QJZ type mechanical drilling jar is a kind of fully-mechanical jarring tools.It can release the drilling

tools sticking accidents by providing a up and down jarring force.Basically,it is part of the drill

stem,whenever needed,the jarring force can increase the working efficiency.

Up-jarring working principle

It show us the jarring state unlocked after be adjusted when it comes to the jarring position the

moving axis should snap in the inside threads of the slips.The outer thread of the slips and

inside sleeve are under the friction state with.When lifting the drill stem,the upper sub,upper

control sleeve,middle sleeve lower control sleeve,lower regularing sleeve,spring type inside

sleeve,spring middle sleeve,and spring

outer sleeve will move upward while friction sleeve keep still.The slips can be opened when its

outer thread top touch the friction sleeve's teeth,at the moment the teeth of the axis will move

out from the slips' inside teeth, Then stored power will release and give a up and down double-

way force,the the tool will return to the state the ready to jarring position.Repeat the following

operation,we can release the sticking drilling tools.

Lower jarring woring principle

There are a set of spring sleeve on the top of the slips. When then stem give a pressure on the jar, it can pass through the upper sub, upper control sleeve, upper regularing sleeve to work on the , spring type inside sleeve, spring middle sleeve, and spring outer sleeve. Slips will move upwards while the friction sleeve keep still, until reach the predetermination position, the teeth top of the slips will touch the teeth of the friction sleeve, slips will open to let the moving axis release from the slips teeth, the down-way jarring  force against the upper jarring force.