An upgraded product developed with new materials and new technologies. Its basic structure and principle still retain the advantages of the old tamping machine, namely the double guide column frame and single cylinder lifting method. At the same time, by increasing the insertion depth of the tamping pick and adopting methods such as adding a travel limit device for the guide columns, it can perform tamping operations not only on domestic Type II and Type III concrete sleeper tracks but also on various foreign concrete sleeper and steel sleeper tracks. Its main technical performance is higher than that of the old tamping machine. This machine is suitable for tamping operations after large and medium-sized maintenance and screening operations on tracks with different types of rails and concrete sleepers; it is also suitable for tamping operations on ballast beds of newly built tracks. The machine has superior performance, a reasonable structure, is safe and reliable, and has high operational efficiency, fully meeting the needs of railway ballast tamping operations.

I. Main Technical Parameters
1. Power: GX390 gasoline engine; power: 9.7kW; speed: 2300 rpm
2. Hydraulic system working pressure: 5.5～6MPa
3. Vibration frequency: 65-66Hz
4. Excitation force: 22kN
5. Maximum insertion force: 16kN
6. Clamping force: 7.2kN×2
7. Insertion depth: 110mm±10mm (below the bottom surface of the sleeper)
8. Production efficiency: ≥270 sleepers/(group·hour)
9. Net weight of main unit: 395kg
10. Overall dimensions: 1460mm×725mm×1650mm
11. Operation form:
(1) Two machines as a group, dismounting on one side, suitable for double tracks or single tracks with wider shoulders.
(2) Two machines as a group, dismounting on both sides, suitable for single tracks with narrower shoulders.
12. Track gauge of walking frame: 1435mm (special requirements must be specified when ordering)

II. Working Principle: The YD—22II hydraulic tamping machine uses a gasoline engine as the power source, driving the oil pump and vibration shaft respectively via V-belts. The eccentric body, rotating at high speed with the vibration shaft, generates excitation force due to centrifugal force. The high-pressure oil output by the oil pump enters the lifting cylinder and clamping cylinder through the directional valve, thereby driving each executive component to achieve tamping functions such as rail clamping, insertion, and compaction.