Test index The test performance index is 1y for grain cleaning rate and 2y for cleaning loss rate. If the total mass of the sample in the tank B3 is Q, the grain quality is 1W, and the grain quality in the straw mouth B1 and B2 is 2W and 3W respectively, the grain cleaning rate is 1y=QW/1×% cleaning loss rate 2y=) 32132W+)/(×%3 regression test and results. Determination of the range of test factors The factors of this test are 1n for the front cylinder screen and 2n for the rear cylinder screen. Currently, the single-fan cylinder screen cleaning mechanism is harvested on the market. The installation parameters of the machine are: the front cylinder screen speed is about 1.8m/s, and the rear cylinder screen speed is about 0.83m/s. The cleaning mechanism is equipped with a cross flow fan on the rear of the cylinder screen. Analysis, before and after the cylinder screen speed must be reduced; at the same time, before the formal test, the test was carried out on the test bench with the prepared materials several times: the current screen speed is lower than 70r / min, the rear screen speed is lower than At 50r/min, the cleaning rate decreased significantly; when the current screen speed was higher than 130r/min and the rear screen speed was higher than 100r/min, the cleaning loss increased significantly, and the cleaning rate also decreased significantly. The screen rotation speed is set between 70 and 130r/min, and the rear cylinder screen speed is set. The range of variation is set between 50 and 100 r/min. The experimental design and test results were tested using a quadratic orthogonal rotation combination design. The two factors were comprehensively tested, the asterisk arm r=1.414, and the number of repeated trials at the center point was 0m=8. Parameter Optimization and Verification Test In order to obtain the best combination of parameters, the above equations were optimized by the main objective function method. In this study, the grain cleansing rate is taken as the main objective function, and the cleaning loss rate is taken as the performance constraint. The mathematical model is constructed as follows: 1) (yxF=performance constraint:=2) (yxG0.30≤0 boundary constraint Condition: -1.414 ≤ ix ≤ 1.414 optimization to obtain the optimal parameter combination in the factor coding space: 1x = -0.75, 2x = -0.30, that is, the front cylinder screen speed 1n = 85r / min, the rear cylinder screen speed 2n = 69r /min. Converted to cylindrical screen speed, then: 1v = 1.33m / s, 2v = 0.90m / s. This value is compared with the single fan cylinder screen cleaning mechanism mentioned above, the front screen speed is reduced Then, the screen speed is slightly increased. This shows that under the action of the cross flow fan, the material on the front screen is subjected to the suction force at the upper rear, and the material on the rear screen is subjected to the upward suction. In order to maintain the optimum separation condition of the material on the screen, the front screen speed must be Decrease, and then the screen speed can be slightly increased. This will help improve the cleaning rate while controlling the cleaning loss. If there is no cross-flow fan function, the rear screen speed will increase, and the material throwing distance will increase, which will increase the cleaning loss. Since the optimal combination of parameters provided by the optimization does not appear in the regression equation, the optimization results must be tested and verified. Influence of parameters on cleaning performance In order to visually understand the influence of motion parameters on cleaning performance, the dimensional regression analysis is performed on the two regression equations, that is, one parameter is fixed at the optimization point, so that the cleaning performance index changes with another parameter. The cleaning rate of 1y increases with the increase of the front screen speed. When the current screen speed reaches about 85r/min, the cleaning rate reaches the maximum. At this time, if the front screen speed is continuously increased, the cleaning rate will decrease. This is because the front screen throws too much material to the rear screen, which causes the post-screen cleaning load to be too large, and the cleaning rate decreases. The loss rate 2y gradually increases with the increase of the front screen speed. Also, because too much material is thrown to the rear screen, the chance of being blown out by the centrifugal fan is increased. The cleaning rate is then increased by an increase in the screen speed. When the rear screen speed reaches about 69r/min, the cleaning rate reaches the maximum. Similarly, if you continue to increase the screen speed, the cleaning rate will decrease. This is because the rear screen speed is too high, the material is too late to be separated, and is thrown to the trough plate, causing material accumulation. The double-fan cylinder screen cleaning mechanism can improve the grain cleaning rate and effectively control the cleaning loss. The cross-flow fan is installed on the single-fan cylinder screen cleaning mechanism, and the rotation speed of the front cylinder screen must be reduced. If the installation position of the cross flow fan is in front of the rear cylindrical screen, the rotation speed of the rear screen can be appropriately increased. Under the optimal parameters, the cleaning rate of the double-fan cylinder screen cleaning mechanism can reach 98.7%, and the cleaning loss rate can be controlled to 0.19%. CNC Lathe With Linear Guideway Slant Bed Desktop Cnc Lathe,Cnc Turning Machine,Cnc Lathe Machine,Slant Bed Cnc Lathe Ningbo junfa CNC Equipment Co. Ltd. , https://www.nbintimecnc.com