RU2819195C1 - Forming tool with three-axis force measurement system - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: deforming tool contains a body including a base with two side walls, two side faces, a bottom cover and a top cover. A strain gauge is installed in the central part of the base to measure the force directed along the vertical axis of the working element. A strain gauge is also installed in the central part of each of the lateral integral walls of the base to measure the force on the working element along an axis perpendicular to the lateral integral walls of the base. Two side faces are fixed to the base and have strain gauge sensors installed on their central parts with the ability to measure the force of the working element along the axis perpendicular to the side faces. The lower housing cover is fixed to the upper parts of the side walls of the base and the side faces, and a disk spring is installed in it, on which the lower part of the insert is placed with a sphere held by the upper part of the insert, which, in turn, is fixed by the upper cover. The working element is installed in a sphere with the possibility of axial movement, rotational movement together with the sphere, as well as the influence of its lower part on the strain gauge sensors present in the tool.

EFFECT: increasing the sensitivity and accuracy of measuring forces and moments during incremental shaping, as well as improving the quality of the resulting products.

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Description

The invention relates to the field of mechanical engineering, in particular to deforming tools that are used in incremental shaping.

Incremental forming is a sheet metal processing process in which the workpiece is locally deformed by a ball-faced punch by moving one or more tools along a specified direction. The end parts of the workpiece are rigidly fixed between the bottom plate and the clamp. The technology allows you to work with structural, stainless, high-strength and galvanized steels, non-ferrous metals, titanium and other materials.

A force-torque sensor is known (patent RU209704, IPC G01L 5/16, publ. 03/18/2022), which is made in the form of a cylindrical body. In which a control board is installed, a mounting plate having fastenings for installing the sensor on the manipulator, an elastic element in the form of a cross with four arms, in the central part of which there are four threaded holes, in each arm there is a cutout dividing it into two parts and forming four measuring pads on each arm. At the edges of the arms there are holes for fastening in the cylindrical body. The front panel is installed on the elastic element through threaded holes and is connected to the body through a sealing seal. On the front part of the front panel there are threaded holes for installing tools and accessories; there are also holes for installing screws that serve to adjust the gap between it and the body.

The disadvantage of this solution is its rather complex design. Also, a sensor of this design is not able to withstand the loads that incremental shaping requires.

A force sensor is known (patent RU 216434, IPC G01L 1/22, publ. 02/03/2023), containing a body in the form of a cylinder, with a piston lever, one of its heads is the base of the piston lever, and the second side is a head in the form a solid ball with a diameter of about 5 mm touching the area being measured. The cylinder has a groove located along the longitudinal axis of the cylinder. A linear variable resistor is installed on top of the cylinder, containing connecting wires and a small handle about mm long, the handle of the resistor is connected to another groove located at the base of the piston lever, the first spring is installed in front of the base of the piston lever, and the second spring after it (in order to obtain the zero position of the sensor when there is no external influence). The force sensor also contains a nut located about 20 mm from the cylinder head to secure the force sensor.

The disadvantage of this solution is the ability to measure force only along the sensor axis, as well as the impossibility of simultaneous reproduction of incremental shaping.

The closest analogue is a force sensor (patent RU2795669, IPC G01L 1/22, publ. 05/05/2023), contains a bridge of strain gauges, which is made of foil in a discretely distributed design in the form of four strain gauges located on a substrate. In this case, the bridge consists of two chains of transversely located discrete resistors and two chains of longitudinally located resistors. Each of the four strain gauges represents a continuous chain elongated in the longitudinal direction, while the longitudinal and transverse chains alternate with each other and are combined into a single structure using four contact pads located at the edges of the chains.

The main disadvantage of the device is the complexity of its manufacture, as well as the insufficient strength of the structure to carry out incremental shaping.

The technical result of the proposed solution is to increase the sensitivity and accuracy of measuring forces and moments during incremental shaping, as well as to improve the quality of the resulting products.

The technical result is achieved due to the fact that the deforming tool, containing a body with a working element connected to strain gauges, includes a base with two side one-piece walls, two side faces, a bottom cover and an top cover, and a strain gauge is installed in the central part of the base a sensor with the ability to measure force directed along the vertical axis of the working element in the form of a cylindrical punch, and in the central part of each of the side one-piece walls of the base there is also a strain gauge sensor with the ability to measure the force on the work element along the axis perpendicular to the side one-piece walls of the base, with two side the faces are fixed on the base and in the same way have on their central parts, installed with the ability to measure the force of the working element along the axis perpendicular to the side faces, strain gauges, the lower cover of the housing is fixed on the upper parts of the side walls of the base and the side faces, and a disc spring is installed in it , on which the lower part of the insert is placed with a sphere held by the upper part of the insert, which, in turn, is fixed by the upper cover by its detachable connection with the lower cover, while the working element is installed in the sphere with the possibility of axial movement, rotational movement together with the sphere, as well as the impact of its lower part on the strain gauge sensors present in the tool.

The device is a device for measuring the forces of the incremental shaping process in various directions and at each point where the deforming tool is located, which, in combination with software that solves the problems of systematization, analytical analysis and subsequent visualization of the obtained data, allows you to obtain information about the progress of the process, which increases the available accuracy indicators. Determining the values of the forces acting at each moment in time of the process allows us to obtain a clearer understanding of the changes in the macro and microstructure of the material being processed, study its properties in more detail, perform a comparative analysis and identify individual positive characteristics of the process.

Using a sphere to install a punch and strain gauges located along three axes allows you to increase the sensitivity and accuracy of measuring forces and moments during incremental shaping, and, accordingly, improve the quality of the resulting products

The essence of the technical solution is illustrated by the following drawings:

- in fig. 1 shows a top view of the deforming tool;

- in fig. 2 shows a section A-A of the deforming tool;

- in fig. Figure 3 shows a section B-B of the deforming tool.

The deforming tool includes a body that contains a base (1), two side faces (2), a lower cover (3) and an upper cover (4), a working element in the form of a punch (5), an insert (6), in which a sphere (7), a disc spring (8), adapters for sensors (9) and strain gauges (10) are installed.

The device is assembled as follows.

In the central parts of the lower base plate, as well as the side one-piece walls of the base (1) and the side removable edges (2), strain gauges (10) are installed through adapters (9). The side faces (2) are installed between the side walls of the base (1) to form a rectangular cavity. Next, install the punch (5) into this cavity with its lower part tightly pressing it against the sensors. From above, through the punch (5), the bottom cover (3) is installed on the upper edges of the side walls of the base (1) and the removable side edges (2). A disc spring (8) is installed through the punch (5) into the cavity of the lower cover (3), then the lower part of the insert (6) is placed on top of it, then the sphere (7), the upper part of the insert (6), after which all parts are closed and fixed. top cover (4). Thus, the punch (5) rests on strain gauges (10) and the middle part interacts with the sphere (7), which in turn has the ability to rotate inside the insert (6).

The device works as follows.

When carrying out incremental shaping, when moving the tool along a given direction, the punch (5) with a spherical end exerts pressure on the workpiece. If the force acts along the axis of the punch (5), then the measurement is made by a strain gauge installed in the central part of the lower base plate (1). If the force acts in a different direction, then due to the possibility of rotating the punch due to the fact that it is installed in a sphere, measurements can be made by strain gauges installed on the side walls of the base and the side removable edges (2).

Claims (1)

A deforming tool containing a housing with a working element connected to strain gauges, characterized in that the housing includes a base with two side integral walls, two side faces, a bottom cover and an upper cover, and in the central part of the base a strain gauge is installed with the ability measuring the force directed along the vertical axis of the working element in the form of a cylindrical punch, and in the central part of each of the side one-piece walls of the base there is also a strain gauge sensor with the ability to measure the force on the work element along the axis perpendicular to the side one-piece walls of the base, while two side faces are fixed on the base and in the same way have on their central parts strain gauge sensors installed with the ability to measure the force of the working element along the axis perpendicular to the side edges, the lower cover of the housing is fixed to the upper parts of the side walls of the base and the side edges, and a disc spring is installed in it, on which houses the lower part of the insert with a sphere held by the upper part of the insert, which, in turn, is fixed by the top cover by its detachable connection with the bottom cover, while the working element is installed in the sphere with the possibility of axial movement, rotational movement together with the sphere, and also impact with its lower part on the strain gauge sensors present in the tool.

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