Injection force sensor arrangement and injection molding unit and injection molding machine equipped therewith

Abstract

An injection force sensor arrangement (10) for an injection molding unit (20) of an injection molding machine for processing plastics has two annular flange disks (30) that are integrally connected by means of a hollow cylinder (40). A wall (45) of the hollow cylinder (40) is arranged either flush with an inner radius of a wall (35) of the annular flange disks (30) or in the middle between an inner radius and an outer radius on the wall (35) of the annular flange disks (30). At least one deformation sensor (50) is arranged on a circumferential surface of the hollow cylinder (40), and the injection force sensor arrangement (10) can be arranged between a component (70) of a spindle drive (80) of the injection molding unit (20), which transmits a translational force, and a part of a metering drive (55), in particular a metering gear (60), of the injection molding unit, which part is movable relative to this component.

Description

Field of the invention

[0001] The present invention relates to an injection force sensor arrangement for an injection molding unit of an injection molding machine for processing plastics and other plasticizable materials, having the features according to the preamble of claim 1, an injection molding unit of such an injection molding machine, having the features according to the preamble of claim 11, and an injection molding machine for processing plastics and other plasticizable materials, having the features according to the preamble of claim 14. State of the art

[0002] For the production of precise plastic components, an exact determination of the plastic melt pressure during the injection process is essential. Of particular interest is the melt pressure upstream of a conveying device such as a screw or non-return valve. However, the screw is a machine component that moves both rotationally and translationally during the process. This fact makes the direct determination or measurement of the injection pressure or injection force difficult.

[0003] To make this possible, there are already systems on the market that measure the pressure directly in the screw pre-chamber or in the injection mold using internal pressure sensors. These components are located in the melt chamber and are therefore exposed to the high temperature, pressure, and abrasive flow velocity of the melt. These boundary conditions make internal pressure measurements subject to wear and tear and costly.

[0004] Other systems aim to exclude the rotation of the screw by means of suitable measures in order to realize an injection force measurement in the injection line.

[0005] From WO 2023 / 152168 A1, for example, an injection molding unit is known which has at least one motor and at least one drive for the rotational and translational movement of the screw. A force sensor is provided for measuring the force and / or for determining the forces exerted on the screw of the injection molding unit. The force sensor is arranged in a rotationally fixed manner with respect to the rotational movement of the screw. At least one decoupling element is provided which decouples the forces exerted on and / or by the screw in the axial direction along and / or parallel to the screw axis from other forces exerted on and / or by the screw. The force sensor is also designed to detect the force exerted on and / or by the screw in the axial direction along and / or parallel to the screw axis.These measures result in a simple, cost-effective, precise and reliable determination of the force exerted on the screw of the injection molding unit, e.g. the back-up and / or injection force or the corresponding pressure.

[0006] DE 19 525 142 C1 discloses a method and a device for detecting the forces occurring on a conveyor on an injection molding unit of an injection molding machine, which forces are characteristic of a pressure exerted on the conveyor by the material to be processed. A first static sensor and a further dynamic sensor are installed in a force measuring ring arranged on an injection bridge of the injection molding unit between the axial thrust bearing and a molded portion of the injection bridge. The further dynamic sensor detects the forces occurring during injection as a second measured value. As soon as the measured value of the first static sensor reaches a limit value, the first static sensor transfers further force detection to the further sensor, with the limit value simultaneously serving as a calibration value for the further sensor.

[0007] DE 10 2019 134 955 A1 discloses an injection device for an injection molding machine, which comprises an injection drive, which rotates an injection spindle relative to a spindle nut, an injection slide, which is connected to the spindle nut on a side surface in a rotationally fixed manner and is held movable along a slide guide, a guide housing on which a plasticizing cylinder is held, a bearing housing in which a drive shaft is rotatably mounted and which is connected to the injection slide, and a metering drive, which is attached to the injection slide and which rotates the drive shaft. A force detection device is mounted externally on a force transmission component arranged between the bearing housing and the spindle nut and located in the force flow of the injection device.

[0008] DE 102 10 923 A1 shows a pressure measuring device for an injection molding machine, which is arranged between the plasticizing screw and a lifting drive of an injection molding machine that actuates it in the axial direction and has an elastically deformable force transmission element that undergoes a bending deformation under the axial force effect of the lifting drive, which is measured electrically or optoelectrically to determine the injection pressure. Description of the invention

[0009] The invention is therefore based on the object of specifying an injection force sensor arrangement for an injection molding unit of an injection molding machine, which makes it possible to carry out an injection force measurement centrally in the injection line, wherein only a few components are installed between the measuring device and the melt pressure and wherein the measurement result is not influenced by a rotational force of a conveying means such as a conveying and plasticizing screw.

[0010] The problem is solved by an injection force sensor arrangement according to the features of claim 1. The injection force sensor arrangement comprises two annular flange disks which are integrally connected by means of a hollow cylinder. A wall of the hollow cylinder is arranged either flush with an inner radius of a wall of the annular flange disks or in the middle between an inner radius and an outer radius on the wall of the annular flange disks. At least one deformation sensor is arranged on a circumferential surface of the hollow cylinder, and the injection force sensor arrangement can be arranged between a component of a spindle drive of the injection molding unit which transmits a translational force and a part of a metering drive of the injection molding unit which is movable relative to this component, such as a metering gear.To measure the injection force, the relative movement between the component of the spindle drive that transmits a translational force and serves the injection device for the axial movement of a conveying medium and the dosing drive is recorded and preferably evaluated as both a compressive and a tensile force.

[0011] The injection force sensor arrangement is geometrically designed so that overloads of up to 100% do not lead to failure. At the same time, sufficient deformation on the sensor base body is ensured in the small-signal range, with a maximum of 20% of the injection force being generated during decompression or positive back pressure, so that the installed deformation sensor still enables reliable and process-accurate force measurement. Due to the small number of components installed between the measuring device and the melt pressure, the measurement result is generally only slightly influenced by the components.

[0012] The problem is also solved with an injection molding unit for an injection molding machine with an injection force sensor arrangement according to one of claims 1 to 10 according to the features of claim 11. The injection molding unit comprises a metering drive, e.g., with a metering gear and a spindle drive connected thereto. The injection force sensor arrangement is arranged between a component of the spindle drive that transmits a translational force and a part of a metering drive, in particular the metering gear, of the injection molding unit that is movable relative to this component. This sensor arrangement is thus capable of sensing the relative movement.

[0013] Furthermore, the object is also achieved with an injection molding machine for processing plastics and other plasticizable materials having the features of claim 14. It comprises an injection force sensor arrangement according to one of claims 1 to 10 for an injection molding unit according to one of claims 11 to 13.

[0014] Advantageous further training is the subject of dependent claims.

[0015] In a preferred embodiment which advantageously optimally suppresses the rotational force of the conveyor and plasticizing screw or simplifies the design of the injection force sensor arrangement, when the injection force sensor arrangement is arranged between the component of the spindle drive which transmits a translational force and the part of the metering drive which is movable relative to this component, such as the metering gear, of the injection molding unit, the translational force is transmitted at right angles to annular surfaces of the annular flange discs in the vicinity of the outer radius of the annular flange discs when the wall of the hollow cylinder is arranged flush with the wall of the inner radius of the annular flange discs.Alternatively, the translational force is transmitted perpendicular to the circular surfaces of the circular flange discs, midway between an inner radius and an outer radius of the circular flange discs, if the wall of the hollow cylinder is positioned midway between an inner radius and an outer radius on the wall of the circular flange discs. The translational force thus acts on the circular flange discs in the wall of the hollow cylinder parallel to a central axis of the circular flange discs and thus generally parallel to the injection axis.

[0016] Preferably, a further embodiment of the injection force sensor arrangement advantageously avoids a transmission of a rotational force of the spindle drive in that the component transmitting the translational force is a non-rotating spindle nut or a housing surrounding the non-rotating spindle nut and a screw drive and connected to them.

[0017] Advantageously, in another preferred embodiment, the design of the deformation sensor and the measurement of the injection force are simplified in that the at least one deformation sensor is at least one strain gauge which is configured to detect an expansion or contraction of the wall of the hollow cylinder.

[0018] Likewise, in a further preferred embodiment, the measurement of the injection force is advantageously simplified in that the at least one deformation sensor is an optical and / or metrological unit which is configured to detect a change in distance between the annular flange discs.

[0019] A preferred embodiment of the injection force sensor arrangement advantageously enables highly precise injection force measurement by arranging either four deformation sensors on the circumferential surface of the hollow cylinder, each offset by 90°, or two deformation sensors arranged on the circumferential surface of the hollow cylinder, offset by 180°, and two further deformation sensors, also arranged on the circumferential surface of the hollow cylinder and also offset by 180°, offset by a value less than 90° from the first two deformation sensors. The deformation sensors are each interconnected to form an electrical half-bridge or full-bridge.

[0020] Preferably, in a further embodiment which advantageously simplifies the signal transmission of the injection force sensor arrangement and its assembly, the at least one deformation sensor is connected via at least one electrical signal line to an electrical coupling arranged on one of the annular flange discs and / or the hollow cylinder, which electrical coupling can be connected to an electrical signal amplifier and evaluation unit.

[0021] Another preferred embodiment of the injection force sensor arrangement advantageously increases protection of the at least one deformation sensor, the at least one electrical signal line and the electrical coupling in that the at least one deformation sensor is arranged on a prefabricated, in particular recessed, surface on the circumferential surface of the hollow cylinder - inside or outside -, the at least one electrical signal line is arranged in at least one prefabricated channel of the wall of the hollow cylinder and / or the wall of one of the annular flange discs and the electrical coupling is arranged on a prefabricated, recessed surface of one of the annular flange discs.

[0022] In a further preferred embodiment, the assembly is advantageously facilitated in that the at least one deformation sensor, the at least one electrical signal line and the electrical coupling are pre-assembled on a carrier system, in particular a sheet metal ring, which is designed to be connected to the injection force sensor and to arrange the at least one deformation sensor on the circumferential surface of the hollow cylinder.

[0023] In a preferred embodiment of the injection force sensor which advantageously expands the application range of the injection force sensor, the geometry of the injection force sensor, in particular the inner radius, the outer radius and the thickness of the wall, the annular flange discs as well as the length and thickness of the wall of the hollow cylinder can be adapted to a force range to be measured.

[0024] In a preferred embodiment of the injection molding unit which advantageously facilitates assembly and maintenance of the injection molding unit, either the injection force sensor is operatively connected, such as screwed, to the part of the dosing drive of the injection molding unit and / or to the component of the spindle drive which transmits a translational force, or the injection force sensor and the part of the dosing drive are cast in one piece, or the injection force sensor is integrated into the dosing gear and operatively connected, such as screwed, to the component of the spindle drive which transmits a translational force.

[0025] Another preferred embodiment of the injection molding unit advantageously shortens the installation length of the injection molding unit in that an inner diameter of the wall of the annular flange discs is larger than an outer diameter of a threaded spindle of the spindle drive.

[0026] The invention will now be explained in more detail using an exemplary embodiment. Shown are: Fig. 1 a perspective overall view of an injection molding unit of an injection molding machine, Fig. 2 a perspective partial view of the injection molding unit from Fig. 1 with a first embodiment of the injection force sensor arrangement, Fig. 3 a perspective detailed view of the first embodiment of the injection sensor arrangement from Fig. 2 with a detailed cross-section, Fig. 4 a perspective detailed view of the first embodiment of the injection sensor arrangement from Fig. 2 with a carrier unit and a detailed section, Fig. 5 a perspective partial view of the injection molding unit from Fig. 1 with a second embodiment of the injection force sensor arrangement, Fig. 6 a perspective detailed view of the second embodiment of the injection sensor arrangement with a detailed sectional view, Fig. 7 a perspective view of a metering gear with an integrated injection force sensor arrangement. Description of preferred embodiments

[0027] Before describing the invention in detail, it should be noted that it is not limited to the specific components of the device and the specific method steps, as these components and methods may vary. The terms used herein are intended solely to describe particular embodiments and are not intended to be limiting. Furthermore, when the singular or indefinite articles are used in the description or claims, this also refers to the plural of these elements, unless the overall context clearly indicates otherwise.

[0028] The Fig. 1 shows an injection molding unit 20 with a spindle drive 80 as part of an injection molding machine for processing plastics and other plasticizable materials, which is arranged on a machine stand 130.

[0029] The design and operation of an injection molding machine are generally known to those skilled in the art. Plastics or other plasticizable materials are fed to the injection molding machine, which are mixed, plasticized, and homogenized in a plasticizing cylinder 140 of the injection molding unit 20. During the plasticizing process, plasticized material is metered in front of a conveying means 75, such as a screw. Subsequently, by an axial movement of the conveying means 75, the plasticized material is injected into a mold cavity of an injection mold (not shown in the drawing), which, in operation, is positioned between a Fig. 1 not shown in the drawing, and a non-movable mold carrier 150. During the injection process, the injection mold is closed by a mold closing unit, which is in Fig. 1 would be arranged on the side of the non-movable mold carrier 150 opposite the injection molding unit 20, but for the sake of simplicity in Fig. 1 is not shown. Once the injected plasticized material has hardened in the mold cavity, the injection mold is reopened by the mold clamping unit so that the finished molded part can be removed. This process occurs cyclically.

[0030] In the exemplary embodiment, the spindle drive 80 for the axial movement of the conveying means 75 comprises a rotating threaded spindle 85, which is connected via a threaded drive (not shown), in particular a ball screw drive or planetary roller screw drive, to a non-rotating spindle nut (also not shown). The spindle nut thus forms a component 70 that transmits a translational force, of which only the outer side is visible, acting like a housing 90. However, the spindle nut and the threaded drive can also be arranged in a housing 90 and connected to it. The component 70 or the housing 90 forms or contains the spindle nut, which, together with the threaded spindle 85, forms the spindle drive (planetary roller screw drive or ball screw drive).

[0031] Typically, the 85 threaded spindle is installed without a housing. However, if an oil bath lubrication system is desired instead of a grease lubrication system, the 85 threaded spindle is best installed in a housing, as sealing is easier there.

[0032] Fig. 2 is a partial view of the injection molding unit of Fig. 1, which shows the spindle drive 80 on the right side of the figure and a dosing drive 55 with a dosing gear 60 housed in a housing on the left side of the figure. The mount 65 for the dosing drive motor is also visible below.

[0033] The metering drive 55 and the metering gear are axially movable in the direction of an injection axis, which runs through the conveyor 75, so that the conveyor 75 can be pushed forward like a screw in the plasticizing cylinder 140 via the spindle drive 80. Through this movement, the plasticized mass is injected into the mold cavity of an injection mold. In the embodiment shown in FIG. Fig. 1 the rear injection gear 160, on which the spindle drive 80 is supported in order to apply the injection force.

[0034] In the Fig. 3 and Fig. 4 are detailed views of the Fig. 2 depicts a first embodiment of the injection force sensor assembly 10. Therein, the injection force sensor assembly 10 comprises two annular flange disks 30, which are integrally connected by means of a hollow cylinder 40, wherein an inner wall 45 of the hollow cylinder 40 is arranged flush with an inner radius of a wall 35 of the annular flange disks 30.

[0035] Flush means that the wall 35 on the inner radius of the circular surfaces 30 is approximately the same area as the wall 45 of the hollow cylinder, ie the walls merge into one another.

[0036] In Fig. 5 is a partial view of the injection molding unit of Fig. 1 and in Fig. 6 is a detailed view of the Fig. 5 depicts a second embodiment of the injection force sensor assembly 10. Therein, the injection force sensor assembly 10 comprises two annular flange disks 30, which are integrally connected by means of a hollow cylinder 40. A wall 45 of the hollow cylinder 40, which extends transversely to the annular flange disks 30 and parallel to the center axis of the annular flange disks, is arranged midway between an inner radius and an outer radius on the wall 35 of the annular flange disks 30.

[0037] In this case, at least one deformation sensor 50 is arranged on a circumferential surface of the hollow cylinder 40, preferably in an Fig. 6. Detail B, visible thinned area. The injection force sensor arrangement 10 is designed to be arranged between a component 70 of the spindle drive 80 of an injection device of the injection molding unit 20, which transmits a translational force and moves the conveying means 75 axially, and a part of a metering drive 55, in particular a metering gear 60, of the injection molding unit, which is movable relative to this component. To measure the injection force, the relative movement between the component 70 of the spindle drive, which serves the injection device for the axial movement of the conveying means 75, and the metering drive 55 is recorded and evaluated. This relative movement deforms the injection force sensor arrangement 10, so that the deformation can be measured for evaluating the injection force using at least one deformation sensor 50.This largely eliminates the influence of screw rotation of a conveying and plasticizing screw of the injection molding unit 20 and enables simple and accurate force measurement of the tensile and compressive forces that correspond to the melt pressure.

[0038] The influence of a rotational force of the conveying means 75, such as the conveying and plasticizing screw, can advantageously be optimally suppressed by the screw rotation taking place inside the dosing drive 55 or the dosing gear 60, while the injection force sensor arrangement 10 is attached to the "only" translationally displaceable part of the dosing drive and thus installed in such a way that the rotation has no influence on the sensor.

[0039] According to the first embodiment, the Fig. 2, Fig. 3 and Fig. 4 in an arrangement of the injection force sensor arrangement 10 between the component 70 of the spindle drive 80 which transmits a translational force and the part of the metering drive 55 which is movable relative to this component, such as the metering gear 60, the translational force is transmitted at right angles to annular surfaces 30a of the annular flange discs 30 in the vicinity of the outer radius of the annular flange discs 30, when the wall 45 of the hollow cylinder 40 is arranged flush with the wall 35 of the inner radius of the annular flange discs 30. Fig. 3 and Fig. 4 illustrate this, wherein the respective sectional view A shows that the walls 35 of the annular flange discs 30 and the wall 45 of the hollow cylinder 40 have a one-piece U-shaped configuration. This arrangement converts the bending of the injection assembly into compression and elongation, which can be detected by the deformation sensor 50.

[0040] The translational force thus acts parallel to a central axis of the annular flange discs 30 and thus generally parallel to a spray axis on the annular flange discs 30 and is thereby transmitted in the wall 45 of the hollow cylinder 40 parallel to a central axis of the hollow cylinder.

[0041] The design of the injection force sensor arrangement can be simplified in that, as in a second embodiment according to the Fig. 5 and Fig. 6, the translational force is transmitted perpendicular to the annular surfaces 30a of the annular flange discs 30 in the middle between an inner radius and an outer radius of the annular flange discs 30 when the wall 45 of the hollow cylinder 40 is arranged in the middle between an inner radius and an outer radius on the wall 35 of the annular flange discs 30. As in Fig. 6 in detail B, the walls 35 of the annular flange discs 30 and the wall 45 of the hollow cylinder 40 in this case have an H-shape. Compared to the first embodiment, the hollow cylinder 40 can have a thinner wall thickness. In the area of ​​the thin cross-section, compression or expansion occurs due to the tensile and compressive forces, which can be detected by the deformation sensor 50.

[0042] The translational force thus also acts on the annular flange discs 30 parallel to a central axis of the annular flange discs 30 and thus generally parallel to the injection axis. It is also transmitted here in the wall 45 of the hollow cylinder 40 parallel to a central axis of the hollow cylinder.

[0043] The component 70 transmitting the translational force can be the non-rotating spindle nut or can, as in Fig. 2 and Fig. 5, a housing 90 surrounding and connected to the non-rotating spindle nut and a screw drive, as explained above. This advantageously avoids the transmission of a rotational force of the spindle drive 80 in the state of the injection force sensor assembly 10 in which it is operatively connected to the part of the metering drive 55 and the non-rotating spindle nut or to the housing 90 surrounding and connected to the non-rotating spindle nut and a screw drive.

[0044] The at least one deformation sensor 50 may be at least one strain gauge configured to detect an expansion or contraction of the wall 45 of the hollow cylinder 40, as shown in Fig. 3, Fig. 4 and Fig. 6. This advantageously simplifies the design of the deformation sensor and the measurement of the injection force.

[0045] The at least one deformation sensor 50 can also be an optical and / or measuring unit configured to detect a change in the distance between the annular flange discs 30. This also advantageously simplifies the measurement of the injection force.

[0046] If either four deformation sensors 50 are arranged on the circumferential surface of the hollow cylinder 40, each offset by 90°, as in Fig. 3, Fig. 4, an injection force can advantageously be determined with high precision. This is also the case if, alternatively, two deformation sensors 50, which are arranged on the circumferential surface of the hollow cylinder 40 and offset from one another by 180°, are arranged, and two further deformation sensors 50, which are also arranged on the circumferential surface of the hollow cylinder 40 and also offset from one another by 180°, are arranged offset from the first two deformation sensors 50 by a value that is less than 90°. In both arrangements of the deformation sensors 50, the deformation sensors 50 can be arranged such that an electrical half-bridge or full-bridge is created.

[0047] The signal transmission of the injection force sensor arrangement 10 and its assembly 10 can advantageously be simplified in that the at least one deformation sensor 50 is connected via at least one electrical signal line 100 to an electrical coupling 110 arranged on one of the annular flange discs 30 and / or the hollow cylinder 40, which coupling can be connected to an electrical signal amplifier and evaluation unit 108, as in Fig. 3, Fig. 4 and Fig. 6 shown.

[0048] As in Fig. 3 and Fig. 4, protection of the at least one deformation sensor 50, the at least one electrical signal line 100 and the electrical coupling 110 against external influences, such as contact when the threaded spindle 85 passes through the cavity of the hollow cylinder 40, can be advantageously improved by arranging the at least one deformation sensor 50 on a prefabricated, in particular recessed, surface 38 on the peripheral surface of the hollow cylinder 40 and / or by arranging the at least one electrical signal line 100 in at least one prefabricated channel in the wall 45 of the hollow cylinder 40 and / or the wall 35 of one of the annular flange disks 30 and / or by arranging the electrical coupling 110 on a prefabricated, recessed surface 48 of one of the annular flange disks 30.

[0049] The at least one deformation sensor 50, the at least one electrical signal line 100 and the electrical coupling 110 can be pre-assembled on a carrier system 120, in particular a sheet metal ring, as in Fig. 4, which is configured to be connected to the injection force sensor assembly 10 and to arrange the at least one deformation sensor 50 on the circumferential surface of the hollow cylinder 40. This advantageously facilitates the assembly of the injection force sensor assembly 10.

[0050] The at least one deformation sensor 50 and / or the at least one electrical signal line 100 and / or the electrical coupling 110 can also be coated with a protective layer, in particular a resin, a lacquer and / or a film, whereby their protection against external influences is also advantageously improved.

[0051] Particularly advantageously, the application range of the injection force sensor arrangement 10 can be expanded in that its geometry, in particular at least one of the elements comprising the inner radius, the outer radius and the thickness of the wall 35 of the annular flange discs 30 as well as the length and thickness of the wall 45 of the hollow cylinder 40, can be adapted to a force range to be measured.

[0052] An injection molding unit 20 of an injection molding machine can thus advantageously be equipped with an injection force sensor assembly 10 according to the invention. The injection molding unit 20 comprises a part of the metering drive 55 and a spindle drive 80 connected thereto, wherein a relative movement, as a result of the injection force, occurs between a component 70 of the spindle drive 80 that transmits a translational force and a part of the metering drive 55 that is movable relative to this component 70, in particular a metering gear 60. The injection force sensor assembly 10 arranged here detects and measures this injection force.

[0053] Assembly and maintenance of the injection molding unit can advantageously be facilitated by either the injection force sensor arrangement 10 being operatively connected to the part of the metering drive 55, such as the metering gear 60, and / or to the component 70 of the spindle drive 80 transmitting a translational force, as shown in Fig. 2, or the injection force sensor assembly 10 and the part of the metering drive 55, such as the metering gear 60, are made of one piece, as in Fig. 5 or alternatively the injection force sensor arrangement 10 is integrated into the part of the metering drive 55, such as the metering gear 60, as in Fig. 7, and is operatively connected to the translational force transmitting component 70 of the spindle drive 80, as shown in Fig. 5 and Fig. 7. The effective connection can be made in any way, e.g. by screwing, riveting, welding or the like. According to Fig. 7, the injection force sensor arrangement 10 does not have to be integrated into an additional part, but can be a component of the gearbox housing.

[0054] An installation length of the injection molding unit can advantageously be shortened by making an inner diameter of the wall 35 of the annular flange discs 30 larger than an outer diameter of a threaded spindle 85 of the spindle drive 80. This allows the threaded spindle 85 to penetrate through a cavity defined by the inner diameter of the annular flange discs 30. List of reference symbols 10 Injection force sensor arrangement 20 injection molding unit 30 circular flange discs 30a circular areas 35 Wall of the flange disc 38 recessed surface of the flange disc 40 hollow cylinders 45 Wall of the hollow cylinder 48 recessed area on the peripheral surface of the hollow cylinder 50 deformation sensor 55 Dosing drive 60 dosing gears 65 mount for engine of 55 70 translational force transmitting component 75 funding 80 spindle drive 85 threaded spindle 90 housings 100 electrical signal cables 105 Line 108 Signal amplifier and evaluation unit 110 electric clutch 120 carrier system 130 machine stands 140 plasticizing cylinders 150 non-movable mold carrier 160 injection gearbox

Claims

[1] Injection force sensor arrangement (10) for an injection molding unit (20) of an injection molding machine for processing plastics and other plasticizable materials, characterized by , that the injection force sensor arrangement (10) has two annular flange discs (30) which are connected in one piece by means of a hollow cylinder (40), wherein a wall (45) of the hollow cylinder (40) is arranged either flush with an inner radius of a wall (35) of the annular flange discs (30) or in the middle between an inner radius and an outer radius on the wall (35) of the annular flange discs (30), that at least one deformation sensor (50) is arranged on a circumferential surface of the hollow cylinder (40) and that the injection force sensor arrangement (10) can be arranged between a component (70) of a spindle drive (80) of the injection molding unit (20) which transmits a translational force and a part of a metering drive (55), in particular a metering gear (60), of the injection molding unit which is movable relative to this component. [2] Injection force sensor arrangement (10) according to claim 1, characterized bythat when the injection force sensor arrangement (10) is arranged between the part of the metering drive (55) and the component (70) of the spindle drive (80) transmitting a translational force, the translational force is transmitted at right angles to annular surfaces (30a) of the annular flange discs (30) in the vicinity of the outer radius of the annular flange discs (30) when the wall (45) of the hollow cylinder (40) is arranged flush with the wall (35) of the inner radius of the annular flange discs (30), and that the translational force is transmitted at right angles to annular surfaces (30a) of the annular flange discs (30) in the middle between an inner radius and an outer radius of the annular flange discs (30) when the wall (45) of the hollow cylinder (40) is arranged in the middle between an inner radius and an outer radius on the wall (35) of the circular flange discs (30). [3] Injection force sensor arrangement (10) according to one of the preceding claims, characterized by that the component (70) transmitting the translational force is a non-rotating spindle nut or a housing (90) surrounding the non-rotating spindle nut and a screw drive and connected to them. [4] Injection force sensor arrangement (10) according to one of the preceding claims, characterized by that the at least one deformation sensor (50) is a strain gauge which is designed to detect an expansion or contraction of the wall (45) of the hollow cylinder (40). [5] Injection force sensor arrangement (10) according to one of the preceding claims, characterized by that the at least one deformation sensor (50) is an optical and / or measuring unit which is designed to detect a change in distance between the annular flange discs (30). [6] Injection force sensor arrangement (10) according to one of the preceding claims, characterized by that either four deformation sensors (50) are arranged on the circumferential surface of the hollow cylinder (40), each offset by 90°, or two deformation sensors (50) which are arranged on the circumferential surface of the hollow cylinder (40) are offset from one another by 180°, and two further deformation sensors (50), which are also arranged on the circumferential surface of the hollow cylinder (40) and are also offset from one another by 180°, are arranged offset from the two first deformation sensors (50) by a value which is less than 90°, wherein the deformation sensors (50) can each be connected to form an electrical half or full bridge. [7] Injection force sensor arrangement (10) according to one of the preceding claims, characterized bythat the at least one deformation sensor (50) is connected via at least one electrical signal line (100) to an electrical coupling (110) arranged on one of the annular flange discs (30) and / or the hollow cylinder (40), which coupling can be connected to an electrical signal amplifier and evaluation unit (108). [8] Injection force sensor arrangement (10) according to claim 7, characterized by that the at least one deformation sensor (50) is arranged on a prefabricated, in particular recessed, surface (48) on the circumferential surface of the hollow cylinder (40) and / or the at least one electrical signal line (100) is arranged in at least one prefabricated channel of the wall (45) of the hollow cylinder (40) and / or the wall (35) of one of the annular flange discs (30) and / or the electrical coupling (110) is arranged on a prefabricated, recessed surface (38) of one of the annular flange discs (30). [9] Injection force sensor arrangement (10) according to claim 7, characterized by that the at least one deformation sensor (50) and / or the at least one electrical signal line (100) and / or the electrical coupling (110) are pre-assembled on a carrier system (120), in particular a sheet metal ring, which is designed to be connected to the injection force sensor arrangement (10) and to arrange the at least one deformation sensor (50) on the circumferential surface of the hollow cylinder (40). [10] Injection force sensor arrangement (10) according to one of the preceding claims, characterized by that the geometry of the injection force sensor arrangement (10), in particular at least one of the elements comprising the inner radius, the outer radius, the thickness of the wall (35) of the annular flange discs (30), the length and thickness of the wall (45) of the hollow cylinder (40), is adaptable to a force range to be measured. [11] Injection molding unit (20) of an injection molding machine for processing plastics and other plasticizable materials, comprising a metering drive (55) and a spindle drive (80) connected thereto, characterized by that an injection force sensor arrangement (10) according to one of claims 1 to 10 is arranged between a component (70) of the spindle drive (80) which transmits a translational force and a part of the metering drive (55) which is movable relative to this component (70), in particular a metering gear (60). [12] Injection molding unit (20) according to claim 11, characterized bythat either the injection force sensor arrangement (10) is operatively connected to the part of the metering drive (55) and / or to the component (70) of the spindle drive (80) transmitting a translational force, or the injection force sensor arrangement (10) and the metering gear (60) are cast in one piece, or the injection force sensor arrangement (10) is integrated into the metering gear (60) and is operatively connected to the component (70) of the spindle drive (80) transmitting a translational force. [13] Injection molding unit (20) according to claim 11 or 12, characterized by that an inner diameter of the wall (35) of the annular flange discs (30) is larger than an outer diameter of a threaded spindle (85) of the spindle drive (80). [14] Injection moulding machine for processing plastics and other plasticisable materials, characterized bythat it comprises an injection molding unit (20) according to one of claims 11 to 13 with an injection force sensor arrangement (10) according to one of claims 1 to 10.

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