SU1636767A1 - Installation for bending creep tests of refractories - Google Patents

Abstract

The invention relates to the construction, in particular to the testing of samples of building materials - refractories. The purpose of the invention is to improve measurement accuracy. The installation includes a heating furnace 1, rollers 2, for installation of sample 3, a support block 4 and a load device in the form of a lever 5 with rollers 6 and a load 7. A device for measuring the deformation of sample 3 contains a displacement sensor 8 with a holder 9. A probe pressure system 10 and 11 is made in the form of a main lever 12 with a set of weights 13 and two intermediate levers 14 and 15. 2 Il. c & (L

Description

The invention relates to the field of construction, in particular to testing samples of building materials - refractories.

The purpose of the invention is improving the accuracy of measurements.

Figure 1 shows the installation, General view; figure 2 is a section aa in figure 1.

The installation includes a heated furnace 1, rollers 2, on which a sample 3 is mounted, a support block 4 and a loading device in the form of a lever 5 with rollers b and a load 7. There is a device for measuring the deformation of the sample 3, containing a displacement sensor 8 with a holder 9 and a system pressing three probes: middle 10 and extreme 11. The system of pressing the probes 10 and is made in the form of a main lever with a set of weights 13 and two intermediate levers: upper 14 and lower

15. Moreover, the main lever 12 is connected by an articulated rod 16 to the upper intermediate lever 14, one end of which is connected by an articulated rod 17 with the middle probe 10, and the second to the end of the lower intermediate lever 15. The middle part of the lower intermediate lever 15 is connected by an articulated rod to the holder 9 displacement sensor 8, pivotally connected to the extreme probes 11. The shoulders of the intermediate levers 14 and 15 are connected by an articulated rod 19, are adjustable and provided with adjusting screws.

20. The rods 16, 17, 19 and 22 are equipped with screw couplings for adjusting their length and for horizontal mounting of the levers 12, 14 and 15 and the holder 9. The deflection of sample 3 is recorded using the recording device 23. There is a support screw 24 and a counterweight 25 .

Installation works as follows.

The principle of operation of the proposed installation is as follows. Before starting the test, set the sample 3 on the supports 2 and gain the desired value of the load 7, which ensures that the sample receives the stress value specified by the experimental conditions. After that, based on the desired pressing force of the measuring probes 10 and 11, the size 2 control lever-weight system of pressing the probes as follows. First set the working to

1636767 4 the length L _{x of the} adjustable shoulder of the upper intermediate arm 14, which is determined by the following relationship:

L <(L <+ b.g)

Lx where

Ρχ (1)

- the length of the constant shoulder of the upper intermediate arm 14, mm;

- the length of the constant shoulder of the lower intermediate arm 15, mm;

2P _h + P, + P _and ; Pk ^{+ p} 2 ~ ^P N>

cargo next

- the specified pressure force of the probes 10 and 11 to the sample 3;

- the total weight of both extreme probes 11, holder 9 of the sensor, sensor 8 and rods 22, N;

- the weight of the average probe 10, N;

- the force of the interference spring sensor .. 8, N.

Accordingly, the length of the shoulder L * set the working length (Ly + Lx) of the adjustable shoulder of the lower intermediate arm 15. After that, set the desired amount of weight 13 P _g (N) which is determined by singing dependence:

* L B (in ---------),

L L d

RR L3-L4 ^p . - in (2) the main lever

12, the shoulders of the main load-bearing weight 13, mm.

where L * is the length of mm;

Bd - length: ha 12,

An analysis of the forces in the lever-weight system for pressing the probes shows that when setting the indicated values L * and (Ly + L x) of the working length of the adjustable arms of the intermediate levers 14 and 15 and when the weight of the load 13 is equal to P _g , the pressing force of all three probes 10 and 11 are equal to each other and equal to a given value of P *.

The adjustment of the lever-weight system for pressing the probes 10 and 11 is carried out only before the start of operation of the installation and in cases where it is necessary to change the force of pressing the probes 10 and 11 to the sample 3.

After the adjustments are made, the sample 3 is heated to the specified test temperature, the support is lowered5

1636767 screw 24 to the lower position and load the sample 3, which begins to deform. In this case, the deflection of sample 3 with the help of probes 10 and 11 is transmitted to the sensor 8 and fixed by the adjusting device 23. Since the pressing force of all three probes 10 and 11 to the sample 3 is the same, the deformation processes in the probes 10 and 11 and in the zone of their contact with the sample 3> pass at the same speed. This prevents distortion of the measured value of the deflection of the sample 3 and increases the accuracy of measuring the deformation of the sample.

In the case of asymmetric deformation of the sample, lateral loads in the probes 10 and 11 do not arise due to the fact that the forces are transmitted to them through the articulated rods 17 and 22. This also contributes to an increase in the accuracy of measuring the deflection of the sample 3.

Claims (1)

SUMMARY OF THE INVENTION Installation for testing bending creep refractories, including a heating furnace, a loading device, a recording device and a device for measuring sample deformation, comprising a 5-location sensor with a holder and a pressure system for three probes. Characterized in that, in order to increase the accuracy of measurements , the pressing system (q probes is made in the form of a main lever with a set of weights and two intermediate levers, the main lever being connected by an articulated rod to the upper intermediate lever, o one end of which is connected by an articulated rod to the middle probe, and the second to the end of the lower intermediate lever, the middle part of which is connected by an articulated rod to the displacement sensor holder, articulated to the extreme probes, while the arms of the intermediate levers are connected by an articulated rod, made adjustable and provided adjusting screws. 7S l Figure 2