Method and device for blow molding a plastic tank with at least one connection element penetrating the tank wall

Patent metadata

Field	Value
Publication number	US-11534954-B2
Application number	US-202117148714-A
Country	US
Kind code	B2
Filing date	Jan 14, 2021
Priority date	Jan 16, 2020
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

A method for blow molding a plastic tank from thermoplastic material, wherein the plastic tank is provided with at least one connection element penetrating the wall of the plastic tank while the plastic tank is being shaped within a blow molding tool. The connection element is fitted onto a blowing needle of the blow molding tool and is positioned in the wall by punching in the blowing needle. Also disclosed is a blow molding tool for use in the method having a blowing needle formed to fit a connection element.

First claim

The invention claimed is:

1. A blow molding tool for blow molding a plastic tank comprising:
a plurality of tool parts enclosing a shaping cavity,
wherein at least one of the plurality of tool parts includes at least one displaceable blowing needle, which is punched into a preform for the purpose of inflating the preform located in the cavity,
wherein the blowing needle fits a connection element to position the connection element in the wall of the plastic tank to be produced by punching in the blowing needle, and
wherein the blow molding tool further comprises a retaining portion for the connection element that is delimited by an axial stop and a head portion which projects beyond the fitted connection element and in which at least one blowing-air opening is located.

2. The blow molding tool of claim 1 , wherein the head portion of the blowing needle comprises at least one tip and/or at least one cutting edge.

3. The blow molding tool of claim 1 , further comprising a heating device by which the connection element is heated before the punching in operation.

4. A method for blow molding a plastic tank from thermoplastic material, wherein the plastic tank includes at least one connection element penetrating the wall of the plastic tank while the plastic tank is being shaped within a blow molding tool, the method comprising:
fitting the connection element onto a blowing needle of the blow molding tool; and
positioning the connection element in the wall by punching in the blowing needle,
wherein the blowing needle with the fitted connection element is moved at a speed of at least 0.50 m/s during the punching in operation.

5. The method of claim 4 , wherein a preliminary blow molding operation takes place before the blowing needle is punched in.

6. The method of claim 4 , wherein the punching in of the blowing needle with the fitted connection element occurs before the shaping of the plastic tank begins or has ended, wherein the connection element is snugly connected to the wall during the shaping of the plastic tank.

7. The method of claim 4 , wherein the connection element is manufactured from a thermoplastic material and is materially bonded to the wall.

8. The method of claim 4 , wherein the connection element is heated before the punching in operation.

Assignees

• Volkswagen Ag

Inventors

• Berlin Ralf
• Mientkewitz Claudia

Classifications

• B29C2049/6072

  being movable, e.g. blow needles move to pierce the parison · CPC title

• B29L2031/7172

  Fuel tanks, jerry cans · CPC title

• B29C2049/6063

  having means which facilitate the puncturing of the parison · CPC title

• B29C49/50

  having cutting or deflashing means · CPC title

• B29C2049/2073

  Means for feeding the inserts into the mould, preform or parison, e.g. grippers · CPC title