When grinding journals with surface roughness Ra0.02-0.04 m and precision h4 - h5 in large construction machinery factories, they are all carried out on expensive high-precision Hangzhou surface grinders. However, the general construction machinery repair factory does not have a high-precision Hangzhou surface grinder. Grinding such low surface roughness and such high journal accuracy is very difficult.

We have carried out a lot of tests on the existing Hangzhou surface grinder, and carried out the necessary inspection, scraping and adjustment. It can achieve ultra-high-precision and low-roughness grinding pins, and can effectively grind parts with a precision of h4--h6 and a roughness of Ra0.02--0.04μm. The method is simple, convenient and easy to implement, and the effect is quite good.

  1.Ultra Precision Grinding Mechanism

  Ultra-precision grinding is based on the fact that a large number of equal-height abrasive micro-edges can be trimmed on the working surface of the grinding wheel. These contoured micro blades can cut tiny, minor defects, minor shape and dimensional errors, and allowances from the work surface. Therefore, the use of these micro knives is very rich. If the amount of grinding is appropriate, the machined surface may leave a large number of very fine cutting marks, so the surface roughness can be very low. In addition, since there are still obvious effects of friction, sliding extrusion, polishing, calendering, etc. in the non-flare grinding stage, the surface roughness obtained by processing is further reduced.

  2. Maintenance of Hangzhou Surface Grinder

  In order to grind workpieces with a roughness of Ra0.02 - 0.04m on a flexible surface grinder, the old flexible surface grinder should be tested for the following items. If it does not meet the accuracy requirements, it should be scraped and overhauled.

  (1)Repair bed rails

  1)The inspection and scraping method of the V-shaped guide rail of the bed: the straightness of the vertical plane in the length of 1 meter shall not exceed 0.01 mm; the straightness in the horizontal plane shall not exceed 0.01 mm, and the length shall be 1 meter; the non-perpendicularity with the saddle guide rail shall not exceed 0.02 mm ; Length is 250mm; Contact point should be 12-14 points (25 by 25) mm.

  2)How to test the plane guide rail of the bed: the unequal length of the V-shaped guide rail does not exceed 0.02mm within 1m. The straightness of the vertical plane is greater than 0.01 mm, and the length is 1 meter; the contact point requires 12-14 points (25 25) mm. Hangzhou surface grinder

  (2)Overhauling the saddle rails

  1)The detection and scraping method of the V-shaped guide rail of the saddle; the straightness in the vertical plane shall not exceed 0.01 mm over the entire length; the contact point requires 10-12 points (25 25) mm. Hangzhou surface grinder

  2)The test and scraping method of the flat guide rail of the skateboard saddle: the non-parallelism of the V-shaped guide rail on the whole length shall not exceed 0.02/1000mm; the contact point requires 10-12 points (25 25) mm.

  (3)Precautions and possible problems when grinding

  Pay attention to the contact between the grinding wheel and the element when grinding.

  When the workpiece surface comes into contact with the grinding wheel, a continuous hissing sound will be heard, the water marks on the workpiece surface will be taken away by the placed grinding wheel, and faint sparks will be seen at the same time, so that the coolant can be increased at the Kunshi, and the coolant The concentration is slightly higher than that of ordinary grinding saponification liquid, but it needs to be filtered and cleaned before feeding.