrate. Accordingly, the overall plate thickness can be reduced by that amount, and the amount of resin used can be reduced. Therefore, the cost and weight of the resin fuel tank 100 can be reduced. Further, since no mold is used, the manufacturing cost can be reduced. In addition, in FIG. 10, although the attaching part 21, the supply port 31, and the pump attachment port 32 are abbreviate | omitted, it is possible to form in another process after the above-mentioned free blow molding.

[Third embodiment]
The resin fuel tank 100 according to the first embodiment described above has been described as being molded by blow molding using a mold. Similarly to the first embodiment, the resin fuel tank 100 according to the present embodiment is also molded by blow molding using a mold. In the present embodiment, the shape molded using the mold is a shape inflated by free blow molding. Hereinafter, the resin fuel tank 100 having such a shape will be described.

  The resin fuel tank 100 according to the present embodiment is molded using blow molding. Since blow molding has been described in the first embodiment, the description thereof is omitted here. As the mold K used in the blow molding according to the present embodiment, one having the shape of the outer surface of the resin fuel tank 100 formed by free blow molding is used. Such a mold K is shown in FIG. The mold K corresponds to a “molding die” according to the present invention. As described in the second embodiment, free blow molding is a molding method in which a tubular parison is partitioned in a predetermined length in the axial direction to form a sealed state, and air is blown into the tubular parison to inflate it. is there. The mold K used in the blow molding according to this embodiment has a shape in which the material (in the present embodiment, a tubular parison) disposed in the mold is inflated with a free blow molding. Form along.

  The mold K is composed of a pair of a first mold K1 and a second mold K2. In the process of forming the resin fuel tank 100, the first mold K1 and the second mold K2 are used by clamping with a predetermined pressure. A cavity KV is formed between the first mold K1 and the second mold K2 thus clamped. A tubular parison is disposed in the cavity KV. Air is blown into the tubular parison disposed in the cavity KV and inflated in accordance with the air pressure. Therefore, the tubular parison is formed along the shape formed in the mold K. Since the shape formed in such a mold K is a shape formed by free blow molding, it is formed by free blow molding if the molding conditions (tubular parison, molten state, etc.) are the same. Similar to the shape to be formed, the resin fuel tank 100 in which the tubular parison swells uniformly is formed.

  Therefore, the resin fuel tank 100 having a uniform thickness over the entire surface can be realized. For this reason, even when the fuel stored in the molded resin fuel tank 100 is volatilized and the pressure is increased, the increased pressure can be evenly applied to the inner wall of the resin fuel tank 100, so that the partial pressure is increased. Stress is less concentrated on For this reason, since the overall plate thickness can be reduced by that amount and the amount of resin used can be reduced, the cost and weight of the resin fuel tank 100 can be reduced.

  An attachment portion 21 is formed in the resin fuel tank 100. The attachment portion 21 enables the resin fuel tank 100 to be attached to the vehicle. That is, when the resin fuel tank 100 is attached to the vehicle, it is attached via the attachment portion 21. Such an attaching portion 21 can be integrally performed when the shape of the resin fuel tank 100 is formed using the mold K described above. In such a case, the shape of the attachment portion 21 is formed in the mold K. Here, FIG. 12 shows a top view of the molded resin fuel tank (molded resin fuel tank) 100. In FIG. 12, a virtual quadrilateral IS that virtually surrounds the resin fuel tank 100 is indicated by a broken line. The mounting portion 21 is formed so as to fit within the virtual quadrilateral IS in a top view of the resin fuel tank 100 after molding. Thereby, the attachment part 21 can be shape | molded, maintaining the resin fuel tank 100 of the state swelled by uniform thickness. For this reason, the resin fuel tank 100 does not have uneven thickness due to the attachment portion 21, so that it is not necessary to increase the thickness of the resin fuel tank 100 in order to form the attachment portion 21. Therefore, it is possible to form the attachment portion 21 while realizing a reduction in cost and weight of the resin fuel tank 100.

  Although not shown, the resin fuel tank 100 according to the present embodiment also has a hollow shape in which the upper collar portion 51 and the lower collar portion 52 are combined, and the upper collar portion 51 and the lower collar portion in the first direction A. The inner surface of the cross section in the second direction B orthogonal to the first direction A at the center of 52 is connected to the connecting portion Z of the upper collar part 51 and the lower collar part 52 to be the center of the upper collar part 51 and the lower collar part 52 And a pair of first arc portions 71 having a predetermined radius r1 and a second arc portion 72 having a radius R1 larger than the predetermined radius r1 and connected across the pair of first arc portions 71. And formed. In addition, the inner surface of the cross section in the first direction A at the center of the upper collar part 51 and the lower collar part 52 in the second direction B is connected to the connection portion Z of the upper collar part 51 and the lower collar part 52 and the upper collar part 51 and a pair of third arc portions 82 extending to the center side of the lower collar portion 52, and a connection portion 81 connected across the pair of third arc portions 82.

  In addition, as shown in FIG. 12, it is also possible to form a plurality of pyramidal portions 77 on the inner surface and the outer surface of at least a part of the upper flange portion 51 and the lower flange portion 52 of the resin fuel tank 100. Furthermore, the supply port 31 and the pump attachment port 32 can be formed simultaneously with the blow molding. Of course, it is naturally possible to form the through-hole 22 in the approximate center of the mounting portion 21.

[Other Embodiments]
In the said embodiment, it demonstrated that the opening part (pump attachment port 32) which has the hollow 41 in the circumference | surroundings in the center part 79 of the upper collar part 51 was formed. However, the scope of application of the present invention is not limited to this. Of course, it is also possible to form an opening (pump attachment port 32) having a recess 41 around the central portion 79 of the lower collar portion 52.

  In the above embodiment, the four pyramid surfaces 78 constituting the pyramid portion 77 are formed as isosceles triangles. In such a case, the lines 77A and 77B are formed along the first direction A and the second direction B, respectively. Explained as being. However, the scope of application of the present invention is not limited to this. One of the lines connecting each vertex 76 of the bottom surface of the pyramid portion 77 and the top 80 of the pyramid portion 77 is the first direction A along the cylindrical central portion 79 of the upper collar portion 51 and the lower collar portion 52 or Needless to say, it may be formed along the second direction B orthogonal to the first direction A. That is, it is naturally possible to form in either one of the first direction A and the second direction B. By adopting such a configuration, it is naturally possible to absorb the load from the side orthogonal to one of the lines connecting each vertex 76 and the top 80.

  In the above embodiment, the pyramid portion 77 is formed over substantially the entire circumference in the second direction B of the upper collar part 51 and the lower collar part 52, and at least in the first direction A of the upper collar part 51 and the lower collar part 52. It has been described as being formed in the central portion 79. However, the scope of application of the present invention is not limited to this. The pyramid portion 77 is formed over substantially the entire circumference of the upper collar portion 51 and the lower collar portion 52 in the first direction A, and is formed at least in the central portion 79 of the upper collar portion 51 and the lower collar portion 52 in the second direction B. Of course it is also possible to do. Even when the pyramid portion 77 is formed in this way, it is naturally possible to obtain the above-described effect.

  In the embodiment described above, the pyramid portion 77 has been described as a portion made of a quadrangular pyramid. However, the scope of application of the present invention is not limited to this. For example, it is naturally possible to form the pyramid portion 77 from a triangular pyramid. FIG. 13 shows a series of such pyramid portions 77 made of triangular pyramids. In such a case, it is preferable that the bottom surface formed by connecting the three vertices 76 is an equilateral triangle. It is preferable that one line 77B connecting the apex 76 and the top 80 is formed along the second direction B. It is natural that the pyramid portion 77 can suitably absorb the load received from the first direction A by forming in this way. The pyramidal surfaces 77 do not have to be all formed of isosceles triangles, but only the hatched triangles shown in FIG. 13 (that is, the pyramid surface not including the line 77B in the three sides constituting the isosceles triangles). 78) need only be formed of isosceles triangles. Of course, the line 77B can be formed along the second direction B. In such a case, the pyramid portion 77 can suitably absorb the load received from the second direction B.

  In the above embodiment, it has been described that at least a part of the inner surface and the outer surface of the upper collar portion 51 and the lower collar portion 52 are formed by connecting a plurality of pyramid portions 77 each having a plurality of pyramid surfaces 78. However, the scope of application of the present invention is not limited to this. Of course, it is also possible to form a plurality of pyramidal portions 77 having a plurality of pyramidal surfaces 78 over the entire inner surface and outer surface of the upper collar portion 51 and the lower collar portion 52.

  In the above embodiment, the pyramid portion 77 has been described as being formed in a form protruding inside the resin fuel tank 100. However, the scope of application of the present invention is not limited to this. Of course, the pyramidal portion 77 may be formed so as to protrude to the outside of the resin fuel tank 100.

  The present invention is applicable to a resin fuel tank formed by blow molding or the like and having a hollow shape in which an upper collar part and a lower collar part are combined.

31: Supply port 32: Pump mounting port 51: Upper collar part 52: Lower collar part 79: Center part 100: Resin fuel tank A: First direction B: Second direction

Claims (3)

In resin fuel tanks molded by blow molding,
A tubular parison is partitioned by a predetermined length in the axial direction to be in a sealed state, and a mold having a shape in which air is blown into the tubular parison by free blow molding is used, and the mold is placed in the mold. Molded by blow molding to blow and inflate air into the arranged tubular parison ,
A mounting part that enables mounting with a vehicle is provided,
The mounting portion is formed in a virtual rectangle surrounding the resin fuel tank in a top view of the molded resin fuel tank,
The mounting portion is a resin fuel tank formed by sandwiching a part of the parison between a first mold and a second mold . In a resin fuel tank formed by blow molding and having a hollow shape in which an upper collar part and a lower collar part are combined,
The inner surface of the cross section in the second direction orthogonal to the first direction at the center of the upper collar part and the lower collar part in the first direction along the cylindrical central part of the upper collar part and the lower collar part. A pair of first arc portions connected to a connecting portion of the upper collar portion and the lower collar portion and extending to a center side of the upper collar portion and the lower collar portion and having a predetermined radius; A second arcuate portion having a radius greater than the radius and connected across the pair of first arcuate portions,
The inner surface of the cross section in the first direction at the center of the upper collar part and the lower collar part in the second direction is connected to the connection part of the upper collar part and the lower collar part, and the upper collar part and the A resin fuel tank having a pair of third arc portions extending to the center side of the lower collar portion and a connection portion connected across the pair of third arc portions. The resin fuel tank according to claim 2 , wherein an opening having a depression around is formed in a central portion of the upper collar portion.

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