SU185536A1 - DEVICE FOR GLASS RESEARCH - Google Patents

Description

The known devices for investigating glass in determining the heat treatment mode, including a stop, a lever with a load and an actuating device, do not protect the glass samples from deformation.

The proposed device is made with an electric furnace controlled by a low-current relay, in which the stop is lowered, and the executive device has a profile link interacting with the relay contacts, the profile of which is expressed by the formula:

R -/

where / is the distance from the axis of rotation of the earring to the middle of cutting it, equal to 5-10 hedgehog; e- base of natural logarithms; v-angle between the vertical and the variable radius vector of the earring profile; The k-coefficient of friction of the materials from which the earring and contiguous relay contacts are made.

FIG. 1 shows the kinematic scheme of the device proposed; in fig. 2- electrical circuit.

The device includes an electric furnace 1, an emphasis 2, a lever 3 with a load 4 and an actuating device with a shaped earring 5.

the boot relay 6 with a slight force, the same along the entire length of the profile, and reliable disconnection of the contact in case of deformation of the sample 7 glass.

The principle of operation of the device is as follows.

As heating in the electric furnace, the sample temperature exceeds the temperature of the onset of deformation Td, which corresponds to the critical viscosity 1 (g.

for the device, the relay 6 switches off part of the heaters of the electric furnace I. The temperature drops by a predetermined value, for example, by, and some time is kept at the same level. It then automatically turns on.

an electric furnace, and the actuator is preparing for the next cycle.

Thus, the temperature in the electric furnace is automatically maintained, periodically fluctuating around the value of Gd, which corresponds to the critical viscosity. The critical viscosity simulated on the device for each sample is calculated by calculation. The basis of the calculation

where 2a / -thermal expansion 2a I b

stop 2, stand and sample in the vertical direction when the temperature changes by 1 ° C; b is the rate of temperature rise. The critical viscosity of the sample, found by calculation, is verified experimentally by the method of comparison with the behavior of the sample of the reference glass under similar conditions.

If structuring and crystallization processes occur in the sample, then the temperature Td tends to increase.

dT

Recorder records all

with speed

di

changes in temperature in the electric furnace /, which, after smoothing the oscillations, give the desired curve of the isocular mode of crystallization. The device allows you to simulate bending, compression and stretching. Samples can be loaded by creating stresses in them that the products experience when they are heat treated under practical conditions.

The automatic control system includes an electronic potentiometer (EPP-107) 8, an isodromic controller (ИР-130) 9 and an actuator IMT2-120. The design of the drive of the rheostatic sensor of the potentiometer 8 provides, with an increase in the fixed temperature, the constant position of the slider of the rheostatic sensor located at such a distance from the midpoint, which corresponds to the temperature lag set by the controller, from the true 20-30 ° C. After the beginning of the deformation and the inclusion of a part of the electric heaters, the temperature drops, and the sensor slider begins to move to the midpoint. Approximately three minutes after the beginning of the deformation, the line is briefly closed with a motor, through which the imbalance signal enters the isodromic regulator 9, which commands the actuator connected to the voltage regulator (RNO-250-10) 10. Four minutes after the beginning of the deformation, the same motor removes the fxonon earring 5, and the contact closes. The device is ready for the next cycle.

As samples, you can use bars of size 10X10X40 mm, made of slag glass.

Subject invention

A device for examining glass in determining its heat treatment mode, including a stop, a lever with a load and an actuating device, characterized in that, in order to protect the glass sample from deformation, the device is made with an electric-controlled relay with an electric furnace, into which the stop is lowered, the device has a shaped stud interacting with the contacts of the relay, the profile of which is expressed by the formula: P / -

V,

- -, where / is the distance from the axis of rotation of the earring to the middle of the notch in it, equal to 5-10 s; e - the basis of natural logarithms; v is the angle between the vertical and the variable radius-vector profile of the earring; The k-coefficient of friction of the materials from which the earring and contiguous relay contacts are made.

Rig 2