Methyl Hydroxyethyl Cellulose,Paint Cellulose,Drymix Cellulose,High Viscosity Cellulose Nanjing Jinshan Chemical Technology Co., Ltd , https://www.jinschem.com
The turbine flowmeter has a compact structure, in which the impeller is a key part of the flowmeter and is a sensor detection element. The impeller is made of hard-aluminum 2A12, a highly-conducting magnetic material, coaxial with the body, and the number of blades is usually 12 to 24 pieces. The geometry and size of the impeller have a great influence on the performance of the sensor, and the degree of rotation of the blade and the precision of the lead, Directly related to the accuracy of the turbine flow meter, which is the value of the detection linearity.
This type of part is first processed in the company. If it is a normal process, it is best processed in the milling center, but this will inevitably increase the processing cost several times. Considering that the flowmeter is still in the R&D trial stage, it is necessary to save costs without affecting the dimensional accuracy. Therefore, we decided to process the ordinary horizontal milling on the processing capability of the workshop's existing equipment.
Impeller processing difficulties include:
(1) The impeller material is 2A12, which requires high precision parts and is easily deformed in the machining process;
(2) The blade wall of the impeller is thin and its wall thickness is only 1 to 2mm. During machining, the larger the diameter, the more vibrating the component during processing, which has a great influence on the dimensional accuracy, directly affecting the gas flow rate and detection linearity. The value of degree;
(3) The diameter difference between the center hole and the outer circle is large, and the coaxiality requirement is 0.015mm.
For the above processing difficulties, we formulate corresponding measures.
The two sets of process plans we have formulated take into consideration various factors and formulate the following two process plans:
(1) Plan one. Outer circle, a few pieces of one - milling spiral blade - fitter to remove burrs - car broken into a single piece, countersink hole and cylindrical - milling groove - impeller dynamic balance - surface oxidation treatment. For the first trial of the program, the result is not ideal. Because the thickness of the blade after milling is only 1mm, and it is used as a reference datum boring, it is easy to deform the blade, and the coaxiality of the inner and outer circles is difficult to guarantee. Draw improvement program two.
(2) improvement program two. Roughing car (each surface is 1mm in length, the left boss is extended by 15mm, and the chuck is reserved for milling) - heat treatment (the material has the heat treatment strengthening ability, so a heat treatment process is arranged after the part rough processing to eliminate the processing stress)— Fine car (under the hole and outer circle with a knife, turn the soft claw on the head, so to ensure the coaxiality) - milling (hanging wheel, with tooling milling constant speed spiral blade) - pliers (remove all burrs) - milling (milling groove, To chuck) - The impeller is balanced - surface oxidation.
Dedicated fixture
The principle of the mechanical part of the intelligent turbine flowmeter is that when the flow flows into the flowmeter, it is adjusted and accelerated under the action of the guiding fluid. Since the impeller and the fluid flow are at a certain angle, the turbine generates a rotating torque and overcomes the frictional moment and fluid resistance. After the moment, the turbine starts to rotate.
February 28, 2023