Measuring roller for measuring strip tension and methods for its manufacture

Abstract

Measuring roller (M) for the spatially sensitive measurement of strip tension across the strip width, e.g., during rolling, punching, or winding of strip material made of aluminum, steel, paper, or plastic, wherein a rotating hollow cylinder (7), consisting of a sensor carrier (1) and a shell (2) bonded thereto with a closed and low-wear shell surface, contains sensors (6) secured against loosening during operation (e.g., vibrations), which can be installed and removed and electrically connected via the inside of the hollow cylinder (7), wherein the radially acting sensors (6) form a positive connection with the sensor carrier (1) and a spatially sensitive frictional connection through contact with the shell (2), wherein recesses (3) are located on the inside of the hollow cylinder (7) and the sensors (6) are received via threads or threaded sleeves (5) or grooves inserted into the recesses (3).

Description

[0001] The invention relates to a measuring roller for the spatially sensitive measurement of a belt tension and a method for manufacturing the measuring roller.

[0002] German patent DE 10 2004 043 150 A1 describes a measuring roller for the spatially sensitive measurement of strip tension across the strip width. A circular hollow cylinder comprises a sensor carrier and a jacket bonded to it. The jacket includes electrically connectable sensors that form a positive connection with the sensor carrier and a spatially sensitive frictional connection through contact with the jacket.

[0003] A measuring roller for measuring the belt tension and an associated method are also known from DE 101 57 792 A1.

[0004] DE 28 48 638 A1 proposes a roller for measuring tension, which can be used, for example, in the cold rolling of a metal strip.

[0005] From EP 2 447 198 A1, a roller arrangement for determining the web tension profile of a web is known. Openings for receiving sensor arrangements are provided in a roller, wherein a sensor arrangement comprises a sensor and a sensor housing.

[0006] EP 0 262 002 A1 describes a manufacturing process for a roller for monitoring a strip profile.

[0007] US Patent 3,688,571 A describes a device for monitoring the shape of cold-rolled sheet metal. The device includes sensors arranged on a roller to detect the stress distribution across the width of the sheet.

[0008] Another measuring roller is known, for example, from DE 92 18 981 U1. In this design, the sensors are inserted into radial bores in a pattern distributed across the cylindrical surface of the measuring roller. Screw-on caps are provided to secure the sensors in the radial bores and to close the bores. The annular gap on the cylindrical surface requires careful sealing to prevent contamination. This is only partially successful. Furthermore, replacing defective sensors is a complex and costly process.

[0009] German patent DE196 16 980 A1 describes a measuring roller in which the annular gap is sealed with a plastic layer. Contaminants can accumulate in the plastic.

[0010] From EP 1 432 536 B1, various designs of the sensor cover and sensor mounting are known, which serve to seal the mounting bores for the sensors in the measuring roller without an annular gap. Replacing defective sensors in such a measuring roller is particularly complex.

[0011] DE102 07 501 C1 discloses a method that circumvents the problem of annular gaps by using axially parallel bores or channels running close to the surface to accommodate the pressure sensors. However, the method is very uneconomical and replacing individual sensors is very costly.

[0012] DE198 38 457 A1 describes a measuring roller in which a sheathed tube is shrunk onto a base body, the base body containing the radial bores with the sensors. Replacing defective sensors is particularly difficult with this measuring roller.

[0013] The object of the invention is to eliminate the disadvantages of the prior art, to provide an improved measuring roller and a more economical method for installing or replacing the sensors in the measuring roller. Furthermore, the economic potential of such measuring rollers is to be improved by reducing their weight.

[0014] This problem is solved by the features of dependent claims 1 and 5. Advantageous embodiments of the invention result from the features of claims 2 to 4.

[0015] According to the invention, it is proposed that the component of the measuring roller containing the sensors and their mounting consists of a hollow cylinder. This hollow cylinder can be made of steel or light metal. Furthermore, the hollow cylinder can be made of fiber-reinforced composite material, such as carbon fiber-reinforced plastic or reinforced light metal. The hollow cylinder can also be composed of metal and fiber-reinforced composite material.

[0016] The sensors can be mounted inside this hollow cylinder using a positive-locking fastening system that prevents loosening during operation. This fastening can be manually released to replace a sensor. Such a sensor fastening could, for example, be a screw connection with a locking mechanism.

[0017] For sensor mounting, corresponding recesses are located on the inside of the hollow cylinder. These recesses can be circular and can have a diameter ranging, for example, from 10 to 50 mm. Their depth is between 0.5 and 10 mm less than the wall thickness of the hollow cylinder.

[0018] The recesses may contain threads or grooves. However, the threads may also be in the form of pressed-in or glued-in threaded inserts, for example.

[0019] Each of these recesses can, for example, accommodate a radially pressure-sensitive sensor. The sensor is guided until it makes contact with the cylinder shell and then positively secured to the side of the recess. This can be achieved using a thread. When using bending- or strain-sensitive sensors, these can also be directly bonded to the cylinder shell on the recessed side.

[0020] Advantageously, the recesses and sensors are distributed in an arrangement such that imbalance, loss of strength and stiffness of the measuring roller are avoided.

[0021] According to an advantageous embodiment of the invention, the recesses and sensors are distributed in such a way that in each measuring position, the belt tension and the deflection of the measuring roller can be simultaneously recorded on the corresponding sections of the measuring roller.

[0022] Each sensor has a cable or plug, which allows the sensors to be connected to electronics located in the measuring roller for signal processing or signal transmission.

[0023] The following steps are suggested for the production of such a measuring roller: The first step is the production of a circular hollow cylinder with the appropriate geometry (diameter, wall thickness) that meets the requirements for strength and stiffness for the measurement task. This first hollow cylinder can be made of metal or fiber-reinforced composite material and is referred to below as the sensor carrier.

[0024] The sensor carrier has holes at the planned sensor positions. These can be circular holes with a diameter between 5 mm and 50 mm, created by drilling or milling. The holes may also be threaded.

[0025] Next, placeholders are inserted into the holes, temporarily sealing the cylindrical surface of the sensor carrier. The resulting annular gap on the cylindrical surface can be between 0.01 and 0.2 mm. The placeholder can be made of metal or plastic. It can also have an external thread, allowing it to be easily screwed in if a thread is already present in the hole.

[0026] The placeholder can at least be structurally aligned with the cylinder's surface. This means it has the same curvature on the outside as the cylinder's surface. Additional securing of the placeholder and sealing of the annular gap can be achieved by lightly gluing or filling the gap on the side of the cylinder's surface.

[0027] The placeholder can also be fixed in place by a mechanical device, such as a mandrel inside the hollow cylinder. Alternatively, placeholders that protrude beyond the cylinder's outer surface can be used. After fixing, these can be machined flush with the cylinder's outer surface to match the existing structure, for example, by grinding or turning.

[0028] The surface of the placeholder can be provided with a separating layer. This separating layer can be a lacquer or a film.

[0029] To create the concentric and closed surface, an outer layer is bonded to the cylindrical surface of the sensor carrier after the adapted placeholders have been inserted. Conveniently, continuous fibers impregnated with resin or plastic are wound around the surface of the sensor carrier until the desired wall thickness is achieved. Alternatively, fiber composite prepregs can be laid or wound around the sensor carrier until the desired thickness is reached.

[0030] The winding or fabric is then cured. Curing is preferably carried out at an elevated temperature and under pressure.

[0031] To improve concentricity, the resulting new cylindrical surface can be easily machined, for example by grinding or turning. It is also advantageous to coat the new cylindrical surface with a wear-resistant protective layer. Suitable coating materials include metal, ceramic, rubber, or plastic.

[0032] To expose the recesses, the inserted placeholders are removed again.

[0033] In a particularly advantageous design, threaded sleeves are inserted into the pre-formed recesses. They can be fastened by screwing and / or adhesive bonding.

[0034] The sensors are screwed into the recess or threaded sleeves and secured. Conveniently, the sensors can be adjusted and calibrated in the same step.

[0035] The proposed arrangement is particularly robust. Defective sensors can be replaced with very little effort.

[0036] In an advantageous embodiment, the inner cylinder is made of carbon fiber composite material. This makes the proposed arrangement particularly lightweight.

[0037] According to a further particularly advantageous embodiment, the sensor is a pressure-sensitive piezoelectric sensor which, after installation, has a force-fit connection with the shell of the hollow cylinder.

[0038] With such a measuring roller, it is possible to monitor the strip tension distribution in rolling processes.

[0039] Advantageous embodiments of the invention are explained in more detail below with reference to the drawings. They show: Fig. 1 A schematic sectional view of the measuring roller without sensors, Fig. 2 a schematic sectional view of a placeholder, Fig. 3 a schematic sectional view of a threaded sleeve, Fig. 4. A schematic axial sectional view of the measuring roller, Fig. 5 a schematic radial sectional view of the measuring roller, Fig. 6 A schematic sectional view of a section of the measuring roller.

[0040] In the Fig.Reference numeral 1 to 6 denotes the sensor carrier. This can be made, for example, of carbon fiber reinforced plastic. Reference numeral 2 denotes the sheath. It can also be made of carbon fiber reinforced plastic and is applied by a winding process followed by curing. Reference numeral 3 denotes the recesses, which can be threaded or fitted with a threaded sleeve. Reference numeral 4 denotes the placeholders used to close the holes, ensuring a flush finish during subsequent lamination or winding processes and preventing any remaining indentations. Reference numeral 5 denotes the threaded sleeves, which can optionally be glued or screwed into the recesses. Reference numeral 6 denotes the sensors themselves.These are either screwed directly into the recesses or into the threaded sleeves. Reference numeral 7 designates the hollow cylinder, which is materially bonded together from the sensor carrier and the casing. Reference symbol list 1 sensor carrier 2 coats 3. In-depth study 4 placeholders 5 threaded sleeve 6 Sensor 7 hollow cylinders M measuring roller

Claims

[1] Measuring roller (M) for the spatially sensitive measurement of strip tension across the strip width, e.g., during rolling, punching, or winding of strip material made of aluminum, steel, paper, or plastic, wherein a rotating hollow cylinder (7), consisting of a sensor carrier (1) and a shell (2) bonded thereto with a closed and low-wear shell surface, contains sensors (6) secured against loosening during operation (e.g., vibrations), which can be installed and removed and electrically connected via the inside of the hollow cylinder (7), wherein the radially acting sensors (6) form a positive connection with the sensor carrier (1) and a spatially sensitive frictional connection through contact with the shell (2), wherein recesses (3) are located on the inside of the hollow cylinder (7) and the sensors (6) are received via threads or threaded sleeves (5) or grooves inserted into the recesses (3). [2] Measuring roller according to claim 1, wherein the sheath (2) consists of a fiber composite material. [3] Measuring roller according to one of the preceding claims, wherein the casing (2) is provided with a wear-resistant layer. [4] Measuring roller according to one of the preceding claims, wherein the sensor carrier (1) is made of metal or is a fiber composite material. [5] Method for manufacturing a measuring roller (M) according to any one of the preceding claims, comprising the following steps: a. Production / provision of a circular hollow cylinder (7) as a sensor carrier (1) made of metal or fiber composite material with the required dimensions and radial holes in the cylinder shell, which are to be distributed as the sensors (6) are to be used later. b. (Alternative to h.) Inserting threads or threaded inserts (5) into the holes, c. surface-conforming sealing of the holes by inserting placeholders (4) made of metal and / or plastic, d. Construction of the outer shell (2) made of fiber composite material around the sensor carrier (1) using winding or prepreg technology and subsequent curing, e. Exposing the recesses (3) for the sensors (6) by removing the placeholders (4) from the sensor carrier (1), f. Reworking of the outer shell (2) by mechanical processing such as grinding or turning, g. Coating of the outer shell (2) with a wear-resistant protective layer made of metal, ceramic, rubber or plastic, h. (Alternative to b) Inserting threads or threaded inserts (5) into the recesses (3), i. Screw in and secure the sensors (6) via the threaded sleeves (5) from the inside of the hollow cylinder (7), and j. Adjustment and calibration of the sensors (6).

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