WO2014075756A1

WO2014075756A1 - Method for controlling the temperature of a transfer mould and transfer mould

Info

Publication number: WO2014075756A1
Application number: PCT/EP2013/003155
Authority: WO
Inventors: Simon Brack; Willy Dauner; Till Zimmermann
Original assignee: Daimler Ag
Priority date: 2012-11-15
Filing date: 2013-10-19
Publication date: 2014-05-22
Also published as: DE102012022374A1

Abstract

The invention relates to a method for controlling the temperature of a transfer mould (10) for plastics components (18), in which the temperature of at least one ejector (16) for demoulding a plastics component (18) is controlled, wherein, prior to injection of a plastics material (12) into a cavity (14) of the transfer mould (10), at least one part of the ejector (16) that is enclosed by a guide element (20) is heated up. Furthermore, the invention relates to a transfer mould (10) for plastics components (18).

Description

Method for tempering a transfer molding tool and transfer molding tool

The invention relates to a method for controlling the temperature of a transfer molding tool for plastic components specified in the preamble of claim 1. Art Furthermore, the invention relates to a transfer molding tool for plastic components specified in the preamble of claim 3 Art.

To demould plastic components from a tool cavity ejector pins are usually used. These have the task of pressing the solidified component out of the cavity. During the processing of low-viscosity, thermosetting resin compounds, the penetration of resin into a gap between ejector pin and guide bore occurs time and again. As a result, the ejector pin jams and must be removed and the guide bore cleaned. This leads to increased maintenance and unnecessary downtime.

A generic method is known from DE 100 05 300 C1. To the

Tempering a transfer molding tool for plastic components is tempered at least one ejector for demolding a plastic component. The temperature control serves to be able to cool the ejector as quickly as possible, especially in the area of thorns of the mold, in order to reduce the overall cooling time of the mold.

DE 20 201 1 104 237 U1 describes ejector pins by means of constructive

Measures are sealed. However, no concrete solution for sealing the gap between the ejector pins and guide bores is disclosed.

It is therefore an object of the present invention to provide an improved method for controlling the temperature of a transfer molding tool and a transfer molding tool of the type mentioned, by means of which the reliability of a

Injection molding tool is increased. This object is achieved by means of a method for tempering a

Transfer molding tool with the features of claim 1 and by a transfer molding tool with the features of claim 3 solved. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the dependent claims.

To improve the reliability of a transfer molding tool, it is provided in a method according to the invention that, prior to injection of a plastic into a cavity of the transfer molding tool, at least one part of the ejector enclosed by a guide element is heated. In other words, it is thus provided according to the invention to close a gap between the ejector leading guide element and the ejector resin-tight by a part of the ejector is heated. Preferably, the ejector has a stronger

Thermal expansion as the surrounding this guide element. Thus, a variable clearance is achieved by utilizing the thermal expansion of the ejector pin. This prevents that between the ejector and the guide element plastic or resin can penetrate, so that a blockage of the ejector can be prevented. As a result, elaborate cleaning work on the

Guide element or omitted on the ejector, whereby a total of

Maintenance costs and associated downtime can be significantly reduced.

In an advantageous embodiment of the invention, it is provided that, prior to removal of the plastic component by means of the ejector, at least the part of the ejector arranged in the guide element is cooled. As already explained, as a result of the temperature increase, the ejector first expands and closes a gap between the guide element and the ejector, so that penetration of the resin is prevented. By cooling down the ejector, this tension is released, so that the ejector is movable again and to be demolded

Plastic component can be easily removed from the mold. By cooling down the ejector, moreover, the cycle time of the transfer molding process can be improved since the mobility of the ejector can be restored particularly quickly.

An injection molding tool according to the invention for plastic components comprises at least one temperature-controlled ejector for demolding the plastic component, wherein the injection-compression molding tool according to the invention is characterized in that the ejector Tempering element comprises, by means of which one of a guide element

umschließbarer part of the ejector is heated. Advantageous embodiments of the method according to the invention are as advantageous embodiments of

View injection molding tool, in which case in particular the transfer molding tool comprises means with which the method steps are feasible.

In an advantageous embodiment of the transfer molding tool, it is provided that the part of the ejector which can be enclosed by the guide element by means of the

Temperierelements is coolable. Due to the coolability of the ejector, the

Agility of the ejector relative to the guide member are made in a particularly fast manner, so that the plastic component to be demoulded can be removed from the mold in a simple manner. This improves the cycle time of the transfer molding process.

A further advantageous embodiment of the transfer molding tool provides that the transfer molding tool comprises an ejector plate for receiving the ejector, wherein in the ejector at least one tempering bore through which a temperature control medium, in particular water or oil can flow, is provided

Temperiermedium conductively connects to the tempering. Characterized a temperature of the ejector is made possible in a particularly simple manner, in particular both a heated and a cooled temperature control of the tempering and the tempering is fed.

Finally, it is provided in a further advantageous embodiment of the injection-compression molding tool, that the tempering is formed as a riser or heat pipe, by means of which the tempering is the part of the ejector fed. This allows a reliable temperature control of the ejector can be achieved.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features mentioned above in the description and

Feature combinations as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures are not only in the respectively indicated combination but also in others

Combinations or alone, without departing from the scope of the invention. The drawing shows in:

Fig. 1 is a schematic representation of a method for tempering a

Injection molding tool, wherein the transfer molding tool is shown once in the moment in which an injection of a plastic takes place in a cavity of the transfer molding tool, and wherein the

Once injection molding tool is shown in the situation in which the plastic component is removed from the mold;

Fig. 2 is a schematic representation of a part of the transfer molding tool, showing an ejector plate and an ejector received thereon in detail; and

3 shows a perspective view of an embodiment of the ejector plate with the ejector received thereon, wherein a tempering bore and a tempering element for tempering the ejector are shown.

A method for tempering a transfer molding tool 10 is shown with reference to FIG. 1. In the left figure, the transfer molding tool 10 is shown at the time in which a plastic 12 has been injected into a cavity 14. The plastic 14 is, for example, low-viscosity, thermosetting

Resin compositions which are used for the production of injection-molded components.

Prior to the injection of the plastic material 12 into the cavity 14, the ejectors 16 designed as ejector pins are heated. Thereby, a mechanical jamming of the ejector 16 is provided with a comprehensive, not shown here, serving as a guide element socket, whereby 16 creates a positive and / or frictional connection between the respective sockets and the ejectors. This prevents penetration of the present as a melt plastic.

In the right-hand illustration of FIG. 1, the transfer molding tool 10 is shown in the open state, in which a demolding of the solidified and cured

Plastic component 18 takes place. Before the demoulding of the plastic component 18 by means of the ejector 16, at least the part of the ejector 16 arranged in the guide element (not shown here) is cooled. By cooling the ejector 16 shrink this something, so that a gap between the ejector 16 and the surrounding bushes is reduced, as a result, the ejector 16 can be easily operated again.

In Fig. 2, the transfer molding tool 10 is shown in a detailed view. As can be seen in the present illustration, the bushing serving as guide element 20 surrounds a part of the ejector 16. The guide element 20 can be hardened, for example, and the ejector 16 can, for example, have a so-called

Lasercusing be prepared. Furthermore, the ejector 16 is attached to an ejector plate 22. Within the ejector 16, a channel 24 may be formed, in which a tempering medium unspecified here can circulate. For supplying or discharging the tempering medium not shown here inlet or outlet openings may be provided in the ejector, via which a supply of the channel 24 can be done with cold or hot tempering.

In Fig. 3 is an alternative embodiment of a tempering of the

Transfer molding tool 10 shown. The ejector 16 is in turn at one

Ejector plate 22 is mounted, in the present case one at the

Ejector 22 provided Temperierbohrung 26 can be seen. The

Temperierbohrung 26 is in this case with a tempering, for example, water or oil, flowed through and connects the temperature control conductive with a

Tempering element 28 of the ejector 16. On the ejector 22, a plurality of such tempering holes 26 may be provided.

In the present case, the tempering element 28 as a riser or heat pipe

formed, by means of which the temperature control medium to the part of the ejector 16 can be fed, which is encompassed by the guide member 20.

By means of the described method for tempering a transfer molding tool 10 and the illustrated injection-compression molding tool 10, the maintenance costs

Injection molding tools 10 can be significantly reduced. By the targeted heating or cooling of the ejector 16, a thermal expansion of the ejector 16 is purposefully exploited to prevent on the one hand penetration of liquid plastic 12 between ejector 16 and ejector plate 22, and on the other hand, by the cooling of the ejector 16 is a reduction the demolding time allows. Furthermore, a balancing of the entire ejector system with respect to overall thermodynamic relationships in the transfer molding tool 10 can take place. Because of the engagement low-failure mechanical ejector 16 thus significantly reduces the demolding times and shortens the overall cycle time.

Claims

claims

A method for tempering a transfer molding tool (10) for plastic components (18), wherein at least one ejector (16) for demolding a

Plastic components (18) is tempered,

characterized in that

before injection of a plastic (12) into a cavity (14) of the

Injection molding tool (10) at least one of a guide element (20) enclosed part of the ejector (16) is heated.

Method according to claim 1,

characterized in that

before the removal of the plastic component (18) by means of the ejector (16) at least in the guide element (20) arranged part of the ejector (16) is cooled.

Transfer molding tool (10) for plastic components (18), with at least one temperature-controlled ejector (16) for demolding of the plastic component (18), characterized in that

the ejector (16) comprises a tempering element (28), by means of which a part of the ejector (16) which can be enclosed by a guide element (20) can be heated.

Transfer molding tool (10) according to claim 3,

characterized in that

the part of the ejector (16) which can be enclosed by the guide element (20) can be cooled by means of the tempering element (28).

5. transfer molding tool (10) according to claim 3,

characterized in that

the injection-compression molding tool (10) comprises an ejector plate (22) for receiving the ejector (16), wherein in the ejector plate (22) at least one with a tempering medium, in particular water or oil, through-flow

Temperature control bore (26) is provided, which conductively connects the temperature control medium with the temperature control element (28).

6. transfer molding tool (10) according to any one of claims 3 or 4,

characterized in that

the tempering element (28) is designed as a rising bore or heat conducting tube, by means of which the tempering medium can be fed to the part of the ejector (16).