Abstract: Disclosed in the present application are a concrete protection material, and a preparation method and a construction method therefor. The concrete protection material consists of 50%-90% of a component A and 10%-50% of a component B in percentage by weight, where the component A is prepared from 30%-65% of organic silicon, 2%-5% of nano-silicon dioxide and the balance of an organic solvent in percentage by weight; and the component B is prepared from 20%-50% of an organic base and the balance of water in percentage by weight. The present application not only can form nano-particles having a strengthening effect in capillary channels of a concrete surface layer, but also can achieve a technical effect of superhydrophobicity on the concrete surface layer.

Abstract: The invention provides a nested numerical control rotary table, which comprises a large numerical control rotary table, a small rotary table, a large rotary table board and a small rotary table board nested in the large rotary table board, wherein the small rotary table board may be driven by the large numerical control rotary table as a part of the large rotary table board to run together with the large rotary table board, or be driven by the small rotary table to run independently. When the small rotary table board runs independently, the small rotary table is driven to ascend by a lifting oil cylinder, and a pull pin under the small rotary table board and a positioning pin on the small rotary table fixedly connect the small rotary table board with the small rotary table, which are locked by a clamp. The nested numerical control rotary table may complete the tasks of numerical control rotary tables with both large and small dimensions, which saves the production cost and improves the working efficiency.

Abstract: The present invention discloses a double-swing angle spindle head, in which an A-axis swing shaft is connected to the spindle head through the flange on the end face to realize the swing of the A-axis, and a crank connecting rod mechanism composed of a first rotating shaft, a second rotating shaft, a B-axis rotating shaft and a swing connecting rod realizes the swing of the B-axis under the push-pull action of the B-axis mechanism. Under the action of the linear push-pull mechanism, the linear axis feed movement between a ram and a saddle is realized. Thus, the freedom of movement range of the spindle head is improved, the rigidity, torque and precision of the spindle head are enhanced, and the volume and weight of the spindle head equipment are reduced.

Abstract: The invention provides a nested numerical control rotary table, which comprises a large numerical control rotary table, a small rotary table, a large rotary table board and a small rotary table board nested in the large rotary table board, wherein the small rotary table board may be driven by the large numerical control rotary table as a part of the large rotary table board to run together with the large rotary table board, or be driven by the small rotary table to run independently. When the small rotary table board runs independently, the small rotary table is driven to ascend by a lifting oil cylinder, and a pull pin under the small rotary table board and a positioning pin on the small rotary table fixedly connect the small rotary table board with the small rotary table, which are locked by a clamp. The nested numerical control rotary table may complete the tasks of numerical control rotary tables with both large and small dimensions, which saves the production cost and improves the working efficiency.

Abstract: A horizontal five-axis turning plate type machining center includes a support base, a lathe bed arranged on the support base and a column arranged on the support base, wherein the lathe bed and the column are fixedly connected through a connecting arm, a turning plate device is arranged on the support base, an X-direction sliding plate capable of sliding in an X direction on the lathe bed is arranged on a side, facing the column, of the lathe bed, and a third driving unit capable of driving a workbench to perform position conversion between a turning plate and the X-direction sliding plate is arranged on the turning plate.