In the use environment of the joystick on the construction vehicle, the friction positioning type joystick is often used in the heavy load equipment. Under normal circumstances, the friction type joystick is generally used for continuous acceleration or retreat of the vehicle.
This type of joystick is usually different from the self-resetting joystick, and the life expectancy is not as long as that of the self-resetting joystick. The focus is on the uniformity of the handle friction, the reliability of the friction function, and the resistance under heavy loads. Receptive and so on.
There are mainly two types of friction structures currently used in the market:
1. The friction structure where the plane is in contact with the plane.
The contact structure of the plane and the plane usually presses the friction part through the pressure plate, and uses the elastic element to provide the elastic force to prop up the friction structure to ensure the friction force.
Commonly used materials of friction parts are: alloy copper, ceramic sheet, POM, etc.
Commonly used elastic elements are: compression springs, disc-shaped washers, spring washers and so on.
Advantages of this structure:
1. Simple assembly and high structural stability.
2. After compression, there is elastic support to ensure the stability of friction.
Shortcoming:
1. Due to the contact between the plane and the plane, uniform friction cannot be guaranteed.
2. The friction plate has high requirements, while being resistant to friction, it needs a certain degree of rigidity to prevent brittle cracks during installation.
Main failure modes:
When the friction form of plane-to-plane contact fails, the main reason is that the gap between the fixed side and the rest of the friction side is uneven, resulting in uneven friction, and even the overall grip of the handle.
At this time, if the operator uses too much force to pull the joystick, it may cause irreversible damage to the joystick such as bending and breaking of the rocker of the joystick.
The correct way to deal with it:
A. If you find uneven friction, you can adjust the locking force of the fixing screws/nuts appropriately.
B. If the jam has occurred, please contact the supplier for repair or replacement.
2. The friction structure in which the outer circle contacts the inner circle.
The friction structure of the outer circle and the inner circle is usually locked by an external locking member, and the circular friction structure is supported by elastic elements to provide elasticity to ensure the friction.
The outer-circle friction structure can evenly rub the hand. Because the friction part and the adjusting part are wrapped in a circle, the friction between the friction ring and the friction roller is used to ensure the friction force. The entire friction surface is in contact with the outer circle and the inner circle, so The friction force can be very uniform.
Advantages of external friction structure:
1. The friction force is uniform and the friction structure is stable.
2. The structure is wear-resistant and has a long life.
Disadvantages of external friction structure:
1. The precision requirements for machining parts are high.
2. After long-term use, the friction will gradually decrease, and the friction needs to be adjusted regularly
Main failure modes:
When the friction between the outer circle and the inner circle fails, it is mainly due to insufficient friction caused by the reduction of friction after long-term use, which causes the position of the handle to stop shifting with the vibration of the vehicle.
The correct way to deal with it:
A. If you find uneven friction, you can adjust the locking force of the fixing screws/nuts appropriately.
B. If the jam has occurred, please contact the supplier for repair or replacement.
For the choice of two forms of friction:
Generally, the friction-type handle of the high-altitude vehicle handle is generally selected as the flat contact type, and the stability of the friction force needs to be ensured to ensure safety.
However, the handles used by agricultural machinery usually have more friction-type handles with round surfaces to ensure the stability of friction and the reliability of operation.
