WO2021209790A1

WO2021209790A1 - Process and apparatus for manufacturing a blow molded plastic tank equipped with an internal component

Info

Publication number: WO2021209790A1
Application number: PCT/IB2020/053570
Authority: WO
Inventors: Stephen GAO; Jeff Wang; Dolny TOMASZ; Rex Wang; Barry Xu; Tony Wang
Original assignee: Ti Automotive (Tianjin) Co., Ltd.
Priority date: 2020-04-15
Filing date: 2020-04-15
Publication date: 2021-10-21

Abstract

A blow molding apparatus (100) for producing a hollow structure provided with an internal component (14) by a clamping process includes a first mold portion (102) and a second mold portion (104) defining a mold cavity (106) and being configured to receive a parison (12) in the mold cavity (106), and first and second movable arms (110) slidably mounted in each of the first and second mold portions (102, 104), having a distal end, and being configured to engage the parison (12) at a location where the parison (12) contacts first and second ends (16, 18) of the internal component (14). Each of the movable arms (110) includes a pair of fingers (112) at the distal end of the movable arm (110) to clamp simultaneously and locally opposing portions of the parison (12) on the first and second ends (16,18) of the internal component (14).

Description

PROCESS AND APPARATUS FOR MANUFACTURING A BLOW MOLDED PLASTIC TANK EQUIPPED WITH AN INTERNAL COMPONENT

FIELD

[0001] The present disclosure relates to the production of a blow molded plastic tank. In particular, the present disclosure relates to a process and an apparatus for manufacturing the blow molded plastic tank equipped with an internal component.

BACKGROUND

[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] A blow molding process for blow molded hollow articles is well-known process in the automotive and other fields. The blow molding process is a common technique to make hollow articles such as fuel tanks or containers. In addition, various processes exist for attaching or fastening accessories to interior of the hollow articles. Recently, a demand of the fuel tanks for supporting high pressure is increased due to fuel economy vehicles such as a hybrid electric vehicle (HEV). Accordingly, the process for integrating components inside the hollow plastic articles for supporting the high pressure is needed and is generally completed after the blow molding process is finished.

[0004] A well-known technique is that the internal components are inserted inside the fuel tank by a robot arm when the mold closes once and the tank cut open by the machine such that the internal components are attached to the interior of the fuel tank. However, we have discovered that the cycle time of the blow molding process with the opening and reclosing steps is longer due to the more steps of the blow molding process and more components and/or equipment are used for completing the opening and reclosing steps. Accordingly, the cost of the blow molding process is increased. [0005] In addition, a welding process is used for integrating the components inside the fuel tank but due to the cycling of the over-pressure and under-pressure inside the fuel tank, there is a risk that the fuel tank breaks or peals at the welding area so that it leads a potential leakage issue of fuel in the tank. Also, for supporting the high pressure inside the fuel tank, the fuel tank can be encased by a metal crash cage from outer surface of the fuel tank, but encasing the fuel tank increases the weight of the fuel tank, which leads an increased fuel consumption.

SUMMARY

[0006] The present disclosure relates to a process and an apparatus for manufacturing the blow molded plastic tank equipped with an internal component. According to one aspect of the present disclosure, a process for clamping an internal component inside a tank molded from a parison of plastic material includes steps of providing first and second mold portions together defining a mold cavity and each having a movable arm configured to clamp locally part of the parison on the internal component, positioning the parison in the mold cavity defined between the first and second mold portions and having a top end, a bottom end, and sides defining an interior space, inserting the internal component through the top or bottom end of the parison into the interior space, being elongated, and having a first end and a second end opposite from the first end, extending each movable arm from each of the first and second mold portions towards the parison until each of the movable arms in the first and second mold portions touches the parison at a location where the parison is adjacent the first and second ends of the internal component, clamping simultaneously and locally opposing portions of the parison on the first and second ends of the internal component such that the first and second ends of the internal component are partially surrounded by the parison, applying a main blow molding pressure within the parison while the parison is clamped to the first and second ends of the internal component, and opening the first and second mold portions and operating the movable arms to release the internal component.

[0007] According to a further aspect of the present disclosure, the process includes the steps of closing the top and bottom ends of the parison and applying a pre-blow molding pressure within the parison after the inserting step.

[0008] According to a further aspect of the present disclosure, the process includes the step of moving the first and second mold portions to an intermediate closing position at which the first and second mold portions are not pressed against each other and at which the parison contacts the first and second ends of the internal component, respectively.

[0009] According to a further aspect of the present disclosure, the process includes the step of closing the mold cavity by moving the first and second mold portions to a final closing position at which the first and second mold portions are pressed against each other. The movable arms are slidable within passageways in the first and second mold portions, and the step of closing the mold cavity occurs while the movable arms are held in a fixed position such that the first and second mold portions move relative to the movable arms. In addition, the relative movement between the movable arms and the first and second mold portions causes operation of clamping mechanisms on the movable arms. Accordingly, the step of closing the mold cavity induces the step of clamping the parison on the first and second ends of the internal component.

[0010] According to a further aspect of the present disclosure, ends surfaces of the movable arms flush with a surface of the mold cavity in the final closing position. Each of the movable arms includes a pair of fingers formed with a flat end surface for keeping in plane with the surface of the mold cavity in the final closing position. [0011] According to a further aspect of the present disclosure, the movable arms are kept in a fixed position during opening the first and second mold portions after the final closing position.

[0012] According to a further aspect of the present disclosure, the process includes the step of providing a clamp ring for reinforcing the clamped portions of the parison on the first and second ends of the internal component after the opening step of the first and second mold portions with the movable arms.

[0013] According to another aspect of the present disclosure, a blow molding apparatus for producing a tank provided with an internal component includes a first mold portion and a second mold portion defining a mold cavity and being configured to receive a parison in the mold cavity, and first and second movable arms slidably mounted in each of the first and second mold portions, each having a distal end, and being configured to engage the parison at a location where the parison contacts first and second ends of the internal component. The blow molding apparatus is operable between an open position, a final closing position, and an intermediate closing position at which the first and second mold portions are not pressed against each other and at which the parison contacts the first and second ends of the internal component. In the final closing position, the first and second mold portions are pressed against each other. Each of the movable arms includes a pair of fingers at the distal end of the movable arm to clamp simultaneously and locally opposing portions of the parison on the first and second ends of the internal component, and each of the pair of fingers is formed with a flat end surface for keeping in-plane with each surface of the first and second mold portions respectively such that the flat end surfaces of the pair of fingers flush with a mold surface of the mold cavity at the final closing position.

[0014] According to a further aspect of the present disclosure, the blow molding apparatus further includes a gripper and a pinch plate operatively and respectively disposed above and below the first and second mold portions to seal top and bottom ends of the parison.

[0015] According to a further aspect of the present disclosure, the flat end surfaces of the pair of fingers are configured to prevent puncture of the parison during a blowing process.

[0016] According to a further aspect of the present disclosure, the first and second ends of the internal component is partially surrounded by the parison clamped by the pair of fingers of the movable arms.

[0017] According to a further aspect of the present disclosure, the pair of fingers are formed as an L-shape with a straight-bar type for clamping simultaneously and locally the opposing portions of the parison on the first and second ends of the internal component. The pair of fingers formed as the straight-bar type having a constant thickness are configured to form an ear structure of the parison at the final closing position of the first and second mold portions such that the formed ear structure of the parison clamps and holds the first and second ends of the internal component.

[0018] According to a further aspect of the present disclosure, the movable arm further includes a heat insulation pad at the distal end for locally holding the parison on surfaces of the first and second ends of the internal component.

[0019] According to a further aspect of the present disclosure, each of the first and second mold portions includes a first passageway for slidably guiding the first and second movable arms and a second passageway for slidably guiding the pair of fingers on each of the movable arms such that the first and second passageways are coaxial. In addition, the first passageway defines a first diameter and the second passageway defines a second diameter, which is greater than the first diameter.

[0020] According to a further aspect of the present disclosure, the movable arms including the pair of fingers move relative to the first and second mold portions through the first and second passageways so that the relative movement causes operation of clamping mechanism on the movable arms.

[0021] According to another aspect of the present disclosure, a blow molding apparatus for producing a tank provided with an internal component includes a first mold portion and a second mold portion defining a mold cavity and being configured to receive a parison in the mold cavity, first and second movable arms slidably mounted in each of the first and second mold portions, each having a distal end, and being configured to engage the parison at a location where the parison contacts first and second ends of the internal component, and a pair of fingers disposed in the distal end of the movable arm. The blow molding apparatus is operable between an intermediate closing position, a final closing position, and an open position. At the intermediate closing position, the first and second mold portions are not pressed against each other, the parison contacts the first and second ends of the internal component, and the first and second movable arms each extend from the first and second mold portion towards the parison such that the first and second movable arms touch and hold the parison at a location where the parison is adjacent the first and second ends of the internal component as a fixed position. At the final closing position, the first and second mold portions are pressed against each other and move towards the mold cavity while the movable arms are held in the fixed position so that the pair of fingers is closed by the first and second mold portions and clamp simultaneously and locally opposing portions of the parison on the first and second ends of the internal component. At the open position, the first and second mold portions are not pressed each other and the movable arms are returned inside passageways so that the mold cavity is fully opened.

[0022] According to a further aspect of the present disclosure, each of the pair of fingers is formed with a flat end surface for keeping in-plane with each surface of the first and second mold portions respectively such that the flat end surfaces of the pair of fingers flush with a mold surface of the mold cavity at the final closing position [0023] According to a further aspect of the present disclosure, each of the first and second mold portions includes a first passageway for slidably guiding the first and second movable arms and a second passageway for slidably guiding the pair of fingers coupled to the distal end of each movable arm.

[0024] According to a further aspect of the present disclosure, the relative movement in the operable position of the blow molding apparatus allows the pair of fingers to clamp locally the portions of parison on the first and second ends of the internal component by enclosing the pair of fingers inside the second passageway in each of the first and second mold portions.

[0025] Further details and benefits will become apparent from the following detailed description of the appended drawings. The drawings are provided herewith purely for illustrative purposes and are not intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS [0026] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

[0027] FIG. 1 shows a cross-section view of a blow molding apparatus in an open position in accordance with an exemplary form of the present disclosure;

[0028] FIG. 2 shows a cross-section view of the blow molding apparatus having an extruded parison in a mold cavity of FIG. 1 ;

[0029] FIG. 3 shows a cross-section view of the blow molding apparatus having a carrier with internal components inside an interior space of the parison of FIG. 1 ; [0030] FIG. 4 shows a cross-section view of the blow molding apparatus having a gripper and a pinch plate for sealing of FIG. 1 ;

[0031] FIG. 5 shows a cross-section view of the blow molding apparatus in an intermediate closing position of FIG. 1 ;

[0032] FIG. 6 shows a cross-section view of the blow molding apparatus with the withdrawn carrier in the intermediate closing position, and FIG. 6A shows a detailed cross- section view of the blow molding apparatus in the intermediated closing position of FIG. 6;

[0033] FIG. 7 shows a cross-section view of the blow molding apparatus in a final closing position, and FIG. 7A shows a detailed cross-section view of the blow molding apparatus in the final closing position of FIG. 7;

[0034] FIG. 8 shows a cross-section view of the blow molding apparatus in an intermediate closing position after a hollow article is completed;

[0035] FIG. 9 shows a cross-section view of the blow molding apparatus separated from the completed hollow article of FIG. 8;

[0036] FIG. 10 shows a cross-section view of the blow molding apparatus in the open position after the hollow article is completed;

[0037] FIG. 11 shows a detailed cross-section view of the completed hollow article with the attached internal component of FIG. 10;

[0038] FIG. 12 shows a detailed cross-section view of the completed hollow article with a clamp ring of FIG. 11 ; and

[0039] FIG. 13 shows a detailed cross-section view of a completed hollow article with an attached internal component in accordance with another exemplary form of the present disclosure, and FIG. 13A shows a detailed cross-section view of a blow molding apparatus with a movable arm in accordance with another exemplary form of the present disclosure. [0040] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

[0041] The following description is merely exemplary in nature and is in no way intended to limit the present disclosure or its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0042] FIGS. 1 and 2 illustrate a blow molding apparatus 100 for manufacturing a hollow article equipped with an accessory. In the blow molding process, a hollow tube like segment of thermoplastic material generally referred as a hollow parison 12 is extruded from an extrusion system (not shown). After a predetermined length or segment of material has been extruded, the parison 12 is taken and held by a suitable conveying device (not shown). In addition, a parison gripper 107 grasps and releases a top end 11 of the parison 12 to permit for parison transport and control. The released parison 12 has the top end 11, a bottom end 13, and sides 21 defining an interior space 23.

[0043] As shown in FIGS. 1 and 2, on grasping and retaining parison 12, the conveying device removes the parison 12 from the extrusion system and delivers the parison 12 to a blow molding station which is set up by a first mold portion 102 and a second mold portion 104. The first and second mold portions 102 and 104 provide a mold cavity 106 shaped to form the desired hollow article. For example, in FIGS 1 and 2, the mold cavity 106 is shaped to form a fuel tank 10 (see FIG. 10). The first and second mold portions 102 and 104 are movable to open/close the mold cavity 106 such that the mold cavity 106 enables the loading of the parison 12 at the beginning of a mold cycle and unloading of the finished hollow article at the end of the mold cycle. [0044] In FIG. 1 , the first and second mold portions 102 and 104 are in an open position. In the open position of the first and second mold portions 102 and 104, the mold cavity 106 has an internal mold surface 101 defined by a first mold surface 103 and a second mold surface 105, which corresponds to an external surface 15 of the tank 10 to be molded later (see FIG. 10). Each of the first and second mold portions 102 and 104 provides at least one respective movable arm 110 that is displaceable relative to the first and second mold portions 102 and 104. In FIG. 1 , for example, each of the first and second mold portions 102 and 104 has two movable arms 110 such as a first movable arm 113 and a second movable arm 115. Each of the movable arms 110 slidably moves inside respective first passageways 124 formed in each of the first and second mold portions 102 and 104. The movable arms 110 are slidably mounted within the first passageways 124 by a hydraulic system including a pneumatic or electrical actuator system (not shown) positioned in the first and second mold portions 102 and 104. Accordingly, in the open position, the first and second mold portions 102 and 104 are not pressed each other and the movable arms are returned inside the passageways 124 so that the mold cavity 106 is fully opened.

[0045] The movable arms 110 move slidably within the first passageways 124 relative to the first and second mold portions 102 and 104 along a longitudinal direction 116 of the movable arms 110. Accordingly, the movable arms 110 and the first and second mold portions 102 and 104 are relatively moved from each other during the blow molding process. The movable arms 110 protrude from the first and second mold portions 102 and 104 and are drawn back into the first and second mold portions 102 and 104 so that the movable arms 110 are engaged or disengaged with the parison 12.

[0046] Referring to FIGS. 3 and 4, at least one internal component 14 being elongated and having a first end 16 and a second end 18, is provided and positioned inside the parison 12 by a carrier 108. As shown in FIG. 3, for example, two internal components 14 loaded onto the carrier 108 are inserted inside the parison 12 through a bottom end 13 of the parison 12. In another approach, however, the carrier 108 having at least one internal component 14 may be inserted inside the parison 12 through the top end 11 of the parison 12. As shown in FIG. 4, after the internal components 14 are inserted inside the parison 12, the parison gripper 107 grasps and closes the top end 11 of the parison 12 and a pinch plate 109 closes and seals the bottom end 13 of the parison 12. After the top and bottom ends 11 and 13 of the parison 12 are closed and sealed, a pre-blow molding pressure operation of the blow molding apparatus 100 is started. [0047] Referring to FIGS. 5 and 6, with the internal components 14 positioned within the parison 12 (that is, the interior space 23 of the parison 12), the first and second mold portions 102 and 104 are moved in an intermediate closing position at which the first and second mold portions 102 and 104 are not pressed against each other. In addition, the movable arms 110 in each of the first and second mold portions 102 and 104 extend into the mold cavity 106 relative to the first and second mold portions 102 and 104, thereby locally pushing the molten parison 12 to bring it into contacting with the internal component 14. So, in the intermediate closing position, the parison 12 contacts the first and second ends 16 and 18 of the internal component 14, respectively such that each of the movable arms 110 touches the parison 12 at a location where the parison 12 is adjacent the first and second ends 16 and 18 of the internal component 14. Accordingly, a portion of the parison 12 locally contacted to the first and second ends 16 and 18 of the internal component 14 maintains the internal component 14 in a fixed position, in which the internal component 14 is held by pushing operations of the movable arms 110. Once the fixed position of the internal component 14 is established, the carrier 108 is detached from the internal component 14 and withdrawn from the mold cavity 106 (that is the interior space 23 of the parison 12). As shown in FIGS. 5 and 6, the molten parison 12 does not contact the internal mold surface 101 formed by the first and second mold portions 102 and 104, and the pre-blow molding pressure operation of the blow molding apparatus 100 keeps continuing in the intermediate closing position of the first and second mold portions 102 and 104.

[0048] FIG. 6A illustrates a detailed view of one of the movable arms 110 in the intermediate closing position. As shown in FIG. 6A, each of the movable arms 110 includes a pair of fingers 112 coupled to a distal end 111 of the movable arm 110. The pair of fingers 112 with an elastic element such as a pair of springs 122 are configured to clamp locally portions of the parison 12 when the internal component 14 is placed in the interior of the tank 10. The movable arms 110 further include a heat insulation pad 120 between the pair of fingers 112 at the distal end 111 of the movable arms 110 for locally holding and pressing the molten parison 12 on the first and second ends 16 and 18 of the internal component 14 such that the parison 12 is held on a first end surface 17 and a second end surface 19 defined by each of the first and second ends 16 and 18 during the clamping of the pair of fingers 112. Accordingly, a space or gap between the parison 12 and the first and second end surfaces 17 and 19 is prevented during the clamping process due to the pressure operation of the heating insulation pads 120 of the movable arms 110.

[0049] As described above, the movable arms 110 slidably mounted in the first and second mold portions 102 and 104 are guided by the first passageways 124 formed in the first and second mold portions 102 and 104. As shown in FIG. 6A, furthermore, the pair of fingers 112 are also guided by second passageways 126, which extend towards the mold cavity 106 along the longitudinal direction 116 of the movable arms 110 such that the pair of fingers 112 touch the parison 12 at the location where the parison 12 is adjacent the first and second ends 16 and 18 of the internal component 14. Accordingly, in the intermediate closing position, the pair of fingers 112 slidably extend from the first and second mold portions 102 and 104, and the pair of fingers 112 are opened and touch the parison 12, but the pair of fingers 112 do not clamp the part of the parison 12 on the internal component 14.

[0050] As described above, the first and second passageways 124 and 126 are formed inside the first and second mold portions 102 and 104 for guiding the movable arms 110 including the pair of fingers 112. The first and second passageways 124 and 126 are formed along the longitudinal direction 116 of the movable arms 110 so that both passageways 124 and 126 are coaxial. Furthermore, as shown in FIG. 6A, the first passageways 124 define a first diameter 125 and the second passageways 126 define a second diameter 127, which is greater than the first diameter 125.

[0051] Referring to FIGS. 7 and 7A, the first and second mold portions 102 and 104 are fully closed by moving towards the mold cavity 106 while the movable arms 110 are held in the fixed position such that the first and second mold portions 102 and 104 move relative to the movable arm 110. The process of closing the mold cavity 106 is defined as a final closing position (ora closed position), at which the first and second mold portions 102 and 104 are pressed against each other. In the final closing position, as described above, the pair of fingers 112 is enclosed with the second passageways 126 by the relative movement of the first and second mold portions 102 and 104. The relative movement between the movable arms 110 and the first and second mold portions 102 and 104 causes the operation of the clamping mechanisms on the movable arms 110 and the closing step of the mold cavity 106 induces the step of the clamping the parison 12 on the first and second ends 16 and 18 of the internal component 14. Accordingly, the pair of fingers 112 of the movable arms 110 in each of the first and second mold portions 102 and 104 clamp simultaneously and locally opposing portions of the parison 12 on the first and second ends 16 and 18 of the internal component 14 such that the first and second ends 16 and 18 of the internal component 14 are partially surrounded by the molten parison 12. While the parison 12 is clamped with the first and second ends 16 and 18 of the internal component 14, a main-blow molding pressure is applied to the interior space 23 of the parison 12. In the final closing position, accordingly, the internal component 14 is secured to the interior surface of the parison 12 and the main-blow molding pressure is operated so that the parison 12 is caused to bear completely against the contour of the mold cavity 106, thus forming the final hollow tank 10 equipped with the internal component 14 (see FIG. 10).

[0052] As shown in FIG. 7A, for example, the internal component 14 is a rod 24 having enlarged ends 26 formed as a mushroom shape 28 such that the pair of fingers 112 of the movable arms 110 clamp locally part of the parison on the enlarged ends 26 of the rod 24. In addition, the pair of fingers 112 are formed with a flat end surface 114 respectively, which keeps in-plane with the first and second mold surfaces 103 and 105 in the final closing position of the first and second mold portions 102 and 104 such that the flat end surfaces 114 of the pair of fingers 112 flush with the internal mold surface 101 of the mold cavity 106. Accordingly, the flat end surfaces 114 of the pair of fingers 112 are configured to prevent puncture of the parison 12 during the blowing mold process. [0053] Referring to FIGS. 8, 9, and 10, on completion of the blow molding step of the hollow article and cooling period, the first and second mold portions 102 and 104 are opened. In FIG. 8, the first and second mold portions 102 and 104 move back to the intermediate closing position of the mold portions such that the first and second mold portions 102 and 104 move relative to the movable arms 110. While the first and second mold portions 102 and 104 are moved back to the intermediate closing position, the movable arms 110 maintain in the fixed position but the pair of fingers 112 are opened from a clamped position because the pair of fingers 112 move out of the second passageways 126 of the first and second mold portions 102 and 104. In FIG. 9, the first and second mold portions 102 and 104 are fully opened and the movable arms 110 also separated from the molded parison 12 (that is, a hollow structure is completed at this stage). As shown in FIG. 10, in addition, the movable arms 110 including the pair of fingers 112 moves back into the first and second passageways 124 and 126 respectively, which is defined as the open position. Accordingly, the completed hollow structure can be taken from the mold cavity 106 and the internal component 14 is securely and permanently fastened to the interior surface of the tank 10 by the clamping process as described above.

[0054] FIGS. 11-13 generally illustrate detailed views of the completed hollow structure having the internal component 14. FIG. 11 shows a detailed view of the completed hollow structure with the internal component 14 of FIG. 10. For example, as shown in FIGS. 10 and 11 , the clamped rod 24 with the parison 12 is configured for supporting high pressure inside the fuel tank 10. As described above, the enlarged first and second ends 16 and 18 of the internal component 14 are clamped with the molten parison 12 during the blow molding process and securely fastened to the inside of the tank 10. Furthermore, due to the pair of fingers 112 of the movable arms 110 having the flat end surface 114 flushed with the first and second mold surfaces 103 and 105, a portion 29 of a tank wall 30 formed by the flat end surface 114 of the pair of fingers 112 is kept in-plane with the other portions 31 of the tank wall 30 formed by the internal mold surface 101 as shown in FIGS. 10 and 11.

[0055] Referring to FIG. 12, a clamp ring 22 is additionally provided in a clamped location of the tank 10 after the molding process of the tank 10 is completed as in FIG. 10. In the tank 10 with the fastened internal component 14 as shown in FIG. 12, the covered first and second ends 16 and 18 of the internal component 14 by the parison 12 protrude from the tank wall 30 such that a neck 32 is defined in the protruded portion. So the clamp ring 22 is placed around the neck 32 for achieving the additional higher strength at the clamped location of the fuel tank 10. The clamp ring 22 is generally made of high strength materials such as a steel and also configured for supporting the higher pressure inside the fuel tank 10.

[0056] FIG. 13 illustrates a detailed view of a completed hollow structure having the internal component 14 in accordance with another form of the present disclosure. Referring to FIG. 13, an ear structure 20 of the parison 12 is formed at the clamped location of the tank 10. As shown in FIGS. 13 and 13A, the ear structure 20 is formed by a pair of fingers 128 having an L-shape with a straight-bar type during the blow molding process. The L-shaped pair of fingers 128 with the straight bar type may have generally and preferably a constant thickness. Accordingly, while clamping the portions of the parison 12 on the first and second ends 16 and 18 of the internal component 14, the L- shaped pair of fingers 128 form the ear structure 20 by thickening around the neck 32 with more molten parison such that the formed ear structure 20 of the parison 12 is clamped with the enlarged first and second ends 16 and 18 of the internal components 14 and provides a high strength at the clamped location of the tank 10. Thus, the formed ear structure 20 of the parison 12 is configured to support the high pressure inside the fuel tank 10 and achieve a higher strength at the clamped location.

[0057] The foregoing description of various forms of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Numerous modifications or variations are possible in light of the above teachings. The forms discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various forms and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.

Claims

CLAIMS What is claimed is:

1. A process for clamping an internal component inside a tank, the tank being molded from a parison of plastic material, the process comprising steps of: providing first and second mold portions together defining a mold cavity, the first and second mold portions each having a movable arm configured to clamp locally part of the parison on the internal component; positioning the parison in the mold cavity defined between the first and second mold portions, the parison having a top end, a bottom end, and sides defining an interior space; inserting the internal component through the top or bottom end of the parison into the interior space, the internal component being elongated and having a first end and a second end opposite from the first end; extending each movable arm from each of the first and second mold portions towards the parison until each of the movable arms in the first and second mold portions touches the parison at a location where the parison is adjacent the first and second ends of the internal component; clamping simultaneously and locally opposing portions of the parison on the first and second ends of the internal component such that the first and second ends of the internal component are partially surrounded by the parison; applying a main blow molding pressure within the parison while the parison is clamped to the first and second ends of the internal component; and opening the first and second mold portions and operating the movable arms to release the internal component.

2. The process of claim 1 , further comprising, after the inserting step, the steps of: closing the top and bottom ends of the parison, and applying a pre-blow molding pressure within the parison.

3. The process of claim 1 , further comprising the step of moving the first and second mold portions to an intermediate closing position at which the first and second mold portions are not pressed against each other and at which the parison contacts the first and second ends of the internal component, respectively.

4. The process of claim 1, further comprising the step of closing the mold cavity by moving the first and second mold portions to a final closing position at which the first and second mold portions are pressed against each other.

5. The process of claim 4, wherein the movable arms are slidable within passageways in the first and second mold portions, and wherein the step of closing the mold cavity occurs while the movable arms are held in a fixed position such that the first and second mold portions move relative to the movable arms.

6. The process of claim 5, wherein the relative movement between the movable arms and the first and second mold portions causes operation of clamping mechanisms on the movable arms.

7. The process of claim 6, wherein the step of closing the mold cavity induces the step of clamping the parison on the first and second ends of the internal component.

8. The process of claim 5, wherein ends surfaces of the movable arms flush with a surface of the mold cavity in the final closing position.

9. The process of claim 8, wherein each of the movable arms includes a pair of fingers formed with a flat end surface for keeping in-plane with the surface of the mold cavity in the final closing position.

10. The process of claim 4, wherein the movable arms are kept in a fixed position during opening the first and second mold portions after the final closing position.

11. The process of claim 1 , further comprising the step of providing a clamp ring for reinforcing the clamped portions of the parison on the first and second ends of the internal component after the opening step of the first and second mold portions with the movable arms.

12. A blow molding apparatus for producing a tank provided with an internal component, the blow molding apparatus comprising: a first mold portion and a second mold portion defining a mold cavity, the first and second mold portions being configured to receive a parison in the mold cavity; and first and second movable arms slidably mounted in each of the first and second mold portions, the at least one movable arm having a distal end and being configured to engage the parison at a location where the parison contacts first and second ends of the internal component, wherein the blow molding apparatus is operable between an open position, a final closing position, and an intermediate closing position at which the first and second mold portions are not pressed against each other and at which the parison contacts the first and second ends of the internal component, the final closing position having the first and second mold portions pressed against each other, wherein each of the movable arms includes a pair of fingers at the distal end of the movable arm to clamp simultaneously and locally opposing portions of the parison on the first and second ends of the internal component, and wherein each of the pair of fingers is formed with a flat end surface for keeping in plane with each surface of the first and second mold portions respectively such that the flat end surfaces of the pair of fingers flush with a mold surface of the mold cavity at the final closing position.

13. The blow molding apparatus of claim 12, wherein the blow molding apparatus further includes a gripper and a pinch plate operatively and respectively disposed above and below the first and second mold portions to seal top and bottom ends of the parison.

14. The blow molding apparatus of claim 12, wherein the flat end surfaces of the pair of fingers are configured to prevent puncture of the parison during a blowing process.

15. The blow molding apparatus of claim 12, wherein the first and second ends of the internal component is partially surrounded by the parison clamped by the pair of fingers of the movable arms.

16. The blow molding apparatus of claim 12, wherein the pair of fingers are formed as an L-shape with a straight-bar type for clamping simultaneously and locally the opposing portions of the parison on the first and second ends of the internal component.

17. The blow molding apparatus of claim 16, wherein the pair of fingers formed as the straight-bar type having a constant thickness are configured to form an ear structure of the parison at the final closing position of the first and second mold portions such that the formed ear structure of the parison clamps and holds the first and second ends of the internal component.

18. The blow molding apparatus of claim 12, wherein the movable arm further includes a heat insulation pad at the distal end for locally holding the parison on surfaces of the first and second ends of the internal component.

19. The blow molding apparatus of claim 12, wherein each of the first and second mold portions includes a first passageway for slidably guiding the first and second movable arms and a second passageway for slidably guiding the pair of fingers on each of the movable arms such that the first passageway and the second passageway are coaxial.

20. The blow molding apparatus of claim 19, wherein the first passageway defines a first diameter and the second passageway defines a second diameter, and the second diameter is greater than the first diameter.

21. The blow molding apparatus of claim 19, wherein the movable arms including the pair of fingers move relative to the first and second mold portions through the first and second passageways so that the relative movement causes operation of clamping mechanisms on the movable arms.

22. A blow molding apparatus for producing a tank provided with an internal component, the blow molding apparatus comprising: a first mold portion and a second mold portion defining a mold cavity, the first and second mold portions being configured to receive a parison in the mold cavity; first and second movable arms slidably mounted in each of the first and second mold portions, the at least one movable arm having a distal end and being configured to engage the parison at a location where the parison contacts first and second ends of the internal component; and a pair of fingers disposed in the distal end of the movable arm, wherein the blow molding apparatus is operable between an intermediate closing position, a final closing position, and an open position, wherein at the intermediate closing position at which the first and second mold portions are not pressed against each other and at which the parison contacts the first and second ends of the internal component, the first and second movable arms each extend from the first and second mold portion towards the parison such that the first and second movable arms touch and hold the parison at a location where the parison is adjacent the first and second ends of the internal component as a fixed position, wherein at the final closing position at which the first and second mold portions are pressed against each other, the first and second mold portions move towards the mold cavity while the movable arms are held in the fixed position so that the pair of fingers is closed by the first and second mold portions and clamp simultaneously and locally opposing portions of the parison on the first and second ends of the internal component, and wherein at the open position at which the first and second mold portions are not pressed each other and the movable arms are returned inside passageways so that the mold cavity is fully opened.

23. The blow molding apparatus of claim 22, wherein each of the pair of fingers is formed with a flat end surface for keeping in-plane with each surface of the first and second mold portions respectively such that the flat end surfaces of the pair of fingers flush with a mold surface of the mold cavity at the closed position.

24. The blow molding apparatus of claim 22, wherein each of the first and second mold portions includes a first passageway for slidably guiding the first and second movable arms and a second passageway for slidably guiding the pair of fingers coupled to the distal end of each movable arm.

25. The blow molding apparatus of claim 24, wherein the relative movement in the operable positions of the blow molding apparatus allows the pair of fingers to clamp locally the portions of parison on the first and second ends of the internal component by enclosing the pair of fingers inside the second passageway in each of the first and second mold portions.