Introduction of Combine Stem Cutter

The chopper is an accessory product of a combine harvester that can crush the stalk thrown from the drafter or the separator roller. With the further implementation of China’s environmental protection policies, many places have introduced regulations prohibiting the burning of stalks on the spot. As a result, people began to demand more and more for the combine harvester to shred the device. The chopper is one of the functional components with large power consumption in the combine harvester, and the influencing factors of its work quality are also various. The poor design of the blade shape will double the power consumption and cause adverse effects such as vibration; Another function of the blade is to ensure the shredding quality of the material, so from the design point of view, the arrangement pattern of the blade on the chopper drum and the shape of the blade, and the interface method should be considered first. Due to the reasons such as the blade type and the interface of the chopper, the traditional shredding device often has the disadvantages of uneven chopping length, easy clogging, and the like, resulting in damage to the relevant parts of the harvester.

1, structure and function

The John Deere combine harvester stalk chopper mainly consists of a chopper drum, a knife holder, a movable blade, and a fixed blade, and is then fixed on the cutter housing, and then the housing and the host are connected together. On the chopper shell, use a piece of material deflector to connect with the host.

1.1 Roller and knife holder

The chopper drum is composed of φ121X5 seamless steel tube and welded at both ends. The movable blade seat is formed by five thick plates and is welded to the chopper roller strictly according to the spiral configuration. This ensures that the moving blades operate with uniform load and small fluctuations, thereby reducing the vibration of the machine. The fixed tool holder is composed of a long hole uniformly machined in the longitudinal direction of the chopper and a fixed knife beam. The fixed blade is fixed on the fixed knife beam through the long hole. The angle of the fixed blade can be obtained according to the different crops and needs. Different stems are chopped and adjusted in length.

1.2 Blade

The moving blade is used after being combined with a fixed blade on a chopper drum. The chopper roller rotates at high speed and the friction between the stalk and the blade is large. In order to reduce the wear of the blade, the blade is fully taken into consideration. Material and shape, material used 50CrVa, surface hardness HRC52 ~ 56 and increase the geometric position tolerance requirements, while reducing the contact area of ​​the fixed blade part. This reduces the power consumption of the chopper and overcomes clogging of the chopper due to excessive friction between the chopper blade and the stem.

1.3 Material deflector

A material deflector is installed at the inlet of the boom-type chopper and the outlet of the host material, the lower part is hingedly connected with the chopper shell, and the upper part is bolted to the side wall of the machine, so that the material discharged from the document-retrieving device or the separating drum is smooth Into the chopper, in order to make the stems do not form a build-up blockage on the deflector during the process of entering the chopper, the natural angle of repose of the falling process of the stem on the iron plate has been tested for several times during the design. After the material deflector can fully play the material diversion effect. When the harvester does not need to crush the stem, the material deflector fixing bolt can be loosened and re-fixed on the back cover of the machine. The material will directly fall on the machine under the action of the deflector without the chopper. On the ground. This allows the complete crop stem to be retained without dismantling the chopper.

2, the working principle

The stalk is thrown from the drafter or separation roller and falls onto the material deflector. After the material enters the chopper along the baffle, the stalk is crushed under the action of a high-speed rotating blade and a fixed blade. At the same time, under the action of powerful airflow generated by the high-speed rotation of the blade, the stem is thrown from the dispenser. In order to make the chopper work smoothly and reduce the vibration, the dynamic balance level of the chopper drum after the blade is installed is designed to be 6.3, and the theoretical maximum dynamic balance is 1.471 Nm.

3, use adjustment

3.1 Cutting length adjustment

During work, the cut length of the material can be adjusted as needed. For harvesting different crops or at different harvests, the position of the stationary tool holder can be adjusted. The lower the handle position, the greater the degree of coincidence of the moving blade and the stationary blade, and the better the shredding effect on the crop. However, the larger the power consumed by the chopper is, the less the position of the handle should be adjusted as low as possible in the case of satisfying the requirements for cutting the stem.

3.2 Blade Replacement

Damage to the moving blade can cause vibration, so when the moving blade is damaged, it must be replaced in time. After one side of the blade is damaged, the other side of the blade can be replaced. When the blade needs to be replaced, the weight of the newly replaced blade should be substantially equal to that of the original blade. When there are a large number of blades to be replaced, balancing should be done again.

3.3 Stem spreader

Before the chopper is used, a stalk diffuser with a guide plate must be installed. It not only functions as a throwing but also acts as a guard. The distance and width of the stalk can be adjusted by adjusting the angles of the baffles distributed symmetrically on the left and right sides of the spreader. .