Method for repairing cracks in cylinder block forgings

2019-03-27 11:47:52 6

In the process of forging, it is inevitable that there will be more or less cracks, so how to fix it when cracks appear, there are several ways to repair, then take a look at the cylinder block forgings What method can I use to fix it?

       1. Patch method.

       The patching method is mainly used to repair the outer surface of the body with more cracks, relatively concentrated, or partially broken holes. The repair method is as follows: (1) remove the oil stain, patent leather and other materials in the vicinity of the crack preparation part; 2 drill the crack hole at the end of each crack with a drill bit of 3 to 5 mm to prevent crack extension; 3 use a low carbon steel plate of 2.5 to 3 mm To make up the plate, the patch is 20~30mm larger than the crack around; 4 is drilled around the patch, the hole distance is 15~20mm, the hole diameter is 3~5mm; 5 the patch is covered on the crack to make it with the cylinder block or cylinder The cover is tightly fitted, and then the patch plate is used as a template to drill holes in the cylinder block or cylinder head, and tapping; 6 fixing the patch with screws, and a layer of asbestos between the patch plate and the cylinder block or the cylinder head Pad, or apply red dan oil on both veneers.

       2. Cutting silk method.

       This method is often used to repair a single crack. The method is as follows: 1 using a drill bit of φ3 to 5 mm to drill the crack holes 1 and 2 at both ends of the crack, and then drilling the holes 3 and 4 every 2 to 4 mm; 2 tapping in the drilled hole; 3 The copper rod screw is screwed into the hole, the length of the screw is the same as the thickness of the cylinder wall, and then the copper rod is cut off, and the section is 2 mm higher than the cylinder forging. 4 In the same way, a series of holes are drilled according to the order of the holes. , tap and screw into the copper rod screw. Form a screw chain on the whole crack; 5 gently tap the left part of the riveted copper screw with a small hand hammer to rive and bite each other; 6 Finally, check the crack at the crack by water pressure method. If there is a slight water leak, continue to use the hammer to gently rive the copper screw at the leak.

       3. Electric welding method.

       First use a φ4mm drill bit to drill the crack hole at both ends of the crack, and along the crack "V" shaped groove groove, the depth of the groove should not exceed 2/3 of the wall thickness of the body. Use φ4mm metal electrode (need to use a reasonable process) or use a cast iron electrode to weld under heating. In order to prevent internal stress or warpage after welding on the welding part, use a small hammer to gently tap from the sides of the weld bead to the middle of each weld. When the weld bead is red hot, tap the weld bead with a chisel hammer to eliminate the weld. Slag. If the crack is too long, it must be separated by welding. Generally, the length is 20~30mm. When it is cooled to 70mm from the weld bead, it can be welded to the next section. If the crack is too deep, a multi-layer surfacing method can be used, and it cannot be welded once.

       4. Bonding method.

       For example, to repair the crack of the cylinder forging, the method is as follows: 1. Remove the silver powder and rust around the crack of the cylinder block with No. 1 coarse sandpaper, the grinding width is 30mm, the length exceeds 30mm at both ends of the crack; 2 the width of the crenel is cut along the crack line. It is a 3mm, 2mm deep "V" shaped groove, and drills the crack hole at both ends of the crack; 3 first clean the crack around with the metal cleaning agent, and then scrub it again with the sprinkle; 4 blend the agricultural machine No. 1 glue; 5 Fill the crack-proof hole and the “V”-shaped groove with the adjusted glue first, and apply the liquid to the surrounding area of the groove and the prepared good cloth (width 20mm. Longer than the length of the crack, stick the strip to the crack In the place where the leakage is serious, stick the second layer of strips in the same way, and finally apply a layer of glue evenly on the outside of the strip. After this treatment, the engine can be put into use after 24 hours. In winter, in order to speed up the curing speed of the glue, hot water should be injected into the water tank to keep the body at a higher temperature.