Mechanical tensioning device for dowm pressing

Abstract

The present invention provides a down pressing mechanical tension device which adopts a simple conformation of the handle ratchet wheel style of the rotating sleeve, and the mechanical tension device pushes and presses the upside crotch of the chain which is coiled and suspended between the sprocket wheels and exerts a definite fastening force; wherein: the main body is formed with a cylinder in which the cylindrical plunger piston is accommodated with the mode that the plunger piston can move freely at the up-and-lower direction but can not revolved, a pawl activating cylinder in the plunger piston with the mode that the pawl activating cylinder will not drop but can freely fitted rotatably, and a return spring which accommodates the exerted force to the plunger piston in the pawl activating cylinder. A helical groove is arranged at the surrounding wall of the pawl activating cylinder and a plurality of junctions are formed along the helical groove at the same time. The junction which is jointed at the helical groove that forms at the surrounding of the pawl activating cylinder prevents the retreating of the plunger piston when the plunger piston fixes the claw pin and the load in the reverse direction acts on the head of the plunger piston.

Description

technical field [0001] The present invention relates to a mechanical tensioner for preventing slack in transmission chains. Background technique [0002] A hydraulic tensioner is generally used as a tensioning device for preventing chain vibration caused by elongation and excessive tension caused by vibration, but such as the engine of a small and medium-sized motorcycle, it cannot When supplying oil exclusively for the tensioner, a mechanical tensioner utilizing spring force is used. [0003] Generally, in such a tensioner, a spring biases a push rod movably held to a fixed portion (main body) to push the chain in the tensioning direction. In such a tensioner, in order for the plunger not to move in the backward direction due to lower chain tension when a load in the return direction acts on the chain, a strong resistance to the force of movement in the backward direction of the push rod is required. [0004] In order to obtain such a backward preventing resistance, there...

AI Technical Summary

Problems solved by technology

However, since the bottom surface of the rotary sleeve which should be able to withstand the reaction force of the chain is on the upper side, the self-weight and the vibration inertial force generated by the self-weight cause the rotary sleeve to fall, forming a gap on the bottom surface of the rotary sleeve. Creates a gap that cannot bear the load, so it is not used in push-down mechanical tensioners

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