Mini Excavator Bucket Hole Repair: A Comprehensive Guide

When it comes to repairing the bucket hole of a mini excavator, precision is key. The core shaft plays a crucial role in ensuring the coaxiality of the four new pin seats on the bucket after welding. To achieve this, the material used for the core shaft should be strong and weldable, such as 40Cr or 45# steel.

The first step in the repair process is to create a new lower pin holder according to the determined size. There are several reasons why adjustment is necessary. Firstly, it ensures proper axial clearance of the lower pin seat by taking into account the measured axial wear and estimated axial clearance. Secondly, it allows for thickening of the bucket pin seat on both sides to compensate for wear thinning of the lower arm pin hole.

Thirdly, easy welding ensures a firm connection, while fourthly, the thicker bucket pin seat is not restricted in its space position, preventing adverse effects. If the measured thickness of the lower pin holder is 35mm, it can be adjusted to 45mm when determining the new size.

There are several methods to determine the new size of the lower pin holder, including finding technical drawings, comparing measurements with a newer machine, or using a vernier caliper to measure the size under light wear conditions. However, it's essential to ensure accurate size data by measuring the old pin block before processing the new one.

When repairing the pin block by welding, the damaged pin block must be cut down and re-welded to the newly processed pin block. It's crucial to record the wear condition of the hinge pin, pin sleeve, and pin sleeve seat hole, as well as measure the clearance of the lower hinge pin and shaft sleeve.

The maximum use limit should also be considered, and if the wear exceeds this limit, repair is necessary. For example, in the case of friction damage to the pin seat under the bucket of a certain type loader, replacement and welding repair methods can be employed.

In conclusion, repairing the bucket hole of a mini excavator requires attention to detail and careful consideration of the material and process used. By following these guidelines, operators can ensure precise repairs that extend the lifespan of their equipment.

Mini excavator bucket hole repair