In the steel and metallurgical industries, in order to control the quality of thin strip steel on the rolling production line, it is necessary to continuously measure and control the dynamic tension of the running thin strips during processes such as annealing, cleaning, and galvanizing. At this time, high-capacity force sensors are generally used for tension detection.
In the automotive industry, the quality of car tires is directly related to the dimensional stability and tension control of their extruded components. In the structure of all-steel radial tires, components such as the inner liner, sidewall, tread, and cushion gum are all produced by extrusion line systems, where tension control of the line is a key point in process management.
Tension detection based on force sensors has a wide range of applications. By measuring and controlling tension, the safe operation of related equipment and structures can be ensured, and the production process can be optimized and improved. Although force sensors are used in various industries for tension detection, this article categorizes their application methods in tension detection according to the type of equipment and installation method, and provides a brief analysis of their design requirements.
A force sensor directly connected in series with a flexible cable along the same line is the simplest and most effective method to detect the tension of the cable. The following three typical application examples illustrate the design technology of the force sensor and its detection device under this method.
The tension of the running flexible cable cannot be detected using the aforementioned series method. In this case, one set of rollers in the original flexible cable operating system can be modified into a tension detection device (as shown in Figure 4). Alternatively, an additional set of rollers can be installed according to the detection requirements to achieve the purpose of online tension detection.
In practical applications, steel wire ropes bend repeatedly over the three pulleys of the tension measuring device, which accelerates their wear and breakage. By appropriately increasing the pulley diameter while increasing the angle, thereby reducing the curvature of contact between the steel wire rope and the pulley, the impact of the device on the normal service life of the steel wire rope can be minimized.
With the advancement of force sensor design technology, tension detection devices can now be simplified. This can be summarized into the following three technical solutions: (1) Pin-type tension detection technologyWhether it is a two-roller or three-roller tension detection device, their common feature is the addition of one or more measuring rollers, and the conversion of tension into load for measurement through mechanisms such as levers. Based on this purpose, the roller pin can be transformed into a pin-type force sensor to measure tension. The pin-type force sensor is essentially a circular shaft subjected to shear force. Depending on the cross-section of the shaft, it can be divided into two internal structural forms: I-beam cross-section and hollow cross-section (cylindrical). Both have strong resistance to lateral loads. Therefore, as long as the loading axis of the force sensor is aligned with the resultant force of the rope tension, there is no need for additional anti-lateral structures to measure the tension of the rope in operation.
If a shaft-mounted sensor is designed with a crossbeam structure forming a 90° angle, and flexible mechanisms are used to isolate them from each other, the working principle of a dual-component sensor can be utilized to measure horizontal and vertical force components separately. The resultant force can also be displayed through signal processing, as in Honeywell's 6443 series force sensors.
