Coordination Based On Force And Speed The Development Of The New Manual Machines

There is a conflict between force and speed in traditional manual instrument for a long time. For a kind of manual instrument, the speed is constant, which is designed according to the biggest work-load, and can't be changed for light-load or heavy-load. The characteristics of a conventional manual instrument are as below: greater the rated- load lower the speed. Therefore, it has a lower power for the work-status without load and a lower efficiency.Existing double-speed hydraulic instruments have two speeds: one is a quick-speed, which is suitable for the work-status without load; the other is a slow-speed, which is suitable for the work-status with heavy load. This kind of hydraulic instruments make force and speed unified in a certain extent.In order to make force and speed accordant each other, we invent a new multi-speed manual hydraulic instrument. It's speed can be changed automatically according to different environments, such as unload, light-load and heavy-load. It has a lot of advantages such as rapid speed, strong force and automatic adjustment, etc, which fully makes force and speed accordant with each other. For this new instrument, we design two size oil-pumps and two size oil-cylinders, consisting of double-pump and double oil- cylinders closed system. It highly integrates hydraulic system with an additional oil pump but any additional valves and pipes. And it has an inner inherited hydraulic system to obtain multi-speed by changing control-valves according to work-load and matching method for big and small pumps, as well as big and small cylinders. For the first time, we make a big-bump with an oil box in order to provide a high speed in the status without load and provide a strong force in the status with heavy load. In this way, the hydraulic system of this new type of instruments can automatically change speed according to the load, and therefore avoid the conflict between force and speed. The working principles of this new type of manual hydraulic instrument can be used in all kinds of instruments such as jacks and vices with different functions. Therefore, it is very meaningful for scientific research and practical application.