CN113696437A

CN113696437A - Mold clamping unit, molding machine and method for measuring force distribution

Info

Publication number: CN113696437A
Application number: CN202110549196.XA
Authority: CN
Inventors: M·布赫纳; G·肖特
Original assignee: Engel Austria GmbH
Current assignee: Engel Austria GmbH
Priority date: 2020-05-20
Filing date: 2021-05-20
Publication date: 2021-11-26
Also published as: AT523853A1; AT523853B1; DE102021112673A1

Abstract

The invention relates to a mold clamping unit (1) for a molding machine, comprising: a stationary mold clamping plate (2) comprising a first clamping area (16) for clamping at least one first mold piece (5); and a movable mould clamp plate (3) comprising a second clamping area for clamping at least one second mould part (6); at least one surface sensor (7) arranged on the stationary mold platen (2) and/or the movable mold platen (3) is provided, said surface sensor being designed to measure a force distribution (8) in the first clamping region (16) and/or in the second clamping region. The invention also relates to a method for measuring a force distribution in a first clamping area of a stationary mold jaw for clamping a first mold part and/or in a second clamping area of a movable mold jaw for clamping a second mold part in a clamping unit for a molding machine.

Description

Mold clamping unit, molding machine and method for measuring force distribution

Technical Field

The present invention relates to a clamping unit for a molding machine having the features of the preamble of claim 1, a molding machine having such a clamping unit and a method for measuring a force distribution in a clamping unit.

Background

The same type of mold clamping unit for a molding machine has: a stationary mold clamp plate including a first clamping region for clamping at least one first mold piece; and a movable mold clamp plate including a second clamping area for clamping at least one second mold piece.

A molding machine is understood here to mean an injection molding machine, a die casting machine, a press and the like. The prior art shall be briefly outlined below with the aid of an injection molding machine. Similarly, it is of course generally applicable to molding machines.

The clamping unit of an injection molding machine usually has a stationary mold clamping plate and a movable mold clamping plate which is movable relative thereto. In the clamping area on each of these mold jaws, a mold can be fastened so that the respective mold fastened on the movable mold jaw can move relative to the mold fastened on the stationary mold jaw. In the clamped state of the mold, in which the mold parts lie against each other or almost against each other, the mold parts form a mold cavity (Formhohlraum) which can be opened by a movement of the movable mold clamp plate, so that the molded part can be removed from the mold cavity of the mold or, if appropriate, an insert can be placed in it.

When the mold is closed, plasticized plastic can be injected in the injection molding machine, which is delivered to the mold cavity with increased pressure. A force causing expansion of the mold is caused to occur by the injection force, wherein the force is resisted by the clamping unit by applying a pressure (clamping force) to the mold through the movable mold clamping plate and the fixed mold clamping plate by the clamping unit.

In order to be able to optimally apply the clamping force to the mold, it is necessary to orient the mold in the clamping region of the stationary mold platen and the movable mold platen such that the direction of action of the clamping force substantially coincides with the direction of action of the expansion force generated.

If these forces are not substantially aligned with their direction of action, significant deformations of the clamping unit result (forces and spacings lead to bending moments), wherein the quality of the resulting molded part may be impaired and the clamping unit may also be damaged.

In the case of asymmetrical loading in the clamping unit with guide pins, increased wear of the guide elements can result, since these are unevenly loaded during the clamping cycle and can even slightly jam against one another. Therefore, in the case of small cycle times or increased clock frequencies, the wear elements may already wear out within hours or days, which naturally adversely affects the productivity of the clamping unit (and therefore of the injection molding machine) through increased maintenance costs.

In the prior art, in order to determine the force distribution during the production cycle, it is known, for example, to determine the clamping force by deformation of the guide columns or beams and to derive the force distribution therefrom. However, a limited resolution of the force distribution is provided by a limited number of guide posts or beams, since only point-wise measurements are carried out.

Disclosure of Invention

The object of the invention is to provide a clamping unit and a method with which information about the force distribution in the clamping area of a mould part can be obtained with a greater or more precise quality than in the prior art.

Said object is achieved by the invention by means of a mold clamping unit for a molding machine having the features of claim 1 and by means of a method having the features of claim 10.

According to the invention, at least one surface sensor is provided on the stationary and/or movable mold clamping plate, which is designed to measure the force distribution in the first clamping area and/or in the second clamping area.

By arranging the area sensor on the stationary mold platen in a first clamping region for clamping the at least one first mold part and/or on the movable mold platen in a second clamping region for clamping the at least one second mold part, the force distribution spread over the area can be determined in a simple manner.

With the arrangement according to the invention, it is possible in a simple manner and method to improve also existing systems in order to detect a force distribution in the clamping region of the stationary mold clamping plate for clamping the first mold part and/or in the clamping region of the movable mold clamping plate for clamping the second mold part.

By means of the force profile, for example, a clamping force characteristic can be created in order to infer, for example, a deformation of the clamping unit and/or of the stationary mold clamping plate and/or of the movable mold clamping plate and/or of the first mold part and/or of the second mold part and/or of further components of the clamping unit. Measures for reducing or eliminating the deformation can then be taken from the determined deformation. Such measures can be, for example, the orientation of the tool parts in the receiving region or the arrangement of geometric solutions (preferably the projection of the tool clamping plate or of the tool, i.e. the convex shape of the clamping surface).

In the same way, it is entirely conceivable to determine the tear force (Aufrei β kraft), preferably during production, and if necessary to take measures for avoiding, reducing or adapting the force profile of the tear force. It is thus possible to protect the components of the molding machine and/or the mold and to increase the durability of the molding machine and/or the mold (life), and to minimize the energy consumption in the sense of an ecological and economical way of operating the molding machine.

However, it is also fully conceivable to carry out the measurement only during the course of the test design by means of the area sensor, in order to use the data collected to carry out changes on the mold or mold clamping unit already during the development phase of the mold and/or mold clamping unit.

Subsequent processes of the clamping unit are not affected by the use of at least one surface sensor (which may be only a few hundredths of a millimeter to a few tenths of a millimeter thick). Furthermore, such a surface sensor has a very high resistance, in particular with regard to pressure and shear forces which may occur due to deformations of the clamping plates, the clamping module itself or the mold, so that the use of the surface sensor is particularly robust.

A molding machine may be understood as an injection molding machine, a die casting machine, a press machine or the like.

In the course of this document, a plate, if it is said, is not to be regarded as a flat, planar plate. The plate may also have a recess and a raised portion. Embodiments with ribs for stabilization or for producing certain deformation properties are also fully conceivable.

A clamping region is understood in the course of this document as a part or component of the clamping plate which adjoins the mold or mold part and/or is subjected to a force flow through the mold or mold part.

Each mold support configured to be movable relative to the stationary mold jaw is understood to be a movable mold jaw within the meaning of the present invention, as long as it supports the mold piece. An intermediate plate, for example, known per se in the prior art, is therefore understood to be a movable mold clamping plate in the sense of the present invention.

In this respect, on the one hand, embodiments are conceivable which have both a movable mold clamping plate, for example in the form of an intermediate plate, and a "conventional" movable mold clamping plate. On the other hand, however, embodiments are of course also conceivable in which the area sensor according to the invention is present only on the intermediate plate (i.e. the movable mold clamping plate in the sense of the invention).

In the course of this document, if an area sensor is referred to, it should not be absolutely necessary to consider a flat, planar sensor with a constant thickness. The area sensor may have a recess, a void, and a raised portion. Embodiments with a plurality of sensor elements along a plane for detecting a force distribution (by means of a plurality of measured values detected substantially simultaneously by a plurality of sensors) are also fully conceivable.

Advantageous embodiments of the invention are defined in the dependent claims.

It can be provided that the at least one area sensor is designed as a pressure-sensitive sensor and preferably has a piezoelectric and/or pyroelectric or activatable layer. By applying piezoelectric and/or pyroelectric layers, a particularly precise and highly resolved measuring method for the force distribution is provided, which as far as possible has no influence on the production process of the molding machine.

It is known, for example, from EP 2609142B 1 (in the case of inorganic particles) to produce piezoelectric and pyroelectric or activatable layers. This is done by applying a solution and/or suspension containing piezoelectrically and thermally electrically activated or activatable particles and subsequently removing the suspension and/or solvent. In this connection, the measures disclosed in EP 2609142B 1 can be preferably used in the present invention.

It is therefore possible to produce solutions of inorganic particles additionally containing piezoelectrically and thermoelectrically activated or activatable oxides (oxide ceramics). Examples are PZT (lead-zirconate-titanate), BTO (barium titanate), PTO (lead titanate) and BNT-BT (sodium bismuth titanate-barium titanate). For this purpose, a suspension of inorganic particles is first produced in a suitable, preferably low-boiling, suspending agent. This gives the possibility that the compound of the suspension and polyvinylidene fluoride (PVDF) or polyvinylidene fluoride copolymer solution can be applied to a substrate for a surface sensor by spin coating, knife coating or by screen printing methods, wherein the solvent can be removed by the action of temperature in order to harden the layer. The substrate may be, for example, a film and/or directly a stationary mold clamp and/or a movable mold clamp.

It can be provided that the at least one area sensor has at least one conductor path or electrode which is arranged on the stationary and/or movable mold platen. It is therefore also possible to determine the force distribution by a change in the capacitance of at least one conductor circuit or electrode on the stationary and/or movable mold clamping plate. The conductor circuit can naturally also be regarded as an electrode and serve as such an electrode.

Preferably, however, at least two conductor circuits or electrodes are provided, which are preferably stacked on top of one another, wherein the two conductor circuits or electrodes form a capacitor. A voltage change due to a change in the position of the at least two conductor circuits or electrodes relative to one another (for example due to a force effect) leads to a measurable voltage between the at least two conductor circuits or electrodes.

Reference may be made to WO2014/037016a1 for a preferred embodiment of the structure of the area sensor. Therefore, a particularly preferred layer structure for an area sensor can be provided as follows:

a first layer, which is formed by the mold clamping plate or a film (e.g. polyethylene terephthalate substrate, PET) applied to the mold clamping plate;

-one or more (lower) electrodes in the second layer, the (lower) electrodes being composed of an electrically conductive polymeric material;

piezoelectric and pyroelectric sensor materials, for example comprising polyvinylidene fluoride (PVDF) and trifluoroethylene (TrFE); and

-one or more (upper) electrodes comprising carbon or a conductive polymer.

It is preferably provided that the area sensor has a plurality of sensor elements, for example in a lattice structure, for detecting a force distribution (by means of a plurality of measured values detected substantially simultaneously by a plurality of sensors), along a plane, wherein the sensor elements are optionally superimposed and are particularly preferably connected to one another in a signal-conducting manner.

It can be provided that the layer designed as an area sensor is designed as a film (e.g. a plastic film) or on a plate (e.g. a thin metal plate or a mold clamping plate).

Provision may be made for at least one further conductor circuit to be provided, wherein a capacitance or a change in capacitance is determined between the two conductor circuits. However, it is also fully conceivable to provide only one conductor circuit and to use the capacitance of this conductor circuit relative to the stationary or movable mold clamping plate or the first or second mold part.

It can be provided that the at least one area sensor has a film, wherein the at least one area sensor is mounted, in particular glued, on the stationary and/or movable mold platen.

Preferably, it is provided that the at least one area sensor is applied to the stationary and/or movable mold platen by a printing method, preferably a screen printing method.

It can be provided that the at least one area sensor is arranged on the stationary mold platen and/or the movable mold platen on a clamping device, preferably a holding claw, for clamping the mold part.

Preferably, the at least one surface sensor is arranged at least partially on a surface of the stationary mold clamping plate and/or of the movable mold clamping plate facing the first and/or second mold part.

By arranging the at least one surface sensor on the surface facing the first and/or second mold part, the possibility arises of determining the clamping force (in other words, the force distribution) applied to the mold that is distributed over the surface.

In addition, the mold cavity filling can be evaluated, observed and/or detected in the process by inferring the situation in the mold cavity from the change in the clamping force distribution and correlating this change to the injection force or the injection pressure. If changes in the force distribution during the continuous operation are determined, changes in the filling of the mold cavity can therefore also be inferred and, if appropriate, ongoing faults can be detected.

In the case of a clamped mold part, the at least one surface sensor may be arranged in the clamping region between the entire contact surface of the mold part and the stationary mold clamping plate and/or the movable mold clamping plate or only in partial regions. Furthermore, it is entirely conceivable for the area sensor to also be designed to be larger than the contact area. This has the particular advantage that also higher and/or non-linear force distributions in the edge region of the mold can be determined.

By arranging the surface sensor on the clamping device, not only the clamping force (which is applied to the mold part by the clamping unit) can be determined, but also the tearing force, which can be used for opening the mold, can be monitored.

In order to monitor or determine the tear force, for example, a change in the prestress, more precisely the prestress of the clamping device, can be observed and the tear force can therefore be inferred.

In addition, however, it can also be provided, for example, that the clamping of the mold is detected or monitored by providing a surface sensor on the clamping device, in order to determine, if necessary, a reduction in the holding force of the mold on the movable mold platen and/or the stationary mold platen and to output a warning in good time and/or to take countermeasures.

Furthermore, a molding machine, preferably an injection molding machine, is claimed, which has a mold clamping unit according to the invention.

In the method according to the invention, the force distribution in the first clamping area and/or in the second clamping area is measured by means of at least one surface sensor arranged on the stationary and/or movable mold clamping plate.

As already mentioned, it can be provided that the detected force profile is used to determine the deformation of the stationary and/or movable mold jaws under the clamping force.

Adapting the geometry of the stationary and/or movable mold jaws and/or the first and/or second mold pieces based on the detected deformation.

If the evaluation according to the invention is already present during the development phase of the clamping unit, it can also be provided during the development that the stationary and/or movable mold clamping plates and/or the first and/or second mold part are designed with projections or other geometries on their contact surfaces, which projections or geometries then compensate for the deformation under the clamping force, at least in part.

However, it can also be provided that the surface sensor is connected to an active material on a stationary and/or movable mold clamping plate, which changes its geometry by activation, control and/or adjustment, so that deformations under the clamping force can also be compensated.

This type of active material is characterized by a high force density and a large number of deformation cycles with little wear. Force density is a measure of the strength of force that can be applied to a material having a unit volume. Since high clamping forces must be achieved, for example, during the injection molding process, materials with a high force density are naturally advantageous in terms of minimizing the installation space.

It may be provided that the activation material is a piezoelectric material (which may be, for example, a crystal, a polymer or a ceramic), a shape memory alloy (which may be, for example, a crystal or a polymer), a magnetostrictive material and/or an electrostrictive material.

Piezoelectric materials and electrostrictive materials refer to materials that change their length by the action of an electric field. Magnetostrictive materials change their length under the influence of a magnetic field. Shape memory alloys have a phase change in which there are different fixed phases with different shapes. In particular, the length change can occur by the deformation occurring during the phase change. The phase change is induced by a temperature change.

Preferably, the detected force profile can be used to determine or monitor the clamping force of the mold.

Provision can be made for the detected force profile to be used for determining process parameters, preferably the tearing force and/or the clamping force, during operation of the clamping unit.

Drawings

Further details and embodiments of the invention will become apparent from the drawing and the description thereof. In the figure:

figure 1 shows the clamping unit according to the invention under clamping force,

figure 2 shows the clamping area of the stationary or movable mold clamp plate,

figures 3a-c show the force distribution on the stationary or movable mold jaws,

figure 4 shows the clamping unit according to the invention in the mold opening,

figures 5a-b show additional clamping areas of the stationary mold clamp plates,

FIGS. 6a-b illustrate exemplary interconnections of sensor elements, an

Fig. 7 shows another embodiment of the mode locking unit according to the present invention.

Detailed Description

Fig. 1 shows a mold clamping unit 1 for a molding machine according to the present invention. The mode locking unit 1 includes: a stationary mold clamp plate 2 comprising a first clamping area 16 for clamping at least one first mold piece 5; and a movable mold clamp plate 3 comprising a second clamping area for clamping at least one second mold piece 6.

By means of the clamping unit 1 and the stationary and movable

mould clamping plates

2, 3, a clamping force 4 can be applied to the mould, which in this embodiment is constituted by the first and

second mould parts

5, 6.

The clamping force 4 is illustrated in fig. 1 by an arrow, however the clamping force 4 can be understood as the sum of the individual forces. These forces can be applied to the stationary mold jaw 2 and/or the movable mold jaw 3 in different ways and methods. For example, exemplary embodiments are conceivable in which the clamping force 4 is applied to the movable mold platen 3 and/or the stationary mold platen 2 via the beam 15 and/or the toggle mechanism.

A surface sensor 7 is arranged between the stationary tool clamping plate 2 and the first tool part 5 in the clamping region 16. In this exemplary embodiment, a further surface sensor 7 is furthermore provided between the movable mold clamp 3 and the second mold part 6. However, embodiments are also fully conceivable in which only one such area sensor 7 is provided (either on the stationary mold platen 2 or on the movable mold platen 3). In particular, in the case of a symmetrical design of the mold with a mold cavity, a sufficiently precise/resolved evaluation of the force distribution 8 can already be achieved by means of a surface sensor 7.

The force distribution 8 can be determined by the area sensor 7, which is embodied as a membrane in this exemplary embodiment.

The ideal force distribution 8 with uniform loading shown in fig. 1 is naturally to be understood only as an exemplary visualization of the principle. In practical measurements, a uniform (right-angled) force distribution 8 is not desired. But in practice it is possible to derive a curve with areas of maximum and discontinuity (more precisely, higher-order facets in the case of spatial considerations).

The area sensor 7 embodied as a film of this exemplary embodiment can be glued to the stationary mold platen 2 and/or the movable mold platen 3 or can be held on the

mold platens

2, 3 only by the clamping force of the

mold parts

5, 6.

In this exemplary embodiment, the area sensor 7 is selected to be larger than the actual contact area between the

mold parts

5, 6 and the

mold clamping plates

2, 3. However, embodiments are also fully conceivable in which the at least one area sensor 7 is arranged only over a partial region of the contact area. Such a partial region may be, for example, a region in which an increase in force should be expected.

Fig. 2 shows a view of the clamping area 16 of the stationary mold clamp plate 2. In this embodiment, four beams 15 are provided for applying the clamping force, said beams extending through the stationary mould jaw 2.

The following layer structure for the area sensor 7 can be provided:

a first layer constituted by the

mold jaws

2, 3 or a polyethylene terephthalate (PET) substrate applied to the

mold jaws

2, 3;

one or more (upper) electrodes, either consisting of carbon or of a polymer capable of conducting electricity.

The electrodes are connected to one another in a grid-like manner, so that in this exemplary embodiment individual sensor elements 9 are realized, wherein the individual sensor elements 9 are connected to one another via connecting sections 10.

This results in the significant advantage that, due to the intelligent design of the sensor connection, the area sensor 7 can continue to provide an instructive measurement result even in the event of a failure of the sensor element 9 or a disconnection of the individual conductor paths, in such a way that the remaining sensor elements 9 can continue to communicate with one another via the connection 10 (see fig. 6).

The measurement signals of the area sensor 7 can be transmitted via a signal-conducting connection to an evaluation device 11, in which, for example, the electrical signals of the area sensor 7 can be converted into further physical variables, such as the clamping force distribution, i.e., the pressure distribution, and, if necessary, monitoring or regulation of further process parameters can be taken into account for the production cycle.

The functions of the evaluation device 11 can also be assumed by a central control or regulation unit (machine controller) of the molding machine or mold clamping unit 1, for example, or by a separate evaluation device 11.

Furthermore, it can be seen in fig. 2 that the first mold part 5 is connected to the stationary mold platen 2 by means of a clamping device 12, wherein the area sensor 7 is arranged between the first mold part 5 and the mold platen 2. In this exemplary embodiment, the clamping device 12 is designed as a quick clamping device for the first mold part 5 on the mold clamp plate 2, wherein the area sensor 7 is adapted accordingly.

The thermoplastic material can be supplied to the first mold part 5 via a nozzle 14, wherein the nozzle 14 acts on the first mold part 5 via a nozzle opening 13 in the stationary mold clamping plate 2.

Since the embodiment of fig. 2 is an injection molding machine, nozzles 14 for thermoplastics are provided. Of course this particular embodiment can generally be transferred to a molding machine.

Fig. 2 shows an exemplary sensor arrangement for fastening the mold platen 2, because of the recess in the region of the central opening, through which the nozzle reaches the mold and injects the plasticized plastic into the mold.

Fig. 3a shows an exemplary visualization of the force distribution 8 in the case of a clamping force being applied to the movable mold clamp 3. The force distribution 8 can be determined, for example, on a test design or a testing machine, so that the force distribution 8 can also be influenced during the development phase, if necessary, by the geometric design of the mold jaws.

Such a geometric design can be, for example, a projection 18 of the movable mold clamp 3 (as shown in fig. 3 b). As can be clearly seen, the force distribution 8 can be designed to be more stable (more uniform) over the entire face by the projections 18 of the movable mold clamp 3. The projections can be modified by geometric design, for example by machining the shape of the mold jaws, or by active changes (otherwise, for example, flat mold jaws) caused by auxiliary systems, such as movable elements or hydraulics in the mold jaws.

Fig. 3c shows the force distribution 8 on the movable mold platen 3 of fig. 3a and 3b superimposed on one another, the influence of the projections 18 on the force distribution 8 acting more significantly. Here, the force distribution 8 onto the movable mold clamp 3 without the projection 18 is shown by a dashed line, while the force distribution 8 onto the movable mold clamp 3 with the projection 18 is shown by a solid line. The parametric design of the clamping unit 1 and the vector quantities of the applied clamping force are naturally the same, so that the respective design options can be compared.

Fig. 4 shows an embodiment which is essentially identical to the embodiment already explained with reference to fig. 1, however now in fig. 4, as is again indicated by the arrows, a tearing force 17 is applied to the clamping unit 1, more precisely to the

mould parts

5, 6 by the

mould clamping plates

2, 3 for opening said mould parts.

The tearing force 17 is again to be understood as the sum of the individual forces and can be applied to the stationary mold jaw 2 and/or the movable mold jaw 3 in different ways and methods. Exemplary embodiments are conceivable, for example, in which the tearing force 17 is applied to the movable die clamping plate 3 and/or the stationary die clamping plate 2 via the beam 15, via hydraulic cylinders mounted on the

die clamping plates

2, 3, via a mechanical drive (for example a spindle drive) and/or a toggle mechanism.

The tearing force 17 can also be determined as a force distribution 8 by means of the area sensors 7, one area sensor 7 being arranged between the movable mold clamp plate 3 and the second mold part 6 and the other area sensor being arranged between the stationary mold clamp plate 2 and the first mold part 5.

Fig. 5 shows a further clamping region of the stationary mold clamping plate 2, wherein the first mold part 5 is connected to the stationary mold clamping plate 2 by means of a clamping device 12. Fig. 5a shows a front view of the exemplary embodiment, while fig. 5b shows a side view.

The clamping device 12 shown in fig. 5a, b is formed by a holding claw 19 which acts on the connecting portion of the first mold part 5 and thus holds the mold part 5 on the stationary mold clamp plate 2, more precisely, fastens them to one another.

In the contact region of the holding claw 19 on the connection of the first mold part 5, a surface sensor 7 is provided. The area sensor 7 can be glued either to the first mould part 5 or to the retaining claw 19. Alternatively, it can also be provided that the area sensor 7 is merely inserted between the holding claw 19 and the first mold part and then clamped together.

This arrangement of the surface sensor 7 between the holding claw 19 and the mold part 5 makes it possible in particular to monitor the clamping parameters of the mold and, for example, to detect a release of the mold. However, with such an arrangement it is particularly advantageous to measure a force profile, preferably a buoyancy force (auftiebskraft), during the course of the molding machine.

Fig. 6 shows an exemplary interconnection of the sensor elements 9 to each other. In this particular embodiment, the sensor elements 9 are interconnected in parallel with each other by means of electrical connections 10. The entirety of the individual sensor elements 9 thus forms the area sensor 7, which is connected to the evaluation device 11.

This interconnection yields the particular advantage that, even in the event of a failure of the sensor elements 9 or of an open individual conductor circuit, the area sensor 7 can continue to provide an instructive measurement result in such a way that the remaining sensor elements 9 can continue to communicate with one another via the connection 10.

Thus, for example, in fig. 6a an undamaged embodiment is shown, while in fig. 6b a damaged area sensor 7 is shown, in which the individual conductor paths are damaged/broken (shown by dashed lines). It can be seen well how this damage to the conductor circuit affects only the right-hand sensor element 9 (shown by dashed lines), whereas the right-hand sensor element 9 has already been separated from the remaining, operating left-hand part of the area sensor.

Fig. 7 shows a further exemplary embodiment according to the invention of a clamping unit 1 which, analogously to the embodiment of fig. 1 and 4, has a stationary mold clamping plate 2 and a movable mold clamping plate 3 together with a first clamping area 16, a second clamping area, a first mold part 5 and a second mold part 6.

Additionally, the mold clamping unit 1 shown in fig. 7 is configured to have an intermediate plate 20. This enables two molds to be run simultaneously. The intermediate plate 20 is likewise mounted so as to be movable relative to the stationary mold platen 2.

In the intermediate plate 20, a third mold part 21 is arranged in a third clamping region of the intermediate plate 20 relative to the first mold part 5 supported on the stationary mold clamping plate 2, and in a fourth clamping region of the intermediate plate 20 a fourth mold part 22 is arranged relative to the second mold part 6 supported on the movable mold clamping plate 3.

In the clamping region of the intermediate plate 20, in turn, a surface sensor 7 is provided, which is designed to measure a force distribution 8 in a first clamping region of the intermediate plate 20 and/or a force distribution in a second clamping region of the intermediate plate 20, wherein each surface sensor is arranged between the intermediate plate 20 and the

tool parts

5, 6.

In addition, surface sensors 7 are also provided on the fixed mold platen 2 and the movable mold platen 3 in the clamping area.

The measurement signals of the area sensors can in turn be transmitted via a signal-conducting connection to an evaluation device 11, in which, for example, the electrical signals of the area sensors 7 can be converted into further physical variables, such as the clamping force distribution, i.e., the pressure distribution, and, if necessary, monitoring or regulation of further process parameters can be taken into account for the production cycle.

The intermediate plate 20 of this embodiment can be regarded as a movable mold clamp plate in the sense of the present document.

List of reference numerals

1 mode locking unit

2 fixing the clamping plate of the mould

3 Movable mold clamping plate

4 clamping force

5 first mold part

6 second mould part

7-plane sensor

8 force distribution

9 sensor element

10 connecting part

11 analysis processing device

12 clamping device

13 nozzle opening

14 nozzle

15 Beam

16 clamping area

17 tearing force

18 projection

19 holding claw

20 middle plate

21 third mould part

22 fourth mould part

Claims

1. Mould-clamping unit (1) for a moulding machine, comprising:

-a stationary mould clamping plate (2) comprising a first clamping area (16) for clamping at least one first mould part (5); and

-a movable mould jaw (3) comprising a second clamping area for clamping at least one second mould part (6);

characterized in that at least one surface sensor (7) is provided on the stationary mold clamping plate (2) and/or on the movable mold clamping plate (3), said surface sensor being designed to measure a force distribution (8) in the first clamping region (16) and/or in the second clamping region.

2. The mode locking unit according to claim 1, characterized in that the at least one area sensor (7) is configured as a pressure-sensitive sensor and preferably has a piezoelectric and/or pyroelectric-activated and/or activatable layer.

3. Mould locking unit according to at least one of the preceding claims, characterized in that said at least one surface sensor (7) has at least one conductor circuit and/or electrode provided on the fixed mould clamping plate (2) and/or the movable mould clamping plate (3).

4. Mode-locking unit according to at least one of the preceding claims, characterized in that the at least one surface sensor (7) has a suspension of an oxide that can be electrically and thermally activated.

5. Mould locking unit according to at least one of the preceding claims, characterized in that said at least one surface sensor (7) has a film, said at least one surface sensor (7) being mounted, in particular glued, on the stationary mould clamping plate (2) and/or the movable mould clamping plate (3).

6. Clamping unit according to at least one of the preceding claims, characterized in that said at least one surface sensor (7) is applied on the stationary mold clamping plate (2) and/or the movable mold clamping plate (3) by a printing method, preferably screen printing.

7. Mould locking unit according to at least one of the preceding claims, characterized in that the at least one surface sensor (7) is arranged on the stationary mould clamping plate (2) and/or the movable mould clamping plate (3) on a clamping device (12), preferably a holding claw (19), for clamping the mould parts (5, 6).

8. Mould locking unit according to at least one of the preceding claims, characterized in that the at least one surface sensor (7) is at least partially arranged on a surface of the stationary mould clamping plate (2) and/or the movable mould clamping plate (3) facing the first and/or the second mould part (5, 6).

9. Moulding machine, preferably injection moulding machine, comprising a clamping unit (1) according to at least one of the preceding claims.

10. Method for measuring a force distribution (8) in a first clamping region (16) of a stationary mold platen (2) for clamping a first mold part (5) and/or in a second clamping region (16) of a movable mold platen (3) for clamping a second mold part (6) in a clamping unit (1) for a molding machine, wherein the force distribution (8) in the first clamping region (16) and/or in the second clamping region is measured by means of at least one surface sensor (7) arranged on the stationary mold platen (2) and/or the movable mold platen (3).

11. Method according to at least one of the preceding claims, characterized in that the detected force profile (8) is used for determining the deformation of the stationary mold jaw (2) and/or the movable mold jaw (3) under the clamping force (4).

12. Method according to at least one of the preceding claims, characterized in that the geometry of the stationary mould clamping plate (2) and/or the movable mould clamping plate (3) and/or the first mould part (5) and/or the second mould part (6) is adapted on the basis of the detected deformation.

13. Method according to at least one of claims 10 to 12, characterized in that the detected force profile (8) is used for determining or monitoring the clamping force of the mould parts (5, 6).

14. Method according to at least one of claims 10 to 13, characterized in that the detected force profile (8) is used for determining, monitoring and/or adjusting process parameters during operation of the clamping unit (1), preferably the tearing force and/or the clamping force (4).