RU215025U1 - DYNAMOMETRIC ARRIVAL - Google Patents

Abstract

The utility model relates to mechanical engineering and can be used to determine the components of cutting forces during turning. SUBSTANCE: dynamometric mandrel contains a body with a cylindrical shank, holes for supplying lubricant-cooling fluid and strain gauges. The tangential cutting force strain gauge is located in the lower part of the housing, the radial cutting force strain gauge is located on the front part of the housing, the axial cutting force strain gauge is located on the left end of the housing. Each strain gauge is additionally equipped with an autonomous power source and a radio transceiver unit with an antenna. EFFECT: increased accuracy of measuring the tangential, radial and axial components of the cutting force. 3 ill.

Description

The utility model relates to the field of determining the parameters of the cutting process during turning and can be used in engineering production, in higher educational institutions, research centers to determine the components of the cutting force during turning.

A mandrel is known (Patent US No. 2017252884, IPC: B23B 29/04, B23Q 17/09, H04B 1/034, publ. 09/07/2017), consisting of a tool holder on which a cutting plate is mounted and a load cell connected by cables through special openings in the housing containing a sealing connection between the cover and the battery, a plate holder, a fixing bar, a printed circuit board on which the radio transmission and signal pre-processing units are installed.

The disadvantage of this design is the large number of components and the lack of rigid fixation, which reduces the reliability of the device during operation. Third-party vibrations that occur during the cutting process when the cutter contacts the surface to be machined are taken into account when measuring the cutting force, and since the sensor is located directly on the cutting part of the cutter, it is impossible to obtain reliable data. And also the presence of wires in the cutting zone significantly reduces the reliability of the device.

A device "Single-component dynamometer for measuring cutting forces when turning with cutters" (RF Patent No. 131157, IPC: G01L 5/16, publ. 10.08.2013), consisting of sensors, a cruciform part of an elastic element, which is located inside a rectangular frame, on which a tool holder and a fixed plate are mounted for fixing on the machine.

The disadvantages of this device are its low reliability in comparison with a one-piece design and an increase in errors due to the use of component parts. Also, this device fixes the cutting forces during turning in only one plane, which excludes the possibility of determining the displacements of the technological system in the "X", "Y" planes in order to determine the deflection of the workpiece.

Known multi-component (or three-component) dynamometer, developed by a Swiss company, "Kistler Type 9129AA" (KISTLER. Official website. / Compact Multi-Component Dynamometer up to 10 kN. URL: https://www.kistler.com/en/product/ type-9129aa/, accessed June 24, 2022). The system consists of four load cells that are installed between the plate cover and two side support plates. The dynamometer is attached to even and clean surfaces with bolts or mounted on magnetic plates.

Disadvantages of the dynamometer described above are the predisposition to internal distortions, as well as to additional stress on individual measuring elements and increased crosstalk when mounted on uneven mounting surfaces.

The closest is the mandrel (Patent US No. 4899594, IPC: B23Q 17/09, publ. 13.02.1990), consisting of a body with a cylindrical shank. Holes are made in the body for supplying cutting fluid (coolant) and conductors, for power supply and data transmission to strain gauges. The strain gauges are placed inside the mandrel body in the same plane.

The main disadvantage of the design is the location of the sensors, in which the resulting value of the cutting force is recorded, which does not allow determining and, if necessary, correcting the value of each component of the cutting force, since each component of the cutting force has its own direction of force application.

The technical result is an increase in the accuracy of measuring the tangential, radial and axial components of the cutting force, the autonomy of the device.

The technical result is achieved by the fact that the dynamometric mandrel contains a body with a cylindrical shank, holes for supplying cutting fluid, load cells, and the load cell of the tangential cutting force is located in the lower part of the body, the load cell of the radial cutting force is located on the front of the body, the load cell of the axial cutting force located on the left side of the body, each load cell is additionally equipped with an autonomous power source and a radio transceiver unit with an antenna.

The tangential component of the cutting force acts in the direction of the main movement and is directed downwards (along the “Z” axis), the action of this force exerts a significant load on the cutter (for example, bending of the holder from the action of this cutting force). Therefore, the placement of the tangential cutting force strain gauge in the lower part of the body, namely in the cutter installation area, directly above the holder, makes it possible to most accurately measure the value of the tangential component of the cutting force.

The radial component of the cutting force is directed perpendicular to the axis of rotation (along the "Y" axis) of the workpiece being machined. It affects the vibrations that occur during the cutting process, presses the cutter from the workpiece, and can also cause its longitudinal bending. The use of a radial cutting force load cell allows a more accurate measurement of the force value by placing it on the front of the housing, directly in the direction of the radial cutting force.

The axial component of the cutting force acts parallel to the axis of rotation of the workpiece (along the "X" axis) and opposite to the feed direction. It affects the wear of machine feed mechanism parts. Mounting the load cell on the left end of the housing makes it possible to obtain more accurate values, since the measurement is carried out in the direction of the axial cutting force.

The positions of the strain gauges are determined based on the maximum deformation that occurs under the action of the components of the cutting force, which makes it possible to achieve more correct operation of the strain gauges, which increases the accuracy of measuring the components of the cutting force. It also makes it possible to achieve the minimum temperature error, increase the accuracy of measuring the components of cutting forces, due to the possibility of all sensors operating simultaneously and under constant conditions, directly in the cutting process. Data on changes in the values of the components of the cutting forces are obtained throughout the entire technological cycle, which will allow you to control the processing process and make timely adjustments. Thus, it will allow to provide the specified characteristics of the machined surface and the specified period of tool life.

The use of strain gauges equipped with autonomous power sources and transceiver radio units with antennas ensures autonomous operation of the device: it eliminates the need to connect to external devices, which increases the safety of using a torque mandrel in an aggressive environment of the machine working area (the absence of a conductor connected to an external power source in the cutting zone , eliminating the need for a person to be in close proximity to the device - the received data is transmitted automatically to the information collection units). In addition, due to the possibility of data transmission in automatic mode, it eliminates the human factor, which increases the accuracy of measurement.

In FIG. 1. - a general view of the torque mandrel is presented.

In FIG. 2. - view of the torque mandrel on the left.

In FIG. 3. - view of the torque mandrel from below.

A torque mandrel containing a body 1 with a cylindrical shank 2, through which the torque mandrel is fixed in the turret of the machine.

Holes for supplying cutting fluid (coolant) 3 and sockets 4 are made in the body 1, with the possibility of placing a tangential cutting force load cell 5 in them, to measure the component of the cutting force directed along the Z axis, the radial cutting force load cell 6, for measuring the component of the cutting force directed along the "Y" axis of the strain gauge of the axial cutting force 7, to measure the component of the cutting force directed along the "X" axis.

The socket 4 of the load cell of the tangential cutting force 5 is made in the lower part of the body 1, in the area of the cutter installation (above the cutter holder). The socket 4 of the load cell of the radial cutting force 6 is made on the front part of the housing 1 (the exit side of the cutting part of the cutter), to the left of the installation site of the cutter. The socket 4 of the load cell of the axial cutting force 7 is made on the left end of the body 1 (closer to the front corner).

Each load cell is equipped with an autonomous power source 8 and a transceiver radio unit 9 with an antenna 10.

The torque mandrel works as follows.

The pre-working tool is fixed in the body 1 of the mandrel by means of clamping plates fixed with screws. Socket 4 of each load cell is isolated from the aggressive working environment, for example, by a cover.

In the process of processing the workpiece, coolant is supplied to the cutting zone through the holes for supplying coolant 3, and three components of the cutting force act on the cutter. In turn, the load cell of the tangential cutting force 5, located in the zone of installation of the cutter, captures the change in the force acting on the cutter directed along the Z axis, and, converting it into an electrical signal, transmits data to the transceiver radio unit 9. The transceiver radio unit 9 transmits the received signal to the receiving device through the antenna 10.

The load cell of the radial cutting force 6, located on the front of the housing 1, captures the change in the current force directed along the "Y" axis, and, converting it into an electrical signal, transmits data to the transceiver radio node 9. The transceiver radio node 9 transmits the received signal to the receiving device via antennas 10.

Axial cutting force load cell 7, located on the left end of the housing 1, detects the change in the current force directed along the "X" axis, and, converting it into an electrical signal, transmits data to the radio transceiver node 9. The radio transceiver node 9 transmits the received signal to the receiving device via antennas 10.

The signals received from all strain gauges are collected at the receiving device, from which it is displayed, for example, on the screen.

Thanks to the power supply 8, each strain gauge and transceiver radio units 9 receive energy for the conversion and data transmission process.

Thus, the use of a torque mandrel containing a body with a cylindrical shank, holes for supplying a cutting fluid, a tangential cutting force load cell located in the lower part of the body, a radial cutting force load cell located on the front of the body, an axial cutting force load cell placed on on the left side of the case, power sources and transceiver radio units with antennas, allows to increase the accuracy of measuring the tangential, radial and axial components of the cutting force, as well as to ensure the autonomy of the device.

Claims (1)

A torque mandrel containing a body with a cylindrical shank, holes for supplying a cutting fluid, strain gauges, characterized in that the tangential cutting force strain gauge is located in the lower part of the housing, the radial cutting force strain gauge is located on the front part of the housing, the axial cutting force strain gauge is located on the left at the end of the housing, each load cell is additionally equipped with an autonomous power source and a radio transceiver unit with an antenna.

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