2results about How to "Avoid free fall" patented technology

This utility model discloses a hydraulic control system, working device, and engineering machinery, including a speed-increasing valve, a shuttle valve, and a hydraulically controlled directional valve, all composed of a balance valve and a hydraulically controlled check valve. The speed-increasing valve includes ports A1, B1, A, and B. Port B1 is connected to the large chamber of the hydraulic cylinder, and port A1 is connected to the small chamber of the hydraulic cylinder. The inlet of the hydraulically controlled directional valve is connected to port A1, and its outlet is connected to the first inlet of the shuttle valve. The control port of the hydraulically controlled directional valve is connected to port B. When a preset pressure oil flows into the control port, the hydraulically controlled directional valve shifts and disconnects its inlet and outlet. The second inlet of the shuttle valve is connected to the outlet of the balance valve, and its outlet is connected to the control port of the hydraulically controlled check valve. When a preset pressure oil flows into the control port, the hydraulically controlled check valve remains closed. This utility model achieves the pressure-holding function of the small chamber of the hydraulic cylinder, preventing the upper tool from falling independently, and also achieves the speed-increasing function.

The utility model belongs to locking device technical field especially relates to a locking device and box body that upper cover opens and shuts, including base plate, the upper end of base plate is rotatably connected with flap, and the base plate is connected with the flap and has locking mechanism, the locking mechanism includes toothed structure spare, dog, locking elastic part, the dog can be connected or is separated with the realization of the card groove that is provided on toothed structure spare, one end of the dog away from toothed structure spare is equipped with handle, locking elastic part is located the one side of the dog away from toothed structure spare, first pivot is equipped between handle and dog, handle and dog can rotate around first pivot. The utility model is through the rotatable connection cooperation locking mechanism of base plate and flap, has realized the reliable locking of upper cover multi -angle and flexible opening and closing function.