The heavy sword has a sharp edge, breaking the ground into the rock - remember the Trinity heavy load pick

With the increasing number of urban subways, large-scale hydropower and water conservancy projects and ultra-deep foundation pits, the development of underground space has become a trend of urban development. As the core component of double-wheel milling, the grinding resistance and rock-breaking ability of the picks play a key role in the construction efficiency, milling energy consumption and operation stability of double-wheel milling.

The double-wheel milling construction is mainly impact milling, and the traditional pick main alloy is prone to brittle fragmentation. In order to make the double-wheel milling pick "faster, longer-lasting, and less expensive", Sany redeveloped and designed the double-wheel milling pick and launched two special picks for double-wheel milling.

Design Highlights:

1. Alloy remodeling

The use of coarser grain size WC, the particle size is increased by more than 25%; A higher proportion of the bonding phase Co is increased by more than 15%, and trace rare earth elements are added to improve the alloy properties, so that the toughness of the main alloy is better, the impact resistance is better, and the proportion of main alloy fragmentation is effectively reduced.

2. Tooth profile reengineering

Simulating the cutting trajectory of double-wheel milling, the whole adopts an inverted cone design, the tooth tip forms an effective contact with the rock arc surface during milling, and the middle part of the parent body adopts a concave arc design, which makes the slag discharge smoother;

3. Parent process upgrading

The matrix is made of special structural steel as the matrix material, using warm forging process, and graded through 4 heat treatments, so that the matrix has the characteristics of high head hardness and good shank toughness;

4. New body alloy technology

For the first time, the body guard alloy is set on the shoulder of the mother, and through the automatic inlay welding process, it is closely attached to the mother, which enhances the wear resistance of the head of the mother, and significantly improves the service life of the mother.

Case Study

Project Name: Pingshan Subway Station Project of Shenzhen-Huizhou Intercity Dapeng Branch Line

Engineering geology overview: 0~23m is plain fill + fully weathered granite, 23~30.5m is medium-slightly weathered granite, and the uniaxial compressive strength is up to 80MPa.

Ground wall parameters: groove width 1.0m, groove depth 30.5m.

Construction method: 0~23m is constructed with a grab, and 23~30.5m is constructed with double wheel milling;

Construction model: Sany SDC120

It can be seen that in the construction process of medium-weathered granite formation, the tooth consumption of SYC6030-22SDC is more than 30% lower than that of similar products. In the construction process of slightly weathered granite formation, the milling efficiency of SYC6030-20SDC-H is 25% higher than that of similar products, and the tooth consumption is 20% lower than that of similar products. The cost of picking a single groove can be saved by more than 20%.

At present, the construction of double-wheel milling is developing in the direction of ultra-deep and ultra-hard formations, and the harsh construction conditions also put forward more requirements for double-wheel milling picks. Sany Twin Wheel Milling Pick will continue to innovate in combination with the research results of milling wheel tooth distribution, provide customers with better pick products and services, and escort the construction of urban underground space.