SU439696A1 - Pneumatic differential linear measurement instrument - Google Patents

Description

one

The invention relates to the field of measurement technology - and can be used to control linear dimensions.

A pneumatic linear measuring device is known, comprising a hollow body, an elastic element, such as a spring-loaded diaphragm separating the body cavity into a measurement chamber and a backpressure chamber, feed channels with throttles at the entrance to the chambers, a measuring nozzle communicated with the measuring chamber, and rod with a conical needle, bonded with an elastic element.

The known devices operate according to the principle of compensation of the forces on the membrane, the needle acting as a direct-reducing valve and located, for example, at the outlet of the backpressure chamber.

However, the known devices have significant inertia.

The purpose of the invention is to increase the speed of the device.

To do this, in the proposed device, the needle is placed in the throttle of the measuring chamber from its outer side.

The drawing shows the proposed device.

The device consists of a housing 1, a membrane 2, which separates the cavity of the housing to the measuring chamber A and the backpressure chamber B.

springs 3 With adjusting screw 4, channel

5 lines with adjustable throttle 6 at the entrance B of the measuring chamber A, unregulated throttle 7 at the entrance to the back pressure chamber B and the tuning throttle 8, the measuring nozzle 9 connected with the channel with the camera A, the stem 10 with the conical needle And fastened with the membrane 2. Object 12 the measurements are positioned in front of the measuring nozzle.

The device works as follows. Compressed air with pressure PTSHT is fed into the channel 5 of the pitan and flows through the throttle

6 into chamber A, and through throttle 7 - into chamber B. From the measuring chamber A, air goes

to the measuring nozzle 9.

In the absence of the measurement object 12 at the measurement position, air freely exits through the measuring nozzle 9, and the taper needle II is in its lowest position, which ensures maximum air flow through the device. When an object 12 is measured, in front of the measuring nozzle 9, the air pressure in the measuring

chamber A increases, causing the membrane 2 and the conical needle 11 to move upwards. The movement will continue until a new equilibrium is established between the air pressure drop across the membrane 2

and the force of compression of the spring 3. Because

the spring stiffness 3 is small; the newly established air pressure in the measuring chamber A is slightly different from the previous pressure, which, in combination with the small volume of the measuring chamber, ensures the speed of the instrument. The movement of the rod 10 is recorded from the indicator rail (not shown in the drawing), judging by the size of the movement, the size of the object of measurement is judged.

The device is tuned to the largest flow area of the adjustable throttle 6 with a lump of the adjusting screw 4 when there is no object to be measured, and to the desired back pressure in chamber B using the adjusting throttle 8.

Subject invention

A pneumatic differential linear measurement device comprising a hollow body, an elastic element, such as a spring-loaded diaphragm separating the body cavity into the measuring chamber and the backpressure chamber, the feed channel with Drossel at the chamber entrance, the measuring nozzle communicated with the measuring chamber, and the rod with a conical needle, fastened with an elastic element, characterized in that, in order to increase the speed of the device, the needle is placed in the throttle of the measuring chamber on its outer side.

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