DD147579A1 - MEASURING HEAD FOR THE THERMO-ANALYTICAL QUICK DETERMINATION OF CASTING MATERIALS - Google Patents

Abstract

The invention relates to a measuring head for thermoanalytical rapid determination of the chemical composition and some Gefuegemerkmale of Guszwerkstoffen. The use of this measuring head gives the foundries the opportunity to examine their quality before melting the casting and not to correct quality melting. According to the invention, the measuring head consists of a cylindrical hollow body with a bottom. In the cavity of the measuring head is a centric about a threaded connection to the ground anchored thermocouple in a U-shaped bent protective tube. The lamp base protrudes through the floor and can be firmly connected via a corresponding socket with a holding device. As a result, a secure contact and a quick replacement of the measuring head are guaranteed.

Description

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! Vain of the invention

Measuring head for thermoanalytical tendon over immung of cast materials

Field of application of the invention

The invention relates to a measuring head for the thermoanalytical rapid determination of the chemical composition and some microstructure of cast materials.

Characteristic of the known technical solutions

There are known measuring heads, which are designed as core blocks. To produce these core blocks, a relatively high production and material costs are required. The sensitivity of these measuring heads is low through the use of thick-walled thermocouple protection tubes or relatively strong thermo wires. The handling of the measuring heads is inconvenient and complicated. Industrial manufacturing is not possible.

Other known measuring heads have cup-shaped form and can be produced by the known mask molding method.

In these Meßkopfausführungen either a straight thermocouple is switched on or performed centrally from below along the center axis or perpendicular to the center axis. These measuring heads are attached to a corresponding holding device. The electrical contact is made only by touching the extended Thertnodrahtes with the corresponding contact lug in Ha.ltevorrichtung, The advantages of this embodiment - low manufacturing and material costs, shortest response sides of the thermocouple and ease of use and the possibility of industrial manufacturing - are

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not fully usable, since the formation of the plug contact by changing the contact resistance between the thermocouple and contact lug allows measurement error.

Object of the invention

The aim of the invention is to provide by using a measuring head and appropriate registration or evaluation the foundries the ability to investigate melting before casting the casting on their quality or not to correct quality smelting accordingly and thus to avoid a considerable proportion of rejects.

Explanation of the essence of the invention

The invention is based on the technical problem of developing an insulating head for thermoanalytical tendon determination of the chemical composition and also some structural characteristics of cast materials. This Ließkopf is to ensure a high sensitivity of the thermocouple, easy handling and sicher.Eichere electrical contact to the fixture. Furthermore, it should be designed so that an industrial production is possible.

According to the invention, the object is achieved in that a thermocouple in a thin-walled, U-shaped protective tube with a length of 25 - 60 mm, preferably 40 - 50 mm, and the protruding from the protective thermocouple ends directly or via an intermediate piece with a commercial Lamp base are connected by soldering, welding or clamps. The inner diameter of the protective tube should be 0.1 to 2.5 mm, preferably 0.2 to 0.6 mm, and the thickness should be 0.1 to 1.5 mm. The diameter of the thermowire it is according to the inner diameter of the protective tube 0.05 - 1.5 mm, preferably 0.08 - 0.16 mm. The legs of the protective tube have a distance of 10 - 25 mm to each other. This unit - protective tube with thermocouple, if necessary intermediate piece and lamp base - is surrounded for exact fixation with a fire-resistant hate. This creates a 'cylindrical hollow body into which the protective tube with the thermocouple protrudes centrally from below 10-40 mm, preferential prices 15-25 mm and which receives the liquid metal sample. This cylindrical hollow body with an inner diameter of

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20 - 80 mn, preferably 30 - 45 mn, a height of 30 - TOO mm, preferably 40 - 60 mm and a height - diameter ratio of 1.0 1.5, preferably 1.25 is sealed down with a refractory material , love the sealing function isolated this !, leave the thermo wire ends against each other and -stop the lamp base. The lamp cap of the., Measuring head, which projects through the sealing Iilasse, can be firmly connected via a corresponding fit with a holding device v / ground. As a result, a secure contact and a quick replacement of the measuring head are guaranteed.

Ausführun ^ SExample

According to the invention, the measuring head consists of a U-shaped bent quartz glass protective tube (2) with an inner diameter of 1.0 mm, a wall thickness of 0.5 mm and a length of 45 mm. The leg distance of the protective tube is 15 mm.

In this protective tube (2) is a thermocouple (1) with a wire diameter of 0.1 mm. The solder joint of the thermocouple lies exactly in the center of curvature of the protective tube. The thermal wire ends projecting from the protective tube are soldered to an intermediate piece (3). These spacers are soldered to a standard E 14 screw socket (4).

This unit, consisting of protective tube with thermocouple, spacer, and screw, is surrounded by a hollow body produced by the shell molding process. In this hollow body (5) with an inner diameter of 45 mm and a height of 55 mm protrudes from the bottom (6) starting the protective tube (2) 20 mm centrally into the cavity (7) into it. The bottom (6) serves to seal the body down and the insulation of the thermocouple wires. He also gives the lamp baseJHalt. The lamp base is anchored in the ground up to the waistband; the exposed thread grooves of the Lampenxjsockels serve to attach the measuring head on a corresponding holding device and the electrical contact.

Claims (4)

Erfindungaansprüche 1. Measuring head for thermoanalytical Schnellbestimraung of cast materials, consisting of an upwardly open cylindrical hollow body of refractory material, protrudes into the bottom of a thermocouple, and a holding device, characterized in that / the thermocouple is in a thin-walled U-shaped protective tube and the from the protective tube protruding thermocouple ends directly or via an intermediate piece by soldering, welding or clamping via © ine screw, which results in a firm contact with the holding device is connected. 2. Measuring head according to item 1, characterized in that the U-shaped protective tube has an inner diameter of 0.1 to 2.5 mm, preferably 0.2 to 0.6 mm, a length of 25 to 60 mm, preferably 40 to 50 mm, and has a wall thickness of 0.1 to 1.5 mm and that the leg distance is 10 to 25 mm. 3. Measuring head according to item 1, characterized in that in the protective tube, a thermocouple with a diameter of the thermowire of 0.05 to 1.5 mm, preferably 0.08 to 0.16 mm, is located. 4. Measuring head according to item 1, characterized in that the thermowell thermocouple 10 to 40 mm, preferably 15 to 25 mm, centrally from below into a cylindrical cavity having an inner diameter of 20 to 80 mm, preferably 30 to 45 mm, a height from 30 to 100 mm, preferably 40 to 60 mm, and a height-to-diameter ratio of 1.0 to 1.5 »preferably 1.25, protrudes. For this 1 string drawings