DE19542102A1 - Moulding tool for injection of multi=component tooth brush handles - Google Patents

Abstract

A tool for multicomponent moulding of plastics handles for toothbrushes or similar products includes ejection side (4) and fixed nozzle side tool plates each with a first set of cavities (6a) for injecting brush body preforms and a second set of tool cavities (6b) for injecting around the moulded preforms to complete the body mouldings. Both sets (6a,6b) of tool cavities have their bristle head ends (7) facing in the same direction and brush body holders (13,14) with cavity sections (18) for the brush heads are moved between both sets of cavities by a transporting system (8). A recess (20) in the ejection side plate (4) at the head end of both sets of cavities (6a,6b) receives the brush bodies holders (13,14).

Description

The invention relates to a tool for multi-component injection molding of plastic brush bodies for toothbrushes or the like, wherein the brush body in some areas from several, components injected one after the other and where the Injection mold at least one ejector-side mold plate and a fixed die plate on the nozzle side, each with the first Mold nests for spraying basic bodies and with second ones Mold nests for overmolding the base body or Has pre-injection of the brush body, with a transport direction for transporting the basic body moldings from the the first mold nests to the second mold nests is provided.

There are already injection molding machines with a turning tool for Spraying of multi-component brushes, for example two-tone toothbrushes.

In these, a base body is first injected, which after this Spraying process remains in the part of the mold half in which none Changes can be made more. After that first splash the tool holding the base body is, for example Rotated 180 degrees and so the base body a second spraying process fed. This second spraying process then takes place at  Example a partial injection molding of the base body, so that as a final product, for example a two or multi-colored toothbrush body arises.

From DE 91 03 553 U1 one also knows a tool for Multi-component injection molding of brush bodies with one Reversible carrier is equipped, which is both a rotary and a Can perform lifting movement and through which the injection molded Molded body from the first mold cavity and through Pivoting through 180 ° into the second mold cavity, whereupon this is then encapsulated. Both this tool and turning tools are also comparatively complex to build. It is also disadvantageous in the case of turning tools that the turning part a comparatively large mass and thus a large inertia torque, which increases wear on the drive caused.

The object of the present invention is to provide a tool for Multi-component injection molding to create that in terms of Construction is simplified and its manufacturing costs overall is significantly reduced.

To solve this problem it is proposed that the first and the second mold nests with their brush head ends in the same Direction are arranged so that the first and in the second mold nests of the ejector-side mold plate positionable brush body holding devices with mold cavity sections are provided at least for brush head areas, that in this mold plate at the head ends of the first and second Mold cavities each have at least one recess for receiving the Brush body holders are provided and that a Transport device for alternating, linear back and forth Transporting the brush body holding devices between the two receiving recesses is provided.

The intended design of the transport device is for the injection mold itself a simple basic construction, like it can also be used for one-component spraying. The effort compared to multi-component turning tools  injection molding is considerably reduced.

The effort for the transport device is also compared for turning tools and tools with a turning carrier less. By holding the brush body Base body or base body molded parts can existing elements, namely those that already intervene in the brush body head Punch punches are used, which is also used for the construction ver simplification.

By the same direction with the brush head molding area pointing first mold nests for the base body and the second Shape nests for the finished brush body, enough for the Transport of the basic body moldings from the first mold nests a simple linear movement to the second form nests, the is mechanically simple to implement.

The alternately engaged with the mold nests Brush body holders allow a very quick Change, since both holding devices in the opposite direction at the same time are positionable.

One embodiment provides that the transport device at least two longitudinally movable portal parts with between the Form plates located, the brush body holding devices has transverse traverses and that the outer contour of one Portal part is smaller than the clear internal cross section of the other portal part.

This construction results in a particularly stable and precise guidance of the office formed here by cross members body support devices.

The portal parts of the transport device are advantageously laterally outside of the mold plates on longitudinal sliding guides stored, with lifting drives at the side supports of the portal parts provided for the lifting movement of the cross members or the like are.

The motion drives and guides for the positioning motion the brush body holders formed in particular by cross members devices are thus outside the mold plates, so that no changes to the mold plates have to be made.  

This also means that the guides are simple to construct and the movement drives favored.

The longitudinal sliding guides are expediently the transport unit direction in the opening and closing direction of the mold one above the other arranged. Laterally next to the mold plates or next to the ejector-side mold plate is thus little space claimed for the guides.

According to another embodiment it is provided that the Transport device each within the outline of the mold plates Has longitudinal sliding guides with which each lifting elements are connected, each at their free ends Wear crossbar forming brush body holders. This variant is also simple in construction and enables a particularly space-saving construction.

The cavity sections are expedient in the crossbeams at least for brush head areas of the ejector-side mold plate provided, in this ejector-side mold plate at the Head ends of their mold cavities recesses for receiving the Cross members are provided and that the cross members height adjustable and alternating with the different mold nest areas of the mold plates are positionable.

These crossbars with the mold cavity sections on the head can varies in size depending on the number and location of the mold cavities and be adapted to the respective requirements.

At a small footprint and a design simplification also contributes if in the longitudinal sliding guides and / or the Side supports and / or the lifting elements of the transport devices Lift actuators are integrated.

According to one embodiment of the invention, the first mold cavities and the second mold nests in preferably aligned rows arranged lengthwise one behind the other.

According to another embodiment, the first mold nests and the second mold nests in preferably parallel rows are arranged side by side.

Both embodiments have in common that for transport  the basic body from the first to the second form nests simple Linear movements are sufficient. This also applies if the Mold cavities are arranged at an angle, but pointing in the same direction are.

The orientation of the mold cavities in relation to the linear trans port movement can depend, among other things, on the number the mold nests of a mold nest group to be arranged side by side be provided.

Additional embodiments of the invention are in the others Subclaims listed. The following is the invention with their essential details with reference to the drawings explained.

It shows something schematically:

Fig. 1 is a side view of a tool for multi-component injection molding at the open injection mold,

Fig. 2 is a plan view of an ejector die plate with transport means for the brush body,

Fig. 3 is a sectional view of the tool shown in Fig. 1 corresponding to FIGS. 1 position,

Fig. 4 is a view according to FIG. 3, but here ner at geschlosse injection mold,

Fig. 5 is a view according to Fig. 3 and 4, but here in the open injection mold

Fig. 6 is embodied as a stack mold tool for the multicomponent injection molding,

Fig. 7 is a side view of a tool for multi-component injection molding with the injection mold open with opposite

Fig. 1 modified transport device and

Fig. 8 is a plan view of the ejector-side mold plate according to FIG. 7 with transport device for brush bodies.

An example shown in Fig. 1 Tool 1 is 2 (Fig. 5) for multi-component injection molding of plastic or the like brush bodies for tooth brushes. In some areas, these brush bodies consist of several components that are sprayed one after the other. There is first a main body 2 a (Fig. 1, 3 to 6) injected, which is then encapsulated in a second operation, in certain areas to form a finished brush body.

The tool 1 shown in Fig. 1 comprises an injection mold 3 with an ejector die plate 4 and a nozzle-side mold plate 5.

As can be seen well in the ejector-side mold plate 4 according to FIG. 2, two groups of mold nests, namely first mold cavities 6 a for spraying basic bodies 2 a and second mold cavities 6 b for overmolding the basic bodies and for pre-spraying the brush bodies 2, are provided. Both the first and the second group of mold nests consisting of several, parallel arranged mold nests. In the exemplary embodiment, four mold cavities of one type are arranged next to one another, the number also being significantly larger, for example 16 mold cavities next to one another.

It can also be clearly seen that the individual mold nests of the first group are arranged in longitudinal alignment with the individual mold nests of the second group. Furthermore, it can be seen that they are arranged with their brush head regions 7 pointing in the same direction.

Depending on the available space, the mold nests of the individual groups can also be arranged in a different position, for example transversely to the linear transport direction, in which the base bodies 2 a are converted from the first mold nest group to the second. In such an arrangement, the mold cavities are preferably arranged at right angles to the direction of transport.

After injection of the base body 2 a in the first mold nests 6 a, these are transported into the second mold nests 6 b.

For this purpose, a transport device 8 is used , which in the exemplary embodiment according to FIGS. 1 and 2 is essentially formed by two portal parts 9 and 10 which are mounted laterally displaceably on the longitudinal slide guides 11 and 12 next to the ejector-side mold plate 4 .

The portal parts 9 and 10 each have a crossbar 13 and 14 and side supports 15 and 16 , the side supports are expediently formed by lifting cylinders 17, which are on the one hand with the crossbars 13 and 14 and on the other hand with the associated longitudinal sliding guides 11 and 12 are connected. As can be clearly seen in Fig. 1, the portal parts 9 and 10 are designed so that they can be moved past each other in opposite movements. The clear inner cross section of the portal part 9 is larger than the outer contour of the portal part 10 . As a result, these portal parts can be practically moved through one another in opposite directions.

As can be clearly seen in FIG. 2, the crossbars 13 and 14 forming the brush body holding devices have mold cavity sections 18 for the brush head regions 7 , which together with the mold cavity sections 19 a and 19 b located in the mold plate 4 form the first mold cavities 6 a and form the second mold cavities 6 b. To accommodate the crossbeams 13 and 14 , preferably open-edge receiving grooves 20 are provided in the molding plate 4 (cf. FIGS . 3 to 6).

The receiving grooves 20 are dimensioned such that perforated pin arrangements with perforated pin holding plates 21 arranged on the underside of the crossbar 13 or 14 have space. On the hole pin holding plates 21 hole pins 22 are attached, the number and position of which correspond to the later bristle field of the toothbrush. The perforated pins 22 pass through guide holes 23 in the crossbeams 13 and 14 and, in the injection position, protrude into the mold cavity area when the mold is closed (cf. FIG. 4).

The perforated pin holding plates 21 with the perforated pins 22 can be moved relative to the crossbeams 13 and 14 , and from an injection and holding position ( FIG. 3 on the left), where they protrude into the mold cavity, into an ejection position spaced apart from the crossbeam ( FIG. 3 right side), where they are pulled out of the fully sprayed brush body 2 , are adjustable. The receiving groove 20 assigned to the second mold nests 6 b is correspondingly deeper for this pull-out movement of the pin holder plates 21 with the pin pins 22 .

Starting from the working position of the tool 1 shown in FIG. 4 with the injection mold 3 closed, the injection mold is opened, the ejector-side mold plate 4 being moved away from the nozzle-side, fixed mold plate 5 . In the injection process, a number of Grundkör were simultaneously pern 2 a and sprayed a number of finished brush bodies. 2 In Figs. 2 to 6 while the main body in the first mold cavities 6 a left side and the finished brush body in the second mold cavities are 6 b injected right side.

After the injection mold has been opened, the finished brush bodies 2 are ejected, as shown in FIG. 5. Ejector pins 24, which are attached to ejector plates 25, are used for this purpose. These are adjustably mounted within a free space 28 between the mold plate 4 and a base plate 26 (cf. also FIG. 1) and connected to an ejector rod 27 .

After ejection of the finished brush body 2 in which the punching pins 22 are retracted, the transverse members are lifted 13 and 14 via the lifting cylinder 17 of the portal members 9 and 10 out of their receiving grooves 20, so that the position shown in Fig. 3 is established. In a counter-rotating transfer movement according to the arrows PF 1 and PF 2, the portal parts 9 and 10 travel along their longitudinal sliding guides 11 and 12 respectively in an alternating position with the cross-member 14 empty at the receiving groove 20 of the first mold cavities 6a and the transverse member 13 hanging with it Base bodies 2 a are brought into the receiving groove 20 of the second mold cavities 6 b.

During transport, the main body molded parts 2 a are securely held at their head ends with the aid of the pin 22 engaging there. The mold is then closed and the starting situation results again, as shown in FIG. 4 after the subsequent injection process.

For the transport movement of the portal parts 9 and 10 along the longitudinal sliding guides 11 and 12 , pneumatic lifting drives can preferably be provided, which are optionally integrated into the guide rods of these longitudinal sliding guides. As already mentioned, the side supports 15 and 16 are preferably formed by lifting cylinders 17 . However, telescope guides could also be provided here and separate linear actuators. As can be clearly seen in FIG. 1, the longitudinal sliding guides 11 and 12 are arranged one above the other on both sides of the molding plate 4 in order to keep the lateral space requirement small.

FIGS. 3 to 6 can still well recognize that are conically formed, the partition walls of the receiving grooves 20 and the respective partition walls of the cross beams 13 and 14 toward widening the free, open end. As a result, a self-centering when inserting the cross members 13 and 14 and a precise fit in the inserted position is achieved.

FIG. 6 shows a so-called stack mold 1 a, which is formed by two injection molds 3 arranged in mirror image to a central plane of symmetry S. The fixed mold plates 5 on the nozzle side lie here directly at the plane of symmetry S and, as described for the tool according to FIGS . 1 to 5, adjoin the mold plates 4 on the ejector side, ejector plates 25 and base plates 26 on the outside. It is advantageous here that a much larger number of mold nests can be accommodated with the same circumferential cross section and that despite this high number of mold nests, the same closing forces as with the molds according to FIGS. 1 to 5 or FIGS. 7 and 8 are sufficient with respect to the injection molding machine.

In addition to the construction of the shown in the embodiment Transport device with portal parts, there is also the Possibility of one-sided mounted on a longitudinal sliding guide To provide trusses. In addition, a cross beam could also be attached Longitudinal sliding guides that are guided with the nozzle-side Form plate are connected.  

FIGS. 7 and 8 show a tool 1 b with respect to FIG. 1 and 2 modified transport device 8 a.

This transport device 8 a has a longitudinal sliding guide 29 , 29 a, which is arranged in the center of the mold plates 4 , 5 and on which two lifting elements 30 , 30 a are mounted so as to be longitudinally displaceable. At the free ends of the lifting members 30, the cross traverse 13 and a is the cross-member 14 attached to the lifting elements 30th

In the extended position of the crossbeams 13 , 14 shown in FIG. 7, they are located in mutually spaced planes, so that they can be moved past one another for the alternating movement. With this transport device 8 a, the cross members 13 and 14 between the two mold nest groups 6 a, 6 b can be implemented alternately.

Characterized in that the guide and the associated lifting elements of the cross-beam 13 are in the nozzle-side mold plate and the guide and associated lifting elements for the cross-beam 14 in the ejector-side mold plate 4 , the cross beams 13 and 14 can be moved past one another without any problems during a positioning change, only a linear movement and a lifting movement are also required here.

The integrated within the mold plates Längsschiebeführun gen 29, 29 a particularly compact tools 1b can be realized. In addition, the design effort is again considerably reduced.

Common to all of these embodiments is that each is simple Linear movements without turning movements to position the Parts carrying mold cavity sections at the head end are sufficient.

Claims (17)

1. Tool for multi-component injection molding of plastic brush bodies for toothbrushes or the like, wherein the brush bodies ( 2 ) consist in some areas of a plurality of components that are sprayed one after the other, and wherein the injection mold ( 3 ) has at least one ejector-side mold plate ( 4 ) and a nozzle-side, fixed mold plate ( 5 ) each with first mold nests ( 6 a) for injecting base bodies ( 2 a) and at least with second mold nests ( 6 b) for overmolding the base body or for pre-spraying the brush body, with a transport device ( 8 ) for transporting the base body molded parts ( 2 a) is provided from the first mold nests to the second mold nests, characterized in that the first and the second mold nests ( 6 a, 6 b) with their brush head ends ( 7 ) are arranged pointing in the same direction, that in each case with the first and in the second mold nests of the ejector-side mold plate ( 4th ) positionable brush body holding devices ( 13 , 14 ) with mold cavity sections ( 18 ) at least for brush head areas are provided that in this mold plate at the head ends of the first and second mold nests at least one recess ( 20 ) for receiving the brush body holder devices ( 13 , 14 ) is provided and that a transport device ( 8 ) for alternating, linear back and forth transport of the brush body holding devices ( 13 , 14 ) is provided between the two receiving recesses ( 20 ). 2. Tool according to claim 1, characterized in that the transport device ( 8 ) has at least two longitudinally displaceable portal parts ( 9 , 10 ) with cross members ( 13 , 14 ) located between the mold plates ( 4 , 5 ) and forming the brush body holding devices, and in that the outer contour one portal part ( 10 ) is smaller than the clear internal cross section of the other portal part ( 9 ). 3. Tool according to claim 1, characterized in that the transport device ( 8 a) in each case within the outline of the mold plates ( 4 , 5 ) has longitudinal sliding guides ( 29 , 29 a), with each of which lifting elements ( 30 , 30 a) are connected, each carry at their free ends a crossbar ( 13 and 14 ) forming the brush body holding devices. 4. Tool according to one of claims 1 to 3, characterized in that in the cross members, the mold cavity sections ( 18 ) are provided at least for brush head areas of the ejector-side mold plate ( 4 ) that in this ejector side mold plate gene at the head ends of their mold nests ( 6 a , 6 b) Recesses ( 20 ) for receiving the cross members ( 13 , 14 ) are provided that the cross members are adjustable in height and can be positioned alternately in the different cavity areas of the mold plates. 5. Tool according to claim 1, 2 or 4, characterized in that the portal parts ( 9 , 10 ) of the transport device ( 8 ) laterally outside of the mold plates ( 4 , 5 ) on longitudinal slide guides ( 11 , 12 ) are mounted and that at the Side supports ( 15 , 16 ) of the portal parts or the like, lifting drives ( 17 ) are provided for the lifting movement of the crossbeams. 6. Tool according to one of claims 1 to 5, characterized in that the lateral longitudinal sliding guides ( 11 , 12 ) for the brush body holding devices or cross members ( 13 , 14 ) or the like are arranged one above the other in the opening and closing direction of the mold. 7. Tool according to one of claims 1 to 6, characterized in that in the longitudinal sliding guides ( 11 , 12 , 29 , 29 a) and / or the side supports ( 15 , 16 ) and / or the lifting elements ( 30 , 30 a) the transport device ( 8 , 8 a) lifting drives are integrated. 8. Tool according to one of claims 1 to 7, characterized in that the recesses provided in the ejector-side mold plate ( 4 ) for receiving the cross members or the like brush body holding devices are designed as continuous, open-edge receiving grooves ( 20 ). 9. Tool according to one of claims 1 to 8, characterized in that the partitions of the recesses ( 20 ) for receiving the cross members ( 13 , 14 ) or the like and the partitions of the cross members in the transverse to the longitudinal extension of the mold cavities Separation area are conical. 10. Tool according to one of claims 1 to 9, characterized in that the brush head holding devices through the crossbars ( 13 , 14 ) or the like and by arranged below them, relative to the crossbars movable pin assemblies with pin holding plates ( 21 ) and the crossbars penetrating Hole pins ( 22 ) are formed. 11. Tool according to one of claims 1 to 10, characterized in that on the side facing away from the mold nests of the ejector-side mold plate ( 4 ), between a base plate ( 26 ) and this mold plate, are arranged with a Hubvor direction connected ejector plates ( 25 ), to which the ejector pins ( 24 ) are attached. 12. Tool according to one of claims 1 to 11, characterized in that it has a multi-level mold ( 1 a) with one or two central, die-side mold plates ( 5 ) and adjoining ejector-side mold plates ( 4 ) as injection mold. 13. Tool according to one of claims 1 to 12, characterized in that the first mold cavities ( 6 a) and the second mold cavities ( 6 b) are arranged longitudinally one behind the other in preferably aligned rows. 14. Tool according to claim 13, characterized in that for the base body ( 2 a) and for the finished brush body ( 2 ) parallel rows of mold nests ( 6 a, 6 b)) are provided, preferably each four to sixteen mold cavities. 15. Tool according to one of claims 1 to 12, characterized in that the first mold cavities ( 6 a) and the second mold cavities ( 6 b) are arranged next to each other in preferably parallel rows. 16. Tool according to one of claims 1 to 15, characterized in that with each within the outline of the mold plates ( 4 , 5 ) arranged longitudinal sliding guides ( 29 , 29 a), these are arranged approximately centrally and longitudinally within the mold plates. 17. Tool according to one of claims 1 to 16, characterized in that the longitudinal sliding guides ( 29 , 29 a) and the respective cross members ( 13 , 14 ) are each connected to one another via two parallel and preferably spaced apart lifting elements ( 30 , 30 a) .