Resin vehicle part manufacturing method and resin vehicle part

Patent metadata

Field	Value
Publication number	US-9751240-B2
Application number	US-201314413844-A
Country	US
Kind code	B2
Filing date	Dec 26, 2013
Priority date	Jan 15, 2013
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A method for manufacturing a resin vehicle part provided with a panel body having a decorative surface on the front surface and a stepped reinforcing rib, which stands on the back surface of the panel body and the thickness of the base end of which is formed to be thinner than the thickness of the leading end. On the injection molding die thereof, a sliding piece for forming the stepped reinforcing rib is provided so as to be movable. During shrinkage movement of the stepped reinforcing rib in the height direction after molten resin has been filled in the injection molding die, the sliding piece is pressed by the leading end of the stepped reinforcing rib and moves towards the panel body.

First claim

The invention claimed is:

1. A method for manufacturing a resin vehicle part provided with a panel body having a front surface including a design surface and a stepped reinforcing rib formed standing on a back surface of the panel body, the stepped reinforcing rib having a base end portion with a thickness thinner than a leading end portion,
wherein an injection molding die for the resin vehicle part includes a movable slide piece to form the reinforcing rib,
after molten resin is filled in the injection molding die, the slide piece is pushed by the leading end portion of the stepped reinforcing rib and moved in a direction to come close to the panel body according to shrinkage of the stepped reinforcing rib in a height direction.

2. The method for manufacturing a resin vehicle part according to claim 1 , wherein the slide piece is movably connected to a lifting part of a lifting device provided in the injection molding die through an elastic element that urges the slide piece in a direction to come close to the lifting part, and the slide piece is moved upward together with the lifting part during product demolding.

3. The method for manufacturing a resin vehicle part according to claim 1 , wherein the injection molding die includes an insert die in which the slide piece is slidably fitted, and the method includes filling molten resin in a cavity provided in a gap between the slide piece and the insert die to form the stepped reinforcing rib.

4. The method for manufacturing a resin vehicle part according to claim 3 , wherein a groove-shaped cavity is provided in a shoulder of the slide piece or the insert die, the groove-shaped cavity being communicated with the cavity for forming the stepped reinforcing rib, and the method includes filling molten resin in the groove-shaped cavity to form a triangular reinforcing rib for reinforcing only a root of the base end portion of the stepped reinforcing rib.

5. A method for manufacturing a resin vehicle part provided with a panel body having a front surface including a design surface and a stepped reinforcing rib formed standing on a back surface of the panel body, the reinforcing rib having a base end portion with a thickness thinner than a leading end portion,
wherein an injection molding die for the resin vehicle part includes a first slide piece for forming one stepped reinforcing rib so that the first slide piece is movable in a demolding direction and a second slide piece for forming the other stepped reinforcing rib so that the second slide piece is movable in a direction different from the demolding direction, after molten resin is filled in the injection molding die, the first slide piece and the second slide piece are pushed by the leading end portions of the stepped reinforcing ribs in a direction to come close to the panel body according to shrinkage of the stepped reinforcing ribs in a height direction.

6. The method for manufacturing a resin vehicle part according to claim 5 , wherein
the injection molding die includes lock pins for fixing the first slide piece and the second slide piece in respective positions,
the method includes
locking the lock pins in the first slide piece and the second slide piece before the molten resin is filled in the injection molding die, and
releasing the lock pins from the first slide piece and the second slide piece after the molten resin is filled in the injection molding die.

7. The method for manufacturing a resin vehicle part according to claim 5 , wherein the injection molding die includes a second insert die in which the second slide piece is slidably fitted,
the method includes filling molten resin in a cavity provided in a gap between the second slide piece and the second insert die to form the stepped reinforcing rib.

8. The method for manufacturing a resin vehicle part according to claim 7 , wherein the method includes moving the second insert die in a direction to expand a cavity of the stepped reinforcing rib formed in the gap between the second slide piece and the second insert die during product demolding.

9. The method for manufacturing a resin vehicle part according to claim 7 , wherein the cavity for the stepped reinforcing rib formed in the gap between the second slide piece and the second insert die is formed linearly in almost the same direction as the demolding direction of the injection molding die.

Assignees

• Toyota Auto Body Co Ltd

Inventors

• Ikeno Katsuya
• Arakawa Tomohiro
• Yamashita Yoshihisa
• Nishikawa Nobuyoshi

Classifications

• B29C2045/363

  using a movable core or core part · CPC title

• B29C33/42 Primary

  characterised by the shape of the moulding surface, e.g. ribs or grooves · CPC title

• B60R2019/1886

  Bumper fascias and fastening means therefor · CPC title

• B29L2031/3005

  Body finishings · CPC title

• B60R19/18

  {characterised by the cross-section;} Means within the bumper to absorb impact · CPC title