RU2791459C2 - Test bench for reciprocating mechanisms - Google Patents

Abstract

FIELD: reciprocating mechanisms.

SUBSTANCE: invention relates to testing devices of machine parts, namely to reciprocating mechanisms. A test bench for reciprocating mechanisms containing a complex of measuring and control equipment connected by an electrics system, including a force measurement sensor, a linear displacement sensor, an initial position sensor, an electromechanical loading device, a set of equipment controlling a reciprocating mechanism, and a set of equipment controlling an electromechanical loading device. In addition, the electromechanical loading device contains a synchronous servo motor and a gearbox, on the output shaft of which a gear is mounted that engages with a rail that moves along a rigidly fixed guide and is connected to the working body of the reciprocating mechanism.

EFFECT: possibility of setting and controlling the normalized resistance to the movement of the working body in a wide range of values, the movement of the working body by a given amount, as well as the number of cycles of movement of the working body of the tested reciprocating mechanism of various types.

1 cl, 1 dwg

Description

The invention relates to testing devices for machine parts, in particular reciprocating mechanisms.

Known "Stand for testing hydraulic cylinders" (RF patent for the invention No. 2234004, published 10.08.2004). The stand for testing hydraulic cylinders contains a tank, an adjustable hydraulic pump, a safety valve with a pressure gauge, an electro-hydraulic distributor reversible by limit switches, a rod and piston loading device, working fluid leakage meters, hydraulic cylinders connected to each other by rods by means of a carriage installed in the frame guides. The rod cavities are connected by means of rod flow meters to the working section of the electrohydraulic distributor, the drain hydraulic line of which is connected to the tank by means of a rod loading device, and the piston cavities of the tested hydraulic cylinders are connected to each other by means of serially connected piston flow meters and a piston loading device located between them. Moreover, a make-up check valve is connected to one of the inputs of the piston loading device with the help of an additional hydraulic line connecting the piston cavities of the tested hydraulic cylinders with the tank, and the control handles of the rod and piston loading devices are kinematically connected by means of cam mechanisms with the corresponding replaceable templates - profiles fixed on the carriage.

The disadvantage of the above design is:

- inability to test non-hydraulic reciprocating mechanisms;

- complex reconfiguration of the loading device.

From the prior art studied by the applicant, a "Test bench for testing spline joints for wear resistance" is known (RF patent for invention No. 2735259, publ. 29.10.2020, Bull. No. 31). Stand for testing spline joints for wear resistance, consisting of a frame, an axial load mechanism with a servo motor and a distributor, a torque loading device for a splined part (glass), connected by a system of levers, sample holders, characterized in that the axial reciprocating movement mechanism, consisting of hydraulic cylinder, the rod of which is connected by a fork and a leash with a splined part (tip), and a torque loading unit made in the form of a spindle of a splined part (cup) connected by a lever to the hydraulic cylinder rod, are made with the possibility of providing a complex effect of high specific load up to 100 MPa, torque up to 10 kNm, axial impulse load with a set frequency in the range of 10-50 Hz and a constant displacement amplitude of 100 μm, to measure the forces developed by the axial load hydraulic cylinders and torque, force-measuring sensors are installed connected to a strain gauge station for monitoring i and record test parameters.

This stand can only be used for testing spline connections and is not suitable for testing various reciprocating type mechanisms. We also note that in this stand the servo motor is used as a drive for the reciprocating movement of the hydraulic cylinder rod, in contrast to the proposed stand for testing reciprocating mechanisms, in which the servo motor is used to create a loading force.

Known from the prior art is a “Servomechanical testing machine for mechanical testing of material samples for tension, compression and bending” (RF patent for the invention of the Russian Federation No. 2642557, publ. 25.01.2018, Bull. No. 3). Servo-mechanical testing machine for mechanical testing of samples of materials for tension, compression and bending, including a two-zone loading device containing a base and a fixed traverse rigidly interconnected by two smooth columns, along which a movable traverse moves with the help of a servomotor and two worm-screw gears, forming tension and compression zones, a force sensor attached to the movable traverse from the side of the compression zone, two grips for fixing the test samples in the tensile zone: the upper one, fixed in the fixed traverse by two hinge nodes in a position coaxial with the axis of application of force to the test sample, and the lower - articulated with a movable traverse through a force sensor, two supports for compression testing (or a device for bending testing) installed in the compression zone, a displacement sensor, and also including a pumping unit containing a low pressure pump, a high pressure pump, low pressure safety valves and high pressure, distributors for controlling the closing and opening of the grips, pressure gauges for recording pressure in the low and high pressure lines, characterized in that, during a tensile test, the lower grip, articulated with the movable traverse through a force sensor by a hinge assembly, is set in a position coaxial with axis of application of force to the sample and when the sample is destroyed, the hinge connecting the force sensor with the lower grip opens, releasing the force sensor from the dynamic impact of the mass of the lower grip, which perceives the body of the movable traverse through the damping pad.

This machine is not intended for testing reciprocating mechanisms. In addition, in this testing machine, the servo motor is used as a drive for worm gears, in contrast to the proposed reciprocating test bench, in which the servo motor is used to create a loading force.

The technical problem that the present invention solves is the creation of a bench that allows testing a wide range of different reciprocating mechanisms according to the test requirements, while setting and controlling the normalized resistance to movement of the working body in a wide range, moving the working body by a given value, and also the number of cycles of movement of the working body of the tested reciprocating mechanism.

The technical result of the claimed stand is the ability to set and control the normalized resistance to movement of the working body in a wide range of values, the movement of the working body by a given value, as well as the number of cycles of movement of the working body of the tested reciprocating mechanism of various types.

The specified technical result is achieved due to the fact that the stand contains an electromechanical loading device that allows you to create the necessary resistance to the movement of the working body in a wide range of values, a complex of control and instrumentation that sets the test conditions (the value of the resistance to movement, the stroke of the working body, the number of cycles of movement working body) depending on the type of the tested-mechanism of reciprocating action, as well as a means of visualization and storage of controlled parameters.

The essence of the claimed invention is illustrated by the drawing:

FIG. 1 - Structural and functional diagram of the stand for testing mechanisms of reciprocating action.

The proposed stand contains an electromechanical loading device designed to create a normalized resistance to the movement of the working body when testing reciprocating mechanisms; a complex of control and measuring equipment, which serves to measure the necessary parameters and control the progress of the test; a complex of equipment that controls the tested mechanism of reciprocating action; a set of equipment that controls the electromechanical loading device.

The complex of control and measuring equipment contains a force measurement sensor 1, a linear displacement sensor 2, and an initial position sensor 3.

The electromechanical loading device consists of a synchronous servo motor 4 and a gearbox 5, on the output shaft of which a gear 6 is installed, which engages with the rack 7, which moves along a rigidly fixed guide 8 and is connected to the working body 19 of the reciprocating mechanism 9. The body of the mechanism is reciprocally - translational action 9 is connected to the force measurement sensor 1, the second end of which is fixed on a fixed support (not shown).

The loading force is generated by a synchronous servomotor 4, which is powered and controlled by a frequency converter 10, which consists of a control module, a memory card, a power module and a choke (not shown). The frequency converter 10 with the help of a programmable logic controller 11 is adjusted to a certain function of maintaining torque, depending on the movement and speed of movement of the working body 19 of the reciprocating mechanism 9. The torque on the output shaft of the gearbox 5 using the gear 6 and the rack 7 is converted into linear force directed against the force created by the working body 19 of the reciprocating mechanism 9. The complex of control equipment 14 sets in motion the working body 19 of the reciprocating action mechanism 9, while the associated rack 7 moves along the fixed guide 8 and rotates the gear 6, which through the gearbox 5 rotates the shaft of the servomotor 4. The servomotor 4 operates in the mode of braking (generator). The electrical energy generated in this case is dissipated by the braking resistor 12. The servomotor 4 can create a loading force in both one and both directions of movement of the working body 19 of the reciprocating mechanism 9, depending on the test requirements.

The amount of current generated by the servomotor 4 is stabilized by the frequency converter 10 at a level at which the generated braking torque on the servomotor shaft is equal to the set value at a given time. The servomotor 4 has an angular velocity sensor (encoder), and the frequency converter 10 contains shunts for measuring the current strength. The frequency converter 10 receives data on the current speed of rotation of the shaft of the servomotor 4 and the current load current, analyzes and makes the necessary adjustments to the parameters of the electrical energy dissipated by the braking resistor 12 in order to maintain the load torque on the shaft of the servomotor 4 specified at a given time and, accordingly , loading forces on the working body 19 of the reciprocating mechanism 9.

Upon reaching the required stroke of the reciprocating mechanism 9, monitored by a linear displacement sensor 2, the central processor 13 using the complex of control equipment 14 stops the movement of the working body 19 of the reciprocating mechanism 9, and then returns it to its original position. When testing single-acting mechanisms during the stop of the working body 19 on the shaft of the servomotor 4, the external torque disappears, after which the servomotor 4 switches to the drive mode and independently returns the working body 19 of the reciprocating action mechanism 9 to its initial position. In the initial position, the initial position sensor 3 is triggered, which, through the discrete signal input / output module 15, transmits information about the completion of one test cycle to the central processor 13. The force measurement sensor 1 and the linear displacement sensor 2 transmit the measured values to the central processor through the signal converters 16 and the module input of analog signals 17.

Logic control of the stand is performed by a programmable logic controller 11 consisting of a central processor 13, an analog signal input module 17, a discrete signal input / output module 15 and an operator panel 18.

The testing process takes place automatically in accordance with the software. On the operator panel 18, a program is selected corresponding to the type of reciprocating mechanism 9, which determines the required mode and procedure for testing (sets the required loading force, the stroke of the working body 19, the number of cycles (repetitions), as well as the functional dependence of the loading force on the movement of the working body 19 reciprocating mechanism 9). Also, the operator panel 18 displays the measured parameters, control buttons, necessary indicators, a graph of changes in the load from displacement, and other parameters and tools necessary for testing. The functional set of the control panel 18 can be changed or supplemented using software depending on the type of reciprocating mechanism being tested, the test requirements and the wishes of the customer (user).

The procedure for testing on the proposed stand:

It is necessary to install and fix the reciprocating action mechanism 9 on the stand, connecting its working body 19 with the rail 7. Connect the complex of control equipment 14 to the reciprocating action mechanism 9, with the help of which the working stroke of the reciprocating action mechanism 9 will be carried out. Next it is necessary to select a program on the operator panel 18 that corresponds to the type of reciprocating mechanism being tested, and start the testing process. The screen of the operator panel 18 will display the necessary measured and controlled parameters (the current movement and speed of movement of the working body 19 of the reciprocating mechanism 9, the loading force of the reciprocating mechanism 9, the number of test cycles, etc.). If the controlled parameters are within tolerance, then the signal lamps on the operator panel will light up, corresponding to the successful completion of one test cycle. Further cycles will be repeated automatically until their number becomes equal to the number specified in the requirements for testing the reciprocating mechanism 9. If the controlled parameters go beyond the allowable values, the test process stops, and a warning signal is displayed on the operator panel 18 .

Thus, the proposed stand allows you to test a wide range of different mechanisms of reciprocating action according to the requirements for testing, while setting and controlling the normalized resistance to movement of the working body in a wide range, moving the working body by a given value, as well as the number of cycles of moving the working body of the test reciprocating mechanism.

Claims (1)

A stand for testing mechanisms of reciprocating action, containing a complex of control and measuring equipment connected by an electroautomatic system, including a force measurement sensor, a linear displacement sensor, an initial position sensor, an electromechanical type loading device, a complex of equipment that controls the tested mechanism of reciprocating action, and a complex equipment that controls an electromechanical loading device, characterized in that the electromechanical loading device includes a synchronous servomotor and a gearbox, on the output shaft of which a gear is installed, which engages with the rack, which moves along a rigidly fixed guide and is connected to the working body of the reciprocating mechanism actions.

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