SU678367A1 - Standard force-measuring machine - Google Patents

Description

one

The invention relates to the field of instrumentation and can be used to create large efforts, for example, when taring or calibrating load measuring dynamometers.

A known force-measuring machine, comprising a stationary frame with a fixed beam, on which a movable frame is installed with a fixed headboard, grips for setting up gauges, and a force-generating device in the form of a hydraulic cylinder with a piston, capable of transmitting forces to the calibrated dynamometer through an exemplary, self-propelled frame carrier. in the form of a hydraulic cylinder with an annular piston in contact with a fixed cross-piece movable frame, with the working volume forming the hydraulic cylinder and the annular pores It is connected to a source of fluid pressure and the piston silovozbuzhdayuschego device associated with hydraulic cylinder autonomous energizer not provide the required measurement accuracy effort 1. The closest in technical essence to the invention is a force-measuring machine.

containing a bed with still. the columns on which a movable yoke is installed, an autonomous energizer connected to a hydrostatic pressure source, a support plate and a dynamometer 2. The disadvantages of the known exemplary force-measuring machine are low effort measurement accuracy.

0

The purpose of the invention is to improve the accuracy of force measurements. This goal is achieved by introducing at least three exemplary dynamometers into the described machine, and the autonomous force actuator is designed as a hydraulic cylinder with lower and upper pistons, with a support plate mounted on the upper piston, and the lower piston is mounted on the frame, while the exemplary dynamometers are located between the hydraulic cylinder and the base plate is symmetrical about the axis of the machine.

The drawing shows an exemplary force-measuring machine.

On the base 1, there is an installed EG column 2, along which the movable cross-member 3 moves. On the base 1 gesture, the lower piston 4 is installed

cylinder 5, and in the upper part of the cylinder is installed upper piston b. A support plate 7 is installed on the upper piston 6. The spacing and the cylinder 5 are installed on the periphery symmetrically with respect to the machine axis, at least three model dynamometers e. A dynamometer 9 is installed between the movable crosshead, 3 and the support plate 7 5 is hydraulically connected to the hydrostatic pressure source 11, and the working cavity 12 of the lower part of the cylinder 5 is hydraulically connected to the hydrostatic source 13. The cylinder with the upper and lower 4 pistons forms an autonomous energizer.

To calibrate the dinanometers, at first all the moving parts of the machine are weighed and a calibrated force is applied to the dynamometer 9. At the same time, hydrostatic pressure from the source 13 creates an overpressure in the working cavity 12 of the lower part of the cylinder 5, under the action of which the cylinder 5 through three reference dynamometers 8 and the reference plate 7 acts on a calibrated dynamometer 9. Since columns 2, movable yoke 3 and frame 1 form a rigid load frame, and the pressure in the upper part 10 of cylinder 5 is absent, The action on the load cell 9 and the total force on sin exemplary dynamometers 8 will be the same. According to the indications of three exemplary dynamometers 8, a dynamometer 9 is tested. If the turning dynamometer is designed for a force, the maximum forces of three dynamometers are exceeded, the created force is recorded on the dynamometer 9 and at the same time this force is removed from the three exemplary dynamometers 8. For this, upon reaching the limit force effects, which are designed for three exemplary dynamometers 8, or any given force action within the scale using self-hydrostatic pressure source 11 create an overpressure in the upper part 10 of the cylinder 5. Under the action of oil pressure, the upper piston b abuts against the base plate 7. As the oil pressure is further increased, the cylinder 5 will be lowered, thereby relieving three exemplary dynamometers from the force effect. the dynamometer 9 remains unchanged and the accuracy of the force effect will be determined by the accuracy of the total readings of the three exemplary dynamometers 8.

Thus, the fixing of the calibrated force action on the dynamometer 9 is accomplished by replacing the force action through the group

model dynamometers 8 on direct force action on a dynamometer 9.

When the indications of the group of three exemplary dynamometers 8 are equal to O, the overpressure is stopped and again with the help of (the hydrostatic pressure source 11 creates an overpressure. In this case, the force applied to the dynamometer 9 will be equal to the previously generated impulse plus the indications of the group of three exemplary dynamometers 8 this moment in time.

This ensures the verification of the dynamometer 9 at the following point at

5 force action, which exceeds the limiting force action, for which the group is designed (three model dynamometers 8).

Upon reaching the limit value of the scale of three exemplary dynamometers 8, the hydrostatic pressure source 11 is again put into operation, creating an overpressure until the force is removed from the group of three exemplary dynamometers 8.

5 The cycle is repeated until it reaches the limiting forceful influence for which the dynamometer 9 is designed.

Since the creation of a force action on the dynamometer 9 is carried out according to the indications of the group of three model dynamometers 8, the relative error of the force action will not exceed the errors of the group of model dynamometers 8.

Claims (2)

Invention Formula An exemplary force-measuring machine containing a frame with stationary columns on which a movable traverse is installed, an autonomous force-exciter connected to a hydrostatic pressure source, a support plate and a dynamometer, which in order to improve the accuracy of measurement, at least three exemplary dynamometers, autonomous exciter is made in the form of a hydraulic cylinder with lower and upper pistons, and a support plate is installed on the upper piston, and the lower piston is installed on the frame, with Om model dynamometers are located between the hydraulic cylinder and the base plate symmetrically relative to the axis of the machine. Sources of information taken into account in the examination .one. Avdeev B. A. Technique for determining the mechanical properties of metals. M., Mashgiz, 1952, p. 174-194. 2. Smushkovich B. L. Machines for technological testing of metals. Central Research Institute of Information and SEI of Instrument Engineering, Automation and Control Systems. M., 1972, p. 23, Fig.7. Gz