Injection-moulding machine with an index shaft having a channel for a fluid

An injection-moulding machine, having a first platen, which is designed for carrying a first mould half of an injection mould, a second platen, which is designed for carrying a second mould half of the injection mould in such a way that in a closed state of the injection mould the first mould half and the second mould half delimit at least one cavity of the injection mould, and having an index shaft, which is mounted rotatably and axially adjustably on the injection-moulding machine outside the injection mould, is rotationally driven by of a motor of the injection-moulding machine arranged outside the injection mould and has an end portion which protrudes into the injection mould in the installed position of the injection mould in the injection-moulding machine, is designed for fastening on the index shaft an index plate to be arranged within the injection mould and has at least one channel which is designed to feed a fluid to the index plate or to remove a fluid from the index plate, wherein by means of the index shaft, driven by the motor, the index plate is automatically adjustable between a first plate position of the index plate and at least one second plate position of the index plate, and wherein the motor has a hollow motor shaft, through which the fluid is passed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a National Stage application of PCT international application PCT/EP2019/053653 filed on Feb. 14, 2019, which claims the priority of European Patent Application No. 10 2018 110 223.2, filed Apr. 27, 2018, which are incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The invention relates to an injection-moulding machine, having a first platen, which is designed for carrying a first mould half of an injection mould, a second platen, which is designed for carrying a second mould half of the injection mould in such a way that in a closed state of the injection mould the first mould half and the second mould half delimit at least one cavity of the injection mould, and having an index shaft, which is mounted rotatably and axially adjustably on the injection-moulding machine outside the injection mould, is rotationally driven by means of a motor of the injection-moulding machine arranged outside the injection mould and has an end portion which protrudes into the cavity of the injection mould in the installed position of the injection mould, which end portion is designed for fastening on the index shaft an index plate to be arranged within the cavity, and wherein by means of the index shaft, driven by the motor, the index plate is automatically adjustable between a first plate position of the index plate and at least one second plate position of the index plate.

BACKGROUND OF THE INVENTION

From DE 20 2015 101 432 U1 for example an injection-moulding machine is known with a fixed platen for receiving a first part of an injection mould, with a movable platen for receiving a second part of an injection mould, and with two further plates which are arranged outside the installation space of the injection mould behind one of the platens, in particular behind the movable platen, wherein the first further plate is an ejector plate, which is provided for ejecting moulded parts out of the injection mould and which is designed for receiving ejector rods or is provided with ejector rods, wherein the second further plate is an additional plate on which a rotary drive is provided, wherein the rotary drive is in operative connection with a rotary shaft, which is connectable or connected with a rotatable part of the injection mould, in particular with an index plate, and wherein the ejector plate and the additional plate are able to be moved independently of each other in the longitudinal direction of the machine. In order to be able to feed media, in particular fluid media, to the rotatable part of the injection mould, in particular the index plate, optionally there a rotary feed-through or a hose feed-through can be provided. In the case of such a hose feed-through, the hoses for the media supply are connected directly to the rotary shaft, more precisely to the channels, running in the rotary shaft, for the media supply. The rotary shaft can therefore only be rotated forward and back to a limited extent. A spinning or cycling through of the rotary shaft is not possible with such a hose feed-through.

The object of the invention is to create an injection-moulding machine in which fluids can be directed over an index shaft in a simple and reliable manner to an index plate which is able to be repositioned by the index shaft.

BRIEF SUMMARY OF THE INVENTION

The problem is solved by an injection-moulding machine, having a first platen, which is designed for carrying a first mould half of an injection mould, a second platen, which is designed for carrying a second mould half of the injection mould in such a way that in a closed state of the injection mould the first mould half and the second mould half delimit at least one cavity of the injection mould, and having an index shaft, which is mounted rotatably and axially adjustably on the injection-moulding machine outside the injection mould, is rotationally driven by means of a motor of the injection-moulding machine arranged outside the injection mould and has an end portion which protrudes into the injection mould in the installed position of the injection mould in the injection-moulding machine, is designed for fastening on the index shaft an index plate to be arranged within the injection mould and has at least one channel which is designed to feed a fluid to the index plate or to remove a fluid from the index plate, wherein by means of the index shaft, driven by the motor, the index plate is automatically adjustable between a first plate position of the index plate and at least one second plate position of the index plate, and wherein the motor has a hollow motor shaft, through which the fluid is passed.

In addition to the use of at least one channel of the index shaft as a flow channel for fluids or as a tunnel for a fluid line, the channel or the tunnel can also be used in order for example to pass through electric lines or electric cables. Generally, the channel in the index shaft can be configured as a bore.

In a first basic variant embodiment, the channel can be configured as a flow channel in which the fluid is conveyed between an end portion of the index shaft facing away from the index plate and the end portion of the index shaft protruding into the injection mould. In order to enable this, the index shaft can have for example at its end portion facing away from the index plate a connection piece which is fluidically connected with the flow channel and to which a fluid feed line is connected. The fluid feed line can be connected to the index shaft at an end portion of the index shaft, facing away from the index plate, in a manner leading radially away, and laterally to the index shaft can be directed into an energy chain of the injection-moulding machine rolling around the rotation axis of the index shaft. In this embodiment, the connection piece can be arranged on an outer wall of the index shaft. Alternatively, the fluid feed line can be axially connected to the index shaft at a front end of the index shaft facing away from the index plate and outside of the index shaft guided substantially about a 90 degree bend away from the rotation axis of the index shaft and subsequently directed into an energy chain of the injection-moulding machine rolling around the rotation axis of the index shaft. In this embodiment, the connection piece can be arranged at the front end of the index shaft facing away from the index plate.

In a second basic variant embodiment, the channel can be configured as a tunnel in which a fluid line or a portion of a fluid line is laid, wherein the fluid is conveyed within the fluid line or within the portion of the fluid line between an end portion of the index shaft facing away from the index plate and the end portion of the index shaft protruding into the injection mould.

By the motor, which is configured for the rotating of the index shaft, having a hollow motor shaft, through which the fluid line is directed, the fluid line can be passed in an axial direction to the rotational movement of the index shaft through the motor and at the same time can be passed through the channel of the index shaft. For example, through an energy chain which is put up in a rotationally movable manner, situated at the end of the index shaft, it is not necessary to introduce the fluid line into the index shaft for example via a rotary feed-through. The structure of the index shaft can thereby be considerably simplified. Complex, expensive and maintenance-intensive rotary feed-throughs can be omitted. As the motor has a hollow motor shaft, the motor can be arranged coaxially to the index shaft or at least flush with the rotation axis of the index shaft. Such an arrangement is particularly advantageous, because the motor shaft in this respect can continue directly into the hollow index shaft. Owing to the hollow motor shaft of the motor, the fluid line can be fed axially at the front side of the index shaft. An axial feeding of the fluid line is particularly favourable.

At the outlet of the index shaft, the fluid line can then be redirected in a simple manner into an energy chain. The energy chain serves for the protection and the directing of the portion of the fluid line exiting from the index shaft. The energy chain can also be designed as an energy guiding chain. An energy chain or energy guiding chain can generally consist of several individual members which are connected with one another in an articulated manner and in this respect forms a chain of a plurality of individual members. Owing to the articulated connection of the individual single members, the entire chain can be directed and moved with minimum application of force along an arc line. The individual members form here an inner guide channel, into which the fluid line can be inserted. The individual members delimit the fluid line from the exterior and form a protection for the fluid line against damage from the exterior. The energy chain can guarantee here a smallest permissible bending radius for the fluid line and at the same time can reduce a wear of the fluid line. The energy chain can be mounted on the injection-moulding machine in such a way that the fluid line can follow the rotation of the index shaft with minimal bending load and minimal wear. If applicable, the fluid line can be fixed within the energy chain, for example clamped, so that hereby an optional strain relief can be formed.

The fluid line can be configured in a single core or multicore manner. For example, a first individual line can be provided within the channel of the index shaft for feeding a fluid to the index plate and a second individual line can be provided within the channel of the index shaft for discharging a fluid to the index plate. At the same time for example a first individual line can be provided within the energy chain for feeding a fluid to the index plate and a second individual line can be provided within the energy chain for discharging a fluid to the index plate.

In this respect, the fluid line can be configured as a one-piece fluid line, i.e. free of connection coupling points. The fluid line can be configured in particular in one piece leading away from the energy chain into the index shaft free of connection coupling points. Alternatively, the fluid line can be formed from several sections of fluid lines or respectively as several portions of fluid lines, in particular separable from one another and able to be joined together again.

The fluid line can be formed for example from one or more hoses. The hoses here generally have a circular-cylindrical outer wall and are configured so as to be hollow internally, so that inside the circular-cylindrical outer wall of the hose the fluid can be transported, in particular pumped. The fluid which is directed in the fluid line or respectively in the hose can be a cooling fluid or a heating fluid. The fluid can be, for example, an oil or water. If applicable, a gas, such as for example compressed air or nitrogen can also be directed as fluid through the fluid line. As owing to the hollow motor shaft a hose line which is in this respect simple and completely tight can be directed through the index shaft, a special preparation or a cleaning or respectively filtering of the fluid is omitted. As the fluid comes into direct contact neither with the hollow motor shaft nor with the index shaft, measures for corrosion resistance can also be omitted.

In all variant embodiments the motor can be configured as a gearless torque motor. A torque motor is generally understood to mean a motor which can generate a high torque at low rotation rates, i.e. few revolutions per minute (for example 10 to 300). Here, also, a high positioning accuracy is achieved. In particular, a torque motor is understood to mean a gearless direct drive. The torque motor can be in particular a multi-pole brushless direct current motor or a switched reluctance motor. The motor, in particular the torque motor, can preferably be configured as an internal rotor. The motor shaft is configured here as a hollow shaft. The index shaft is arranged in the free interior of the hollow shaft. The index shaft is coupled to the hollow shaft of the motor, in particular rigidly connected, so that the index shaft can be driven rotatably by the motor.

The motor and the index shaft can be arranged on the injection-moulding machine in such a way that the central axis of the hollow motor shaft and the central axis of the index shaft lie on a common rotation axis.

The hollow motor shaft and the index shaft having the channel can be in this respect either arranged abutting one another at the front side or arranged inserted coaxially into one another. By the motor and the index shaft being arranged on the injection-moulding machine in such a way that the central axis of the hollow motor shaft and the central axis of the index shaft lie on a common rotation axis, the channel portion within the hollow motor shaft can be flush with the channel of the index shaft, so that the fluid line can be directed through the motor and the index shaft in particular in a bending-free and kinking-free manner.

The hollow motor shaft can extend coaxially to the index shaft, and the index shaft can be directed here out of an end of the hollow motor shaft facing away from the index plate.

In this variant embodiment, the fluid line does not run directly in the hollow motor shaft, but rather only directly within the channel of the index shaft. The index shaft carrying the fluid line then extends entirely through the hollow motor shaft of the motor. In this respect, only the index shaft extends directly through the hollow motor shaft and the fluid line directly through the index shaft.

The fluid line which is directed through the channel of the index shaft can be directed radially out from the channel of the index shaft at an end portion of the index shaft facing away from the index plate, and can be directed laterally to the index shaft into an energy chain of the injection-moulding machine rolling around the rotation axis of the index shaft.

Alternatively, the fluid line which is directed through the channel of the index shaft can be directed out axially from the channel of the index shaft at a front end of the index shaft facing away from the index plate, and can be directed away from the rotation axis of the index shaft outside the index shaft at least substantially about a 90 degree bend, and can subsequently be directed into an energy chain of the injection-moulding machine rolling around the rotation axis of the index shaft.

In all embodiments, the injection-moulding machine can have an adjustably mounted ejector plate, which is arranged on a rear side of the first platen or of the second platen facing away from the injection mould, and which in turn has a rear side facing away from the injection mould, on which both the motor with its motor housing is secured, and also the index shaft is mounted rotatably by the motor and immovably relative to the ejector plate in axial direction.

The hollow motor shaft can have an inner profile, and the index shaft can have an outer profile, wherein the inner profile of the hollow motor shaft and the outer profile of the index shaft are coordinated with one another in such a way that the hollow motor shaft is coupled with the index shaft in a torque-proof manner.

The index shaft can be directed in a displaceable manner in axial direction relative to the hollow motor shaft.

The fluid line can be configured as a hose line extending in one piece through the hollow motor shaft of the motor and the channel of the index shaft up to the index plate.

The fluid line can be configured in a single core or multicore manner. For example, a first individual line can be provided within the channel of the index shaft for feeding a fluid to the index plate, and a second individual line can be provided within the channel of the index shaft for discharging a fluid to the index plate. At the same time, for example, a first individual line can be provided within the energy chain for feeding a fluid to the index plate, and a second individual line can be provided within the energy chain for discharging a fluid to the index plate.

In this respect, the fluid line can be configured as a one-piece fluid line, i.e. free of connection coupling points. The fluid line can be configured in particular in one piece leading away from the energy chain into the index shaft, free of connection coupling points.

The fluid line can be formed for example by one or more hoses. The hoses generally have here a circular-cylindrical outer wall and are configured so as to be hollow internally, so that within the circular-cylindrical outer wall of the hose the fluid can be transported, in particular pumped. The fluid which is directed in the fluid line or respectively in the hose can be a cooling fluid or a heating fluid. The fluid can be, for example, an oil or water. If applicable, a gas, such as for example compressed air or nitrogen, can also be directed as fluid through the fluid line. As owing to the hollow motor shaft an in this respect simple and completely tight hose line can be directed through the index shaft, a special preparation or a cleaning or respectively filtering of the fluid is omitted. As the fluid comes in direct contact neither with the hollow motor shaft nor with the index shaft, measures for corrosion protection can also be omitted.

DESCRIPTION OF EXAMPLE EMBODIMENTS

The exemplary injection-moulding machine1shown inFIG.1has a machine frame2, on which an injection unit3and a clamping unit4are arranged. The injection unit3serves for the preparation of a plastic mass which is to be formed. In the case of the present example embodiment, the injection unit3has an extruder5. The extruder5is configured to melt, mix and homogenize, if applicable degas, at least one intermediate plastic product, such as for example a plastic granulate. For this, or respectively for the feeding or for example the plastic granulate, the extruder5has a feed hopper6.

At a front end of the injection unit3or respectively at a front end of the extruder5, an injection nozzle is arranged, not illustrated in further detail, which is coupled to an injection mould7. The injection mould7is arranged in the clamping unit4of the plastic injection-moulding machine1, which is usually arranged on the machine frame2of the injection-moulding machine1and has a fixed platen8.1and a movable platen8.2. The injection mould7comprises at least two mould halves7.1and7.2, of which the first mould half7.1is fastened on the fixed platen8.1, and the second mould half7.2(not illustrated, i.e. removed, inFIG.1), is fastened on the movable platen8.2, in such a way that with an opening of the clamping unit4, i.e. with a moving apart of the fixed platen8.1and of the movable platen8.2at least one cavity9(FIG.2) of the injection mould7is freed.

The injection-moulding machine1has accordingly several machine parts. Certain machine parts can be movably mounted and can be moved by means of a motor (M) or drive, in particular a hydraulic or electric motor or respectively a hydraulic or electric drive automatically or in a manually controlled manner in a manual operation. Thus, the clamping unit4represents an exemplary machine part which, controlled by a machine control10of the injection-moulding machine1, according to a machine program running in the machine control10, can be controlled, opened or closed automatically or manually in a manual operation for example by means of a user interface device11of the injection-moulding machine1. The injection unit3represents another exemplary machine part which, controlled by the machine control10of the injection-moulding machine1, can be operated, according to a machine program running in the machine control10, automatically or in a manually controlled manner in a manual operation for example by means of the user interface device11, for example by controlling or regulating the rotation speed of the extruder5or by controlling or regulating at least one heating device of the injection unit3which is not illustrated in further detail. The injection-moulding machine1comprises furthermore at least one ejector plate12, which in the case of the present example embodiment is mounted in a linearly adjustable manner on the rear side of the movable platen8.2. On the ejector plate12in addition an index shaft13is mounted, which is drivable by a motor M and on which an index plate14(FIG.2) is fastened.

FIG.2shows the channel15as a flow channel15ain which the fluid is conveyed between an end portion13.2of the index shaft13, facing away from the index plate14, and the end portion13.1of the index shaft13protruding into the injection mould7. In this case, the index shaft13has at its end portion13.2facing away from the index plate14a connection piece19, which is fluidically connected with the flow channel15aand to which a fluid feed line16.1is connected. The fluid feed line16.1is connected axially to the index shaft13at a front end13.3of the index shaft13, facing away from the index plate13, and outside the index shaft13is directed away from the rotation axis of the index shaft13at least substantially about a 90 degree bend, and is subsequently directed into an energy chain18of the injection-moulding machine1rolling around the rotation axis of the index shaft13.

FIG.3shows the fluid feed line16.1, as it is connected to the index shaft13in a manner leading away radially at an end portion13.2of the index shaft13facing away from the index plate14, and is directed laterally to the index shaft13into an energy chain18of the injection-moulding machine1rolling around the rotation axis of the index shaft.

InFIG.4andFIG.5in a modification toFIG.2andFIG.3, the channel15is configured as a tunnel15bin which a fluid line16or a portion of a fluid line16ais laid, wherein the fluid is conveyed within the fluid line16and the portion of the fluid line16abetween an end portion13.2of the index shaft13, facing away from the index plate14, and the end portion13.1of the index shaft13, protruding into the injection mould7.

The exemplary injection-moulding machine1shown inFIG.4andFIG.5therefore has a first platen8.1, which is configured for carrying the first mould half7.1of the injection mould7, and has a second platen8.2, which is configured for carrying the second mould half7.2of the injection mould7, in such a way that in a closed state of the injection mould7the first mould half7.1and the second mould half7.2delimit at least one cavity9of the injection mould7.

The injection-moulding machine1has in addition the index shaft13, mounted rotatably and axially adjustably outside the injection mould7, which index shaft is rotationally driven by means of a motor M of the injection-moulding machine1arranged outside the injection mould7.

The index shaft13has an end portion13.1protruding into the injection mould7in the installed position of the injection mould7in the injection-moulding machine1, which end portion is configured for fastening on the index shaft13an index plate14to be arranged within the injection mould7. The index shaft13has at least one channel15, in which at least one fluid line16runs. The channel15is configured to feed a fluid to the index plate14from outside, or to discharge it from the interior of the index plate14. The index plate14is automatically adjustable between a first plate position, as is shown for example inFIG.4, and at least one second plate position, as is shown for example inFIG.5, by means of the index shaft13, driven by the motor M, wherein the motor M has a hollow motor shaft17, through which the fluid line16and therefore also the index shaft13is passed.

In the case of the present example embodiment, the motor M is configured as a gearless torque motor.

The motor M and the index shaft13are arranged on the injection-moulding machine1in such a way that the central axis of the hollow motor shaft17and the central axis of the index shaft13lie on a common rotation axis. In the case of the present example embodiments, the hollow motor shaft17extends coaxially to the index shaft13and the index shaft13is directed out from an end of the hollow motor shaft17facing away from the index plate14.

In the case of the variant embodiment according toFIG.4andFIG.5, the fluid line16which is passed through the channel15of the index shaft13, is directed axially out from the channel15of the index shaft13at a front end13.3of the index shaft13facing away from the index plate14, and outside the index shaft13is directed away from the rotation axis of the index shaft13at least substantially about a 90 degree bend, and is subsequently introduced into an energy chain18of the injection-moulding machine1rolling around the rotation axis of the index shaft13.

In the case of the variant embodiment according toFIG.6, the fluid line16which is passed through the channel15of the index shaft13is directed radially out from the channel15of the index shaft13at an end portion13.2of the index shaft13facing away from the index plate14, and is introduced laterally to the index shaft13into an energy chain18of the injection-moulding machine1rolling around the rotation axis of the index shaft13.

According to the illustrated example embodiments, the injection-moulding machine1generally also has an adjustably mounted ejector plate12, which in the case of the example embodiments which are shown is arranged on a rear side of the first platen8.1facing away from the injection mould7, and which in turn has a rear side facing away from the injection mould7, on which rear side both the motor M is fastened with its motor housing, and also the index shaft13is mounted rotatably by the motor M and immovably relative to the ejector plate12in axial direction.

The hollow motor shaft17can have an inner profile and the index shaft13can have an outer profile here, wherein the inner profile of the hollow motor shaft17and the outer profile of the index shaft13are coordinated with one another in such a way that the hollow motor shaft17is coupled with the index shaft13in a torque-proof manner. Alternatively, however, the hollow motor shaft17can be coupled with the index shaft13by means of different shaft-hub connections, thus for example with clamping elements known per se, carrier elements, such as feather keys and fitting grooves, and flange couplings, clamp couplings or clamping sleeves.

In the case of the present example embodiments, the fluid line16is configured as a hose line extending in one piece through the hollow motor shaft17of the motor M and the channel15of the index shaft13up to the index plate14.

LIST OF REFERENCE NUMBERS

11user interface device

16aportion of a fluid line

16.1fluid feed line

M motor