Chain saw and the method and process of controlling the guide rod movement

In mechanical cutting, trees are usually cut through the mechanical sawing device (chain saw) of the cutting head of forestry machinery. Similar chain saws can also be used to make short cutters for firewood. In addition, in various cutting waste wrappers, fuel wood wrappers or other wrappers and packaging equipment, corresponding wood cutting chain saws can be set. In this case, the chain saws can cut multiple trunks and/or branches at a time. Wood cutting must be carried out quickly and reliably. Therefore, for mechanical wood processing, some key components depend on the chain saw and its reliable operation.

The chain of the chain saw must be tensioned at least regularly, because the chain extends due to heat and power factors during operation. Automatic chain tensioner is usually used in chain saws of logging machines such as logging machines or processors. Especially in forestry machinery environments, automatic chain tensioners are usually hydraulic, although other tensioning methods are also known. The chain tensioner usually moves the guide rod along its longitudinal axis, so the movement is arranged on a specific support guide rail or surface. Due to the movement of the guide rod, the saw chain is tensioned around the guide rod and the drive sprocket controlling the saw chain.

Many different solutions for chain saw chain tensioners are known. A chain saw chain tensioner for forestry machinery is known from the disclosed fi115706. The invention describes a chain saw in which, in order to tension a saw chain, a guide rod is arranged to move along its longitudinal axis through at least one support guide member. The support guide member is arranged to extend along the longitudinal axis direction of the guide rods on both sides of the driving sprocket, and the driving sprocket provides good support movement along the longitudinal axis direction.

The solution disclosed according to fi101772 is also known, which is a saw assembly including a block element fixed on a guide rod fastener. A gap or groove for fixing the sliding guide member is formed between the inner surfaces of the sheets of the block element. The first and second piston cylinder elements are arranged against the blade retainer to hold the blade attachment in place without clearance.

The invention also discloses wo2015038011, wherein the guide rod is slidably arranged on a saw frame with a fixed sliding guide member. The device comprises a tension detector of the saw chain, a length sensor of the tensioning movement and an electronic control system thereof.

However, there are still some unsolved problems in the existing technology. In the forestry machinery chain saw machine, one of the problems is the wear of the sliding surface of the chain tensioner and related parts. Wear on the sliding surfaces of the components can cause gaps in the chain saw, hampering control of the blade flange, and may damage the chain and other moving parts in the sawing unit.

Replace the chain parts regularly according to the wear of the chain. Replacement of worn parts requires interruption of maintenance and work.

In addition, in the prior art, the clearance caused by the wear of parts often causes the lubricating oil to leak out of the structure and enter the environment through a large clearance. Due to the increase of lubricating oil consumption, lubricating oil leakage leads to the increase of cost and environmental load.