Double damping structure and design of the handle

 

Pneumatic Tool Co., Ltd., Luoyang, Henan Luoyang 471009

 

Held internal combustion rock drill is a set of gasoline engine, compressor and rock drill rock drilling machine Trinity, with energy independence, light and flexible, which is widely used in rock mining, road construction, military engineering and water conservancy construction. However, it will produce an impact rock drilling vibration, only the operator's fingers, wrist and joint damage, and will spread to the heart. Therefore, internal combustion rock drill handheld vibration user response has been one of the most pressing concerns. Staff did not count their structural improvements have been made from the metal handle to install damping rubber handle sleeve, then hollow damping rubber handle sleeve, with a certain damping effect, but the effect is not obvious. The author describes a damping function operates with dual handles.

 

A structure

 

    Dual vibration operating handle shown in Figure l, the torsion spring (referred torsion) 9 and the torsion spring shaft tube 11 into the middle of the rubber (torsion rubber body) formed after the rubber torsion; rubber torsion spring mounted on the handlebar holder 6 slotted hole 12 by a screw 13 and its locking washer fixed; left and right turn 3 7 connected to play the role of the opening are made of an elastic pin 4 - torsion spring shaft 9 is connected at the other end l with the handle shaft connection; handlebar seat six sides cast with circular trough, handle shaft 1 - end into a rubber sleeve 5, the other end of the sleeve with a rubber handle sleeve 2.

 

2 Work

 

    Double damping the operation of the handle is a handle sleeve of the rubber on the basis of a heavy damping, increased damping rubber torsion component. Rubber torsion spring has a high resistance, there is a sudden shock and high vibration absorption function. When the drilling machine when the vibration transmitted to the handlebar, the rubber torsion spring is twisted, drive rotation operating handle at an angle, to absorb and consume part of the vibration wave. Block both sides of the arc-length slot handle the operating handle rotation angle limit, in order to maintain Wang operator can exert on the rock drill shaft thrust.

 

3 rubber torsion spring design

 

3.1 size design

 

    Rubber torsion spring stiffness can play with a good sound damping effect. Rubber torsion spring stiffness is calculated as seven

 

    k = 4 Wu / G (l/r.-1/R2) -1 (N / rad), (1)

 

The formula:, the length of the torsion rubber body, m; G is the shear modulus of the rubber, Pa; R is the radius of the outer rubber body torsion, m;, the torsion rubber body inner hole radius, m .

 

    Rubber shear modulus G calculated

 

    G = 0.117e × 0.034 HS (MPa), (2) Wu in: HS Shore hardness of the rubber.

 

    In the rubber torsion parameter selection, to manage as possible without increasing the dimensions of the handle and consider modifications economy. On this basis, by the formula (1) can be seen, should be selected to ensure the strength of the handle as small as possible;, and the value of R should be as large as possible.

 

3.2 Determination of hardness

 

    The hardness of the rubber torsion select appropriate damping is too soft will not achieve the role; too hard then the rubber body prone to cracking, short life. After testing, it is recommended hardness HS 60 ~ 65.

 

4 Conclusion

 

    The damping handle simple structure, reliable performance, damping effect is obvious, the effective protection of the operator's physical and mental health. The damping handle has been applied in Luoyang Pneumatic Tool Co. YN27T type drilling machines and mass production, domestic and foreign customers have been affirmed. With the development of rubber industry, rubber torsion increase in life expectancy, which can replace the existing handle.