EP1979149A1

EP1979149A1 - Mould for the injection moulding of a part comprising two portions made of different materials

Info

Publication number: EP1979149A1
Application number: EP07730863A
Authority: EP
Inventors: Alain Di Rienzo; Annabelle Roy-Martinache
Original assignee: Faurecia Interieur Industrie SAS
Current assignee: Faurecia Interieur Industrie SAS
Priority date: 2006-01-27
Filing date: 2007-01-25
Publication date: 2008-10-15
Also published as: US20100019124A1; US7938638B2; FR2896719A1; WO2007085735A1; FR2896719B1

Abstract

This mould is of the type comprising a moulding cavity (10), and at least one panel (16, 18, 20) for separating the cavity into at least two moulding compartments (24, 26), said panel being able to move between a position for separating the two compartments (24, 26), and an inoperative position, through an opening (22) made in a wall (12) of the cavity (10). According to one aspect of the invention, it comprises at least one shutter (32, 34) which can move between an open position, in which the shutter (32, 34) is released from the opening (22), and a closed position, in which the shutter (32, 34) closes at least one region of the opening (22). The invention can be applied to moulds for the production of interior trim elements for motor vehicles.

Description

One-piece injection molding mold comprising two portions made of different materials.

The present invention relates to a mold for injection molding of a workpiece comprising at least a first portion and a second contiguous portion from moldings and made of different materials, of the type comprising a molding cavity, and at least one separating panel. the cavity in at least two molding compartments of the first and second portions, the panel being movable between an active position, in which the panel is in extension of the cavity to separate it into at least two compartments, and a rest position, in wherein the panel is removed from the cavity to join the at least two compartments, the panel moving between the active position and the rest position through an opening in a wall of the cavity. Such a mold makes it possible to mold a piece of plastic material comprising two portions of different types and / or colors, by successively molding the first portion with the aid of a plastic material, then the second portion using a other different plastic material. To do this, the panel is placed in the active position so as to isolate a first compartment, injecting a first plastic material intended to form the first portion in the first compartment, waiting for the at least partial solidification of the first portion, moving the panels in the rest position to join the two compartments, and injecting a second plastic material intended to form the second portion in the second compartment. The second portion comes into contact with the first portion, and adheres thereto by welding or gluing the plastics together. To seal between the compartments in the active position of the panel, it is possible for one edge of the panel to be in sealing contact with a first contact area of the wall of the cavity. To seal the second compartment in the rest position of the panel, it is possible that the edge of the panel sealingly closes the opening through which it moves. The edge adapts in this case to the area of the wall surrounding the opening.

Nevertheless, this limits the shapes that can be obtained because it requires that the contact area and the area surrounding the opening correspond.

This constraint is a disadvantage since it is often desirable to make plastic parts having several adjacent portions of different types and / or colors, having non-planar surfaces that do not correspond.

An object of the invention is to provide an injection molding mold for producing a part comprising a first portion and a second contiguous portion from molding and made of different materials, and having non-planar walls do not match.

For this purpose, the subject of the invention is a molding mold of the aforementioned type, characterized in that it furthermore comprises at least one movable flap between an open position, in which the flap is disengaged from the opening for allow the movement of the panel in the active position, and a closed position, wherein the shutter closes at least a region of the opening to close the cavity when the panel is in the rest position.

According to other embodiments, the mold comprises one or more of the following characteristics, taken in isolation or in any technically possible combination: - The panel is movable, between the active position and the rest position, in a direction parallel to a first plane, the flap being movable between the closed position and the open position in a direction parallel to a second plane, the foreground and the second plant being secant;

- It comprises several panels, the panels in the active position being joined and forming a partition wall of the two compartments;

- It comprises at least one panel, which, in the rest position, is set back from the opening on the side opposite the cavity;

- It comprises at least one panel, which, in the rest position, extends across the opening and cooperates with at least one flap in the closed position to close the opening;

- It comprises at least one panel, which, in the rest position, extends across the opening and cooperates with two flaps in the closed position to close the opening, the two flaps being contiguous with the panel interposed between the two parts;

- It comprises two panels, which, in the rest position, extend across the opening and cooperate with a flap in the closed position to close the opening, the flap being joined with the two panels and interposed between the two panels ;

the cavity is delimited between two opposing non-planar surfaces, the opening being formed in one of the surfaces, the panel coming, in the active position, in sealing contact with the other of the two surfaces;

it comprises at least one panel having a recess delimiting, in the active position of the panel, a molding volume in communication with the first molding compartment, of a shape adapted to form on the first portion, a form of mutual engagement between the first portion and the second portion; the recess is formed at the junction between a contact region of the panel in leaktight contact, in active position of the panel with another element of the mold for separating the first and second compartments, and a face of the panel delimiting the first compartment;

the molding volume is defined between the recess and a surface of the wall of the cavity opposite the opening in sealing contact with the contact region of the panel; and the panel having the recess is a panel which, in the rest position, is set back from the opening on the side opposite to the cavity, or a panel which, in the rest position, closes the opening.

The invention also relates to a method for injection molding a workpiece comprising at least a first portion and a second contiguous portion from molding and made of different materials, comprising the successive steps of:

moving at least one panel into an active position in which the panel extends into a mold cavity and separates it into at least two mold compartments of the first and second portions;

injecting a first material into a first of the two compartments;

moving the at least one panel to a rest position, in which the panel is withdrawn from the cavity through an opening in a wall of the cavity, to join the two compartments;

- Close the opening at least partially with at least one closure flap;

injecting a second material into a second of the two compartments. According to optional features of the method: at least one panel is moved into a rest position in which it is set back from the opening.

at least one panel is moved into a rest position, in which the panel cooperates with at least one flap to close the opening.

The invention also relates to a molded part comprising at least a first portion and a second contiguous portion derived from moldings and made of different materials, obtained by means of a mold as defined above, or according to a method as defined herein. - above.

The invention and its advantages will be better understood on reading the description which follows, given solely by way of example, and with reference to the appended drawings, in which:

- Figure 1 is a schematic perspective view of a mold according to a first embodiment of the invention;

- Figures 2 to 4 are schematic views in front section of the mold of Figure 1, illustrating panels and movable flaps of the mold in different configurations;

- Figures 5 to 7 are schematic side sectional views of the mold of Figure 1, illustrating a panel and a flap in positions corresponding to the configurations respectively of Figures 2 to 4;

FIG. 8 is a schematic view of a part molded using the mold of FIG. 1; - Figure 9 is a view similar to that of Figure 1, illustrating a mold according to a second embodiment;

- Figures 10 to 14 are schematic front sectional views of the mold of Figure 9, illustrating panels and movable flaps of the mold in different configurations; - Figures 15 to 17 are views similar to that of Figures 5-7, illustrating a panel according to an alternative embodiment, and a corresponding flap;

- Figures 18 and 19 are views similar to that of Figures 15 and 17, illustrating another panel of the mold according to the third embodiment; and

- Figures 20 and 21 are front views along XX-XX and in section along XXI-XXI of a molded part of Figure 17.

As shown in FIG. 1, the mold 2 comprises a lower die 6 and an upper die 8 defining, when they are joined together, a molding cavity 10 whose wall is defined by a surface 12 of the die 6 and a surface 14 of the matrix 8 opposite. The surfaces 12 and 14 are non-planar.

The mold 2 comprises several panels 16, 18, 20, here three in number, insertable in the cavity 10 by an elongated opening 22 formed in the surface 12, to divide the cavity 10 into two molding compartments 24 and 26. The panel 18 is located between the panels 16 and 20.

The mold 2 comprises separate supply means of the compartments 24 and 26 of plastic material in the liquid or semi-liquid state, comprising a feed orifice 28 of the compartment 24 and a supply port 30 of the compartment 26 formed in the matrix 8.

The mold 2 further comprises flaps 32, 34, here two in number, each of which makes it possible to close an end region of the opening 22.

As shown in Figures 2 to 4, each of the panels 16, 18 and 20 is movable through the opening 22 between an active position (Figure 2), in which it extends into the cavity 10 to divide into two compartments, and a rest position (Figures 3 and 4), in which it is extracted from the cavity 10 through the opening 22.

In the active position (Figure 2), each of the panels 16, 18 and 20 has an edge, respectively 36, 38 and 40, in sealing contact with the surface 14. The panels 16, 18 and 20 are joined together sealingly. The panels 16, 18 and 20 thus form a partition 42 sealingly separating the compartments.

The edge 38 is rectilinear, and the edges 36 and 40 are in an arc. In the rest position, the panels 16 and 20 are set back from the opening 22 on the side opposite the cavity 10. In other words, the panels 16 and 20 are disengaged from the opening 22. The panel 18 is extracted of the cavity 10 so that the edge 38 sealingly closes the central region of the opening 22. The flaps 32 and 34 are movable between an open position

(Figures 2 and 3), wherein each of the flaps 32 and 34 is clear of the opening 22 to allow the extension of the panels 16, 18 and 20 in the active position in the cavity 10 through the opening 22, and a closing position (FIG. 4), in which each of the flaps 32 and 34 closes an end region of the opening 22.

The flaps 32 and 34 have blades, respectively 44 and 46, inserted in the opening 22 in the closed position of the flaps 32 and 34, and having profiles that adapt to the surface 12 in the end regions. of the opening 22. In the closed position of the flaps 32 and 34, the blades 44 and 46 are contiguous with the edge 38 of the panel 18 in the rest position, and cooperate with the latter to close the opening 22 so as to waterproof. The panel 18 is interposed between the flaps 32 and 34.

Thus, in the rest position, the panels 16 and 20 are replaced by the flaps 32 and 34, the latter cooperating with the panel 18 to close the opening 22, so that the cavity 10 is closed.

Referring to FIGS. 5 to 7, in which only the panel 16 and the flap 32 are visible, the panel 16 is movable through the opening 22 between its active position (FIG. 5) and its rest position (FIGS. 7) in translation in a direction A1, and the flap 32 is movable between its open position (FIGS. 5 and 6) and its closed position (FIG. 7) in a direction A2, the directions A1 and A2 being parallel to secant plans. The panel 20 and the flap 34 move in a similar manner.

Thus, in the open position, the flaps 32 and 34 in the open position do not prevent the displacement of the panels 16 and 20, and the flaps 32 and 34 can move in the closed position without being obstructed by the panels 16 and 20 in the rest position. In a process for producing a molded plastic part, in a first step corresponding to FIGS. 2 and 5, the panels 16, 18 and 20 are in the active position, so that the compartment 24 is delimited by the surfaces 12 and 14 and the panels 16, 18 and 20, and a first plastic material is injected into the compartment 24 to form a first portion 48 of the workpiece. In a second step corresponding to Figures 3 and 6, after solidification of the plastic material, the panels 16, 18 and 20 are moved to the rest position, so that the compartments 24 and 26 are placed in communication. The lateral end regions of the opening 22 are thus released, the central region being closed by the panel 18.

In a third step corresponding to Figures 4 and 7, the flaps 32 and 34 are moved in their closed position, so that the opening 22 is closed by the flaps 32 and 34 and the panel 18, and that the compartment 26 is delimited between surfaces 12 and 14, the first material, and the flaps 32 and 34, and the panel 18. A second plastic material is injected into the compartment 26 to form a second portion 50 of room.

The second material solidifies by contacting the first material and bonding thereto by welding or gluing. Finally, a piece 52 is obtained as illustrated in FIG. 8.

Advantageously, the cooling or the solidification of the first injected plastic material is partial, of such material that the first material is sufficiently ductile to the core so that, during the injection of the second material, a greater or lesser interpenetration occurs. of both matters.

According to an increasing level of cooling, a weld is obtained, that is to say an interpenetration of the two materials or a bond, that is to say a surface adhesion between the two materials by superficial melting.

For the molding of a next part, the panels are moved in a reverse sequence.

The embodiment of FIG. 9, where the references to elements similar to those of FIGS. 1 to 7 have been retained, differs from the first embodiment in the number of separation panels of the compartments 24 and 26.

The mold 2 comprises two lateral panels 16 and 20, a central panel 18, and two intermediate panels 54 and 56 interposed respectively between the panels 16 and 18, and the panels 18 and 20.

In their active position (FIG. 10), the panels 16, 18, 20, 54 and 56 extend into the cavity 10 and are joined to form a partition 42 for the sealed separation of the compartments 24 and 26. In this position, the edges 36, 58, 38, 60 and 40 of the panels respectively 16, 54, 18, 56 and 20 are in sealing contact with the surface 14.

The opening 22 is less extensive along its length than the partition 42. The panels 16 and 20 extend laterally beyond the ends of the opening 22, to come into contact with the surface 14.

In their rest position (FIG. 14), the panels 54 and 56 are set back from the opening 22, on the opposite side to the cavity, so that they do not interfere with the flaps 32 and 34, and the panels 16, 18 and 20 are arranged so that their edges 36, 38 and 40 each close a region of the opening 22.

In the open position (FIG. 10), the flaps 32 and 34 are disengaged from the opening 22.

In the closed position (FIG. 14), the flaps 32 and 34 are respectively interposed between the panels 16 and 18, and the panels 18 and 20, and cooperate with these to close the opening 22.

The displacement of the configuration of Figure 10 to that of Figure 14 is effected for example by first moving the panels 54 and 56 in the rest position (Figure 11), which provides space between the panels 16 and 18, and between panels 18 and 20.

Sequentially or simultaneously, the panel 18 is moved to the rest position (FIG. 11).

Then, the flaps 32 and 34 are moved so that their blades 44 and 46 close the opening 22, on either side of the panel 18, taking advantage of the gaps between the panels 16, 18 and 20 (Figure 12). .

The flaps 32 and 34 are narrower than the panels 54 and 56.

It is therefore possible from the configuration reached (FIG. 12) to bring the panels 16 and 20 closer to the panel 18 (FIG. 13). to then be able to move them to their rest position through the opening 22 (Figure 14).

In this position, each of the flaps 32 and 34 is interposed and joined with two adjacent panels. The panels 16 and 20 move between their active position and their rest position successively in two perpendicular directions, one of the directions being parallel to the direction of movement of the panel 18.

In general, the panels can move in rectilinear or non-rectilinear movements, in parallel directions, perpendicular or inclined with respect to each other, depending on how they must cooperate in the active position and in the rest position.

As shown in Figures 15 to 17, a panel 16 differs from the corresponding panel of Figures 5 to 7 in that it comprises, at the junction between its edge 36 provided for sealing contact with the surface 14, and its face 62 turned to the compartment 24, a recess 64 defining with the surface 14, when the panel 16 is in the active position (Figure 15), a molding volume of a fastening member 66 projecting on the first portion 48 (Figure 15 and 16), complementary to the volume.

During the second molding step performed after displacement of the panel 16 in the inactive position set back from the opening 22 (FIG. 16) and displacement of the flap 32 in the closed position (FIG. 17) of the opening 22, an element of FIG. hooking 68 complementary to the fastening member 66 is formed on the second portion 50 in a molding volume in communication with the compartment 26, and defined between the flap 32 and the portion 48.

As illustrated in FIGS. 18 and 19, in a similar way, it is possible to provide a panel 18 which, in the rest position (FIG. 19), closes the opening 22, adapted to form complementary fastening members engaged on the portions 48 and 50, providing, at the junction between its edge 38 provided for sealing contact with the surface 14, and its face 70 rotates the compartment 24, a recess 72 defining with the surface 14, when the panel 18 is in the active position (Figure 18), a molding volume of a fastening member 74 projecting. In the rest position (FIG. 19), the panel 18 makes it possible to mold a complementary fastening member 76 on the second portion 50 in a molding volume in communication with the compartment 26 delimited between the recess 72 and the portion 48.

A mold comprising one or more panels 16 and / or one or more panels 18 as illustrated in FIGS. 15 to 19 makes it possible to produce a sequentially bi-injected part offering increased mechanical strength between the two portions of the bi-injected part. .

It will be noted that, in FIGS. 15 to 19, each of the panels 16 and 18 extends into the cavity 10 through an opening 22 formed in a surface 12 delimiting the cavity 10, and comes into sealing contact, in the active position, with an opposite surface 14 delimiting the cavity 10. The separation of the compartments and the formation of the fastening members are therefore obtained with a limited number of parts with simple movements.

In Figure 20, there is shown the part 52 in a plan view of its face intended to be the visible face. The part 52 consists of the first portion 48 and the second portion 50.

In this figure 20, it is illustrated that the junction line L between the two portions 48 and 50 could be obtained with great clarity, in the absence of interpenetration of the two plastics.

In Figure 21, the same part 52 has been illustrated, seen in section in its thickness. FIG. 21 illustrates that the shapes 78, 80 of mutual hooking between the two portions 48 and 50 could be of various profiles.

In the plane of Figure 21, the attachment forms shown are a T-shape 78, and a shape 80 harpoon or arrow.

The use of closure flaps makes it possible to close the insertion opening of the panels, even if it has a complex three-dimensional geometry. The use of some of the panels to close the opening limits the number of flaps, which makes the mold less expensive to manufacture. The use of shutters also makes it possible to adapt the size of each of the panels, in order to obtain sufficiently rigid panels to prevent deformation of the panels, during the injection under pressure of the first plastic material, breaking the tightness between the joined panels or with the wall of the cavity. The molds and related methods just described can be used to manufacture a wide variety of plastic parts having a plurality of adjacent portions made of compatible plastic and assembled together by welding or gluing, but of nature and / or of different color. The molds make it possible to obtain bi-material parts by sequentially injecting different materials into the compartments, and also to manufacture single-material parts, by bringing the compartments together before injecting material, then injecting the same material with a material. or multiple feed ports. It is possible to use panels sealing with a wall of the molding cavity and provided with recesses allowing the formation of fastening members between portions of a bi-injected part independently of closure flaps, retaining the advantages of improved mechanical bonding of the portions. Thus, such panels can be used in particular in a mold without shutters, and whose openings for moving the panels are closed, in the rest position of the panels, by all or at least a portion of the panels.

The invention applies to molds for the manufacture of motor vehicle dashboard parts or motor vehicle interior facing parts, or any other plastic parts for interior or exterior of a motor vehicle .

Claims

1. Mold (2) of injection molding of a workpiece comprising at least a first portion and a second contiguous portion from molding and made of different materials, of the type comprising a molding cavity (10), and at least one panel (16, 18, 20, 54, 56) for separating the cavity into at least two molding compartments (24, 26) of the first and second portions, the panel being movable between an active position, wherein the panel (16 , 18, 20, 54, 56) is extended in the cavity (10) to separate the two compartments (24, 26), and a rest position, in which the panel (16, 18, 20, 54, 56) is removed from the cavity (10) to join the two compartments (24, 26), the panel (16, 18, 20, 54, 56) moving between the active position and the rest position through an opening (22) formed in a wall (12) of the cavity (10), characterized in that it further comprises at least one flap (32, 34) movable between a position d opening, in which the flap (32, 34) is disengaged from the opening (22) to allow movement of the panel (16, 18, 20, 54, 56) in the active position, and a closed position, in which the flap (32, 34) closes at least one region of the opening (22) to close the cavity (10) when the panel (16, 18, 20, 54, 56) is in the rest position.

2. Mold according to claim 1, characterized in that the panel (16, 18, 20, 54, 56) is movable, between the active position and the rest position, in a direction parallel to a first plane, the shutter (32, 34) being movable between the closed position and the open position in a direction parallel to a second plane, the first plane and the second plant being intersecting.

3. Mold according to claim 1 or 2, characterized in that it comprises several panels (16, 18, 20, 54, 56), the panels in the active position being contiguous and forming a partition (42) separating the two compartments (24, 26).

4. Mold according to any one of the preceding claims, characterized in that it comprises at least one panel (16, 20; 54, 56) which, in the rest position, is set back from the opening (22). ) on the opposite side to the cavity (10).

5. Mold according to any one of the preceding claims, characterized in that it comprises at least one panel

(18; 16, 18, 20) which, in the rest position, extends across the opening (22) and cooperates with at least one flap (32, 34) in the closed position to close the opening ( 22).

6. Mold according to claim 5, characterized in that it comprises at least one panel (18) which, in the rest position, extends across the opening (22) and cooperates with two flaps (32, 34) in the closed position to close the opening (22), the two flaps (32, 34) being contiguous with the panel (18) interposed between the two flaps (32, 34).

7. Mold according to claim 5 or 6, characterized in that it comprises two panels (16, 18; 18, 20), which, in the rest position, extend across the opening (22) and cooperate with a flap (32; 34) in the closed position to close the opening (22), the flap (32; 34) being joined with the two panels (16, 18; 18, 20) and interposed between the two panels (16, 18; 18, 20).

8. Mold according to any one of the preceding claims, characterized in that the cavity is defined between two surfaces (12, 14) non-planes opposite opposite, the opening (22) being formed in one (12) surfaces (12, 14), the panel (16, 18, 20, 54, 56) coming, in active position, in sealing contact with the other (14) of the two surfaces (12, 14).

9. Mold according to any one of the preceding claims, characterized in that it comprises at least one panel

(16, 18) having a recess (64, 72) delimiting, in the active position of the panel (16, 18), a molding volume in communication with the first molding compartment (24), of a shape adapted to form on the first portion (48), a form of attachment (66, 74, 78, 80) mutual between the first portion (48) and the second portion (50).

10. Mold according to claim 9, characterized in that the recess is formed at the junction between a contact region (36, 38) of the panel (16, 18) in sealing contact, in the active position of the panel (16, 18) with another mold member for separating the first and second compartments (24, 26), and a panel face (16, 18) defining the first compartment (24).

11. Mold according to claim 10, characterized in that the molding volume is defined between the recess (66, 72) and a surface (14) of the wall of the cavity (10) opposite the opening (22). ) in sealing contact with the contact region (36, 38) of the panel (16, 18).

12. Mold according to any one of claims 9 to 11, characterized in that the panel (16, 18) is a panel (16), which, in rest position, is set back from the opening (22) on the opposite side to the cavity (10), or a panel (18) which, in the rest position, closes the opening (22).

13. A process for injection molding a workpiece comprising at least a first portion and a second contiguous portion obtained from molding and made of different materials, comprising the successive steps of:

moving at least one panel (16, 18, 20, 54, 56) into an active position in which the panel extends into a mold cavity (10) and separates it into at least two compartments (24, 26) of molding the first and second portions;

injecting a first material into a first of the two compartments (24, 26); moving the at least one panel (16, 18, 20, 54, 56) to a rest position, in which the panel is extracted from the cavity (10) through an opening (22) in a wall of the cavity to join the two compartments (24, 26);

- Close the opening at least partially with at least one closure flap (32, 34);

injecting a second material into a second of the two compartments (24, 26).

14. A process according to claim 13, wherein at least one panel (16, 20; 54, 56) is moved into a rest position in which it is set back from the opening (22).

15.- Method according to one of claims 13 and 14, wherein is moved at least one panel (18; 16, 18, 20) in a rest position, in which the panel (18; 16; 18; 20) cooperates with at least one flap (32; 34) to close the opening (22).

16.- molded part comprising at least a first portion and a second contiguous portion from moldings and made of different materials, having non-flat surfaces at the junction of the contiguous portions, obtained by means of a mold according to any one of Claims 1 to 12, or according to a process according to any one of Claims 13 to 15.